← Back to Sessions

A Joint Dynamic Model of Seismic and Postseismic Slip of the 2014 South Napa Earthquake

Session: Exploring Rupture Dynamics and Seismic Wave Propagation Along Complex Fault Systems II

Type: Oral

Date: 4/20/2021

Presentation Time: 10:45 AM Pacific

Description: 

Elastic energy on fault planes, accumulated due to the relative motion of tectonic plates, is released abruptly in the form of an earthquake. Part of the energy often releases after the event in the form of a postseismic slip (afterslip) observed over the longer time period in the areas surrounding the ruptured region. An example of earthquake with abundance of coseismic and afterslip records is the 2014 South Napa, California, earthquake. The earthquake produced a significant surface rupture over the length ~12 km, most of which occurred aseismically within the first month after the main event. We employ a novel code FD3D_TSN that simulates the dynamic rupture propagation on a fault during an earthquake and the long-term development of afterslip using a joint framework of laboratory-derived rate-and-state friction with fast velocity weakening. We carry out a Bayesian inversion to infer spatially varying controlling dynamic parameters to fit a variety of data: seismograms capturing the co-seismic rupture and long-term geodetic observations (GPS stations with continuous reading and surface slip measurements). Resulting model is not only in good agreement with kinematic models of both seismic and postseismic slip, but it provides a deeper insight through the joint dynamic model of the co- and post-seismic rupture process.

Presenting Author: Jan Premus

Student Presenter: Yes

Authors