TY  - JOUR
A1  - Wang, Lifeng
A1  - Zöller, Gert
A1  - Hainzl, Sebastian
T1  - Joint Determination of Slip and Stress Drop in a Bayesian Inversion Approach: A Case Study for the 2010 M8.8 Maule Earthquake
JF  - Pure and applied geophysics
N2  - Stress drop is a key factor in earthquake mechanics and engineering seismology. However, stress drop calculations based on fault slip can be significantly biased, particularly due to subjectively determined smoothing conditions in the traditional least-square slip inversion. In this study, we introduce a mechanically constrained Bayesian approach to simultaneously invert for fault slip and stress drop based on geodetic measurements. A Gaussian distribution for stress drop is implemented in the inversion as a prior. We have done several synthetic tests to evaluate the stability and reliability of the inversion approach, considering different fault discretization, fault geometries, utilized datasets, and variability of the slip direction, respectively. We finally apply the approach to the 2010 M8.8 Maule earthquake and invert for the coseismic slip and stress drop simultaneously. Two fault geometries from the literature are tested. Our results indicate that the derived slip models based on both fault geometries are similar, showing major slip north of the hypocenter and relatively weak slip in the south, as indicated in the slip models of other studies. The derived mean stress drop is 5-6 MPa, which is close to the stress drop of similar to 7 MPa that was independently determined according to force balance in this region Luttrell et al. (J Geophys Res, 2011). These findings indicate that stress drop values can be consistently extracted from geodetic data.
KW  - Stress drop
KW  - Fault slip
KW  - Bayesian
KW  - Geodetic measurements
Y1  - 2015
U6  - https://doi.org/10.1007/s00024-014-0868-x
SN  - 0033-4553
SN  - 1420-9136
VL  - 172
IS  - 2
SP  - 375
EP  - 388
PB  - Springer
CY  - Basel
ER  -