Numerical Modeling of Dynamically Triggered Shallow Slow Slip Events in New Zealand by the 2016 Mw 7.8 Kaikoura Earthquake
Document Type
Article
Date of Original Version
5-28-2018
Abstract
The 2016 Mw 7.8 Kaikoura earthquake triggered widespread slow slip events (SSEs) in the northern Hikurangi subduction zone, providing a unique opportunity to study the mechanism of dynamic triggering of SSEs. Here we simulate SSEs near Gisborne, New Zealand, in the framework of rate-and-state friction. Low effective normal stress (~0.4 MPa) on the shallow subduction interface is needed to reproduce the observed repeating, spontaneous SSEs. Dynamic stress perturbations from the Kaikoura mainshock are adequate to trigger SSEs with characteristics similar to observation. SSE propensity to dynamic triggering mainly depends on the timing of perturbation with respect to the SSE cycle and the maximum Coulomb stress change. Once the perturbation amplitude exceeds an initial threshold, prolonged stress perturbations tend to decrease the triggering threshold hence promote dynamic triggering of SSEs. Therefore, shallow SSEs are more likely to be dynamically triggered than their deep counterparts because of enhanced stress perturbation (magnitude and duration) from the sedimentary wedge.
Publication Title, e.g., Journal
Geophysical Research Letters
Volume
45
Issue
10
Citation/Publisher Attribution
Wei, Meng, Yoshihiro Kaneko, Pengcheng Shi, and Yajing Liu. "Numerical Modeling of Dynamically Triggered Shallow Slow Slip Events in New Zealand by the 2016 Mw 7.8 Kaikoura Earthquake." Geophysical Research Letters 45, 10 (2018). doi: 10.1029/2018GL077879.