Global Evaluation of Large Strike-Slip Ruptures Using a Bayesian Estimation of Stress Glut Second Moments
Abstract
Earthquake ruptures are complex processes that may vary strongly according to the structure and tectonics of the region in which they occur. Characterizing this potential variability may yield fundamental insights into how fault zones control how earthquakes happen. To investigate this, we determine second moments of the stress glut for a global dataset of large strike-slip earthquakes. Our approach uses a Bayesian inverse formulation with teleseismic body and surface waves, which yields a low-dimensional probabilistic description of rupture properties including spatial extent, directivity, and duration. This technique is useful for comparing events because there is no bias resulting from grid/velocity parameterization, and because it yields the full ensemble of possible solutions given the uncertainties of the data. We apply this framework to all the great strike-slip earthquakes (Mw≥7.5) of the past three decades, and we use the resultant second moments to compare source quantities like rectilinearity, directivity ratio, stress drop, and depth extent. The resulting solutions allow us to evaluate these quantities from a novel and physically motivated perspective. We find significant differences in these quantities between continental transform, oceanic transform, and intraplate events.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2022
- Bibcode:
- 2022AGUFM.S12B..05A