TY - JOUR
T1 - Prolonged seismically induced erosion and the mass balance of a large earthquake
AU - Hovius, Niels
AU - Meunier, Patrick
AU - Lin, Ching Weei
AU - Chen, Hongey
AU - Chen, Yue Gau
AU - Dadson, Simon
AU - Horng, Ming Jame
AU - Lines, Max
N1 - Funding Information:
We thank Brian Yanites and an anonymous referee for thorough and encouraging reviews and the Leverhulme Trust and the Taiwan National Science Council for generous financial support.
PY - 2011/4/15
Y1 - 2011/4/15
N2 - 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 0.25m, 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.
AB - 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 0.25m, 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.
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U2 - 10.1016/j.epsl.2011.02.005
DO - 10.1016/j.epsl.2011.02.005
M3 - Article
AN - SCOPUS:79953056398
SN - 0012-821X
VL - 304
SP - 347
EP - 355
JO - Earth and Planetary Science Letters
JF - Earth and Planetary Science Letters
IS - 3-4
ER -