000013578 001__ 13578
000013578 037__ $$a1131
000013578 041__ $$aEnglish
000013578 100__ $$aFagre, D. B.
000013578 100__ $$aPederson, G. T.
000013578 100__ $$aReardon, B. A.
000013578 100__ $$aCaruso, C. J.
000013578 245__ $$aSpatial reconstructions and comparisons of historic snow avalanche frequency and extent using tree rings in Glacier National Park, Montana, U.S.A.
000013578 260__ $$c2008
000013578 260__ $$b
000013578 490__ $$aArticle
000013578 507__ $$aMFOLL
000013578 511__ $$aCrysparticle
000013578 511__ $$aCryosphere
000013578 520__ $$aNatural snow avalanches have periodically damaged infrastructure and disrupted railroad and highway traffic at the southwestern corner of Glacier National Park, Montana. The 94-year history of these disruptions constitutes an uncommon record of natural avalanches spanning over nine decades and presents a unique opportunity to examine how natural avalanche frequency and minimum extent have varied over time due to climatic or biophysical changes. This study compared the historic record of natural avalanches in one avalanche path with tree-ring evidence of avalanches from 109 cross sections and increment cores collected in the same path. Results from combined historic and tree-ring records yielded 27 avalanche years in the 1910?2003 chronology, with the historic record alone underestimating avalanche years by half. Mean return period was 3.2 years. Interpolated maps allowed for more spatially precise estimates of return periods throughout the runout zone than previous studies.  The maps show return periods increase rapidly downslope from 2.3 to 25 years. Avalanche years were associated with positive Snow Water Equivalent anomalies at a nearby snow course. Minimum avalanche extent was highly variable but not associated with snowpack anomalies. Most avalanche years coincided with years in which the mean January?February Pacific Decadal Oscillation (PDO) and El Nin?o? Southern Oscillation (ENSO) 3.4 indices were neutral. The findings suggest that changes in Pacific climate patterns that influence snowfall could also alter the frequency of natural snow avalanches and could thus change disturbance patterns in the montane forests of the canyon.
000013578 653__ $$aavalanche
000013578 653__ $$aclimate change
000013578 653__ $$aUnited States
000013578 650__ $$aClimate change
000013578 650__ $$aHazards and disaster
000013578 691__ $$aClimate change
000013578 691__ $$aHazards and disaster
000013578 773__ $$pArctic, Antarctic, and Alpine Research, Vol. 40, No. 1, 2008, pp. 148?160
000013578 8564_ $$uhttp://lib.icimod.org/record/13578/files/1131.pdf
000013578 980__ $$aARTICLE