Title In situ and photographic measurements of avalanche crown transects
Author Bair, E.H.; Birkeland, K.W.; Dozier, J.
Author Affil Bair, E.H., University of California at Santa Barbara, Bren School of Environmental Science and Management, Santa Barbara, CA. Other: U. S. Department of Agriculture, Forest Service, National Avalanche Center
Source Cold Regions Science and Technology, 64(2), p.174-181, ; International snow science workshop 2009, Davos, Switzerland, Sept. 27-Oct. 2, 2009, edited by J. Schweizer. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0165-232X
Publication Date Nov. 2010
Notes In English. Based on Publisher- supplied data GeoRef Acc. No: 309821
Index Terms avalanches; mass movements (geology); measurement; photography; snow; strength; deposition; depth; fractures; geometry; geotraverses; mass movements; overburden; power law; spatial distribution; winds
Abstract Despite its fundamental importance, crown depth is often treated as a scalar rather than a distributed variable in avalanche run-out and fracture models. To date, no studies have examined the distribution of depth across crown transects. We present results on geometry, depth distribution, and spatial correlation for transects along the crowns of small to large avalanches. Crown heights are fit well by normal or Weibull distributions and are spatially correlated. Transects are thinnest and decreasing toward the flanks, perhaps associated with fracture arrest. Underlying and adjacent terrain seems to have little influence on our transects. Instead, wind transported snow and upwind features play a dominant role. We suggest deposition of new snow by wind is a Gaussian process that drives transect shape. Comparing strength distributions and coefficients of variation from previous crown face studies, we suggest differences in overburden drive distributions of strength measured across crown faces.
URL http://hdl.handle.net/10.1016/j.coldregions.2010.08.004
Publication Type conference paper or compendium article
Record ID 65006944