Spatial and temporal patterns of simulated slow slip events on the Cascadia megathrust

Abstract

In recent years, it has been discovered that sections of the subduction interface slip aseismically in slow slip events, during which stress is intermittently transferred to the section of the subduction zone that generates large or great earthquakes. Within the Cascadia subduction zone, the magnitude and frequency of SSEs and accompanying tectonic tremor exhibit complex patterns that vary systematically with depth. However, the loading mechanisms and interactions that precede great subduction earthquakes are poorly understood. Here we present results from physics-based simulations that reproduce the continuum of SSE characteristics reported for the Cascadia subduction zone. The simulations provide a basis for understanding the interactions that control both the observed complex patterns of SSEs and stress transfer to the seismogenic section that produce great earthquakes. Key Points Results support a conceptual model for SSEs previously published Cumulative tremor epicenters are a potential measure of total slip in a region The model suggests a significant slip deficit in the slow slip zone ©2013. American Geophysical Union. All Rights Reserved.