Two end-member earthquake preparations illuminated by foreshock activity on a meter-scale laboratory fault.

ABSTRACT: The preparation process of natural earthquakes is still difficult to quantify and remains a subject of debate even with modern observational techniques. Here, we show that foreshock activity can shed light on understanding the earthquake preparation process based on results of meter-scale rock friction experiments. Experiments were conducted under two different fault surface conditions before each run: less heterogeneous fault without pre-existing gouge and more heterogeneous fault with pre-existing gouge. The results show that fewer foreshocks occurred along the less heterogeneous fault and were driven by preslip; in contrast, more foreshocks with a lower b value occurred along the more heterogeneous fault and showed features of cascade-up. We suggest that the fault surface condition and

SUBMITTER: Yamashita F 

PROVIDER: S-EPMC8280151 | biostudies-literature | 2021 Jul

REPOSITORIES: biostudies-literature