Aftershock Productivity of Large Intermediate Depth Earthquakes
Abstract
The mechanism(s) causing intermediate-depth, intraslab earthquakes are not well understood: dehydration-linked embrittlement and thermal shear runaway are among the more well-supported proposed mechanisms for these events, which occur at temperatures and pressures that ought to disable brittle fracture. Recently, there is increasing evidence that the particular mechanisms enabling these earthquakes may be dependent on the tectonic setting in which they occur. Moreover, although intermediate-depth earthquakes are thought to exhibit few to no aftershocks in comparison to shallow earthquakes, productive aftershock sequences have been observed at intermediate depths in Japan, Colombia, Mexico, and Alaska, among other regions. An enduring question, hence, is why certain intermediate-depth earthquake sequences appear to produce aftershocks whereas others do not, and whether or not the existence of aftershocks can be linked to the underlying mechanism, event depth, or tectonic properties. To answer this, we study the aftershock productivity of intraslab earthquakes as a function of depth in diverse regions, using an ETAS model, and find variations in aftershock decay rate and magnitude-frequency distribution.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.S13C0445C
- Keywords:
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- 3613 Subduction zone processes;
- MINERALOGY AND PETROLOGY;
- 7209 Earthquake dynamics;
- SEISMOLOGY;
- 7215 Earthquake source observations;
- SEISMOLOGY;
- 8170 Subduction zone processes;
- TECTONOPHYSICS