Relocated Hypocenters and Structural Analysis from Waveform Modeling of Aftershocks from the 2011 Prague, Oklahoma, Earthquake Sequence

Abstract

Abstract We present an analysis of aftershocks with M L >3 from the 2011 Prague, Oklahoma, earthquake sequence, an intraplate sequence of moderate‐size earthquakes within the North American craton. We apply waveform analysis to seismograms from temporary local seismograph networks to relocate the aftershocks’ hypocenters. The relocations show that the hypocenters are confined to the Precambrian basement. The character of the recorded seismograms waveforms are reconstructed by finite‐difference forward modeling of seismic sources buried at different depths in 2D crustal models. The numerical modeling indicates that the observed complex waveforms, and particularly the coda, are created by waves scattering off numerous shallow crustal velocity anomalies. We infer that these anomalies correspond to paleoriver channels that are embedded in the Pennsylvanian limestone formation. The modeling indicates that the amount of energy within the coda depends on the depth of the source. Our waveform modeling of the observed seismograms is consistent with our relocations of the aftershocks to depths of 5–10 km, within the Precambrian basement. Electronic Supplement:Empirical and synthetic data, model parameters, and geological figures.