Prolonged seismically induced erosion and the mass balance of a large earthquake

Hovius, Niels and Meunier, Patrick and Lin, Ching-Weei and Chen, Hongey and Chen, Yue-Gau and Dadson, Simon and Horng, Ming-Jame and Lines, Max (2011) Prolonged seismically induced erosion and the mass balance of a large earthquake. Earth and Planetary Science Letters, 304 (3-4). pp. 347-355. ISSN 0012-821X DOI 10.1016/j.epsl.2011.02.005

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Abstract

Large earthquakes deform the Earth's surface and drive topographic growth in the frontal zones of mountain belts. They also induce widespread mass wasting, reducing relief. The sum of these two opposing effects is unknown. Using a time series of landslide maps and suspended sediment transport data, we show that the MW7.6 Chi-Chi earthquake in Taiwan was followed by a period of enhanced mass wasting and fluvial sediment evacuation, peaking at more than five times the background rate and returning progressively to pre-earthquake levels in about six years. Therefore it is now possible to calculate the mass balance and topographic effect of the earthquake. The Choshui River has removed sediment representing more than 30% of the added rock mass from the epicentral area. This has resulted in a reduction of surface uplift by up to 0.25 m, or 35% of local elevation change, and a reduction of the area where the Chi-Chi earthquake has built topography. For other large earthquakes, erosion may evolve in similar, predictable ways, reducing the efficiency of mountain building in fold-and-thrust belts and the topographic expression of seismogenic faults, prolonging the risk of triggered processes, and impeding economic regeneration of epicentral areas.

Item Type:	Article
Uncontrolled Keywords:	2011AREP; IA62; Part III;
Subjects:	02 - Geodynamics, Geophysics and Tectonics
Divisions:	02 - Geodynamics, Geophysics and Tectonics
Journal or Publication Title:	Earth and Planetary Science Letters
Volume:	304
Page Range:	pp. 347-355
Identification Number:	10.1016/j.epsl.2011.02.005
Depositing User:	Sarah Humbert
Date Deposited:	06 Feb 2012 18:42
Last Modified:	23 Jul 2013 10:03
URI:	http://eprints.esc.cam.ac.uk/id/eprint/2359

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