The objectives of this task are to improve the capability of earthquake detection and source parameter inversion, as well as the precision of earthquake location and the resolution of subsurface imaging, by rapidly deploying seismic arrays in and around the focal area soon after the main shock. The improvements will result in more complete and accurate 4D earthquake activities, fine 3D subsurface structure and stress field, which will shed light on the deep seismogenic environment and provide the background for analyzing the earthquake trends, understanding fault anatomy and looking backward at the mechanisms behind earthquake nucleation.