Preliminary analysis of causative faults of Lushan earthquake and Wenchuan earthquake in Sichuan,China

The 7.0 magnitude earthquake occurred in Lushan County(epicenter: 30.3 degrees north latitude and 103.0 degrees east longitude) of Ya'an City in Sichuan at 8:02 a.m.on April 20,2013.It is another destructive earthquake after the 5·12 Wenchuan earthquake.On the basis of data on remote sensing,DEM,surface geology and the seismic profiles of the Lushan quake-struck zone,the paper analyzes the epicenter data,earthquake mechanism,the aftershocks distribution data and surface rupture published online.This paper concludes preliminary that the earthquake-triggering fracture of the Lushan earthquake should be the ventral buried fault or the new fracture in the southwest within the basin.And the comprehensive comparison between the Lushan earthquake and the Wenchuan earthquake shows that both of them are tectonic earthquakes.As viewed from tectonic dynamics,the authors consider that the two earthquakes are relevant to the northward extrusion and collision of the Indian Ocean Plate.However,there are differences between them about their earthquake-triggering fractures and the characteristics of the earthquake-triggering tectonic unit.Above all,the authors conclude that they should be two independent earthquakes.