Analysis of physical mechanisms contributing to the spatial evolution of induced earthquake sequences in southern Kansas

Rosamiel Ries, Gregory C. Beroza, & William L. Ellsworth

Published September 8, 2024, SCEC Contribution #13735, 2024 SCEC Annual Meeting Poster #024

We use the Park et al. (2022) earthquake catalog to explore the possible mechanisms responsible driving swarms of injection induced earthquakes in southern Kansas, particularly the sequence of earthquakes that occurred in Sumner County near Caldwell, Kansas primarily in 2015-2016. We use differential arrival time measurements to develop precise earthquake locations that we use both to identify repeating earthquakes and to carry out modeling of the evolution of stress and its implications for the role of earthquake-to-earthquake interactions, aseismic slip, and pore fluid pressure in the evolution of the swarm. Some swarms in the region show clear along-strike growth with time. The Caldwell sequence in particular shows some of this along-strike growth occurs in regions of the fault that experienced increased stress following earlier earthquakes, suggesting a role of earthquake-to-earthquake triggering in along-strike growth. Additionally, we observe seismicity that overlaps areas that were destressed by the ruptures of previous earthquakes, which might indicate a role for aseismic slip or continuing fault weakening in the presence of increasing pore pressure. Our results indicate that multiple processes are likely to play a role in driving the evolution of earthquakes during induced earthquake sequences in southern Kansas. It is not clear whether we can assign one process as being the primary driver of the evolution of these earthquake sequences.

Citation
Ries, R., Beroza, G. C., & Ellsworth, W. L. (2024, 09). Analysis of physical mechanisms contributing to the spatial evolution of induced earthquake sequences in southern Kansas. Poster Presentation at 2024 SCEC Annual Meeting.

Related Projects & Working Groups
Seismology