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

Abstract

Faults can fail over a range of velocities and durations from plate-rate creep to stick-slip events. Aseismic slip is any fault movement that does not occur at seismic slip speeds, while slow slip occurs at speeds greater than plate-rate and slower than earthquake slip. We are studying an induced sequence in an area far from tectonic boundaries, such that the resolved velocity across this fault pre-induced seismicity should be effectively zero. Therefore, we interchangeably use slow slip and aseismic slip. The importance of aseismic and slow slip is demonstrated by the variety of ways it can interact with earthquakes. Slow slip events can occur as precursory slip that accelerates into large earthquakes (Kato et al., 2012(Kato et al., , 2016, independent events that trigger large earthquakes (Socquet et al., 2017;Uchida et al., 2016), or transient slip events that occur unrelated to a large earthquake (Shaddox et al., 2021). Aseismic slip can also occur as afterslip and triggered transient slip following moderate and large earthquakes (Hirao et al., 2021;Schwartz & Rokosky, 2007). The occurrence of aseismic slip following an earthquake redistributes stress concentrations and changes the seismic hazard of the area. Therefore, pinpointing the location of aseismic slip is necessary for determining where this redistribution takes place to better constrain the processes that control seismic slip behavior.Unraveling the role of aseismic slip in the accumulation and release of elastic strain can be difficult as there are limits to what slip amplitudes can be detected geodetically. Small to moderate sized slow slip events are typically spatially limited with small surface deformations, and thus must be inferred from other observations. Repeating

Relation Between Oceanic Plate Structure, Patterns of Interplate Locking and Microseismicity in the 1922 Atacama Seismic Gap

“…Aseismic slip transients have also been observed to precede large earthquakes (e.g., Ito et al., 2013; Radiguet et al., 2016; Socquet et al., 2017; Voss et al., 2018), as a mixture of slow deformation and foreshocks (Bedford et al., 2015). Finally, aseismic slip unrelated to large earthquakes has also been observed along weakly locked segments of the plate interface (Okamoto et al., 2022). Increased seismicity rates or swarm‐like sequences have been found to occur in direct vicinity to—and likely triggered by—aseismic transients (Hirose et al., 2014; Vallée et al., 2013).…”