Publication Date:
2010-02-28
Description:
Steep hillslopes in mountain belts are eroded by landslides, and landsliding is ultimately driven by the topographic relief produced by fluvial and glacial erosion. Landslide erosion rates are derived from estimates of landslide volume and can help to appraise landscape responses to tectonic, climatic and anthropogenic forcing. However, the scaling relationshipspower-law equations that are used to estimate the volume of the landslide from the area of the failureare derived from a limited number of measurements, and do not discriminate between bedrock and soil landslides. Here we use a compilation of landslide geometry measurements from 4,231 individual landslides to assess the relative volume-area scaling of bedrock and soil landslides. We find that shallow, soil-based landslides can be approximated by an exponent of γ = 1.1-1.3. In contrast, landslides that involve the failure of bedrock have a deeper scar area, and hence larger volume, and are characterized by γ = 1.3-1.6. On the basis of observations that soil residence times in uplifting mountains can be as low as a few centuries, we suggest that both deep bedrock and frequent, shallow soil landslides can erode steep hillslopes at rates commensurate with even rapid tectonic uplift. © 2010 Macmillan Publishers Limited. All rights reserved.
Print ISSN:
1752-0894
Electronic ISSN:
1752-0908
Topics:
Geosciences
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