Characterizing Stress Orientations in Southern Kansas

Rob Skoumal, Elizabeth S. Cochran, Kayla Kroll, Justin L. Rubinstein, & Devin McPhillips

Submitted August 12, 2020, SCEC Contribution #10401, 2020 SCEC Annual Meeting Poster #052

Induced seismicity predominantly occurs along faults that are optimally oriented to the local principal compressive stress direction, and the characterization of these stress orientations is an important component of understanding seismic hazards. Southern Kansas demonstrated a rapid seismicity rate increase in 2013 primarily due to the disposal of large volumes of wastewater into the Arbuckle Group. Previously, local stress orientations in this area were poorly constrained which limited our understanding of the complex faulting and diverse earthquake mechanisms in this region. We use both shear wave splitting and focal mechanism inversions to create multiple, independent estimates of maximum horizontal stress directions and their spatial variation across the study area. We then create an integrated model of stress orientations for southern Kansas and northern Oklahoma using our local results in conjunction with previous, regional stress orientation estimates. We find that the stress orientation in southern Kansas and central Oklahoma both demonstrate an ENE (~078°) orientation and bounds a NE (~059°) rotation in northern Oklahoma near the Nemaha Ridge. With these stress orientation estimates, we identify and characterize both optimally and unfavorably oriented seismogenic faults throughout the region.

Key Words
Induced Seismicity, Kansas, Stress

Skoumal, R., Cochran, E. S., Kroll, K., Rubinstein, J. L., & McPhillips, D. (2020, 08). Characterizing Stress Orientations in Southern Kansas. Poster Presentation at 2020 SCEC Annual Meeting.

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