Foreshocks and Swarms of Induced Seismicity in Southern Kansas
Abstract
Protracted foreshock sequences and swarm-like behavior have been observed for a number of induced earthquakes, including Guy-Greenbrier, Raton Basin, Youngstown, and the Fairview sequences. Many other induced earthquake sequences have seen intermittent seismicity before the largest earthquake in the sequence. The prevalence of foreshocks and swarms as part of induced earthquake sequences likely reflects the ongoing increase in and expansion of fluid pressure in a region, such that higher magnitude events will occur once a large region has been sufficiently influenced by fluid injection. Diffusion of fluid pressure has been observed in some induced seismicity sequences whereby seismicity moves away from an injector, making the earlier events foreshocks. Natural seismicity in other parts of the central and eastern United States experience far fewer foreshock sequences. This is additional evidence that injection-caused increase in fluid pressure is the reason that these foreshocks and swarms are occurring. To better understand foreshocks and swarm-like behavior of induced seismicity, we examine the seismicity in southern Kansas from 2014-2017. The seismic network in southern Kansas represents the densest, longest-running (>3.5 years) network with publicly available data in near-real-time in an area of induced seismicity. This has yielded a magnitude of completeness of 2.0, which is lower than in most other areas of induced seismicity. We further enhance this catalog by using template matching. With this expanded catalog, we identify and examine foreshock and swarm behavior for all M3.5 and larger mainshocks in Kansas.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2017
- Bibcode:
- 2017AGUFM.S13D..03R
- Keywords:
-
- 4475 Scaling: spatial and temporal;
- NONLINEAR GEOPHYSICS;
- 7209 Earthquake dynamics;
- SEISMOLOGY;
- 7223 Earthquake interaction;
- forecasting;
- and prediction;
- SEISMOLOGY;
- 8164 Stresses: crust and lithosphere;
- TECTONOPHYSICS