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Large rock avalanches triggered by the M 7.9 Denali Fault, Alaska, earthquake of 3 November 2002

R.W. Jibson·E. L. Harp·W. Schulz·D. K. Keefer
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Abstract

The moment magnitude (M) 7.9 Denali Fault, Alaska, earthquake of 3 November 2002 triggered thousands of landslides, primarily rock falls and rock slides, that ranged in volume from rock falls of a few cubic meters to rock avalanches having volumes as great as 20 ?? 106 m3. The pattern of landsliding was unusual: the number and concentration of triggered slides was much less than expected for an earthquake of this magnitude, and the landslides were concentrated in a narrow zone about 30-km wide that straddled the fault-rupture zone over its entire 300-km length. Despite the overall sparse landslide concentration, the earthquake triggered several large rock avalanches that clustered along the western third of the rupture zone where acceleration levels and ground-shaking frequencies are thought to have been the highest. Inferences about near-field strong-shaking characteristics drawn from interpretation of the landslide distribution are strikingly consistent with results of recent inversion modeling that indicate that high-frequency energy generation was greatest in the western part of the fault-rupture zone and decreased markedly to the east. ?? 2005 Elsevier B.V. All rights reserved.

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R.W. Jibson, E. L. Harp, W. Schulz, D. K. Keefer. 2006. Large rock avalanches triggered by the M 7.9 Denali Fault, Alaska, earthquake of 3 November 2002. https://doi.org/10.1016/j.enggeo.2005.06.029

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