Research
Other Interests
While I am mostly interested in mountain/temperate glaciers, the erosive processes of ice sheets and ice streams are also important and interesting. As obvious in the Seattle region, ice sheets definitely have a large impact on the post-glaciated geomorphology of a region. Polar ice streams, in particular, pose a very interesting puzzle, as many of them are moving at very rapid rates (upwards of 1000 m/yr), yet the topography does not show high erosion rates.
Glacier seismicity (studied in ice streams) is also of interest to me, as "ice quakes" might be an important mechanism in glacial erosion. These quakes might represent rock fracturing under the glacier, pressure changes in the glacio-fluvial network shifting the ice, or crevasses opening up. All of these are important for erosion.
Lastly, the glacio-fluvial (sub-glacial drainage) network of a glacier has the potential to be a dominant player in glacier erosion mechanisms. Aside from the action of fluvial erosion, these networks can quickly advect eroded material from under the glacier while the pressure changes from changing amounts of water and changing drainage patterns (both seasonal signals) can cause localize high amounts of stress on bedrock in contact with ice. By looking at these pressure fluctuations and stress patterns, along with fracture mechanics of bedrock, a better understanding of the physical processes of glacial erosion can be determined.
AGU Posters
Headley, R., B Hallet, E. Rignot, S. Price, 2007, Measurements of Fast Ice Flow of the Malaspina Glacier to Explore Connections Between Glacial Erosion and Crustal Deformation in the St. Elias Mountains, Alaska. Eos Trans. AGU, 88(52), Fall Meet. Suppl., Abstract C41A-0050. PDF (3.9 MB)
Headley, R. B. Hallet, 2006, Examining the spatial variation in glacial erosion rates and its potential relation to tectonics in the St. Elias range, southern Alaska, Eos Trans. AGU, 87(52), Fall Meet. Suppl., Abstract C33A-1253. PDF (2.7 MB)
Main Research Aims
In general, I am interested in the interactions of erosion and tectonics. I am specifically interested in how glacial erosion may play a large role in exhumation of landscapes. Glaciers have covered large parts of the world at different times in Earth's history. While rivers are often more accessible and more confined, glaciers can cover 100s of kilometers of area. In order to truly understand how landscapes have been formed, it is necessary to take into account all of the complexities that a glacier-covered region includes. On a smaller scale, I am also interested in better descriptions (mathematical or computational) of the actual processes involved in glacial erosion.
I am involved in the St. Elias Erosion Tectonics Project (STEEP), which is a large-scale, multidisciplinary project where researchers from many universities are looking at the dynamics of the South-Eastern/South-Central Alaska orogeny centered around Mt. St. Elias. Currently, I am working with Dr. Bernard Hallet to understand the erosive properties of the large glaciers (Malaspina, Bering, Hubbard) in the region in order to determine what their erosion patterns might mean in the context of a highly faulted and tectonically active region.
