TY  - JOUR
A1  - Marc, Odin
A1  - Hovius, Niels
A1  - Meunier, Patrick
A1  - Uchida, Taro
A1  - Hayashi, Shin-Ichiro
T1  - Transient changes of landslide rates after earthquakes
JF  - Geology
N2  - Earthquakes impart an impressive force on epicentral landscapes, with immediate catastrophic hillslope response. However, their legacy on geomorphic process rates remains poorly constrained. We have determined the evolution of landslide rates in the epicentral areas of four intermediate to large earthquakes (M-w, 6.6-7.6). In each area, landsliding correlates with the cumulative precipitation during a given interval. Normalizing for this meteorological forcing, landslide rates have been found to peak after an earthquake and decay to background values in 1-4 yr, with the decay time scale probably proportional to the earthquake magnitude. The transient pulse of landsliding is not related to external forcing such as rainfall or aftershocks, and we tentatively attribute it to the reduction and subsequent recovery of ground strength. Observed geomorphic trends are not linked with groundwater level changes or root system damage, both of which could affect substrate strength. We propose that they are caused by reversible damage of rock mass and/or loosening of regolith. Qualitative accounts of ground cracking due to strong ground motion abound, and our observations are circumstantial evidence of its potential importance in setting landscape sensitivity to meteorological forcing after large earthquakes.
Y1  - 2015
U6  - https://doi.org/10.1130/G36961.1
SN  - 0091-7613
SN  - 1943-2682
VL  - 43
IS  - 10
SP  - 883
EP  - 886
PB  - American Institute of Physics
CY  - Boulder
ER  -