Seismograms of earthquake pairs in the injection experiment

Numerous small and moderate injection-induced earthquakes have been recorded in North America, Europe and Asia. Here we present a detailed analysis about microearthquakes in an in-situ injection-induced earthquake experiment, which provides an unprecedented opportunity to investigate the mechanisms of induced earthquakes. Our analysis illuminates meter-scale earthquake sources distributed in a network of preexisting rock fractures. The majority of induced earthquakes in our analysis happened when injection pressure reached a peak, indicating a direct response of rock fractures to fluid pressure perturbation. But the relatively low ratio of stress drop to crustal strength reveals that a very small fraction of the crustal shear strength is released by earthquakes, supporting the previous notion that fluid injection induces large aseismic deformation during the experiment. ;Citation for dataset: Huang, Y., De Barros, L. (2019). Seismograms of earthquake pairs in the injection experiment [Data set]. University of Michigan - Deep Blue.