Earthquakes were induced in the Fort Worth Basin from 2008 through 2020 by increase in pore pressure from injection of oilfield wastewater (SWD). In this region and elsewhere, a missing link in understanding the mechanics of causation has been a lack of comprehensive models of pore pressure evolution (ΔPp) from SWD. We integrate detailed earthquake catalogs, ΔPp, and probabilistic fault slip potential (FSP) and find that faults near large-scale SWD operations became unstable early, when ΔPp reached ∼0.31 MPa and FSP reached 0.24. Faults farther from SWD became unstable later, when FSP reached 0.17 and at much smaller ΔPp. Earthquake sequences reactivated with mean ΔPp of ∼0.05 MPa. The response of faults shows strong variability, with many remaining stable at higher ΔPp and few that became seismogenic at smaller changes. As ΔPp spread regionally, an ever-increasing number of faults were impacted and the most sensitive became unstable.
- Digital Object Identifier: 10.1029/2021GL093564
- Source: USGS Publications Warehouse (indexId: 70223134)