2017 Projects

Biogeochemical Characterization in Soils of a Uranium-Contaminated Floodplain

SESUR
Mentors: Dr. John Bargar, Dr. Bradley Tolar, Dr. Kristin Boye, and Callum Bobb

Microorganisms play key roles in mediating biogeochemical cycles, especially in soil environments.  Along with abiotic processes (such as chemical oxidation reactions), biotic processes mediate the availability of metals, nutrients, and other important chemicals.  Our project examines how different moisture and sediment conditions regulate biogeochemical processes in response to changes in moisture content, temperature, and oxygen availability. Experimental data will be used to develop predictive models for understanding water quality in impacted aquifers.  Our study focuses on a uranium-contaminated floodplain near a former uranium ore processing plant in Riverton, WY, where samples have been collected over multiple seasons under varying moisture and oxygen concentrations. Our goal is to determine which microorganisms are present, what are their functional roles (what reactions are they driving), and how water quality is impacted by these changes.  

The student will conduct microbial and chemical analysis of samples involving molecular biology (ex: DNA and RNA extraction, PCR, sequencing) and geochemistry approaches (ex: measurement of dissolved and solid-phase metals and carbon).  Prior laboratory experience is not necessary;  background knowledge in (micro)biology, (geo)chemistry, or Earth sciences is desirable.

Estimating Greenhouse Gas Emissions from Oil Production

SESUR
Mentors: Prof Adam Brandt and Mohammad S. Masnadi

Record-breaking temperatures have induced governments to implement targets for reducing future greenhouse gas (GHG) emissions. Use of oil products contributes ~35% of global GHG emissions, and the oil industry itself consumes ~4% of global primary energy. Because oil resources are becoming increasingly heterogeneous, requiring different extraction and processing methods, GHG studies should evaluate oil sources using detailed project-specific data. Unfortunately, prior oil-sector GHG analysis has largely neglected the fact that the energy intensity of producing oil can change significantly over the life of a particular oil project. Here we propose to perform a field-level time-series GHG and energetic analysis of global oilfields. The data available in the public domain from different countries (e.g. Norway, UK, Nigeria, Denmark, etc.) will be utilized for this analysis. Using probabilistic simulation, we will derive a relationship for estimating GHG increases over time, and compare it with previous models.

Using Satellite Data to Examine Tropical Peatland Hydrology

SURGE or SESUR
Mentors: Prof. Alexandra Konings and Nathan Dadap

Over the past 25 years, 71% of peat forests in Southeast Asia have been logged, drained, and converted to oil palm and pulp wood plantations. This has triggered widespread declines in the water table, which controls peat accumulation and soil carbon emissions. Once one of the world’s major carbon sinks, regional peatlands now emit an estimated 300 Mt CO2 per year, a rate equivalent to the 2013 fossil fuel emissions of India and Japan. The lowered water tables have also increased the severity and frequency of wildfires enormously, with the resulting smoke causing dramatic negative health effects for 70 million people across densely populated Southeast Asia.

Improved understanding of hydrologic conditions in this region would help to understand, monitor, and manage these changes. Dense vegetation in the region means that on the ground measurements are extremely sparse and difficult, and that many satellite observations aren’t able to sense the underlying peat in many locations. New satellite sensors making measurements at microwave frequencies are specifically sensitive to soil moisture and better able to penetrate vegetation.

In this project, we seek an enthusiastic student who will work closely with Nathan Dadap and Alexandra Konings to test whether these new satellite measurements can be used to detect where drainage has occurred and is affecting the surrounding peat. These measurements will be compared against ground measurements and previous coarse-resolution maps. While a background in earth sciences is not required, the student should have some prior experience with scientific programming, preferably with Python or Javascript. 

Understanding Effects of Water Stress on Trees at Stanford Farm

SESUR
Mentors: Prof. Alexandra Konings, Nathan Dadap, and Patrick Archie

The amount of water stress experienced by a tree depends on both how much water it can take up from the soil, and how much water is lost from the leaves. However, the ability of the plant to keep turgor pressure from water in leaves also influences its ability to take up carbon dioxide necessary for photosynthesis. Thus, a variety of tree characteristics influence their ability to balance water stress and carbon uptake, including root growth, stomatal closure, and development of dense, embolism-resistant wood, and the shedding of leaves during the dry season. Furthermore, a phenomenon known as ‘hydraulic redistribution’ has been observed in a variety of plants in dry ecosystems, but is still poorly understood. Hydraulic redistribution occurs because water flows from high (equivalent) pressure regions that are very moist to low pressure regions that are drier at all times – including through roots. If there are gradients of water within the soil, such as soil being drier near the surface than further in the root-zone, plants occasionally take up water in one part of the soil, and then re-release it through root systems elsewhere in a drier region of the soil. This phenomenon has been repeatedly observed but is still poorly understood. The goal of this project is to determine how tree phenological strategies and hydraulic redistribution occurrence interact.

We seek a motivated student interested in both field work and data analysis. Advised by Nathan Dadap, Patrick Archie, and Alexandra Konings, the student will build and install a set of soil moisture sensors that can be used to study hydraulic redistribution (based on a new type of sensor recently developed by two Stanford undergraduates) near several tree species on the Stanford Farm with different rooting, phenological, and plant hydraulic traits. Several dendrometer bands – which measure stem water potential – will also be installed. The student’s primary role will be analyzing the different datasets to determine how hydraulic redistribution likelihood and water stress change between tree species. No prior experience is required, though a desire to improve data analysis skills will be helpful.

Modeling the Temperature Dynamics of a Washcoated Gasoline Particulate Filter used for vehicle emission reduction

SESUR
Mentors: Dr. Simona Onori and Dr. Harikesh Arunachalam, ERE

Recent years have witnessed increasingly stringent legislations being imposed on the fuel economy and exhaust emissions of ground vehicles to address global warming concerns. A notable advancement in engine technology to meet current and future regulation targets is the transition from port fuel injection (PFI) to gasoline direct injection (GDI) systems. GDI systems offer an enhanced fuel economy, increased power output, and reduced greenhouse gas emissions compared to PFI systems. However, it under certain operating modes, GDI engines suffer from poor fuel-air mixing inside the combustion chamber. As a result, hazardous soot particulate matters (PM) are released into the atmosphere. As the number of vehicles using GDI engines increase, the reduction of PM emissions presents an increasingly significant technological and societal concern due to the health hazards they pose among humans and the environmental air quality.

Among different strategies to mitigate PM emissions, automotive manufacturers have identified gasoline particulate filters (GPFs) as the most promising and practically adoptable emission control devices in the exhaust system. As the exhaust gas enters the GPF, soot particulates are trapped within its channels. Over time, this accumulation of soot increases the back pressure on the engine. To minimize this negative performance impact, the soot trapped in the GPF is periodically cleaned. This is accomplished via regeneration, i.e. oxidation of soot at elevated temperatures and oxygen concentration. Recent advancements in GPF technology have led to the development of washcoated GPFs, in which a catalytic washcoat is applied across the channels. In comparison with uncoated GPFs, washcoated GPFs an enhanced soot oxidation ability at relatively lower temperatures. Research and development efforts until now have focused only on uncoated GPFs. Accurate, computationally efficient models must be developed for washcoated filters for on-board vehicle applications. This will enable future vehicles to benefit from the use of GDI engines without suffering from increased soot emissions.

The aim of this project is to capture the thermal and soot oxidation dynamics in a washcoated GPF during regeneration. We seek a highly motivated and meticulous student for this task. A physicsbased mathematical model that is used to predict the internal GPF dynamics will be provided to the student. The student will initially be involved in the understanding and analyzing data from experiments conducted using a washcoated GPF in a vehicle operating a GDI engine. Model parameter identification and model validation studies using different experimental data sets to develop an accurate GPF control-oriented model will be conducted. Previous experience in Matlab and Simulink is expected. The successful outcome of this project will help in the control and optimization of GPF performance, and develop strategies to enhance the longevity of GPFs through health monitoring and prognosis. This project is an excellent opportunity for the student to publish their research findings in conference proceedings, and showcase them in the form of a poster presentation. Finally, the student will have the opportunity to present his/her findings to an automotive industry partner.

Predicting rooting response to climate and environmental factors using a global analysis of rooting depths and volumes

SURGE or SESUR
Advisors: Professor Rob Jackson and Shersingh Tumber-Davila

Root systems have the ability to affect many different processes, and can alter the environment greatly. They also respond differently to certain climatic and environmental conditions. Therefore, it is crucial that we understand the importance of rooting systems to different processes such as soil characteristics, hydrology, climate, and carbon sequestration. This summer project will seek to give insight to and answer the following questions:  1). Do above-ground plant extents and functional traits serve as predictors for below-ground rooting extents? 2). Do large-scale climatic indices of water availability serve as predictors for relative rooting extents? 3). At the individual plant scale, which local and sub-climate factors most influence rooting extents?

Answering these questions will help us better understand the processes determining the coarse root distributions of plants globally. In particular, these analyses will examine the climatic and environmental mechanisms controlling below-ground investment. Understanding these mechanisms is necessary for predicting how this system may change in the future, the potential impacts to the global carbon cycle, the local hydrologic cycle, and may inform Earth Systems Models (ESM) on how plants invest their carbon below-ground.

The student will have the opportunity to test the relationship between root canopies, and the above-ground environment of an individual plant. This will include the analysis of a global database of individual plant root systems. The primary task of this project is to measure below-ground root system volumes and other root system measurements, as well as above-ground plant sizes by digitizing detailed plant profile drawings using the ImageJ software. Additional fieldwork to local California sites may be included as part of the project, measuring root systems directly. The student must have an interest in forest ecology, and a willingness to learn different field measurement, and analysis techniques. 

What is the impact of climate change on high elevation soils and ecosystems?

SESUR
Mentors: Prof. Kate Maher and Sami Chen

Understanding the dynamics between soil moisture and trace gases (CO2, N2O, O2) is essential for predicting the response of high elevation ecosystems to climate change. Soil moisture influences both above- and below-ground productivity in complex ways, making it a critical determinant of the rate of carbon and nitrogen cycling. There is a key knowledge gap regarding the dynamics between soil water content and the diffusion of trace gases in alpine settings.  This project will evaluate the role of soil moisture in moderating oxygen availability and the effect of oxygen limitation on two key greenhouse gases, CO2 and N2O in the East River Watershed, CO. Products of this research will include (but not be limited to) time resolved depth profiles for soil gas flux, soil moisture, organic carbon and total nitrogen; which will lead to synthesis surrounding how topography influences nutrient dynamics within the East River Watershed. The findings of this research will contribute to our understanding of alpine watershed nutrient dynamics and their sensitivity to climate change. As a summer researcher, you will spend the summer hiking through the Rocky Mountains in Crested Butte, Colorado to collect and analyze soil, water, and gas samples alongside Sami Chen and other members of our research group. The ideal student will have a sense of humor, enjoy staying in a cabin with other students at a remote field station- the Rocky Mountain Biological Laboratory (www.rmbl.org)- and be comfortable hiking for several miles in rugged terrain.

Investigating the detrital record of the Anthropocene in Central California

SESUR
Mentors: Prof. Matthew Malkowski and Prof. Marty Grove

Geologists rely on the information stored in sediment and sedimentary rocks to understand the evolution of ancient landscapes (from mountains, to rivers, to ocean basins) and the dynamic forces that change them such as climate, plate tectonics, and the biosphere. Decades of studies have focused on natural sediment source-to-sink systems to understand depositional processes and environments under the assumption that the “Present is the key to the past”. However, in the age of humans (the Anthropocene) the natural signals from processes of rock uplift, erosion, transport, and deposition that govern the composition and distribution of sediment can be significantly altered by anthropogenic forces such as the construction of dams, levees, mining activity, urbanization, etc.

Perhaps nowhere does a human detrital footprint have the potential to be more profound than in Central California. Over the past 200 years, the combined effects of hydraulic gold mining in the Sierran foothills, the construction of large dams in the Klamath and Sierra Nevada mountains, levees along the Sacramento­–San Joaquin Delta, dredging in the San Francisco Bay, and enhanced sea-cliff erosion in response to sea level rise may have significantly altered patterns in sediment supply, sediment geochemistry, and provenance (source-to-sink) relationships. This project seeks to determine if and how the detrital legacy of the Anthropocene is recorded in Holocene-aged sediment in Central California.

The student will prepare, analyze, and interpret geochemical and geochronological data from sand and mud samples collected from a transect along the Sierra Nevada mountains to the deep Pacific Ocean. The student will have the opportunity to simultaneously interpret existing data while acquiring new results. Lab work will consist of heavy mineral separations for zircon extraction as well as grain size separations for geochemical analyses. Samples will be analyzed by X-ray fluorescence and laser ablation inductively coupled plasma mass spectrometry. Interpretation of the data will include identifying trends in the concentrations of major and trace elements in sand and mud, and comparing U-Pb age populations in detrital zircon extracted from sand. Ideally, the student will have at least a basic chemistry background, have taken a course in mineralogy and/or geochemistry, and some lab experience working with geology samples.

Predicting rooting response to climate and environmental factors using a global analysis of rooting depths and volumes

SURGE or SESUR
Advisors: Professor Rob Jackson and Shersingh Tumber-Davila

Root systems have the ability to affect many different processes, and can alter the environment greatly. They also respond differently to certain climatic and environmental conditions. Therefore, it is crucial that we understand the importance of rooting systems to different processes such as soil characteristics, hydrology, climate, and carbon sequestration. This summer project will seek to give insight to and answer the following questions:
I.          Do above-ground plant extents and functional traits serve as predictors for below-ground rooting extents?
II.          Do large-scale climatic indices of water availability serve as predictors for relative rooting extents?
III.          At the individual plant scale, which local and sub-climate factors most influence rooting extents?

Answering these questions will help us better understand the processes determining the coarse root distributions of plants globally. In particular, these analyses will examine the climatic and environmental mechanisms controlling below-ground investment. Understanding these mechanisms is necessary for predicting how this system may change in the future, the potential impacts to the global carbon cycle, the local hydrologic cycle, and may inform Earth Systems Models (ESM) on how plants invest their carbon below-ground.

The student will have the opportunity to test the relationship between root canopies, and the above-ground environment of an individual plant. This will include the analysis of a global database of individual plant root systems. The primary task of this project is to measure below-ground root system volumes and other root system measurements, as well as above-ground plant sizes by digitizing detailed plant profile drawings using the ImageJ software. Additional fieldwork to local California sites may be included as part of the project, measuring root systems directly. The student must have an interest in forest ecology, and a willingness to learn different field measurement, and analysis techniques. 

SNAKES! Snake biodiversity across the land-water boundary

SURGE or SESUR
Mentors: Prof. Jon Payne and William Gearty

Since their emergence nearly 100 million years ago, snakes have diversified into numerous ecological niches, encompassing various diets, habitats, and other life history characters. The most drastic shift, perhaps, is the invasion of water multiple independent times. Due to the differing physical and chemical properties between aquatic and terrestrial habitats, this could have dramatic impacts on the evolution of diversity and disparity within these aquatic clades. This study will quantitatively assess the impact of aquatic invasions on the evolution of various life history characteristics and extinction risk in a phylogenetic framework. Furthermore, this study will include formulating potential explanations for these impacts using ecological and biological mechanisms.

I look forward to collaborating with an enthusiastic student who will: compile IUCN threat rankings for snake species; search the scientific literature to compile data on body size, range size, and other life history attributes of snakes; conduct phylogenetic analyses of these data, using the statistical software R; and creatively combine modelling and theory to explain patterns. No familiarity with the methods is required, but some paleontology or biology background would be helpful.

Air-sea interaction in high-resolution ocean models

SURGE or SESUR
Mentors: Prof. Leif Thomas and Dr. Jacob Wenegrat

Air-sea interaction has important coupled effects on the properties of the upper-ocean and lower atmosphere and the flux of momentum, heat, and gases between the atmosphere and ocean. Much of our understanding of these processes was developed considering relatively large scales (100 km); however, new generations of high-resolution numerical models and satellites require improved understanding of these processes at scales ranging from 100s of meters to 10s of kilometers. In this project we will use high-resolution numerical simulations to explore the effects of air-sea coupling on the evolution of small-scale features (such as eddies and fronts) in the upper ocean--a poorly understood aspect of air-sea coupling with important implications for realistic ocean and climate modeling. The student will have the opportunity to gain experience with running ocean numerical models, scientific programming, and ocean and atmosphere dynamics.  Some prior programming experience (preferably in Python or Matlab) is required and a strong background in math and physics (differential equations, vector calculus, mechanics) is desirable. Prior experience in oceanography or atmospheric sciences is not required.

The future of rice yields in South and Southeast Asia: Impact of climatic and soil stressors

SURGE or SESUR
Mentors: Prof. Scott Fendorf and Tianmei Wang

Rice is a staple for more than half of the world’s population. Soils used for rice cultivation within South and Southeast Asia are derived from Himalayan sediments that have naturally occurring arsenic. Moreover, irrigation with arsenic containing groundwater is increasing the soil concentrations of arsenic. Of the major staple crops, rice is uniquely grown under flooded conditions, the outcome of which destabilizes arsenic bound to soil minerals and enhances its availability for plant uptake. Soil-borne arsenic thus combines with increasing temperatures to act as coupled stressors that may impede rice production and jeopardize grain quality.

The goal of this project is to assess to what extent elevated temperature and atmospheric CO2 (parameters of climate change) combined with soil arsenic affect rice yields and grain quality within South and Southeast Asia. We will use soils from Bangladesh and greenhouse conditions emulating current and future climates to conduct this research. Our research will also assess how climate change impacts the mobility of arsenic in rice paddies of South Asia, and the forms and concentration of arsenic within specific rice plant tissues, focusing on rice grains. Porewater geochemistry will be coupled to rice plant physiology to determine arsenic plant accessibility, transport through the plant, and accumulation in rice grains.

The task of the prospective student will be to 1) maintain greenhouse pot experiment in fully climate-controlled chambers, 2) collect and analyze porewater samples, and 3) assess changes in rice physiology throughout the growth period. Previous laboratory experience in geochemical or environmental science would be useful.

Ice Shelf Seismology

SURGE or SESUR
Mentor: Prof. Eric Dunham 

The disintegration and break-up of several large ice shelves in Antarctica has prompted research efforts to monitor ice shelves using seismometers and GPS instruments on ice. The instruments record a wide range of wave motions, arising from forces exerted by incident ocean waves (storm swell, tsunami, tides, etc.) and seismic waves (e.g., from distant earthquakes). Our research group is developing computational codes for simulating waves in ice shelves and complementing simulations with pencil-and-paper analysis of wave modes (i.e., dispersion relations). There are several opportunities for summer interns to contribute to this overall effort. Students who enjoy mathematical analysis can help with derivations of dispersion relations; prior experience with differential equations, Fourier transforms, and (optionally) complex analysis would be useful. Students with strong programming skills can assist with code development and testing; prior programming experience in MATLAB, C++, or another language is required. In all cases, students must have a strong background in mechanics (but not necessarily continuum mechanics, though the project will involve both fluid and solid mechanics). It is possible that in addition to running forward simulations, students could also work with data from instruments on the Ross Ice Shelf, West Antarctica, to validate the simulations.

Expressing novel molecular fossil proteins from environmental metagenomes in a laboratory model syste

SESUR or SURGE
Mentor: Prof. Paula Welander

Recent advances in sequencing technology have resulted in a wealth of genomic and metagenomic protein sequence data providing insight into the diversity of life, biogeochemical cycles and metabolic processes. In this study, students will take advantage of this sequencing data to experimentally address fundamental biochemical and evolutionary questions regarding one important class of lipids, the cyclic triterpenoids. These are important lipid molecules that can be preserved in sedimentary rocks over billions of years and are used as biomarkers or molecular fossils for ancient microbes and their metabolisms. Bacteria and eukaryotes produce these lipids through a cyclization reaction carried out by a specific type of cyclase enzymes. Analyses of environmental metagenomes reveal a large number of unique cyclase enzymes whose lipid products are unknown. Students will work with a laboratory model system in which they will express these environmental cyclases in a bacterial host (E. coli) and determine what cyclic triterpenoid they produce. These types of experiments will introduce students to bioinformatics analyses, molecular cloning, microbial culturing, and lipid analysis. In addition, students will be exposed to the interdisciplinary field of geobiology and is an excellent opportunity for STEM students to observe how research in biology can address geologically relevant questions. Prior experience in a microbiology lab would be helpful but not necessary.

Solar-generated steam for reducing oilfield’s carbon emissions

SESUR or SURGE
Mentors: Prof. Anthony Kovscek and Dr. Anshul Argawal

In California, heavy oil is produced by injecting steam into the reservoir to heat the oil so it can be pumped to the surface. This process, known as thermal Enhanced Oil Recovery (EOR), typically uses steam generated using natural gas. By harnessing the sun’s thermal energy to replace some of the combustion of natural gas, oilfield operators can reduce the energy consumption and carbon footprint of the crude oil produced. The objective of this project is to devise creative steam injection strategies for a reservoir section taken from the South Belridge oilfield. We will use a commercial reservoir simulator to investigate several different strategies and their influence on cumulative oil production, energy consumption, and carbon intensity. The project involves building the simulation case using various sources of information and then analyzing the different scenarios. Prior knowledge of using reservoir simulation software would be beneficial, but not required.

Measuring the impacts of sea level rise

SESUR or SURGE
Mentors: Prof. Chris Field, Prof. Katharine Mach and Miyuki Hino

Communities around the world are struggling with a new challenge: sea level rise. The impacts are already visible and widespread. In towns from Virginia to Florida, residents move their cars at high tide to avoid saltwater corrosion, and impassable roads often cause missed work or school. Closer to home, damages from erosion and flooding - such as houses lost to erosion in Pacifica and flooding on the Embarcadero during king tides - have driven four Bay Area governments to sue major oil companies. This project aims to measure these impacts from sea level rise, providing critical information to help local governments develop and evaluate potential responses. We are looking for a student interested in exploring how flooding and erosion are already affecting communities in the US. Depending on the student's interest, specific projects may be location-based (e.g., a certain city or town) or sector-based (e.g., impacts on coastal agriculture). The student will compile and triangulate a wide range of social media, industry, geospatial, and meteorological data. Opportunities to visit and conduct interviews in the location of interest will also be explored. A student interested in building or expanding their data processing abilities (in R or another coding language) would be ideal. No prior experience in Earth sciences is required.

Are plants a window to the subsurface? Linking plant chemistry to soil chemistry in the Rocky Mountains

SESUR
Mentors: Prof. Kate Maher and Dr. Dana Chadwick

Vegetation characteristics are intimately linked to soil characteristics, including soil organic matter composition. Carbon stored in soils is a significant portion of the terrestrial stocks of carbon, and shifts in the overlying vegetation or the form of chemical species that carbon takes can influence its storage and cycling. We are currently conducting research at the Rocky Mountain Biological Laboratory (www.rmbl.org ; Gothic, CO) aimed at understanding the spatial distributions of vegetation and soil carbon characteristics along hillslopes in the East River watershed, and the implications this has for hillslope-scale carbon cycling processes. The research project employs research techniques across a range of disciplines, including foliar and litter collection and chemical analysis, biomass surveys, high resolution remote sensing, and stable isotope biogeochemistry.

We are looking for an enthusiastic undergraduate to spend the summer conducting field research at the RMBL field station in Colorado. You will have the opportunity to develop a range of projects to contribute to our ongoing research. Potential projects include (1) biomass surveys across topographic gradients and between vegetation types as ground truth for aerial surveys; (2) leaf and litter sampling across the East River watershed to characterize chemical variability between species and across elevations; (3) soil sampling paired with ongoing foliar sampling across the East River watershed to develop linkages between vegetation, topographic position, and parent material; and soil characteristics for improved soil mapping. Projects will all involve a strong field component with ample opportunity to explore laboratory work and learn about remote sensing and GIS datasets depending on your interests. 

Snail habitat suitability and nature-based approaches to schistosomiasis control

SESUR
Mentors: Prof. Giulio De Leo and Andrea Lund

Schistosomiasis is a parasitic infection transmitted by freshwater snails across the tropics, with >240 million people infected and >800 million at risk worldwide. Occurrence of schistosomiasis is associated with development of water management infrastructure, particularly dams. While dams support food and energy production and attract people to new agricultural resources, they also constitute an impassible barrier for important migratory species, including snail predators of the genus Macrobrachium spp. Thus, dams have contributed to the loss of important ecosystem services, including biodiversity that naturally regulates agents of disease.

The InVEST models developed by the Natural Capital Project can be used to understand the degree to which land use and management affects species distributions. We synthesize literature on the hydrological, biological and socio-behavioral conditions associated with increased schistosomiasis transmission to extend such conservation decision-making tools to include the impact of landscape change on water-associated disease.

We seek a motivated, detail-oriented student interested in the intersection of health, development and the environment to help us synthesize literature on snail habitat suitability and the impact of anthropogenic landscape change on disease risk. We will use literature-derived data to process satellite imagery and identify opportunities for extending the InVEST habitat quality model in collaboration with scientists at the Natural Capital Project. Experience with remote sensing, GIS, R and/or Python is desirable but not required.

Ice on slippery slopes: understanding the processes that govern rapid ice loss from large ice sheets

SURGE or SESUR
Mentors: Prof. Jenny Suckale and Dr. Elisa Mantelli

Continental ice sheets like Greenland and Antarctica contain over 60 m of potential sea level rise. Predicting their future evolution is thus essential to understanding the effects of ongoing climate change. One peculiar trait of large ice sheets is that they exhibit a highly dynamic behavior, and these dynamics influence the pattern of mass loss to the ocean. These dynamics are controlled primarily by processes that happen at the bottom of the ice, which are difficult to observe and thus poorly constrained in models used to predict the future evolution of ice sheets. One way to infer basal conditions is to look at the internal layering inside the ice. Layers are natural features of ice sheets formed through surface accumulation, and then advected and deformed by the motion of the ice. As a result, the geometry of the layers carries information about the nature of the flow and basal conditions as well. This research seeks to disentangle the relationship between layer geometry and basal conditions such as basal slipperiness, bed topography, and the geology of the substrate, with the ultimate goal to use the geometry of internal layer in order to constrain basal conditions. We seek an enthusiastic student to help us compare layer data from airborne radar sounding to the output of mathematical models that capture simplified basal condition scenarios. Work will consist of visualizing an existing radar data set, performing qualitative data analysis and organization, running numerical simulations and performing a parameter study. Strong quantitative skills and prior programming experience in MATLAB or a high-level programming language will be essential, and introductory level numerical methods and fluid mechanics is recommended.

Contaminant mobilization related to groundwater pumping

SURGE or SESUR
Mentors: Prof. Scott Fendorf and Randall Holmes

The use of groundwater for drinking water and agricultural irrigation is on the rise worldwide. In order to increase the availability of fresh water for these purposes, groundwater supplies are being supplemented in a process known as managed aquifer recharge (MAR) in which treated wastewater is either pumped into shallow ponds and allowed to percolate into the ground, or directly injected into deeper formations. The introduction of treated wastewater for the purpose of storage may lead to the mobilization of contaminants such as arsenic as the result of changes in the electrochemical properties in groundwater and surrounding sediments. In California, the water is required to remain in the ground for specific amounts of time before being pumped out for use. Likewise, the intermittent pumping of groundwater is also of interest, as it may induce similar changes in electrochemical properties that can lead to contaminant mobilization. The goal of this research will be to determine how changes in groundwater properties and pumping schedules can lead to contaminant mobilization from aquifer sediments. This will be accomplished through a variety of lab experiments to include setting up column flow experiments, in which water with carefully adjusted electrochemical properties will flow through sediments that have been packed into small laboratory columns. A variety of fundamental lab techniques will be used. Water samples will be prepared and analyzed for trace elements such as arsenic, chromium, uranium, vanadium, etc., using inductively-coupled plasma mass spectroscopy (ICP-MS). Tasks will include cataloguing and preparing sediment samples, preparing and maintaining sediment columns, analyzing sediments for carbon/nitrogen content on a Carlo Erba Elemental Analyzer, as well as determining trace element content using x-ray fluorescence (XRF) and/or mineral content using x-ray diffraction (XRD). This project does not require any previous lab experience.

Developing a Water Sensing Network for the Educational Farm

SESUR
Mentors: Prof. Scott Fendorf and Patrick Archie

Food production is the largest single use of water. Within California, nearly 80% of water use is for agriculture. Optimizing water use within cropping systems, as well as other irrigated landscapes, is thus one of the most significant means of curbing water needs. We are seeking to continue developing a soil moisture sensing network for the Educational Farm on the Stanford campus. A low-cost moisture sensor must be developed that can be deployed wirelessly; autonomous power and the ability to transmit data wirelessly is thus required.  Tracking soil moisture at multiple depths is a further attribute, and the sensors must be easily and rapidly deployable. Further, software that tracks soil moisture from the deployed sensors must be developed, and it needs to be placed in graphic design that allows ease of use for mobile or computer platforms. Finally, advancing toward an automated irrigation system that is based on soil moisture measurement, crop needs, and atmospheric conditions is our goal.  Students with backgrounds in mechanical engineering, electrical engineering, and computer science with interest in agricultural systems are sought. 

How water markets actually work: A Colorado case study

SESUR or SURGE
Mentors: Prof. Steven Gorelick and Philip Womble

Drought, climate change, and population growth stress western U.S. water supplies. Water markets enable adaptation by facilitating water transfers between users in times of scarcity. Prior appropriation water law, the dominant water law regime in the western U.S. which has been in place since the late 19th century, establishes private property rights in water that are increasingly traded.

Exactly how these water markets have moved water over space and time remains unclear. Policy analysts, hydrologists, economists, and water lawyers frequently envision water market behavior as consisting of sets of economically efficient trades of individual rights between users. In practice, water markets do not follow such ideals. Legal and institutional rules that govern trading often yield substantial non-water costs for trades – often in the form of legal and engineering fees of hundreds of thousands or even millions of dollars and years of legal approval processes. As such, economies of scale in these costs may lead water rights buyers to exhaust one source before buying elsewhere. Legal rules also include strict restrictions that trades must not reduce water available to other water rights, which often yields trades with complex sets of water exchanges to remain in compliance. Similar legal rules require groundwater users to offset surface water impacts. Finally, hydrology or infrastructure does not always connect potential buyers and sellers, which influences trading behavior. Each of these factors, common throughout states in the western U.S., may lead to meaningful geographic and temporal trends in water trading that diverge from idealized markets.

We seek a motivated student to perform a network analysis of water trading over the last ~100 years in the State of Colorado’s water markets. The student will develop a database for the network analysis by cataloguing empirical trading data maintained by the State of Colorado. The student will then perform the network analysis to describe how water rights trading occurs in practice, and how such trading diverges from idealized behavior. Such analysis can help researchers and practitioners to develop empirically grounded policies and management strategies.

No prior research experience is necessary. Excitement and willingness to learn about environmental and natural resources law and policy is important. Basic knowledge of statistics and experience with scientific programming would be helpful. 

The Locations and Frequencies of Different Wildfire Management Practices in California

SESUR or SURGE
Mentors: Prof. Chris Field, Prof. Katharine Mach, and Rebecca Miller

California experiences an average of 8,000 wildfires which burn 600,000 acres per year. 2017 has been a particularly bad year for wildfires in California, making adequate wildfire management all the more critical. Prescribed fires and timber thinning are the most common techniques used to manage wildfires. Wildfire management practices in California vary by landowner; for example, the Federal government conducted 98.5% of the total prescribed burns that occurred in California between 2002 and 2016. In order to understand how different types of landowners pursue wildfire management policies, it is important to determine where and when wildfire management does occur and how that wildfire management influences the likelihood of future wildfires.

In this summer research project, we propose using time-series visualizations in GIS to determine how differences in local terrain, slope, and ecosystem type combined with the locations of prescribed burns and logging influence the frequency and severity of wildfires in California. Based on data availability, we will attempt to determine the influence of Federal, state, and local wildfire management policies on subsequent practices and wildfires.

Applicants should be interested in the intersection of science and public policy. Experience with or an interest in GIS or coding preferred. No prior experience with earth sciences is necessary. 

Sedimentology and stratigraphy of the Upper Cretaceous Pigeon Point Formation, California

SURGE or SESUR
Mentors: Prof. Donald Lowe and Chayawan Jaikla

Deep-water depositional system comprises sediments that were transported under gravity-flow processes and deposited in the deep-marine environment from the slope to the ocean floor. Since the system cannot be easily reached, observed, and studied in the modern environment, outcrop study of ancient deep-water deposits is the key to understand how sediments were transported from land to seafloor and their characteristics.

The Upper Cretaceous Pigeon Point Formation, which outcrops along the Pacific Coast south of San Francisco, California, contains a full spectrum of coarse-grained deep-water deposits that are well exposed despite being heavily faulted and structurally deformed. Although the outcrops are widely visited by geologists, the stratigraphy, sedimentology and tectonic implications of the formation are still poorly resolved. Correlating the formation across San Andrea Fault system will contribute to an understanding a complex history of plate convergence.

The enthusiastic undergraduate will help conduct some components of the project, including fieldwork, detrital zircon geochronology, and petrographic interpretation. The student will develop fieldwork skills as well as an understanding of deep-water deposits and their depositional processes. Previous experience with fieldwork and basic knowledge in sedimentology is preferred but not required. 

Landscape Controls on Metal Biogeochemical Cycling in a Floodplain

SURGE or SESUR
Mentors: Prof. Scott Fendorf and Hannah Naughton

Floodplains serve an important role in regulating the transport of metals, which can act either as environmental toxins or micronutrients.  Transient flooding after large storm events or spring thaw leads to saturated soils and reducing conditions, whereas dry periods often lead to oxygenated soils.  This cycling in soil aeration in turn regulates the oxidation state of redox-active metals such as uranium and iron, determining their toxicity and propensity to precipitate versus remain in river and groundwater.  Additionally, organic carbon compounds can bind metals and form soluble complexes, while also fueling microbial activity that contributes to metal cycling in floodplains.  We seek to understand the relationship between the floodplain landscape and biogeochemistry underpinning metal release and movement from soil into the river of a pristine montane floodplain in Colorado, which has implications on water quality in downstream settlements.

In collaboration with a team from several institutions, the student will spend half the summer performing routine field sampling at the East River in Crested Butte, CO.  In-field analysis for dissolved oxygen, pH, conductivity, iron and sulfide content, and redox potential will be performed regularly.  Samples will be collected and sent to Stanford where half the summer will be spent in lab analyzing carbon and metal chemistry using a Total Organic Carbon analyzer and Inductively Coupled Plasma Optical Emission Spectrophotometer.  Previous lab experience is a plus but not required; moderate athleticism and love of the outdoors are a must.

For SURGE, project will have more of a lab component. 

Carbon and Nutrient Source and Fate in a High-Altitude Floodplain

SURGE or SESUR
Mentors: Prof. Scott Fendorf and Hannah Naughton

Soils store more carbon (C) than the atmosphere and earth’s biota combined, with wetlands responsible for more than 10% of this carbon.  As the atmospheric C content increases and societies plan how to adapt to and mitigate climate change, it is critical to have well-constrained predictions of future carbon pools.  While soils serve as an important C sink, the mechanisms retaining soil carbon are incompletely understood, limiting our ability to predict quantities and even the sign (are soils losing or gaining C) of the terrestrial-atmospheric C flux over time.  We will test the hypothesis that anaerobic conditions in soils, largely an outcome of flooding conditions, result in low-energy regimes that inhibit microbial respiration and thus cycling of soil carbon into the atmosphere. The East River Floodplain near Crested Butte, CO lets us constrain inputs of carbon (from plants and upriver) and outputs (downriver, back into soil, and as gas), allowing us to reconstruct the soil processes responsible for mobilizing it.

In collaboration with a team from several institutions, the student will spend half the summer performing field sampling of groundwater and gas fluxes along the East River Floodplain near Crested Butte, CO.  In-field analysis for dissolved oxygen, pH, conductivity, iron and sulfide content, and redox potential will be performed regularly, along with gas sampling of carbon dioxide and methane.  Samples will be collected and sent to Stanford where half the summer will be spent in lab analyzing carbon processing via soil incubations and carbon analysis via Gas Chromatography and a Total Organic Carbon analyzer.  Previous lab experience is a plus but not required; moderate athleticism and love of the outdoors are a must.

For SURGE, project will have more of a lab component.

Understanding lead chromate adulteration of turmeric

SESUR
Mentors: Prof. Steve Luby, Prof. Scott Fendorf and Jenna Forsyth

As a potent neurotoxin, lead poses a serious threat to public health and human intellectual capital worldwide. While there is no safe level of lead exposure for anyone, lead is most detrimental to children when their central nervous systems are still developing, before birth through three years of age. Even low levels of lead can irreversibly lower IQ. Our past research in Bangladesh has identified lead chromate-adulterated turmeric as one important exposure route. Ultimately, this will benefit child health and development in Bangladesh, South Asia, and the world. We are looking for a motivated student to assist with 1) assessing the prevalence of lead chromate adulteration in turmeric, 2) assessing the bioaccessibility of lead in turmeric, and 3) assessing low-cost quick lead tests for field suitability. The student will use Inductively Coupled Plasma Mass Spectrometry and X Ray Fluorescence techniques at the Environmental Measurements Laboratory at Stanford. Previous wet lab experience is desirable but not necessary. Jenna Forsyth will be the primary mentor, but this is a collaborative effort with Professor Scott Fendorf and Professor Steve Luby.

Plantation forestry and soil sustainability

SURGE or SESUR
Mentors: Prof. Rob Jackson and Devin McMahon

Plantation forests, in which trees are grown as a crop, are planted worldwide in order to produce wood for lumber, fiber, and bioenergy, and to restore tree cover to degraded land. The fast-growing trees extract soil nutrients which are repeatedly removed from the site when wood is harvested, and increasing reliance on fertilizer inputs may threaten the plantations' sustainability. We are studying the world's most productive plantation forests, huge expanses of genetically identical, fast-growing eucalyptus trees in southeastern Brazil. We have collected soil from industrial eucalyptus plantations, abandoned plantations, pastures, and native vegetation reserves in southeastern Brazil in 2004 and 2016, and are analyzing the soil samples to determine how these systems alter nutrient stocks and future vegetation growth over multiple harvest cycles. A summer research assistant will gain hands-on experience in laboratory techniques for measuring nutrient content of soils, and will work with a graduate student mentor to develop their own research question as part of a larger analysis. Techniques will include X-ray fluorescence spectroscopy and carbon/nitrogen analysis by combustion. The ideal student will pay close attention to detail and maintain interest in land use issues, plant-soil interactions, and problem solving. Prior laboratory experience is not necessary but would be helpful. A SURGE student who worked on an earlier phase of this project in summer of 2017 just presented a poster at a major scientific conference, and offered rave reviews of the summer experience.

Studying the uptake of water by plants using nuclear magnetic resonance (NMR)

SESUR
Mentors: Prof. Rosemary Knight and Alex Kendrick

In the agricultural Central Valley of California, contaminants such as arsenic and can be found in the groundwater. It has been observed that some plants take up these contaminants, while others do not. It is well known that plants differ in the size of pores from which they can extract water. Our hypothesis: there is a link between the pore-scale location of the contaminants, the region of the pore space from which a plant extracts water, and the uptake of contaminants by plants. Very simply, if a plant cannot extract water from pores smaller than a certain size, and the contaminant resides in those smaller pores, the plants will not take up the contaminant.  We plan to explore the use of nuclear magnetic resonance (NMR) to measure the range of pore sizes accessed by plants to obtain water as they grow in the lab. These measurements will help us understand the sizes of pores containing water that are available to different plants at different stages of growth. 

The proposed project will use NMR to monitor how a proxy for water-filled pore size, known as the transverse relaxation time (T2), changes in response to the growth of plants in the lab. The student will prepare the plant samples and systematically measure T2 as the plants grow using a 2 MHz NMR rock core analyzer in the lab. These measurements of T2 will reveal the pore sizes from which water cannot be extracted by the plant.

We are looking for a student to conduct most of the lab work. The student will prepare the plant samples, grow the plants, collect the NMR data, and analyze the corresponding results. Most of the data analysis will be done in MATLAB. No prior lab experience is required, but a basic understanding of programming is recommended.

What effects do changes in fire regimes have on ecosystems in California?

SESUR or SURGE
Mentors: Prof Rob Jackson and Postdoc Adam Pellegrini

The frequency of fire is changing rapidly, and in some cases is increasing due to climate change creating drier and warmer conditions favorable to fire. This project aims to understand how changes in fire frequency (that is, the rate at which fire recurs) will influence the productivity and biogeochemistry in ecosystems. Specifically, the postdoctoral fellow Adam Pellegrini in the Jackson lab group is investigating how fire changes plant species composition, plant physiological traits, and soil properties by sampling a network of sites that have manipulated fire frequency for decades. This particular project will allow students to work in both field and lab settings, with frequent trips being made to Sequoia and Kings Canyon National Park in California to sample areas of the forest that have experienced different fire frequencies. A large amount of the work takes place in wilderness areas that are not accessible to tourists, allowing for a unique experience of the park. Field work will consist of taking samples of plant and soils over multiple five to seven day trips during which we will be camping in the park (no backpacking is needed). Students will also engage in lab work upon returning from the field, where they will help perform chemical extractions and analyses on the collected samples. Moreover, students will be taught data analysis methods to statistically analyze the data collected. In sum, this project is a balance between field and lab work, with the potential to learn a number of skills and be exposed to incredible ecosystems. Independent projects are welcome, as well, and can be developed dynamically as the student gets exposure to the system. Students with backgrounds in biology, chemistry, and/or environmental science are highly encouraged to apply. Laboratory experience is favorable.

Did environmental change cause the Ordovician radiation?

SESUR or SURGE Proposal
Mentors: Prof Erik A. Sperling and Richard G. Stockey

This project will combine data and approaches from geology, geochemistry, evolutionary biology, and animal physiology. The results will be applicable to understanding how marine animals responded to climate change in the ancient past, and how animals in the modern ocean may respond to current/future environmental change.

The Paleozoic is one of the most interesting times in Earth history. Important evolutionary transitions during this geologic interval include major increases in animal body size and species-level diversity, the appearance of the first coral reefs in the geological record, the rise of fish, and the colonization of land by marine vertebrates and plants. One of the most significant evolutionary events during this time period was the Ordovician radiation, when animal diversity more than doubled. Recently it has been suggested that this evolutionary radiation may have been spurred by increases in marine oxygen levels, or decreases in global temperature. These data are mainly based on information from carbonate rocks, and this project seeks to test these hypotheses using the complementary shale geochemical record. The long-term goal is to apply these data to global ocean models and evaluate the potential impact of these environmental trends on marine ecosystems.

In this laboratory-based sedimentary geochemical study, the student will work as part of a group project to analyze shale samples from the Road River Group in Yukon, Canada. The student will analyze shale samples for their iron, carbon and sulfur geochemistry, and major- and trace-element composition. The student will learn to interpret their data against the stratigraphic record and other geochemical and paleobiological trends at that time. The student will learn the basics of sedimentary geochemistry and paleoenvironmental reconstruction, and learn how animals respond to changing paleoenvironments. They will ultimately compile their data with other data from the Road River Group for a comprehensive understanding of early Paleozoic global change. There are no formal requirements for the research project, but a general geological background will be useful.  

Ice penetrating radar design and data analysis

SESUR or SURGE
Mentors: Prof Dustin Schroeder

The Stanford Radio Glaciology research group focuses on the subglacial and englacial conditions of rapidly changing ice sheets and the use of ice penetrating radar to study them and their potential contribution to the rate of sea level rise. In general, we work on the fundamental problem of observing, understanding, and predicting the interaction of ice and water in Earth and planetary systems

Radio echo sounding is a uniquely powerful geophysical technique for studying the interior of ice sheets, glaciers, and icy planetary bodies. It can provide broad coverage and deep penetration as well as interpretable ice thickness, basal topography, and englacial radio stratigraphy. Our group develops techniques that model and exploit information in the along-track radar echo character to detect and characterize subglacial water, englacial layers, bedforms, and grounding zones.

In addition to their utility as tools for observing the natural world, our group is interested in radio geophysical instruments as objects of study themselves. We actively collaborate on the development of flexible airborne and ground-based ice penetrating radar for geophysical glaciology, which allow radar parameters, surveys, and platforms to be finely tuned for specific targets, areas, or processes. We also collaborate on the development of satellite-borne radars, for which power, mass, and data are so limited that they require truly optimized designs. Student projects are available in support of both ice penetrating radar instrument development and data analysis.

Automating groundwater data extraction through machine learning

SESUR or SURGE
Mentors: Prof. Rosemary Knight and Ryan Smith, Noah Dewar, and Aakash Ahamed

Recent droughts in the Central Valley of California have cost the agricultural industry over $1 billion. Increased drought resilience can be achieved through sustainable use of groundwater, which is the main source of water during times of drought. In order to be sustainable, we must effectively model groundwater flow. Modeling groundwater flow requires an understanding of subsurface geology, which, in the Central Valley, is poorly known.

Millions of well completion reports have recently been made publicly available by the state of California. These reports contain valuable geologic information, which could greatly improve the modeling of groundwater resources. However, the vast majority of these reports are scanned pdf’s which need to be copied manually to extract useful information, a process which could take years and cost hundreds of thousands of dollars.

Recent advances in image and text recognition and in machine learning algorithms have made data extraction from large volumes of records feasible. The project we propose is to apply these methods, and develop new ones, to extract geologic data and location information from the millions of available well reports in the Central Valley.

The successful applicant(s) should have a quantitative and computational background—preferably with experience in python, Matlab or R, and some experience with machine learning or signal processing techniques. No prior experience in geology or the Earth sciences is necessary

Climate change and water availability in the Western US

SURGE only
Mentors: Prof. Page Chamberlain and Tyler Kukla

A critical, unresolved question regarding modern climate change is how the water cycle will respond to anthropogenic forcing. Today’s most advanced climate models do not agree on whether the evolving water cycle will create a wetter or drier world. This uncertainty is particularly problematic in the already water-limited Western US.

Sedimentary rocks that formed during the hottest and coldest periods of the last 65 million years retain the chemical fingerprint of the ancient water cycle. This fingerprint, in the form of hydrogen and oxygen isotopes, tells us about precipitation patterns and allows us to reconstruct ancient temperatures.

We are seeking an enthusiastic student to conduct laboratory measurements of hydrogen isotopes and develop computer simulations that predict ancient temperatures and precipitation. The student will acquire all necessary skills during the program; no prior experience required.

How do slab properties affect mechanisms of intermediate-depth earthquakes?

SESUR or SURGE
Mentors: Prof. Greg Beroza and Shanna Chu

Intermediate-depth earthquakes are still a mystery to seismologists because they occur in a region of the earth where rocks ought to deform in a ductile fashion, hence earthquakes, which are in general brittle fractures, should not occur.  Two commonly proposed mechanisms for such earthquakes are dehydration embrittlement, in which metamorphic reactions release water and enable earthquakes, and thermal shear runaway, in which ductile strain is accommodated in a highly localized region that loses strength as it is heated.  Seismologists are interested in calculating and interpreting source properties from intermediate-depth earthquake data, since earthquake source behavior might help elucidate between these competing mechanisms. 

Some have suggested that these earthquakes may behave differently in tectonic regions.  So far, however, there has not been a comprehensive study done to correlate physical properties of tectonic plates with the energetic properties of intermediate-depth earthquakes.  We are looking for an undergraduate to participate in a study of intermediate-depth earthquakes, using the new Slab2 tectonic model set to be released in January 2018.  The intern would help analyze a large dataset, performing statistical and uncertainty analyses, and using existing code to compute earthquake source parameters.  Some background in statistics and programming (MATLAB or Python, though other languages are fine) are preferred, but more importantly the candidate should be excited about finding patterns in large, complex data sets.  Prior experience in Earth sciences is welcome but not required, and the project is very suitable for a student with computational background seeking to learn about applications to earth science.

Whale low frequency sound generation

SURGE or SESUR
Mentors: Prof. Eric Dunham and Leighton Watson

Large whale species, such as blue and sperm whales, have been observed to generate low frequency calls that sweep down in frequency. These calls are thought to be used for communication between animals as low frequency sound can propagate for long distances in the ocean before being attenuated. Despite significant interest in whale sound generation, the exact mechanism of low frequency sound generation remains unknown. Our group, in collaboration with Professor Jeremy Goldbogen at the Hopkins Marine Station, is testing the hypothesis that the low frequency calls are generated by resonance of the air filled cavities within the whale. Through numerical simulations, we have shown that resonance of whale lungs can explain the dominant frequency of the calls. We have not yet been able to explain the variation in frequency of the calls.

This project is to extend our previous work to account for airflow into the lungs from the laryngeal sac. Airflow into the lungs should cause the lung volume to increase and the sound frequency to decrease, explaining the down-swept nature of the calls. The project will require working with and extending existing Matlab code. In addition, the project will involve reviewing existing literature to estimate parameter values such as the elasticity of the whale lungs. Depending on the student, it may also involve processing and analyzing data of whale calls. Previous programming experience (Matlab or similar language) is required and a strong background in math and physics (differential equations, mechanics) is desirable. No prior experience in earth or biological sciences is required.

Modeling lithium-ion batteries for advanced battery management system applications in electrified vehicles

SESUR
Mentors: Dr. Simona Onori and Dr. Harikesh Arunachalam, ERE

Technological advancements and globalization have been responsible for the ever increasing energy and power demands across different industry sectors. This has led to an extensive use of fossil fuel based resources. In the transportation sector, significant concerns are derived from the excessive emission of greenhouse gases and degradation of air quality. Vehicle electrification can mitigate the negative effects on climate change using electrochemical storage devices, such as lithium-ion batteries, as either secondary or primary energy source. The last decades have seen enormous strides in battery technology and the adoption of lithium-ion batteries in large-scale applications; yet, the largest obstacles for widespread adoption of electric vehicles are cost, safety, performance degradation due to aging, and lack of a comprehensive understanding of battery behavior.

The current practice to optimize battery performance is oversizing the in-vehicle battery pack to meet lifecycle targets. Mathematical models play an important role in the design and utilization of batteries with existing technologies, thanks to their ability to virtually sense battery behavior under various operating conditions.

Advanced electrochemical modeling and estimation of battery internal states are vital to push batteries to operate at their physically permissible limits. Utilizing physics-based models can lead to the development of a sophisticated battery management system for the efficient, safe, and optimal utilization of batteries. Optimal usage of battery hinges on how accurately the mathematical equations describe lithium transport, and how precisely the corresponding model parameters are measured, estimated, and identified.

In this project, we seek a motivated student who will work closely with Harikesh Arunachalam and Simona Onori to design a reduced-complexity model and fully identifying its parameters across variables of operations and chemistry. The student will use experimental data to conduct the identification and compare the reduced complexity models against the high fidelity electrochemical models. The initial part of this project will require the student to get acquainted with the model and the experimental data sets. The student will then perform identification studies for the parameters of the model and conduct model verification. The successful outcome of this project will eventually lead to physically meaningful control-oriented model and higher accuracy virtual sensors for real-time BMS applications. While a background in battery electrochemistry is not required, the student should have some prior experience with Matlab. The student will have an excellent opportunity to publish their research findings in conference proceedings, and do an in-situ presentation of his/her accomplishments to a local automotive industry partner.

Lead as a neurotoxin

SESUR only
Advisors: Prof Scott Fendorf and Jenna Forsyth

As a potent neurotoxin, lead poses a serious threat to public health and human intellectual capital worldwide. Join a team of researchers from Stanford and Bangladesh that has discovered high rates of lead contamination in turmeric. A bright yellow lead chromate powder is being added to dried turmeric root in order to make it more attractive for sale. We are seeking two motivated students to assist with research in professor Scott Fendorf’s lab. Previous wet lab experience is desirable but not necessary:
1) One student will assist with lead analyses of turmeric using Inductively Coupled Plasma Mass Spectrometry and X Ray Fluorescence techniques. The student's summer project goal will be to assess different measurement techniques and explore the possibility of developing a quick and simple test to identify lead contamination at markets in Bangladesh.

2) Another student will assist with experiments to determine how the form of lead and chromium changes before and after cooking in order to better assess the toxicity and risk. The student will also assess the bioavailability of the lead in turmeric.

Forest Responses to Climate Variability in California

SESUR or SURGE
Advisors: Chris Field, Katherine Mach, & Emily Francis

The recent drought in California has had significant impacts on the state’s forest ecosystems, and is estimated to have caused the death of millions of trees in the state. Redwood forests in California have been a notable exception, as they have fared far better than the other forest types in California. This may be because redwoods obtain significant quantities of water from fog, and are therefore buffered from regional climate extremes such as drought. In this project, we will test the hypothesis that redwood responses to climate variability are mediated by topographic position and access to fog water.

In temperate climates, seasonal patterns in tree growth result in visible annual growth rings. Tree-ring widths are an integrated measure of annual tree performance, and their carbon and oxygen isotopes can record additional information about biological responses to climate variability and their water sources. We plan to collect tree rings from redwood trees that differ in their topographic position and access to fog water, and measure their tree ring widths, and carbon and oxygen isotopic compositions. With these data, we will assess how the trees have responded to regional droughts over the past century, and whether spatial variability in responses to drought are consistent across droughts. This information is critical to predict where redwoods are likely to be vulnerable or resilient to future droughts in California.

We are looking for a student to help with the field work and lab analysis of tree ring data. The work will include 2-4 weeks of field work in redwood forests in the state of California, followed by 4-6 weeks of lab work at Stanford. Field work experience and lab work experience are both preferred but not necessary.

Buoyancy-driven bidirectional flow in the conduit of volcano

SESUR or SURGE
Advisors: Professor Jenny Suckale and postdoc Zhipeng Qin

Buoyancy-driven bidirectional flow occurs in volcanic systems, where less dense, gas-rich magma rises through a conduit while denser, degassed magma sinks down into the subsurface. The details of the bidirectional flow, including its development, the flow pattern and the exchange rate, are significant for the understanding of the dynamics beneath volcano craters, yet our understanding of these processes remains incomplete.

Recently, several experiments investigated bidirectional flow in a narrow conduits in the laboratory. Results show that these systems develop instabilities along the interface between rising and sinking fluids expressed in flow fluctuations. However, these experiments did not consider the presence of gas bubbles and solid crystals that may separate from the magma flow and alter the dynamics in real volcanic systems. This summer project will complement these laboratory studies with a numerical phase-resolving model tracking the motion of crystals and bubbles in bidirectional conduit flow and their effect on the overall flow structure.

This project involves running numerical experiments with an existing simulation code to map out different regimes of multiphase interactions. The student will perform a systematic parameter study with the goal of extracting important properties from the results, such as the effective viscosity and permeability of a magma with crystals and bubbles. A strong background in math and physics (partial differential equations, fluid mechanics) and programming (Fortran) are desired. No prior experience in Earth Sciences is required.

Detecting and dating fault scarps in Northern California

SESUR Only
Advisors: Professor George Hilley and Robert Sare

Where historic earthquakes are rare, long-term deformation recorded in landforms often provides essential clues to the degree of past tectonic activity. In these areas, the instrumental record of earthquakes captured by seismic and geodetic networks may give an incomplete picture of seismic hazard. Automated mapping of fault scarps can place important constraints on the relative activity of structures within fault zones for which seismic hazard is poorly constrained, such as the North Coast section of the San Andreas Fault. Tackling the big data problem of identifying and relatively dating fault scarps at the scale of a plate boundary would serve as a quantitative complement to detailed field mapping, paleoseismology, and geophysical observations.

The proposed project will apply a template matching method to estimate scarp location, height, and morphologic age in Northern California and along the North America-Pacific plate boundary. This method identifies fault scarps where topographic steps are produced by vertical displacement of the ground surface by dip- or oblique-slip faults, or where regions of high and low topography are juxtaposed by strike-slip faults. Best-fit scarp parameters can be compared to independent constraints from paleoseismic studies and present-day geodetic slip rate estimates to assess the activity of the fault over time.
 
We are seeking an enthusiastic undergraduate student with some programming experience in Python or MATLAB, familiarity with GIS, and an interest in spatial data analysis. The student will work with an established data processing pipeline to estimate fault scarp maturity using large, high-resolution topographic datasets. Potential projects include (i) analysis of template matching results at sites in Northern California and the Bay Area and (ii) testing and deployment of the pipeline on a cloud computing platform. The student will gain experience with scientific programming, common spatial data processing operations, and the display and interpretation of results from scarp profile diffusion modelling. There will also be an opportunity for a field trip to sites that record historic earthquake surface rupture in the Bay Area.

Analyzing Responses to Drought in Brazilian Coffee Systems

SESUR or SURGE
Advisors:  Professor Eric Lambin and Elinor Benami

As the world’s agricultural regions face increased climate uncertainty, identifying ways to mitigate the effects of unanticipated weather shocks and enhancing farmer resilience matters all the more.  This project focuses on the case of coffee production in the Brazilian southeast, in which a severe and prolonged drought recently afflicted thousands of farmers. Among these farmers, hundreds had joined in eco-certification programs encouraging them to adopt a series of “climate smart agricultural” practices. Using both primary field and secondary data, this project seeks to understand how these programs may have influenced the farmer’s resilience to drought.
 
As part of this project, the student would assess coffee’s biophysical responses to drought and how that varies based on a farmer’s participation in these programs. Data would be drawn from historical satellite imagery of coffee production regions, supplemented by the research group’s data on the locations and dates of coffee farmer participation. The student’s role will focus on (a) helping select appropriate methods to detect hydrological stress (b) implementing and recording the results of selected analytical procedures using geospatial analysis software.
 
Additional project possibilities exist and include analyzing primary survey data to assess the predictors of adopting climate smart agricultural practices and/ or developing and testing your own independent research questions. Overall, the project will support students to develop their research and communication skills, and will encourage students to participate in relevant opportunities (workshops, webinars, data visualization clinics, etc.) while advancing with the project goals.  

This role is suitable for motivated, detail-oriented students with experience in and/or who are curious about how to unite remote sensing tools with techniques to analyze commodity crop governance. No prior research experience is required, although a background with or enthusiasm to learn R, ENVI and/or GIS software basics is essential. Depending on student interest and availability, engagement in the project could be extended through school year. In addition, opportunities to participate in field work to share and test results in Brazil could also be explored.

Nitrous oxide emissions, food production, and bioenergy trade-offs necessary to stabilize global warming

SESUR or SURGE
Advisors: Professor Christopher B. Field, Peter A. Turner, and Katharine J. Mach

To stave off the worst effects of climate change, net greenhouse gas (GHG) emissions must approach zero by the end of the century. However, GHG emissions from some sectors will be particularly difficult to reduce and thus, atmospheric drawdown of CO2 using a mix of forest regrowth and bioenergy with carbon storage will become necessary. Broad-scale deployment of bioenergy for instance, has the potential to provide net negative CO2 emissions and could be an important feature in low-carbon energy systems. Yet, the implications that substantial demand for biomass will have on emissions of nitrous oxide (N2O), a potent GHG and ozone depleting substance, are not well understood. Since N2O is produced primarily in agricultural soils amended with nitrogen fertilizer to grow high yielding food and energy crops, mitigation of N2O must also simultaneously balance the needs for energy and food security. In a future world with large-scale bioenergy deployment and a growing population, how to approach the N2O problem remains a persistent challenge.

We are looking for a student interested in exploring trade-offs between food and energy production that will emerge under a changing climate. Broadly, topics could include how bioenergy and food production will impact N2O emissions, identifying opportunities for pollution reduction at regional to global scales, or improving emission understanding for policy development. A student who is interested in building or expanding their data processing (Matlab or R) capabilities would be ideal.

Exploring natural concrete alternatives – limitations on lime-pozzolan ratios

SURGE or SESUR
Advisors: Professor Tiziana Vanorio and Jackson MacFarlane

The concrete industry is responsible for 7% of global CO2 emissions, and global concrete consumption continues to rise in an ever modernizing world. Concrete forms through a hydration reaction and there are a number of natural processes which utilize the same reaction. We are interested in the lime-pozzolan (silica rich volcanic ash) reaction which occurs in volcanic geothermal systems and was used by the Romans when they created the first hydraulic cement. Increasing our understanding of these natural processes can help us to reduce waste and increase the strength and durability of our construction materials.

The student will be making lime-pozzolan samples in the laboratory and measuring their properties. The properties measured will range from porosity/permeability to strength/elastic velocities. The goal of the project is to understand how the lime-pozzolan ratios affect the sample properties and therefore the limitations for natural formation. This will be a hands on project where the student will be spending the majority of their time performing experiments and collecting/analyzing the results. The student will have support from both academic and laboratory staff to learn laboratory best practices. No prior experience in earth sciences is required. Previous experience in laboratory work is preferred but not required.

Imaging the Canadian Shield with Earthquake Data

SURGE and SESUR
Advisors: Professor Simon Klemperer  and Tianze Liu, PhD candidate

The boundary between the Earth’s crust and mantle, usually called the Mohorovicic discontinuity (Moho), was first discovered by analyzing earthquake data and was later confirmed by numerous seismic studies as a global discontinuity in the Earth’s interior.  However, different seismic techniques do not always give consistent results on the nature (depth, sharpness, etc.) of the Moho. For example, a novel seismic technique called Virtual Deep Seismic Sounding (VDSS) has given very different Moho depths from conventional P-wave Receiver Functions (PRF) in some areas, making it interesting to see whether the discrepancies arise from flaws in one or other methodology, or some unknown features of the Moho itself.

The Yellowknife array in the Slave Province of Canada offers a perfect chance to compare VDSS with other seismic techniques for two reasons: 1) The Yellowknife array has a continuous digital broadband record for ~30 years, a gigantic dataset that will make the result very robust. 2) a nearby seismic refraction profile shows a very flat Moho, which minimizes possible errors caused by lateral variation in crustal structure, and PRF images of the upper mantle are also available. You will use our existing codes to apply VDSS and PRFs to seismic data recorded by the Yellowknife array, and see whether they give consistent results. Additional goals include estimating P and S wave velocity of the crust of the Slave Province, one of the oldest pieces of crust on Earth, in order to constrain its chemical composition. This will help us understand how the Earth evolves in its early age.

Applicants should have basic skills in Unix shell scripting and MATLAB programming. Some fundamental knowledge of seismology and Earth structure is useful but not required.

Dynamic links between subsurface water and carbon in the Rocky Mountains

SESUR
Advisors: Professor Kate Maher and Matthew Winnick

Soils, floodplains, and shallow aquifers are the least understood components of the global carbon cycle, yet they represent the largest reservoir of terrestrial carbon and are highly sensitive to shifts in climate, vegetation, and the resulting water balance. Small changes in the storage and cycling of carbon in the subsurface therefore may have very large impacts on the Earth’s climate system. We are currently conducting research at the Rocky Mountain Biological Laboratory (www.rmbl.org ; Gothic, CO) aimed at addressing this critical knowledge gap by describing the interactions between water and carbon in the subsurface to better understand their sensitivity to future change. We use research techniques across a range of disciplines including stable isotope biogeochemistry, hydrology, microbial ecology, and GIS, and combine fieldwork with laboratory analyses and quantitative models.

An enthusiastic undergraduate will spend the summer conducting field research at the RMBL field station in Colorado and will have the opportunity to develop a range of projects to contribute to our ongoing research. Potential projects include (1) measurement of soil gas fluxes (CO2, CH4, H2O) across a range of scales within the East River watershed; (2) high spatial/temporal resolution stream chemistry measurements to characterize processes such as the effects of summer storm events on solute fluxes and topography on stream CO2 degassing; (3) soil description surveys across ecosystems, topography, aspect to characterize soil carbon stocks and guide hydrologic subsurface flow models. Projects will all involve a strong field component with ample opportunity to explore laboratory work and quantitative hydrologic and geochemical models depending on the student’s interests.

Mapping the direction of the maximum principal horizontal stress in the coterminous United States

SURGE and SESUR
Advisors: Professor Mark Zoback and Kevin McCormack

The orientation of the maximum horizontal principal stress is of integral importance in seismic hazard assessment and analyzing geodynamic phenomena of the lithosphere. At present, there are large swathes of the globe that have no measurements for the orientation of the maximum horizontal principal stress. We are carrying out research on a new approach to measuring this component of the stress field using shear-wave anisotropy in the earth's crust derived from recordings of global earthquakes on densely distributed seismic stations during the deployment of the transportable array across the U.S.

The student will have an active role in improving and utilizing an existing code to process and analyze a large dataset of seismic recordings across the conterminous United States. Ideally, the student should have experience with MATLAB or another coding language and he or she should have an interest in seismology, tectonics or geomechanics.

Understanding economic development using satellites and machine learning

SURGE
Advisors: Professor Marshall Burke and Professor David Lobell

Ending global poverty is an off-stated goal of the international community, but most developing countries – particularly those in Africa – currently collect little or no data on poverty at the local level.  Filling this data gap with more frequent household surveys – the traditional approach to poverty measurement – is likely to be both extremely costly as well as institutionally difficult, given reluctance by some governments in having their performance documented.   The goal of our project is to develop and deliver a new generation of poverty measures, based on a combination of satellite imagery and novel machine learning approaches.  This combination has shown great initial promise in generating poverty estimates at low cost, but we wish to scale the approach up over more countries, over more time periods, and for additional development outcomes such as health and food security.  Many development organizations have expressed interest in using the data we would generate, making this a project that could have real impact.

Students would work with the PIs as well as other members of Stanford’s SustainLab (sustain.stanford.edu) to assemble and geocode new “ground truth” data from a variety of sources, including scattered survey data on household assets, wages, food security, food prices, and health in the developing world.  Knowledge of R or python, or experience programming in similar packages, will be very useful.  Depending on the student’s skillset, s/he could also be involved in developing the computational frameworks to predict these ground truth data with imagery.   Students with remote sensing experience might also work directly with imagery to predict these outcomes.

Investigating the control of carbonate factories on carbonate platform geometry

SURGE
Advisors: Professor Jonathan L. Payne and Xiaowei Li

Carbonate platforms can be generally subdivided into high-relief rimmed shelves and low-relief carbonate ramps. A long-standing hypothesis states that “reef” development at margin-slope facies might transit low-relief ramp into high-relief shelf. Yet, as the taxonomic identities of the most important reef builders changed through geological time, particularly after mass extinction events, the degree to which different reef builders and other carbonate-producing organisms influence platform morphology remains poorly constrained. Our project goal is to explore the relationship between carbonate platform biota and associated platform morphology (e.g., height, width, slope curvature). We will accomplish this goal by gathering data from published examples of carbonate platforms as well as data from our own previous field studies. No prior experience in Earth Sciences is required, but the candidate who knows basics of carbonate sedimentology and statistics is preferred.

Climate change impacts on access to marine resources by subsistence harvesters in Arctic National Parks

SESUR or SURGE 
Advisors: Professor Nicole Ardoin, Professor Larry Crowder, and Kristen Green

As temperatures warm, human access routes to marine subsistence resources are rapidly changing in Arctic Alaska. The National Park Service (NPS) is responsible for sustainable management of park resources as well as subsistence access to those resources.  However, a lack of information on climate change impacts to access routes limits management planning. This research will seek to understand how climate change is affecting subsistence users’ access to marine resources in Bering Land Bridge National Preserve and Cape Krusenstern National Monument. This project will seek to document past and current forms of transportation and technologies for access, interview park staff and the public regarding access of coastal resources within Parklands, and rank vulnerability of coastal sites in park boundaries. This will help NPS anticipate shifts in subsistence use and provide a foundation for adaptive management of access to marine subsistence resources.

We are looking for an enthusiastic undergraduate to spend 2-4 weeks of the summer (June/July) in Northwest Alaska (Kotzebue region) with a graduate student advisor assistant. Travel and housing will be covered as part of the grant. Fieldwork will consist of visiting native villages, interviewing local land users and land owners, and park staff, and visiting coastal subsistence harvest sites. Previous experience with fieldwork is not required, but ability to maintain a good attitude during inclement weather and the occasional mosquito swarm is necessary. Experience with NVivo or GIS software is preferred but not required. In the field, the student assistant will help to set up interviews and transcribe digital interview data; other components of the internship may include gathering or synthesizing existing harvest datasets. The student will access unique ecosystems and get an intimate look at life in Arctic Alaska and there will be ample opportunity for the student to design an independent project in accordance with project datasets.

Coastal fog-mediated interactions between climate change, upwelling, and coast redwood resilience: projecting vulnerabilities and the human response

SESUR
Advisors: Professor Nicole Ardoin, Dr. Lauren Oakes, and Indira Phukan

Coastal ecosystems and human communities have developed an intricate and reliant relationship with the process of coastal upwelling and the resulting fog. As climate change starts to impact ocean temperature, changing temperatures inevitably effect the upwelling process. However, how this process effects coastal ecosystems is unclear: research suggests a myriad of sometimes-contrasting impacts. Working with a collaborative of researchers from several universities, this project seeks to model projections of coastal fog, as well as explore some of the fog-mediated impacts on coastal ecosystems and communities.

In particular, our team’s work focuses on the social dimensions of people’s interactions with the coast redwood, a flagship species. We are examining how changing conditions in redwood forests might influence human perceptions and behaviors. In 2014 alone, more than two million people visited state and national redwood park destinations (Save the Redwoods League, 2014). Additionally, research indicates that place attachments, such as those that develop in coast-redwood forests, may enhance an individual’s willingness to undertake conservation behaviors (Vaske and Kobrin, 2001; Ardoin, 2001; Ardoin, 2006, 2013; Devine-Wright, 2009; Russell et al., 2013). Given both of those factors—high visitation rates coupled with the power of place—the coastal redwood forests may be uniquely positioned to influence and motivate climate change mitigation and adaptation.

Our work in the summer of 2017 will begin to address the research question: How does learning about climate change through place-based educational and interpretive experiences focused on a flagship species influence knowledge of, attitudes toward, and perceptions of climate change? And how might those experiences affect climate-related behaviors, including support of climate mitigation policies? Through interviews, surveys, and eventually an educational intervention, we will explore visitors’ experiences of the coast redwood in local state and national parks.

We are seeking an undergraduate to spend the summer working with our team to collect, organize, analyze, and potentially synthesize data. Fieldwork will consist of visiting local state (and potentially national) parks and pilot testing interview and possibly survey protocols with park visitors as well as park managers. Experience with NVivo (qualitative-data software) preferred but not required. The student will gain experience in fieldwork, interviewing, qualitative data analysis and organization, and working with a research team on a large-scale project.

How do plants affect nutrient and contaminant cycling in Rocky Mountain floodplain soils?

SURGE or SESUR
Advisors: Professor Scott Fendorf and Dr. Kristin Boye

Floodplains are important conduits of exchange between ground and river water. Former mining and ore processing activities have left persistent groundwater plumes of uranium, molybdenum, and other contaminants within floodplains along rivers draining the Rocky Mountains. Plants are strongly involved in both the hydrological (through water uptake) and biogeochemical (through nutrient uptake, root exudation, and respiration) processes that control the exchange of metal contaminants between surface and groundwater. We are conducting field and laboratory research examining the effect of plants (and specifically plant roots) on the behavior of nutrients and contaminants in floodplains to understand the processes regulating water quality and contaminant partitioning.

We are looking for two curious and enthusiastic students to help run a plant experiment using specialized growth boxes (rhizoboxes) to investigate the role of plant roots in driving nutrient and contaminant biogeochemical cycles in floodplain soils and sediments. The students will be responsible for different parts of the experimental and analytical work, which will require close cooperation between the investigatory team members. Potential foci for student projects include: abundance and fate of root carbon in the soil, processes stabilizing or mobilizing contaminants, or redox dynamics in the root zone. Previous wet laboratory experience is desirable, but not required. Willingness to conduct systematic, repetitive research to obtain meaningful and exciting results is important.

Assessing Water Quality and Element Cycling in Alpine Watersheds of the Colorado Rockies

SURGE or SESUR
Advisors: Professor Scott Fendorf, Christian Dewey and Hannah Naughton

We have two projects available to examine water quality and element cycling within alpine watersheds of the Colorado Rockies. Below each are described more fully.

I) Assessing Lead and Copper Levels within Coal Creek Watershed
Water quality within the seemingly pristine wilderness of the Colorado Rockies is threatened in specific locations by current and historic mining. Two mines near Crested Butte, CO have contaminated the Coal Creek watershed with lead (Pb) and copper (Cu). Although the mines are inactive, uncontained waste continues to act as a source of metals to the creek and its floodplain. Not only are metals potentially detrimental to flora and fauna within the ecosystem, but the town of Crested Butte draws its water from Coal Creek, and thus the public water supply is also at risk. To assess the risk associated with Pb occurrence in Coal Creek, it is essential to understand the processes and mechanisms that control Pb retention and mobility within the watershed. Investigating these processes and mechanisms is the broad aim of this project.

Specifically, we intend to assess how Pb retention mechanisms change with depth in creek sediments. We suspect that organic matter (OM) derived from decaying plant material plays an important role in Pb retention; however, the fate of OM-bound Pb is unclear: as water levels change and thus subject sediments to different geochemical conditions, OM likely undergoes transformations that affect Pb stability. Lead might be mobilized as small particles that remain suspended within the water, threatening water quality, or it may remain within the sediments themselves, imposing minimal risk to ecosystem or human health.

We are looking for a student who can spend between 6 and 10 weeks based in the area of Crested Butte, CO, performing fieldwork and laboratory work. Interested students should feel comfortable getting dirty and wet, and working at high altitude. Fieldwork will likely include collecting water and soil samples for lab analysis, installing and monitoring wells, and measuring geochemical parameters on site. Coursework in introductory chemistry and/or environmental science would be advantageous, but it is not a requirement for this project.

II) Defining Nutrient Cycling and Water Quality in East River, CO
Hydrology strongly influences the biological and geochemical processes that control water quality and nutrient cycling in alpine watersheds. Cyclical shifts in water levels (caused by seasonal snowmelt coupled with rainfall patterns) alters the microbial metabolisms within riverine and floodplain sediments, driving nutrient cycles (inclusive of carbon) and modifying stream water chemistry. Climate change is altering the hydrology of alpine systems, and thus it is critical to understand how hydrology influences the biological and geochemical processes that influence water quality and nutrient cycles. We are exploring the biogeochemical response to shifting hydrology within East River, a subalpine river with an active floodplain in Gunnison County, CO. Importantly, East River serves as part of the Colorado River headwaters, and thus finding on this tributary have large scale implications for water quality and associated nutrient cycles.

Specifically, we intend to investigate the impacts of water table fluctuations on carbon and iron dynamics – two elements of enormous importance in controlling contaminant fate in the subsurface – in the East River floodplain. Our project will focus on resolving how these dynamics change with depth under shifting hydrologic conditions. We will pair our work with studies currently underway examining water budgets and carbon cycling within East River.

We are looking for a student who can spend approximately 6 to 10 weeks based in the Crested Butte, CO, area performing fieldwork and lab work. The student should feel comfortable getting dirty and wet and working at high altitude. Fieldwork will likely include collecting water and soil samples for lab analysis, installing and monitoring wells, and measuring geochemical parameters on site. Coursework in introductory chemistry and/or environmental science would be advantageous, but it is not a requirement for this project.

Quantifying the effect of trapping on muskrat numbers in the Peace-Athabasca Delta, Canada

Advisors: Professor Steven Gorelick and Ellen Ward
SESUR

The 6000 km2 Peace-Athabasca Delta (“Delta”) in northeastern Alberta, Canada, is a Ramsar Convention Wetland and UNESCO World Heritage Site (“in Danger” status pending) where hydropower development and climate change are creating ecological impacts through desiccation and reduction in Delta shoreline habitat. Our research is focused on ecohydrologic changes and mitigation and adaptation options to advance the field using interdisciplinary technology by combining, for the first time, satellite remote sensing and hydrologic simulation with population genetics, demographic analysis and individual-based population modeling of Ondatra zibethicus (muskrat), an ecological indicator species native to the Delta. We are building a conceptual and quantitative modeling framework linking climate change, upstream water demand, and hydrologic change in the floodplain to muskrat population dynamics with the objective of exploring the impacts of these stressors on this ecosystem.

An important factor in this conceptual and quantitative modeling framework is the effect of trapping on numbers of muskrat in the Delta. We are looking for a motivated student to analyze a recently digitized archive of Government of Canada documents that record the numbers and locations of muskrats trapped at various lakes in the Delta. Starting from these primary sources, the student will develop maps of trapping intensity in the Delta over time. These maps will then be introduced into the population model. Additional possibilities to contribute to the project include (i) studying the history of the trapping community in this region to better understand reasons for observed changes in trapping intensity over time, and (ii) potentially helping the project by running simulations on a subsection of the Delta to see how well our model is able to represent the sensitivity of the Delta muskrat population to trapping.

No prior research experience is required, although enjoyment of computer work and excitement to learn GIS and population modeling software is essential.

Predicting rooting response to droughts and climate change using a global analysis of rooting depths and volumes

SURGE
Advisors: Professor Rob Jackson and Shersingh Tumber-Davila

As plants become water-stressed, increasing the allocation of carbon to root growth may allow them to reach a bigger pool of soil water, as roots become deeper and spread laterally. A better understanding of the feedback relationship between rooting growth and water availability is needed, as well as an understanding of the plasticity of rooting traits during climatic extremes. This can be done by making measurements of rooting traits during drought-induced mortality events, and by analyzing the rooting demographics of plants under different climatic conditions.

The student will have the opportunity to test the relationship between root canopies, and the aboveground environment of an individual plant. This will include the analysis of a global database of individual plant root systems, and a combination of fieldwork to local California sites, where root profiles will be carefully dug. The dug root profiles will help study the importance of belowground investment in roots to plant fitness during drought stress. The student must have an interest in forest ecology, and a willingness to learn different field measurement, and analysis techniques. Prior field experience would be beneficial, but not mandatory.

Plantation forestry and soil sustainability

SURGE
Advisor: Professor Rob Jackson and Devin McMahon

Forest plantations, in which trees are grown as a crop, are planted worldwide in order to produce wood for lumber, fiber, and bioenergy, and to restore tree cover to degraded land. However, tree plantations also demonstrate the capacity of plants to alter soil properties. Fast-growing trees extract soil nutrients which are repeatedly removed from the site in harvested biomass, requiring fertilizer inputs to maintain productivity and threatening the long-term sustainability of this land use. Therefore, we are investigating the effects of plantation forestry on stocks of soil nutrients over multiple harvests, by comparing soils collected from industrial eucalyptus plantations, pastures, and native vegetation reserves in southeastern Brazil in 2004 and 2016. We are also using remote sensing data to analyze trends in vegetation productivity.

A summer research assistant will gain hands-on experience in laboratory techniques for measuring total nutrient content of soils. Techniques will include X-ray fluorescence spectroscopy and elemental analysis by combustion, as well as possible acid digestions or sodium carbonate fusions. In addition to performing these techniques, the student will have the opportunity to contribute to developing protocols to optimize the detection of nutrient elements with low molecular weight, specifically magnesium and boron, by fluorescence or other methods. If interested, the student may also be able to contribute to the remote sensing component of the project by combining simple coding and visual interpretation to identify the boundaries of individual plantation areas. The ideal student will pay close attention to detail and maintain interest in land use issues, plant-soil interactions, and problem solving. Prior laboratory experience is not necessary but would be helpful.

Developing new techniques for validating remote sensing data

SURGE or SESUR
Advisor: Professor Alexandra Konings

Satellite remote sensing of soil moisture is important for flood forecasting, drought monitoring, climate and weather models, and many more applications. However, remote sensing estimates of soil moisture often represent a much coarser scale than in situ measurements. This presents a challenge for validating these remote sensing measurements – large amounts of high-accuracy in situ measurements are needed to adequately determine the average conditions over the larger remote sensing footprints. As a result, field campaigns for soil moisture validation require large teams of people, are expensive, and can only be done in a few regions. Similar challenges occur for validating estimates from earth system models, and remote sensing retrievals of many other geophysical variables.

However, if three different estimates of soil moisture in the same location can be obtained, it may be possible to validate them (e.g. calculate their error statistics) even without having an explicit ‘perfect’ estimate from in situ measurements for comparison by using a simple, elegant algebraic technique called triple collocation. Triple collocation is very powerful, but still requires certain limiting assumptions to be met. This project will explore modifications of the triple collocation technique to make it easier to use.  After algebraic derivation, the student will write code to test the viability of the technique in synthetic examples with real-world limitations (e.g. number of samples, error correlations and distributions) and apply the technique using global satellite observations of soil moisture. Strong quantitative skills and enthusiasm for quantitative research are required, although the method itself is purely algebraic. A basic knowledge of statistics is helpful but not necessary.

Remote sensing of vegetation drought response

SURGE or SESUR
Advisors: Professor Alexandra Konings and Dr. Mostafa Momen

Microwave remote sensing data are useful to understand how drought and climate change might change vegetation cover throughout the world. Microwave observations, made using radars and radiometers on earth-orbiting satellites or airplanes, are sensitive to vegetation water content, which is a direct measurement of plant drought stress. As such, they can be used to accounts for how various plants respond differently to different types of droughts, including reductions in root-zone soil water availability and increases in atmospheric water demand.

Projects are available along two different lines, depending on student interest and background. A project is available to test and develop a new algorithm to determine vegetation water content from radars in a more general way than is currently available, thereby greatly increasing the spatial resolution of available data. Additionally, a student can work to understand how to optimally parameterize vegetation drought response traits for large-scale earth system models by comparing previously derived remote sensing metrics of drought response to ground based measurements on related plant traits. Experience with scientific programming would be helpful, but enthusiasm is the primary requirement.

Computational simulations of episodic convection in lava lakes

SURGE or SESUR
Advisors: Professor Jenny Suckale and Dr. Tobias Keller

Lava lakes provide a unique opportunity to study the physics and chemistry of magma ascent in an active volcano, because they expose the top of the magmatic system to direct observation. Understanding why lava lakes erupt will help us decipher more generally the drivers behind explosive activity in other volcanic systems.

In lava lakes, hot and gas-rich magma rises through a volcanic conduit to the surface, where it cools and loses much of its dissolved gas content to the atmosphere. The cooled and degassed lava then sinks back into the lake. Because of the dramatic temperature contrast between lava and atmosphere, a stiff skin may form on the surface of the lake, which episodically founders, leading to convective patterns similar to global mantle convection and plate tectonics on Earth, yet on a smaller scale. This project will use numerical simulations of thermal convection with a nonlinear viscous rheology to study the overturn cycles on the lava lake at Mount Erebus volcano, Antarctica.

This project involves using a purpose-built thermal convection software to run numerical experiments, and analysing the results in comparison to surface observations from Erebus. Depending on interest and skills, the student may also contribute to ongoing code development. We are looking for a student with interest and a basic understanding of physical processes and/or scientific computation. We actively encourage applicants from Geosciences, with no previous experience with computational methods, as well as from Physics, Computer Science or Applied Mathematics with no previous experience in Geosciences.

Basin and Petroleum System Modeling of Terrebonne Mini-Basin Gas Hydrates in the Northwest Walker Ridge Area (Gulf of Mexico)

SURGE
Advisors: Professor Stephan Graham and Laura Dafov

Gas hydrates, potential clean-burning “bridge fuel”, hold vast volumes of methane and affect a wide range of scientific interests including drilling hazards, potential future energy resource, global carbon cycling, geohazards, climate change, and global energy security. Although total global estimates of gas hydrate volumes vary, even the most conservative estimates consider methane hydrates to be the world’s largest reservoir of fossil fuel with it potentially being up to 3 times larger than all of the world's conventional and unconventional oil, gas and coal combined.

There is great opportunity for improving our understanding of gas hydrates through the basin and petroleum system modeling (BPSM) approach. BPSM is a well-established discipline that integrates geology, geophysics, geochemistry, engineering, geostatistics, rock physics and more to predict the generation, migration, and accumulation of petroleum. That prediction is accomplished by forward simulating the sedimentary basin through time. Though widely used in academy and industry, BPSM has only rarely been used to study gas hydrate systems. The reasons for that are varied, but BPSM is ideally suited for gas hydrate modeling due to its sophisticated treatment of subsurface pressure and temperature through time. BPSM is also optimally suited for modeling gas hydrates due to its ability to handle very short time steps and very fine spatial resolutions. In this way, BPSM can capture the temporal (and thus spatial) variability in gas hydrate deposits as well as changing conditions in the water column that can affect the gas hydrate stability zone. BPSM has been called the ‘great integrator’ in petroleum exploration (Hosford Scheirer, 2014).

The research project area of interest is the Terrebonne Basin in the northern Gulf of Mexico (GoM) continental slope, a salt-withdrawal mini-basin in northwest Walker Ridge area. Development of a BPSM model of gas hydrates in the Terrebonne mini-basin of the northern GoM will provide a vehicle within which to integrate other early exploration and assessment research being conducted on gas hydrates, a resource likely to provide many decades of energy if proven to be commercially producible in the future. The student will help with components of the project potentially including (but not limited to) data mining, mapping, 1D, 2D, 3D modeling and characterization, using PetroMod, MATLAB, SGeMS, IHS Kingdom suite, ArcGIS, and Move software. See here for a brief (2 minute) video of the research project overview: https://www.youtube.com/watch?v=-C7K3quhJYg. As a former SURGE student, Laura is eager to pay forward the mentorship. Looking for students with geological sciences background, but do consider all talented individuals. Previous skills or experience using Illustrator, Photoshop, PetroMod, MATLAB, SGeMs, IHS Kingdom suite, ArcGIS, Move and Petrel software would be helpful.

Remote sensing for crop monitoring

SESUR or SURGE
Advisors: Professor David Lobell and Dr. George Azzari

Many new exciting satellite sensors are collecting detailed information on the land surface, which should prove useful for improving understanding about agriculture. Our research group has been actively developing methods to map crop locations and productivity with new data streams. The student would participate in one or more of these projects, which include: using new Sentinel-1 radar datasets in India to improve yield estimation for wheat and rice; using new high-resolution sensor data to map wheat fields in Ethiopia and detect outbreaks of stem rust; testing and improving U.S. soybean yield estimation by running multiple soybean crop models and testing against new field-specific datasets on yields; compiling subnational census data from major crop regions around the world and comparing against satellite estimates. Background in some computer programming (preferably javascript or python) is required. Familiarity with satellite datasets is desired but not required.

Food-water nexus

SESUR or SURGE
Advisor: Professor David Lobell

Water scarcity is a growing concern in many regions. Several recent studies have documented the growing rates of scarcity of water supply relative to demand for growing food, as well as depletion of groundwater resources. These trends imply that irrigation cannot continue to expand in many regions, and in some may even contract. The implications of this for regional and global food production are not fully understood. Some studies have estimated the loss in average yields and yield stability that occurs when going from irrigated to rainfed systems, or vice-versa. In this project, the student will work with datasets on annual irrigated area, weather, and crop yields in different countries. The goal will be to estimate for major agriculture regions: (i) what fraction of overall yield trend growth can be attributed to increased irrigated area; (ii) how has changes in irrigation affected the stability of yields, and in particular their sensitivity to heat and drought; (iii) if irrigation was reduced to levels consistent with estimates of “sustainable” water consumption, how would that affect future yield levels and stability relative to a scenario that extrapolates historical trends in irrigation. The results of this project will feed into a broader project attempting to analyze competition between food and water security. Background in R programming and regression analysis is required.

Solar-generated steam for enhanced oil recovery

SESUR
Advisors: Tony Kovscek and Anshul Agarwal

In California, natural gas is burned to create steam for enhanced oil recovery (EOR). While the natural gas is clean burning, it produces carbon dioxide. One way to reduce the carbon footprint of thermal EOR is to substitute steam generated using solar energy for all or a portion of the natural gas fired steam. Using solar generated steam may require different operation of the oil reservoir, however. The objective of this project is to examine potential changes to reservoir properties that might occur because of the intermittent and seasonal nature of solar insolation.

The project consists of running reservoir simulations under various scenarios of steam availability and visualizing the output. An enthusiastic undergraduate student will use a commercial reservoir simulator to investigate several different steam injection strategies and their influence on cumulative oil production, carbon dioxide emissions, and reservoir stresses. Based on the results of the numerical experiments, the student will design an optimal strategy for using solar-generated steam under varied solar insolation scenarios. This project is suitable for students with an interest in engineering, math, physics, and their application to energy problems.

Investigating the marine nitrogen cycle through stable isotope measurements

SURGE or SESUR
Advisor: Professor Karen Casciotti

The availability of nitrogen (N) limits the productivity of phytoplankton throughout much of the ocean. As such, understanding the ocean’s N cycle is an important objective marine biogeochemists. The N isotope, 15N, of different marine N pools provides a wealth of information about microbial N transformations. We have been trying to understand the cycling of nitrogen in marine oxygen deficient zones through stable isotopic measurement of nitrate and nitrite in marine systems. A new project involving measurement of nitrate isotopes in the Benguela upwelling system will provide an opportunity for student(s) to learn oceanography, marine chemistry, and isotope ratio mass spectrometry in the context of the broader program GEOTRACES (www.geotraces.org), an international program to map the distribution of trace elements and isotopes in the world’s oceans. Prior experience in the lab would be helpful but is not required. Enthusiasm for lab work, chemistry, biology, and biogeochemistry are absolutely necessary.

The Impacts of Agricultural Intensification on Species Interactions: Implications for Conservation and Ecosystem Service Provision

Professor Rodolfo Dirzo and Beth Morrison
SESUR

Ecosystem services - valued collectively at $125 trillion USD per year - are being threatened by the global species extinction crisis of the Anthropocene. Many ecosystem services are provided by the maintenance of species interactions such as plant-pollinator and predator-pest interactions. For example, 35% of the world’s crops require pollination, and global declines in pollinator abundance are leading some farmers to spend thousands of dollars each year to pollinate crops by hand. Despite the ecological and economic utility of preserving biodiversity and ecosystem service provision, there is a lack of empirical evidence of the effects of agricultural intensification on species interactions. The goal of this project is to assess plant-pollinator, plant-pest, and pest-predator interactions at 12 sites along a gradient of agricultural intensification – from natural habitats to organic monocultures. We will spend the summer visiting farms and state parks in Santa Cruz and Monterey counties conducting plant surveys and collecting insects. These data will then be combined with data collected in 2016 to study the influence of agricultural intensification on the persistence of species interactions, ecosystem service provision, and biodiversity loss and change across agricultural landscapes.

The student will spend the duration of the internship doing fieldwork in Monterey and Santa Cruz counties with a graduate student advisor and 1-2 other undergraduate assistants. Days start early and typically finish around 3:00pm, with the rest of the afternoon free. The student will learn plant identifications skills, as well as various techniques for sampling insect species, including aerial netting of bees and other pollinators. Given the many components of this project, there are opportunities to design a project tailored to the student’s interests. Previous experience doing fieldwork is not required, but ability to maintain a good attitude even during inclement weather and long days are a must. We will visit some really beautiful places during the field season, and students will get an intimate and unique look into the workings of California’s vast agricultural system.  

Exploring marine microbial diversity in seawater and sediments

Advisors: Professor Anne Dekas and Dr. Alma Parada
SURGE  

Marine microbes greatly influence global biogeochemical cycles, including by consuming greenhouse gases like carbon dioxide and methane. Characterizing the diversity and activity of microbes in different environments within the ocean allows us to understand which microbes are key players in the cycling of major elements, like carbon and nitrogen. Under the supervision of Drs. Alma Parada and Anne Dekas, the student will analyze the diversity of microorganisms in samples previously taken from the marine water column and sediments. The student will learn and apply various molecular and microbiology techniques such as cloning, DNA extraction, and PCR methods, as well as analyzing data using bioinformatics techniques. Prior research experience is not necessary, but an enthusiasm to perform lab work and learn how to analyze data via command line computer software is a must, as well as a general (even if new!) interest in environmental science and microbiology.

Temporal development of plant-soil microbe feedback in coastal sand dunes invaded by non-native plants

Advisors: Professor Tadashi Fukami and Po-Ju Ke
SESUR or SURGE

There is an emerging interest in understanding how interactions between plants and soil microbes affect the species composition of plant communities. Plant-soil interactions can determine plant coexistence and success of non-native plants. However, knowledge on the temporal development patterns of these interactions is still lacking, yet can be important for designing restoration projects and controlling plant invasion for conservation. In this project, we established a long-term dune chronosequence from high-resolution aerial photos at Bodega Bay, a typical California dune ecosystem dominated by invasive plant species. With this unique resource, we are studying how plant-soil microbe feedback varies with the duration of soil cultivation by plants to examine how shifts in their interaction correlate with vegetation dynamics. Students will be asked to join a 2-3 week long field work at Bodega Bay. Students will help collect soils that varied in their host plant and the amount of time they have been under cultivation. We will then set up an experiment to compare plant growth in soils with different cultivation history. For the remainder of the summer program, students will help extract plant demographic data and analysis vegetation dynamics from aerial photos using GIS software. Previous experience with ecological field work is helpful but not required. Enthusiasm for field work and learning GIS software is required.

Detecting local seismic events from seismic data recorded by the Stanford Distributed Acoustic Sensors (DAS) array

Advisors: Professor Biondo Biondi and Fantine Huot
SESUR or SURGE

Since September 2016 we have been recording seismic data using a 2.5  km long fiber optic cable deployed under Stanford campus. One of the main goals for this experiment is to study the feasibility of using Distributed Acoustic Sensors (DAS) technology to record seismic activity under major metropolitan areas, such as the Bay Area. If successful, this technology could be used in earthquakes early warning systems and for cost-effective characterization of seismic hazards. Undergraduate students involved in this project will work with graduate students to develop and test an automatic system that can detect local seismic events from the continuous stream of data recorded by our DAS array. They will learn the basics of seismic processing as well the application of real-time data-analytics to a large data stream. Students will need to have basic programming skills in one of these languages: Python, MatLab, C, and C++.

Geology of calderas associated with flood basalts and Yellowstone plume

Advisors: Professor Gail Mahood and Jackson Borchardt
SESUR

We are searching for an enthusiastic undergraduate that will help conduct summer fieldwork (~3 weeks) and associated lab work on a project near the Nevada-Oregon border studying the nature of the volcanism when the Yellowstone plume first encountered the North American plate some 16 million years ago. The student will have the opportunity to develop a range of field and laboratory-based skills while contributing to our ongoing research. Before fieldwork begins, the student will have the chance to learn about compiling maps and satellite imagery using ArcGIS and how to prepare for fieldwork. Depending on the student’s prior geologic experience, the field work can range from being a field assistant to undertaking independent geologic mapping of part of the study area. After the field work, the student will be involved in preparing samples for chemical analysis and argon geochronology, and there will be an opportunity to interpret the chemical data and its implications for geologic correlations and igneous petrogenesis. There is also potential for a project utilizing paleomagnetism techniques. Previous geologic field mapping and/or geochemical laboratory experience is desirable, but not required. Must be willing and able to hike over rugged terrain and be open to learning how to operate in the field out of camps in isolated areas. Must have a drivers license.

The evolution of wing venation in fossil moths

Advisors: Professor Jon Payne and Sandra R. Schachat
SESUR or SURGE

The insect order Lepidoptera (moths and butterflies) is extremely diverse today, encompassing well over 100,000 species. However, the early fossil record of moths and of their closest relatives, the caddisflies, is poorly understood. Many fossilized wings from the Permian through Jurassic periods (299-145 million years ago) belong to relatives of either the moths or caddisflies, but we have yet to narrow down the affinities of these fossils.

I look forward to collaborating with an enthusiastic student who will: search the contemporary and historical scientific literature to collect illustrations of fossil insect wings, create updated vector versions of old illustrations, measure wing venation and wing size, and analyze these measurements in the statistical software R. No particular experience is required; this project is intended for a student considering a research career in paleontology, biology/entomology, or scientific illustration. The ideal student will have an interest in visual patterns in nature and in the use of fossil evidence to disentangle complicated episodes in evolutionary history.

The student will primarily learn to use vector graphics software, and will also gain experience with insect systematics and morphology, R, the Paleobiology Database, and Google Scholar. In addition, the student will have the freedom to design and conduct various analyses of the evolution of insect wings.

Reconstructing the impact of data deficiency on estimates of extinction threat

Advisors: Professor Jon Payne, Will Gearty, & Sandra R. Schachat
SESUR or SURGE

In recent years, conservation biologists have increasingly made use of evolutionary trees (phylogenies) in studies of extinction risk. Such studies rely on threat rankings in the IUCN Red List for each species (e.g., Vulnerable, Endangered), but these rankings are not available for the many species that are presently classified as Data Deficient. The goal of our study is to quantify the changing influence through time of Data Deficient species in the IUCN Red List. We will focus on snakes.

We look forward to collaborating with an enthusiastic student who will: search the IUCN Red List to reconstruct changes in IUCN threat rankings for snake species; search the scientific literature to compile data on body size, range size, and other life history attributes of snakes; and conduct phylogenetic analyses of these data, using the statistical software R.

The ideal student will be familiar with the core concepts of evolutionary biology and will have experience using R or similar software; students with a strong desire to learn will also be considered. This project is intended for a student considering a research career in paleontology, biology, or environmental science.

Penetrating radar design and data analysis

SESUR or SURGE 
Advisor: Professor Dustin Schroeder

The Stanford Radio Glaciology research group focuses on the subglacial and englacial conditions of rapidly changing ice sheets and the use of ice penetrating radar to study them and their potential contribution to the rate of sea level rise. In general, we work on the fundamental problem of observing, understanding, and predicting the interaction of ice and water in Earth and planetary systems

Radio echo sounding is a uniquely powerful geophysical technique for studying the interior of ice sheets, glaciers, and icy planetary bodies. It can provide broad coverage and deep penetration as well as interpretable ice thickness, basal topography, and englacial radio stratigraphy.  Our group works on develops techniques that model and exploit information in the along-track radar echo character to detect and characterize subglacial water, englacial layers, bedforms, and grounding zones.  

In addition to their utility as tools for observing the natural world, our group is interested in radio geophysical instruments as objects of study themselves. We actively collaborate on the development of flexible airborne and ground-based ice penetrating radar for geophysical glaciology, which allow radar parameters, surveys, and platforms to be finely tuned for specific targets, areas, or processes. We also collaborate on the development of satellite-borne radars, for which power, mass, and data are so limited that they require truly optimized designs. Student projects are available in support of both ice penetrating radar instrument development and data analysis.

Expressing novel proteins from the environment in a laboratory model system

SESUR or SURGE
Advisor: Professor Paula Welander

Recent advances in sequencing technology have resulted in a wealth of genomic and metagenomic data providing insight into the diversity of life, biogeochemical cycles and metabolic processes. These data have also revealed a plethora of novel hypothetical proteins whose functions and biochemical characteristics remain unknown. One of the current challenges faced by scientist is to decipher and characterize all the biochemical transformations that may be represented in sequenced genomes and metagenomes. In this study, students will take advantage of this wealth of sequencing data to experimentally address fundamental biochemical and evolutionary questions regarding one important class of lipids, the cyclic triterpenoids. These are lipids produced by bacteria and eukaryotes that can be preserved in sedimentary rocks for millions of years. These ancient lipids can function as ‘molecular fossils’ or biomarkers that can inform us about the types of microbial organisms and environments on early Earth.

In our research group, we have demonstrated that the synthesis of specific eukaryotic biomarker lipids, sterols and arborinols, is not restricted to eukaryotes. Analysis of environmental sequence data reveals that there might be several uncultured bacterial sources of these lipids as well. We have identified potential biomarker lipid biosynthesis proteins in these sequence databases but need to experimentally verify that these proteins are true cyclic triterpenoid biosynthesis proteins. To do so, students will work with a laboratory model system in which they will express these environmental proteins in a bacterial host (E. coli) and determine what cyclic lipid molecules they produce. These types of experiments will introduce students to bioinformatics analyses, molecular cloning, and microbial culturing and lipid analysis. In addition, students will be exposed to the interdisciplinary field of geobiology. Prior experience in a microbiology lab would be helpful but not necessary.

Assessing outcomes of soil arsenic and climate change on rice productivity and quality

SESUR or SURGE 
Advisors: Dr. E. Marie Muehe and Professor Scott Fendorf

With more than 50% of the global population consuming rice daily, rice is the staple food worldwide. Unfortunately rice productivity is postulated to decrease drastically due to climate change. Today’s rice productivity models for the year 2100 are based on higher annual temperatures and doubled atmospheric CO2 concentrations but do not include the presence of toxic arsenic in paddy soils of the biggest rice producing regions of the world. However, arsenic is currently being enriched in Asian paddy soils via irrigation with arsenic-bearing ground water. Within the soil, arsenic moves between the soil solution and the solid phase as a consequence of the prevailing environmental conditions. The mobile fraction of arsenic is easily taken up by rice plants and enriches in the grain, thereby not just reducing rice productivity but also grain quality.

The goal of this project is to asses to what extent elevated temperature and atmospheric CO2 (parameters of climate change) affect the mobility of arsenic within rice paddies and ultimately arsenic uptake and accumulation in rice. To this end, the geochemistry of the soil solution and changes in rice plant physiology will help to understand the fate of arsenic within the soil-rice continuum.

A motivated student would be required to maintain rice pot experiments in greenhouses with different climates and collect and analyze pore water samples and assess changes in rice physiology throughout the growth period of the rice. Previous laboratory experience in geochemical or environmental science would be useful.

What controls the ‘pay zones’ in natural gas targets? A wide-ranging geochemical survey of North American black shales

SESUR or SURGE 
Advisors: Professor Erik Sperling and Samantha Ritzer

Natural gas is an integral part of the transition from coal to cleaner and renewable energy sources both in the United States and in developing countries. Most often, accumulations of natural gas are formed in restricted basins and deep marine environments, whose oxygenation conditions are not always well understood. While generally achieving the same results, i.e. producing economic hydrocarbon deposits, the depositional conditions of these basins varies significantly and influence where natural gas accumulates. This project aims to study the influence of depositional conditions on natural gas targets and evaluate the role of anoxia, euxinia, and ferruginous conditions during formation through geochemical threads including carbon and sulfur analyses, iron speciation, and redox-sensitive trace metal abundances. We seek to ultimately apply our results to production values and gas quality to make more efficient and inherently more environmentally friendly decisions related to production of natural gas. We are looking for several motivated students interested in geochemistry with opportunities for both hands-on laboratory experience and authorship on an eventual publication, as well as the potential to assist with field-work and sample collection.

The project will consist of an introduction to wet chemistry lab procedures, including sample preparation for total organic carbon and organic carbon isotope analyses, chromium reduction and iron speciation techniques. Students will analyze a sample set from 1-2 basins, working towards elucidating the depositional redox conditions and comparing the results against production zones in that natural gas target. The students will learn about the intersection of geochemistry and industry and the role of natural gas in the coming worldwide transition towards clean energy. The project is unique for the student, as it is both a stand-alone research project as well as part of a larger survey of shale basins within the North America. The goal for the student is to produce and begin to interpret geochemical data, read relevant literature, and eventually complete one section of a survey paper, providing the opportunity for authorship on a broad and useful publication.

Students do not need any specific background knowledge, but knowledge of geological sciences and specifically sedimentary geology and geochemistry will be useful.