Detailed 3D Seismic Velocity Structure of the Prague, Oklahoma Fault Zone and the Implications for Induced Seismicity

Abstract

The unprecedented increase in the seismicity rate in the central United States (CUS) since 2008 has largely been attributed to the large volume of wastewater disposal from oil and gas production (Ellsworth, 2013;Keranen & Weingarten, 2018). In Oklahoma, several significant induced earthquakes have occurred since 2011, including the 2011 Mw 5.7 Prague earthquake and the 2016 Mw 5.8 Pawnee earthquake, both of which caused considerable damage in the epicentral regions (Keranen et al., 2013;Yeck et al., 2016). Although the earthquake rate has been declining in Oklahoma since 2016, in part due to mandated reductions in rates for wastewater injection (Stewart & Ingelson, 2017), it remains well above background levels and puts the state at an elevated level of seismic hazards (

Seismological Evidence for the Existence of Long‐Distance Hydrological Channel and Its Implication for Fluid Overpressure in Southern Sichuan, China

“…The L ‐shaped swarm distributed along the eastern side of the JS, from Xinjie to Longtang Village, is particularly prominent, where four M4.0+ earthquakes occurred in Xingwen County from 3 May to 5 May 2023. These swarms may be located at the boundaries of medium properties, such as lithology or permeability changes, where the fault is prone to be reactivated under stress disturbance (L. He et al., 2021; J. Li et al., 2023). For instance, within the Cambrian strata along Section BB′, there is a swarm that precisely corresponds to the known termination of a fault.…”

“…The numerical simulation suggested that in the absence of permeable faults or other conduits connecting hydraulic fractures, the diffusion ranges of injected fluids and pore pressure are typically on the order of several hundred meters and a few kilometers over 10 years, respectively, even in sandstone or limestone formations with relatively high permeability (Brown & Ge, 2018). However, the hydrological channel could facilitate the propagation of pore pressure and guide fluids to flow from injection wells to distant locations, potentially reaching critically stressed basement faults (Chiarabba et al., 2018; Galloway et al., 2018; L. He et al., 2021; Shah & Crain, 2018; Yu et al., 2019). The hydrological channel thus could play a significant role in controlling the spatial and temporal distributions of subsurface fluid, pore pressure and poro‐elastic stress.…”

Stress Heterogeneity as a Driver of Aseismic Slip During the 2011 Prague, Oklahoma Aftershock Sequence

“…In general, fault intersections should be areas of high permeability due to fault damage where fluids could readily flow, and pore pressures could diffuse away. A recent 3D seismic study suggest that the intersection of faults A and B are indeed very permeable (He et al., 2021). Therefore, we think it unlikely that the slow slip seen at fault intersections, especially over the extended time periods of some of our repeating families, is due to high fluid pressure.…”