Rupture Details of the 20 April 2013 Lushan M7.0 Earthquake

Abstract An M7.0 earthquake struck Lushan, Sichuan, on 20 April 2013. We attempt to reveal its rupture details around 1 Hz using back‐projecting teleseismic P waves. The results show that this event was spawned by a 20‐km‐long and 26‐s‐duration rupturing of the source, which occurred bilaterally during the first 4 s, and unilaterally afterwards. The biggest energy release area is located north of the epicenter. We compared the rupture details of the Wenchuan and Lushan earthquakes, which occurred on the same fault, and found three common characters in rupture direction, location of the biggest energy burst and multi sub‐event. Two sources ruptured along the northeast trending Longmenshan fault zone. The biggest energy release regions are both off the epicenter. The source included more than one sub‐event, with the second one having the biggest energy release. The total rupture length of the Wenchuan and Lushan earthquakes accounts for about two thirds of the entire Longmenshan fault zone.