Investigation of the ability for slow slip events to trigger earthquakes through a comparison of seismic and geodetic observations with fault slip simulations
Abstract
There is growing evidence that slow slip events (SSEs) promote nearby seismicity, often in the form of swarms of small to moderate earthquakes or as tectonic tremor that are primarily swarms of low frequency earthquakes. Yet the question remains whether SSEs are capable of triggering large to great earthquakes due to the generally small stress change associated with typical SSEs. There have been a few recent large to great earthquakes that appear to have been preceded by evidence of a SSE, but whether these cases are rare is not yet clear. Even if several other cases were documented, it would still be difficult to translate this information into quantitative estimates of the hazard increase during a given SSE. In this study, we move towards this long-term goal with an earthquake simulator (RSQSim), which is capable of modeling a variety of fault slip behaviors (i.e. earthquakes, SSEs, and continuous creep), and can generate robust statistics on the relationships between SSEs, microseismicity, and large/great earthquakes. The simulations seek to explain observations like those of the recent Mw 7.4 Ometepec, Mexico and Mw 6.5 Cook Strait earthquakes that show increased seismic activity in small fault patches between the transition zone and mainshock source zone during SSEs that were in process in the months leading up to, and particularly immediately prior to, the mainshock. The potential causative relationships will be probed with models that use a range of fault properties and configurations. One hypothesis to test is whether observed swarms of seismicity during SSEs represent fast slip on weaker areas of the plate interface that are more sensitive to the relatively small stress changes associated with SSEs. An alternative hypothesis is that no area of the fault is more easily influenced by SSEs, just that the relative prevalence of smaller earthquakes leads to more frequent observations of the triggered mainshocks.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFM.T44B..04C
- Keywords:
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- 8170 TECTONOPHYSICS Subduction zone processes;
- 8123 TECTONOPHYSICS Dynamics: seismotectonics;
- 7209 SEISMOLOGY Earthquake dynamics;
- 7223 SEISMOLOGY Earthquake interaction;
- forecasting;
- and prediction