Earthquake-induced snow avalanches: I. Historical case studies

Abstract

AbstractStrong ground motions caused by earthquakes can induce catastrophic avalanches. Massive snow avalanching has also been observed on slopes near quarries and underground mines where ground motions are produced by explosives. To address a lack of information regarding seismogenic snow avalanches, we have compiled an inventory to document case histories. For the period 1899–2010, 22 cases are identified worldwide, related to natural or artificial seismicity with magnitudes of 1.9 ≤Mw≤ 9.2 and source-to-site distances of ∼0.2–640 km. In the extreme case, many thousands of simultaneously released large-scale avalanches have been reported. The obtained distribution and variety of parameters are discussed and compared with earthquake-induced landslides and ice avalanches; the results are similar among these three types of failure events, although all data derived from statistical analyses (i.e. non-witnessed cases) represent outliers, suggesting a significant reduction in the threshold magnitudes proposed for landslides. This proposal could be verified by the collection of additional data.