Seminar: Complexity and Simplicity of Injection-induced earthquakes in the Raton Basin
The G&T seminar series have a great seminar coming up. Ruijia Wang from the University of New Mexico will present their work on Wednesday, June 30th at 11:00am EDT (3pm UTC and 4pm BST/GMT).
Waste-water injection induced seismicity has been active in the Raton Basin for the past two decades, including several M>4.0 normal-faulting earthquakes. To characterize the injection-induced fault reactivation processes, we utilize the state-of-art techniques to automatically detect and locate the seismicity using two datasets: 1) 8 broadband stations available since 2016 with an averaged spacing of ~30 km and 2) 96 high-frequency nodal instruments that were deployed for one month in the southern section of the basin in the summer of 2018. The two catalogs with ~30,000 and ~10,000 earthquakes show consistent patterns: clustering into multiple fault systems ranging from N-S, NE-SW normal to oblique dip-slip regimes. Further focal mechanisms and finite fault analysis suggest high fault and stress heterogeneity in this injection setting. On the other hand, statistical behaviors of the clusters are generally comparable to tectonic sequences. The detailed fault structures and earthquake cycle statistics offer an observational base for future mechanical modeling and hazard mitigation.