Qualitative Analyses of Correlations between Strong Ground Motions of the Three Large Earthquakes and Landslide Distributions

In this work, the correlations between spatial distributions of landslide point density (LPD) and strong ground motions of the three strong earthquakes are qualitatively investigated. Meanwhile the qualitative relationship between the distribution of LPD and the fault rupture process is also characterized. Three strong events are the Lushan, Wenchuan, and Jiuzhaigou earthquakes. In order to reconstruct the near filed strong ground motions and the fault processes of these earthquakes, the broadband ground simulation method of University of California Santa Barbara (UCSB) and the simplified crustal layer structures are applied. To show the rationality of the UCSB method, the fault slip distributions of the three earthquakes reconstructed by the kinematic rupture generator model in the UCSB method are compared with those by inversed. Furthermore, the validation of the UCSB method for the three earthquakes is also carried according to the validation exercise of the Southern California Earthquake Center (SCEC) Broadband Platform (BBP). Lastly, the fields of peak ground acceleration (PGA) and peak ground velocity (PGV) in three mutually perpendicular directions of the three earthquakes are achieved. Generally, the landslide distribution length of large LPD values along the fault strike is less than the fault strike length. Therefore, the slip modes of earthquake faults affect the distributions of landslides. For the strike slip earthquakes, the distributions of large LPD values relate well to PGA and PGV components of the parallel and normal to the fault strike. For the reverse slip earthquakes, distributions of LPD relate to ground motion components in all directions. Moreover, distributions of landslides in near fields of earthquakes are significantly affected by the focus parameters and fault scales.

Automated summary

This study qualitatively investigates the correlations between the spatial distributions of landslide point density (LPD) and strong ground motions of three strong earthquakes, namely the Lushan, Wenchuan, and Jiuzhaigou earthquakes. The study also characterizes the qualitative relationship between the LPD distribution and the fault rupture process. The University of California Santa Barbara (UCSB)'s broadband ground simulation method and simplified crustal layer structures are applied to reconstruct the near-field strong ground motions and fault processes of these earthquakes.