Effects of hydrous minerals in subduction-zones

In subduction zones, one tectonic plate plunges beneath another into the Earth's interior. Some of the earthquakes that occur at subduction zones are unusual due to their occurrence at depths of 70 to 300 km (intermediate depths), or their tremor-like long wave-length seismicity ('slow earthquakes). However, this might be explained through the unique mechanical properties of hydrous minerals and their stability field at depth. Laboratory experiments show that hydrous minerals, such as serpentine, can cause seismicity at depths of 70–300 km.

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​Seismicity is correlated with the faults that formed due to plate bending. This observation can be explained if the amount of faulting prior to subduction controls the amount of hydrous mineral formation, which subsequently determines the intensity and rate of subduction zone‐related intermediate‐depth earthquakes.

RELATED PUBLICATIONS

Intermediate-depth Earthquakes Controlled by Incoming Plate Hydration Along Bending-related Faults

Boneh et al. (part of the 'ORCHID' group, CIDER 2017)

Geophysical Research Letters, 2019