Seismic Intensities, PGA, and PGV for the 20 April 2013, Mw 6.6 Lushan, China, Earthquake, and a Comparison with North America

Abstract

Online Material: Seismic intensity map with observation points; table of geographical coordinates, MMI values. The 20 April 2013 M w 6.6 Lushan earthquake occurred at the geologic boundary between the western Sichuan basin and the eastern flank of the Tibetan plateau. This earthquake occurred 100 km south‐southwest of the epicenter of the 2008 M w 7.9 Wenchuan earthquake (Fig. 1). In response to the deadly Wenchuan earthquake, there has been a significant increase in the density of seismographic, strong‐motion, and Global Positioning System (GPS) stations throughout western Sichuan Province, including the vicinity of the Lushan earthquake. This increased level of earthquake monitoring has provided a dense array of coseismic recordings of the Lushan earthquake. These data have been used for numerous studies of the source properties, aftershock distribution, and the crustal strain field associated with this earthquake (Fang et al. , 2013; Liu et al. , 2013; Shan et al. , 2013; Xie et al. , 2013, 2014; Xu et al. , 2013; Han et al. , 2014; Zhang et al. , 2014). Figure 1. (a) Topographic map of Longmen Shan, western Sichuan Province, with the epicenters of the 2008 Wenchuan and 2013 Lushan earthquakes obtained from China Earthquake Network Center and the focal mechanisms (Global Centroid Moment Tensor project). The black lines show the extent of the rupture planes of the Wenchuan earthquakes (Zhang et al. , 2010; Hartzell et al. , 2013). (b) Finite‐fault slip model for the Lushan earthquake (Liu et al. , 2013); maximum slip is 150 cm and the rupture dimension for slip >25 cm is 20 km by 20 km. We report a field investigation of seismic intensities in the immediate vicinity of the epicenter of the Lushan earthquake. We compare these results with the recorded seismic ground accelerations and ground …