Real-time inversions for finite fault slip models and rupture geometry based on high-rate GPS data

Journal of Geophysical Research
By: , and 

Links

Abstract

We present an inversion strategy capable of using real-time high-rate GPS data to simultaneously solve for a distributed slip model and fault geometry in real time as a rupture unfolds. We employ Bayesian inference to find the optimal fault geometry and the distribution of possible slip models for that geometry using a simple analytical solution. By adopting an analytical Bayesian approach, we can solve this complex inversion problem (including calculating the uncertainties on our results) in real time. Furthermore, since the joint inversion for distributed slip and fault geometry can be computed in real time, the time required to obtain a source model of the earthquake does not depend on the computational cost. Instead, the time required is controlled by the duration of the rupture and the time required for information to propagate from the source to the receivers. We apply our modeling approach, called Bayesian Evidence-based Fault Orientation and Real-time Earthquake Slip, to the 2011 Tohoku-oki earthquake, 2003 Tokachi-oki earthquake, and a simulated Hayward fault earthquake. In all three cases, the inversion recovers the magnitude, spatial distribution of slip, and fault geometry in real time. Since our inversion relies on static offsets estimated from real-time high-rate GPS data, we also present performance tests of various approaches to estimating quasi-static offsets in real time. We find that the raw high-rate time series are the best data to use for determining the moment magnitude of the event, but slightly smoothing the raw time series helps stabilize the inversion for fault geometry.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Real-time inversions for finite fault slip models and rupture geometry based on high-rate GPS data
Series title Journal of Geophysical Research
DOI 10.1002/2013JB010622
Volume 119
Issue 4
Year Published 2015
Language English
Publisher American Geophysical Union
Contributing office(s) Earthquake Science Center
Description 31 p.
First page 3201
Last page 3231
Online Only (Y/N) N
Additional Online Files (Y/N) N