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Spatio-temporal evolution of the 2011 Prague, Oklahoma aftershock sequence revealed using subspace detection and relocation

Nicole D McMahon·Richard C. Aster·William L. Yeck·Daniel E. McNamara·Harley M. Benz
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Abstract

The 6 November 2011 M w 5.7 earthquake near Prague, Oklahoma is the second largest earthquake ever recorded in the state. A M w 4.8 foreshock and the M w 5.7 mainshock triggered a prolific aftershock sequence. Utilizing a subspace detection method, we increase by fivefold the number of precisely located events between 4 November and 5 December 2011. We find that while most aftershock energy is released in the crystalline basement, a significant number of the events occur in the overlying Arbuckle Group, indicating that active Meeker-Prague faulting extends into the sedimentary zone of wastewater disposal. Although the number of aftershocks in the Arbuckle Group is large, comprising ~40% of the aftershock catalog, the moment contribution of Arbuckle Group earthquakes is much less than 1% of the total aftershock moment budget. Aftershock locations are sparse in patches that experienced large slip during the mainshock.

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Nicole D McMahon, Richard C. Aster, William L. Yeck, Daniel E. McNamara, Harley M. Benz. 2017-07-18. Spatio-temporal evolution of the 2011 Prague, Oklahoma aftershock sequence revealed using subspace detection and relocation. https://doi.org/10.1002/2017gl072944

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