Science Daily August 30, 2018
Researchers at UC Santa Cruz analyzed spatial seismicity decay in a global dataset of 18 induced cases with clear association between isolated wells and earthquakes. They found two populations. The first is characterized by near-well seismicity density plateaus and abrupt decay, dominated by square-root space-time migration and pressure diffusion. Injection at these sites occurs within the crystalline basement. The second population exhibits larger spatial footprints and magnitudes, steady spatial decay over more than 10 kilometers, potentially caused by poroelastic effects. Far-reaching spatial effects during injection may increase event magnitudes and seismic hazard beyond expectations based on purely pressure-driven seismicity… read more. TECHNICAL ARTICLE
The blue and red areas represent the spatial footprint of induced seismicity for injection into basement rock (blue) or the overlying sedimentary layer (red). Gray lines represent the fault network. Credit: Goebel and Brodsky, Science, 2018