3D fault architecture controls the dynamism of earthquake swarm

By: , and 



The vibrant evolutionary patterns made by earthquake swarms are incompatible with standard, effectively two-dimensional (2D) models for general fault architecture. We leverage advances in earthquake monitoring with a deep-learning algorithm to image a fault zone hosting a 4-year-long swarm in southern California. We infer that fluids are naturally injected into the fault zone from below and diffuse through strike-parallel channels while triggering earthquakes. A permeability barrier initially limits up-dip swarm migration but ultimately is circumvented. This enables fluid migration within a shallower section of the fault with fundamentally different mechanical properties. Our observations provide high-resolution constraints on the processes by which swarms initiate, grow, and arrest. These findings illustrate how swarm evolution is strongly controlled by 3D variations in fault architecture.

Publication type Article
Publication Subtype Journal Article
Title 3D fault architecture controls the dynamism of earthquake swarm
Series title Science
DOI 10.1126/science.abb0779
Volume 368
Issue 6497
Year Published 2020
Language English
Publisher American Association for the Advancement of Science
Contributing office(s) Earthquake Science Center
Description 5 p.
First page 1357
Last page 1361
Google Analytic Metrics Metrics page
Additional publication details