Research Opportunities

We offer PhD and MS degrees in Earth and Environmental Sciences. Students combine observational, theoretical, and laboratory approaches to tackle critical problems in geoscientific research. Graduate student research spans a wide range of topics, including glacial retreat in Antarctica, storage of water in Martian ice sheets, core-mantle segregation during early Earth formation, as well as delta and river systems and coastal response to sea level rise.

Prof. Brent Goehring: Cosmogenic Nuclide Lab

Team
Keir Nichols, Rachel Sortor, Cari Rand, Tori Kennedy, Colby Lejune

Goals
Our team of graduate students, undergraduate students, and visitors use a variety of tools, but principally cosmogenic nuclides, to place rates and dates on changes in the cryosphere and other surface processes. A main focus is on changes occurring in the deep (millions of years) and more recent (100 thousand years) past in Antarctica, especially its glaciers and ice sheets. Our results inform models of potential future change in the cryosphere by placing geologic constraints on models of past behavior.

Student Opportunities
We seek students interested in the use of cutting-edge cosmogenic nuclide techniques and their application to the cryosphere, climate change, and geomorphology. We operate a state- of-the-art laboratory and work with partners globally. Current research has working in the field in western Canada, Alaska, Antarctica, Norway, and the SW United States. Undergraduates are encouraged to inquire about research opportunities.

Recent Publications (* indicates graduate students)
Goehring, B.M., Balco, G., Todd, C., Moening-Swanson, I., Nichols*, K., accepted. Ice Sheet Thinning and Retreat in the outer Ross Sea Revealed by in situ 14C Exposure Dating. Geology.

Goehring, B.M., Wilson, J.W., Nichols*, K., accepted. A Fully Automated System for the Extraction of in situ Cosmogenic Carbon-14 in the Tulane University Cosmogenic Nuclide Laboratory. Nuclear Instruments and Methods B.

Darvill, C.M., Menounos, B., Goehring, B.M., Lian, O.B., Caffee, M., accepted. Marginal retreat of the western Cordilleran Ice Sheet during the last deglaciation. Geophysical Research Letters.

Menounos, B., Goehring, B.M., Osborn, G., Clarke, G.K.C., Ward, B., Margold, M., Bond, J., Clague, J.J., Lakeman, T., Koch, J., Gosse, J., Stroeven, A., Seguinot, J., Heyman, J., Fulton, R., 2017. Cordilleran Ice Sheet mass loss preceded climate reversals near the Pleistocene Termination. Science. Nov 10, 2017.

Prof Karen Johannesson: Environmental Biochemistry Lab

Team
Segun Adebayo, Omolola Akintomole, Jackie Horn

Goals
Low-temperature aqueous geochemistry and biogeochemistry, emphasizing trace element speciation, chemical hydrogeology, and biogeochemical cycling of trace elements (e.g., arsenic, selenium, and REEs) in the environment.

Student opportunities
All areas above have research opportunities.

Recent Publications (* indicates graduate students)
Cui*, M. and Johannesson, K.H., 2017. Comparison of tungstate and tetrathiotungstate adsorption onto pyrite. Chemical Geology 464, 57-68.
Coleman, D.J., Kolker, A.S., and Johanesson, K.H., 2017. Submarine groundwater discharge and alkaline earth element dynamics in a deltaic coastal setting. Hydrology Research 48.5, 1169-1176.

Prouty, N.G., Swarzenski, P.W., Frackell, J.K., Johannesson, K., and Palmore, D., 2017. Groundwater-derived nutrient and trace element transport to a nearshore Kona coral ecosystem: Experimental mixing model results. Journal of Hydrology: Regional Studies 11, 166-177.

Johannesson, K. H., Palmore, C.D., Frackell, J., Prouty, N.G., Swarzenski, P.W., Chevis, D. A., Telfeyan, K., White, C. D., and Burdige, D.J., 2017. Rare earth element behavior during groundwater – seawater mixing along the Kona Coast of Hawaii. Geochimica et Cosmochimica Acta 198, 229-258.

Prof Nicole Gasparini: Geomorphology and Landscape Evolution 

Team
Dr. Nathan Lyons, Sam Anderson, Sabrina Martinez, Lizmar Rodriguez-Lugo

Goals
We are interested in how landscapes got to where they are and where they are going. Different parts of a watershed are controlled by different surface processes and specific processes may differ from one watershed to another. If we can express these processes as equations and quantify how outside forces drive these processes, we can start to understand why a landscape looks the way it does and how it might be changing.

Student opportunities
Fluvial geomorphology; Tectonic geomorphology; Evolution of alluvial and bedrock river networks; Landscape evolution modeling and numerical model development; Interactions among climate, tectonics, and erosion; Effects of climate change on landscape evolution; Sediment production and transport of sediment from hillslopes to rivers to depositional systems; Human influences on landscape evolution.

Recent Publications (* indicates students, ^indicates post-docs)
*Adams, J.M., Gasparini, N.M., ^Hobley, D.E.J., Tucker, G.E., Hutton, E.W.H., *Siddhartha Nudurupati, S. and Istanbulluoglu, E., 2017, The Landlab OverlandFlow component: a Python library for computing shallow-water flow across watersheds, Geoscientific Model Development (GMD), doi:10.5194/gmd-10-1645-2017.

Whipple, K.X., Forte, A., DiBiase, R.A., Gasparini, N.M. and Ouimet, W., 2017, Timescales of landscape response to divide migration and drainage capture: Implications for the role of divide mobility in landscape evolution, JGR Earth Surface.

^Hobley, D.E.J., *Adams, J.M., *Siddhartha Nudurupti, S., Huttong, E.W.H., Gasparini, N.M., Istanbulluoglu, E., Tucker, G.E., 2017. Creative computing with Landlab: An open-source toolkit for building, coupling, and exploring two-dimensional numerical models of Earth-surface dynamics, ESurf., doi: 10.5194esurf-5-21-2017.

Murphy, B. P, Johnson, J. P. L., Gasparini, N.,M., and Sklar, L.S., 2016. A mechanism for the climatic control of bedrock river incision. Nature, doi: 10.1038/nature17449. 

Prof. Cynthia Ebinger: Geophysics and Active Tectonics Research (GATR)

Team
Sarah Jaye Oliva, Carolina Hurtado-Pulido

Goals
Our team of graduate and undergraduate researchers use seismic and potential fields methods, signal processing and geospatial tools to probe fundamental Earth processes. Our focus is magma-fault interactions within the crust and mantle at rifts and hotspots, both active and ancient. We apply methods and results to explore hydrothermal energy potential and to evaluate earthquake and volcanic hazards.

Student Opportunities
We seek students interested in the use of geophysical and satellite-based tools to determine the rates of tectono-magmatic processes and image subsurface structure for hazard and energy evaluation.  We have active seismic acquisition programs in Kenya and Ethiopia, New Zealand, Ecuador.  Undergraduates keen to acquire command-line programming and analytical skills are welcome.

Recent Publications (* indicates undergrad and graduate students)
Tepp*, G., C.J. Ebinger, H. Zal, N. Accardo, D. J. Shillington, J. Gaherty, D. Keir, A. A. Nyblade, G. J. Mbogoni, P. R. N. Chindandali, R. Ferdinand-Wambura,  G. D. Mulibo, G. Kamihanda, R. Gallacher, (2018) Seismic anisotropy of the upper mantle below magmatic and weakly magmatic sectors of the Western rift, Africa, J. Geophys. Res., DOI:10.1029/2017JB015409.

Weinstein*, A., S. J. Oliva*, C.J. Ebinger, S.  Roecker, C. Tiberi, C., E. Witkin*, M. Aman*, R. Hadfield*, S. Gautier, A. Muzuka, G. Mulibo, G. Kianji, M. Msabi, R. Ferdinand-Wambura, J. Albaric, C. Lambert*, A. Rodzianko, Active deformation and magmatism during early stage rifting of Archaean lithosphere in the Eastern rift, Africa, G-cubed, ;2017. 

Ebinger, C.J., Keir, D., I. Bastow, K. Whaler, J. Hammond, A. Ayele, M. S. Miller, C. Tiberi, S. Hautot, (2017), Crustal structure of rift zones in Africa: Implications for global crustal processes, in Gu, J., editor, Tectonics, 10.1002/2017TC004526.

Davidge*, L., C.J. Ebinger, M. Ruiz, G. Tepp*, F. Amelung, D. Geist, D. Coté*, (2017), Seismicity patterns during a period of inflation at Sierra Negra volcano, Galápagos Islands, Earth Planet. Sci. Letts., 462, 162-172. 2017.

Prof. Colin Jackson:  High Temperature and Pressure Laboratory (HiTaP)

Goals
HiTaP Laboratory investigates the chemical reactions associated with the formation and evolution of Earth and other rocky bodies.  To do this, we conduct experiments that mimic the chemical and physical environments within planetary interiors.  Experiments are analyzed using a variety of microbeam, micro-sampling, and spectroscopic techniques.   Our research areas are broad, spanning from the crust to the core and from the modern day to the birth of the solar system.  We strive to create a laboratory environment that promotes curiosity and the excitement of discovery.         

Student Opportunities
We seek students interested in experimental petrology and geochemistry.  Active areas of research include the initial differentiation of planets (core formation, magma ocean crystallization, and outgassing of primordial atmospheres), deep cycling of volatiles (nitrogen, noble gases, and fluid-mobile elements in general), and exoplanets petrology.  Student will gain experience in material synthesis and microanalytical techniques.  Please contact Prof. Jackson for additional information on specific research possibilities.

Recent Publications (* Denotes mentored student)
Jackson, CRM, NR Bennett, Z Du, E Cottrell, Y Fei, (2018), Early episodes of high-pressure core formation preserved in plume mantle, Nature 553 (7689), 491,
Smye, A., CRM Jackson, M Konrad-Schmolke, MA Hesse, SW Parman, DL Shuster, CJ Ballentine, (2017), Noble gases recycled into the mantle through cold subduction zones Earth and Planetary Science Letters 471, 65-73

Dygert, N., CRM Jackson, MA Hesse, MM Tremblay, DL Shuster, JT Gu, (2018), Plate tectonic cycling modulates Earth’s 3He/22Ne ratio Earth and Planetary Science Letters 498, 309-321

Williams*, K.B., CRM Jackson, LC Cheek, KL Donaldson-Hanna, SW Parman, CM Pieters, MD Dyar, TC Prissel, (2016), Reflectance spectroscopy of chromium-bearing spinel with application to recent orbital data from the Moon, American Mineralogist 101 (3), 726-734

Prof. Mead Allison: River and Coastal Sediment Dynamics and Radiochemical Lab

Team
Marie Mathews, Autumn Murray, Ryder Myers, Katrina Ginsberg

Goals
Our projects are linked to applied issues associated with the protection and restoration of the Mississippi Delta and other areas worldwide, including (1) examining the utility and methodology of large river diversions for rebuilding coastal wetlands harnessing the crevasse splay methodology of natural river evolution, (2) examining river bar evolution and its links to the utilization of sand resources via long-distance pipeline conveyance to build wetlands and restore barrier islands, (3) testing the efficacy of various restoration strategies including the use of green infrastructure to alter morphology of the coastal realm for protecting human and natural resources, and (4) examining the impact of episodic events such as large floods and hurricanes on system evolution and health. We utilize a wide range of tools to address these issues (TRCC link) and a radiochemical geochronology laboratory featuring a variety of alpha and gamma spectrometers that allow us to measure key radiotracers in the natural environment.

Recent Publications (* indicates student)
Allison, M.A. and Pratt, T.C., 2017. Discharge controls on the sediment and dissolved nutrient transport flux of the lowermost Mississippi River:  implications for export to the ocean and for delta restoration.  Journal of Hydrology 555:1-14.

Allison, M.A., Yuill, B.T., Meselhe, E.A., Marsh, J.K., Kolker, A.S., and Ameen, A.D., 2017.  Observational and numerical particle tracking to examine sediment dynamics in a Mississippi River delta diversion. Estuarine, Coastal & Shelf Sci., 194:97-108.

Meselhe, E.A., Sadid, K.M., and Allison, M.A., 2016.  Riverside morphological response of pulsed sediment diversions.  Geomorphology 270:184-202.

Allison, M.A., *Ramirez, M.T., and Meselhe, E.A., 2014.  Diversion of Mississippi River water and sediment to ameliorate coastal land loss in Louisiana, USA.  Water Resources Management 28:4113–4126.

Jeff Agnew:  Palaeobiology

Goals
Our research focuses on identifying the primary patterns and causes of biotic evolution over geologic timescales. We study predator-prey interactions between decapod crustaceans and mollusks to understand the relative roles of top-down and bottom-up forces on morphology. Our group also uses landmark and outline-based methods to study the taxonomy, systematics, and evolution of recent and fossil shark teeth.

Student Opportunities
Undergraduate students are encouraged to develop projects in the areas above.

Prof. Jennifer Whitten: Planetary Science Research

Team
Nadim Abu-Hashmeh

Goals
We use orbital, telescopic, and field measurements of planetary surfaces to probe fundamental geologic processes that generate and modify terrestrial planetary surfaces. Our current research focus falls into three distinct topics: (1) resurfacing due to volcanism and impact cratering, (2) the climate history of Mars, and (3) characterization of the radar properties of planetary surfaces. We study the evolution of planetary surfaces through analysis and synthesis of multiple planetary datasets, such as high-resolution images, topography, and radar imager and sounder datasets.

Student Opportunities
We seek highly motivated students interested in studying the surface and near-subsurface of planetary bodies using orbital datasets. Opportunities exist to characterize volcanic processes, the distribution of crater ejecta, investigate radar properties of planetary surfaces, and study water ice-reservoirs. These active research projects exist on a variety of terrestrial planetary bodies, including Mercury, Venus and Mars. Multiple planetary datasets are integrated, including radar sounders, images, topography, in a Geographic Information Systems framework to address fundamental questions about the surface evolution of terrestrial planetary bodies. Undergraduates interested in learning to analyze remote datasets of terrestrial planetary bodies and acquire quantitative data analysis skills are welcome.

Recent Publications
Whitten, J.L., Campbell, B.A. (2018) Lateral continuity of layering in the Mars South Polar Layered Deposits from SHARAD sounding data, J. Geophys. Res. 123, doi:10.1029/2018JE005578.

Campbell, B., Weitz, C., Morgan, G., Whitten, J. (2018) Evidence for Impact Melt Sheets in Lunar Highland Smooth Plains and Implications for Polar Landing Sites, Icarus 314, doi:10.1016/j.icarus.2018.05.025.

Whitten, J.L., Campbell, B.A., Morgan, G.A. (2017) A subsurface depocenter in the South Polar Layered Deposits of Mars, Geophysical Research Letters 44, doi:10.1002/2017GL074069.

Whitten, J.L., Campbell, B.A. (2016) Recent volcanic resurfacing of Venusian craters, Geology G3768-1, doi:10.1130/G37681.1. Cover Image, Geology July 2016.

Prof. Torbjörn Törnqvist: Quaternary Research and Coastal Geoscience

Team
Udita Mukherjee, Ryan Clarke

Goals
Our group aims to gain a better understanding about the late Quaternary, the most recent portion of Earth history that can serve as a guide for the future of our planet. Our focus is primarily on the land-ocean interface and extends all the way from continental alluvial interiors to the shelf edge. The dramatic climate and sea-level changes that characterize the late Quaternary offer a unique perspective on how to interpret the presently ongoing human-driven perturbation of the climate system, and its impacts on coastal environments in particular.

Student Opportunities
We welcome graduate students who are excited about advancing our fundamental understanding of the ice ages and intervening warm intervals, as well as their effects in coastal lowlands. The range of potential research projects is wide and includes studies over timescales as long as the past few hundred thousand years and as short as the past decade. While much of our research is heavily field-oriented (mainly focused on the US Gulf Coast) there is an increasing number of exciting opportunities to work with large, existing datasets. Several of the findings of this research (e.g., on coastal subsidence, coastal wetland sustainability, and delta evolution) is not only important scientifically, but also relevant for a variety of practical applications and attracts considerable media attention.

Recent Publications (*denotes PhD student, **denotes postdoc)
Nienhuis**, J.H., Törnqvist, T.E. and Esposito*, C.R., 2018. Crevasse splays versus avulsions: A recipe for land building with levee breaches.  Geophysical Research Letters, 45: 4058-4067.

Chamberlain*, E.L., Törnqvist, T.E., Shen, Z., Mauz, B. and Wallinga, J., 2018. Anatomy of Mississippi Delta growth and its implications for coastal restoration. Science Advances, 4: eaar4740.

Jankowski*, K.L., Törnqvist, T.E. and Fernandes**, A.M., 2017. Vulnerability of Louisiana’s coastal wetlands to present-day rates of relative sea-level rise. Nature Communications, 8: 14792.

Fernandes**, A.M., Törnqvist, T.E., Straub, K.M. and Mohrig, D., 2016. Connecting the backwater hydraulics of coastal rivers to fluvio-deltaic sedimentology and stratigraphy. Geology, 44: 979-982.

Prof. Kyle Straub: Tulane Sediment Dynamics and Stratigraphy (TSDS) 

Team
Ripul Dutt, Abdul Wahab, Kevin Reece, Jose Silvestre

Goals
Our research group focuses on the transport of sediment from land through the ocean and into the stratigraphic record. Scales of interest range from the interaction of turbidity currents with channel bends over minutes to the construction and preservation of deltas over millions of years. The sedimentary bodies that arise from these processes are home to millions of people, archives of past Earth conditions, and reservoirs of natural resources. We examine the morphodynamics of these systems using a combination of remote sensing of subsurface sedimentary deposits (visualization and interpretation of seismic data), carefully designed laboratory experiments, field studies of modern and ancient sediment transport systems, and targeted numerical analysis and modeling.

Student Opportunities
We seek students interested in quantifying the dynamics of sediment transport systems and their stratigraphic records to aid prediction of future environmental change, inversion of past Earth states, and characterization of geo-fluid reservoirs.  Active research projects integrate physical experiments performed in our laboratory on Tulane’s uptown campus, with numerical models and field campaigns. Undergraduates interested in experimental methods in the geosciences and keen to acquire quantitative data analysis skills are welcome.

Recent Publications (* Denotes TSDS student)
Esposito, C.R.*, Di Leonardo, D.R., Harlen, M.*, Straub, K.M., 2018, Sediment storage partitioning in alluvial stratigraphy: The influence of discharge variability, Journal of Sedimentary Research, v. 88, p. 717-726, DOI:10.2110/jsr.2018.36. 

Straub, K.M. and Foreman, B.Z., 2018, Geomorphic stasis and spatiotemporal scales of stratigraphic completeness, Geology, v. 46, p. 311-314, DOI:10.1130/G40045.1.

Paola, C., Ganti, V., Mohrig, D., Runkel, A., Straub, K.M., 2018, Time not our time: physical controls on the preservation and measurement of geologic time, Annual Review of Earth and Planetary Sciences, v. 46, p. 409-438, DOI:10.1146/annurev-earth-082517-010129.

Li, Q.*, Benson, W.M.*, Harlen, M.*, Robichaux, P., Sha, X., Xu, K., Straub, K.M., 2017, Influence of sediment cohesion on deltaic morphodynamics and stratigraphy over basin-filling time scale, Journal of Geophysical Research – Earth Surface, v. 122, DOI: 10.1002/2017JF004216.

Prof. Nancye Dawers:  Structural Geology & Tectonics

Team
Dr. Elena Steponaitis, Dr. Michael Hopkins, Akinbobola Akintomide, ThiQuân Pham

Goals
My group’s research focuses on understanding the processes and time-scales over which brittle faults grow, interact and evolve. This includes studying: 1) the structure of propagating fault tips, 2) the pattern of displacement accumulation on faults, 3) how fault displacements scale with fault length, and 4) the temporal evolution of faults via basin analysis and geomorphic studies. Many of these problems are also applicable to other terrestrial planets. Geographically, much of my group’s work has been within the Eastern California shear zone and in the northern Basin & Range. I currently have projects in south Louisiana utilizing 3D subsurface data to study recently active “growth” fault systems, including the contribution of these large fault systems to coastal wetland loss. 

Student Opportunities
We seek students interested in pursuing either PhD or MS degrees.  Opportunities exist to incorporate a wide range of datasets and approaches, ranging from field-based studies to interpretation and analysis of subsurface and remote sensing data.  Students interested in career paths in both academia and industry are welcome.  All of my group’s projects have the potential for related undergraduate research.

Recent Publications (*Denotes Tulane Student)
Hopkins, M. C.*, and Dawers, N. H., 2018, The role of fault length, overlap and spacing in controlling extensional relay ramp fluvial system geometry: Basin Research, v. 30, no. 1, p. 20-34. DOI: 10.1111/bre.12240

Hopkins, M. C.*, and Dawers, N. H., 2015, Changes in bedrock channel morphology driven by displacement rate increase during normal fault interaction and linkage: Basin Research, v. 27, no. 1, p. 43-59. DOI: 10.1111/bre.12072

Shen, Z. X.*, Dawers, N. H., Tornqvist, T. E., Gasparini, N. M., Hijma, M. P., and Mauz, B., 2017, Mechanisms of late Quaternary fault throw-rate variability along the north central Gulf of Mexico coast: implications for coastal subsidence: Basin Research, v. 29, no. 5, p. 557-570. DOI: 10.1111/bre.12184

Hopkins, M. C.*, and Dawers, N. H., 2016, Vertical deformation of lacustrine shorelines along breached relay ramps, Catlow Valley fault, southeastern Oregon, USA: Tectonophysics, v. 674, p. 89-100. DOI: 10.1016/j.tecto.2016.02.015