固体地球物理学术报告通知-程怡芳

Standard mechanical concepts and models assume that a major rupture is a stick-slip along a single surface. While these simplified models provide important insights to the earthquake and fault mechanics, recent detailed inspections of well-recorded large earthquakes illuminate more complex features. For example, the 2019 Ridgecrest earthquake sequence ruptured two major orthogonal faults and activated a complex fault network with numerous previously unmapped faults. For better clarifying the processes associated with the Ridgecrest sequence using the rich seismic dataset recorded in the region, we systematically analyze the space-time variations of seismicity, potency values, focal mechanisms, and full moment tensors of the earthquakes leading to and during the sequence. The results suggest a long-term increase of shear stress in the 20 years prior to the sequence, the termination of the M6.4 and M7.1 earthquakes near fault zone barriers, the significant damage-related radiations in the early stage of the sequence, and the caused diverse volumetric damage in the surrounding upper and lower crust. The results illuminate large deviations of the real earthquake rupture processes from the simplified models and suggests the importance of monitoring and understanding earthquakes and faults from a volumetric perspective.