← Back to Sessions

WITHDRAWN Integrating High Resolution Crustal Stress Maps and Seismicity Catalogs to Study Injection-Induced Earthquake Sequences in Oklahoma

Description: 

WITHDRAWN Combining a detailed understanding of the stress field with high quality seismicity data is essential for anticipating which pre-existing faults are most likely to fail due to fluid pressure perturbations or poroelastic stressing resulting from fluid injection. In the case of induced seismicity, high-quality stress data enables retrospective analysis of earthquake sequences, including evaluating causal mechanisms and estimating the spatial and temporal evolution of pore pressure changes at seismogenic depths. In this presentation, we show the new generation stress map that we recently published for North America, which includes the first quantitative map of the style of faulting (relative stress magnitudes) across the continent, as well as hundreds of new orientations of the maximum horizontal principal stress (S_Hmax). We apply this dataset to study earthquake sequences that occurred in Oklahoma and southern Kansas over the past decade. Of particular interest are remarkable improvements of the seismic catalog by Park and others, who identified over 300,000 events using deep learning methods. This catalog enables improved understanding of earthquake sequences and the geometry of the causative fault networks within the stress field. Across this area, the orientation of S_Hmax varies modestly (ranging from ~N060°E to ~N100°E) but is mostly ENE–WSW, and the style of faulting transitions from normal/strike-slip in southern Kansas to nearly pure strike-slip in central Oklahoma. The orientations of active faults, as indicated by earthquake focal mechanisms and groups of earthquake locations defining fault planes, are generally near-optimal for failure within the mapped stress field; we find that most faults likely required 2 MPa or less to fail. In addition to its utility for understanding and managing induced seismicity, we discuss potential applicability of the improved stress mapping for characterizing natural seismic hazards.

Session: Understanding and Managing Induced Seismicity

Type: Oral

Date: 4/19/2023

Presentation Time: 11:00 AM (local time)

Presenting Author: Jens-Erik Lundstern (Lund Snee)

Student Presenter: No

Invited Presentation: Yes

Authors