Two Comparable Earthquakes Produced Greatly Different Coseismic Landslides: The 2015 Gorkha, Nepal and 2008 Wenchuan, China Events
- Received Date: 2016-12-26
- Rev Recd Date: 2016-12-26
- Publish Date: 2016-12-26
Abstract: The 2015 Gorkha Earthquake in Nepal and the 2008 Wenchuan Earthquake in Chinaoccurred at the south and southeast margins of the Tibetan Plateau, respectively. Both earthquakes hadsimilar magnitudes of Mw 7.8 and 7.9, caused catastrophic loss of life and damage to property, andgenerated tens of thousands of landslides. Comparisons of pre- and post-quake satellite images supported by field investigations show that the Gorkha Earthquake triggered at least 2 064 large landslides(defined as covering an area ≥10 000 m2) over a ~35 600 km2 region with a volume of (444–584)×106(average 509×106) m3 and total area of 44.78×106 m2. In contrast, the Wenchuan Earthquake triggered25 580 large landslides over a region of ~44 000 km2 with a volume of (7 128–9 479)×106 (average8 219×106) m3 and a total area of about 670.65×106 m2. Several controlling factors including topographic relief, slope steepness, and regional peak ground acceleration (PGA) were investigated to try to explain the great differences between the number, volume and area of the coseismic landslides associatedwith the two similar earthquakes. We found that the differences primarily arose from an unexpectedfactor, the dip angle of the seismogenic fault. This discovery should aid understanding the failure mechanisms of quake-triggered landslides, and suggests that more factors should be taken into consideration in estimating coseismic landslide volumes from earthquake magnitudes.
|Citation:||Chong Xu, Xiwei Xu, Yingying Tian, Lingling Shen, Qi Yao, Xueqiang Huang, Junxue Ma, Xi Chen, Siyuan Ma. Two Comparable Earthquakes Produced Greatly Different Coseismic Landslides: The 2015 Gorkha, Nepal and 2008 Wenchuan, China Events. Journal of Earth Science, 2016, 18(6): 1008-1015. doi: 10.1007/s12583-016-0684-6|