Bernard Hallet
  Professor
  Office: JHN-365
     ESS Mailing Address
  Phone: 206-685-2409
  Fax: 206-543-0489 (shared)
  Email: hallet @ ess.washington.edu
  Homepage: http://depts.washingtong.edu/qrc/people/hallet2.html

  Research Groups: Geomorphology, Glaciology, Quaternary Research

Areas of Interest:
Glacial, Periglacial and Arid Lands Geomorphology Planetary surface processes

Current Research Interests:
After receiving his Ph.D. in geology at UCLA in 1975, Bernard Hallet joined the Earth Sciences faculty at Stanford University. In 1981, he became a faculty member of the Department of Geological Sciences and the Quaternary Research Center at the University of Washington.

Hallet is fascinated by the processes that shape alpine and arctic landscapes. The strategy he prefers in his studies of diverse processes is a combination of sound theoretical analysis of the governing physics/chemistry with detailed field or laboratory work.

Much of his past and current work is directed at glacial erosion of bedrock, chemical processes active at the glacier bed, till deformation, and a more precise interpretation of the geological record of past ice sheets. More recently he has become interested in developing a sound physical basis for considering some of the textural and distributional properties of till and other glacial sediments.

Another major area of interest of Bernard Hallet is periglacial geomorphology. Over the last decade he and his students have studied the dynamics of patterned ground in western Spitsbergen. Through detailed field studies, including extensive instrumentation to document year-round activity (temperature, soil displacements, moisture, pore pressure, soil pressure, etc.), they are studying the dynamics of sorted circles. They have learned a lot about the thermal regime, heave/thaw characteristics and other dynamical aspects of very active sorted circles, including long-term circulatory motion of the soil. Another subject of considerable interest is frost weathering, more specifically the precise mechanism by which freezing leads to the propagation of fractures in rocks. This work has been largely theoretical in nature, but it has recently received considerable experimental support from studies of acoustic emissions emitted by crack propagation events due to sustained ice growth. Hallet has also recently joined Greg Dash, of the University of Washington condensed matter physics group, in a collaborative effort to elucidate the fundamental nature of water in porous media at subfreezing temperatures, which underlies a diversity of periglacial phenomena.

Graduate Students:
Kurt Cuffey: Modeling ice sheet and till dynamics

Paul Jacobson: Modeling ice sheet dynamics and patterns of erosion

Yann Merrand: Migration of chemical species through frozen mixed media

Jaakko Putkonen: Atmosphere-soil heat transfer in a permafrost area, western Spitsbergen

James Roche: Field and experimental study of rapid frost weathering, Icy Bay, Alaska

Selected Publications:

Hallet, B., 1976, Deposits formed by subglacial precipitation of CaCO3. Geological Society of America Bulletin, v. 87(7), p. 1003-1015. 

Hallet, B., 1979, A theoretical model of glacial abrasion, Journal of Glaciology, v. 23(89), p. 29-50. 

Walder, J. S., and Hallet, B., 1985, A theoretical model of the fracture of rock due to freezing, Geological Society of America Bulletin, v. 96(3), p. 336-346. 

Werner, B. T. and Hallet, B., 1993, Sorted stripes: a numerical study of textural self-organization, Nature, v. 361, p. 142-145. 

Hallet, B. and Molnar, P., 2001. Distorted Drainage Basins as Markers of Crustal Strain East of the Himalaya, Journal of Geophysical Research-Solid Earth, 106 (B7), 13697-13709. 

Stewart, R.J., Hallet, B., Zeitler, P.K., Maloy, M.A., Allen, C., and Trippett, D., 2008. Brahmaputra sediment flux dominated by highly localized rapid erosion from the easternmost Himalaya. Geology, 36(9); p. 711–714; doi: 10.1130/G24890A.1