Undergraduate ResearchAll of my research projects entail parts that can provide topics for senior thesis or smaller unergraduate projects. In addition, I enjoy exploring new avenues of research with undregrads.
At the present time I supervise two senior theses. Potential topics for future undergraduate research include:
Microscopic analysis of grain shapes in subglacial sediment samples from beneath the West Antarctic ice sheet.
Measurements of morphology of Antarctic ice streams from satellite images.
Field measurements of glacial bed roughness at scales of ~0.1 to 10 m (Sierra Nevada, Cascades, Olympics). Spectral analysis of the collected roughness data.Study of soils involved in landslides and earthflows. Analysis of force balance for landslides and earthflows.
Graduate ResearchMy research group includes three graduate students, two working on doctoral degrees and one on M.Sc. Our work is structured around several NSF-funded projects aimed at elucidating the physical mechanisms behind fast ice flow and its influence on interactions of ice sheets with terrestrial climate system. Here are summaries of the current and near-future projects.
Relationship Between Subglacial Geology and Glacial Processes in West Antarctica: Petrological and Geochemical Analyses of Subglacial and Basal Sediments.
Collaborators: Dr. A. Grunow (Byrd Polar Research Center), Dr. L. Stern (University of Texas, Austin)
West Antarctica is a remote polar region but its dynamic ice sheet, complicated tectonic history, and the sedimentary record of Cenozoic glaciation make it of particular interest to glaciologists and geologists. The subglacial part of West Antarctica has escaped direct geological investigations and all that is known about subglacial geology comes from geophysical remote sensing. Recent acquisitions of new, high-quality geophysical data have led to generation of several enticing models. For instance, subglacial presence of high-magnitude, short-wavelength magnetic anomalies has prompted the proposition that there may be voluminous (>1 mln km3), Late Cenozoic flood basalts beneath the ice sheet. Another important model suggests that the patterns of fast ice streaming (~100 m/y) and slow ice motion (~1-10 m/y) observed within the WAIS are controlled by subglacial distribution of sedimentary basins and resistant bedrock. This project is designed to provide new geologic data, which may help to test the recent models inferred from geophysical observations. The new constraints on subglacial geology and on its interactions with the WAIS will be obtained through petrological and geochemical analyses of basal and subglacial sediments collected previously from seven localities.
I anticipate that this project will be funded in early 2001 and that it will provide an unprecedented opportunity for a new graduate student to break new ground in geology of Antarctica.
Control of ice-till interactions on evolution and stability of ice streams and ice sheets.
Amidst many recent advances, the development of numerical ice-stream models that could reproduce the complexities of ice stream evolution has proven to be a challenging task. Nowhere is the need for reliable ice-stream models more apparent than in West Antarctica where ice streams carry approximately 90% of the total ice discharge. This research project provides an opportunity to make a significant progress towards improving model competence and fidelity to nature. During this project an extensively tested numerical ice-stream model will be merged with a new physical framework for treatment of sub-ice-stream processes which control the commencement, evolution, and cessation of ice streaming.
This is an ongoing project that is already producing some interesting results. See the two posters presented by myself and Marion Bougamont and the 2000 AGU meeting in SF: Stoppage of Ice Stream C, What's next in W. Antarctica?
Subglacial deforming beds as erosive and sedimentary agents - experimental study of rock abrasion and particle comminution.
Collaborator: B. Kamb, California Institute of Tech.
Subglacial sediment deformation is becoming increasingly
accepted as the new, distinct, and perhaps even predominant mechanism of
fast ice flow and till generation. By this mechanism, extensive layers
of till may be generated, transported at fast rates, and deposited entirely
subglacially. A series of experiments is proposed here to study the rates
of particle comminution and bedrock erosion by shearing till. The collected
data will provide an experimental basis for quantitative formulations of
erosion and comminution laws that can be used in future modeling of deforming
beds. Finally, these experiments have the potential to yield solid sedimentological
criteria for testing whether a given till may or may not have been generated
fully by subglacial deformation.