Rapid Response to the 2019 Ridgecrest Earthquake With Distributed Acoustic Sensing

Abstract

Rapid seismic deployments after major earthquakes often produce critical data for characterizing postseismic processes. Taking advantage of pre-existing optical fibers, the recently emerging distributed acoustic sensing (DAS) technology can quickly establish ultra-dense seismic arrays after the mainshocks. Here we present the first example of such a rapid-response experiment using four telecommunication fiber optic cables near the 2019 M 7.1 Ridgecrest earthquake in California. By applying template matching to the Ridgecrest DAS array, we detected 6 times more aftershocks than the standard catalog within the three-month period. The enhanced catalog reveals abundant aftershocks on multiple crosscutting faults near the epicenters of the mainshock and the M 6.4 foreshock. Given the widespread fiber optic networks around the world, DAS has the potential to deliver fast and high-resolution aftershock monitoring and promote better understanding of earthquake physics.