Revisiting the Timpson Induced Earthquake Sequence: A System of Two Parallel Faults

Abstract

The 17 May 2012 M4.8 Timpson earthquake is the largest known earthquake in eastern Texas. It is thought to have been induced by wastewater injection from two nearby, high‐volume wells. Its cataloged aftershocks form a NW‐SE trend, which unlike other induced earthquakes sequences is unfavorably oriented for failure in the local stress field. To understand this, we enriched the catalog using PhaseNet, a deep‐learning‐based picker followed by double‐difference relocation with cross‐correlation‐based differential traveltimes. We clustered the aftershocks based on waveform similarity. Most of the seismicity falls into two clusters, which define a detailed fault structure of two parallel subfaults that are more favorably oriented than the overall trend. We inferred from waveform similarity that the sequence initiated on the northern subfault with a M3.9 foreshock and M4.8 mainshock, then extended to the southern subfault with a M4.1 aftershock, and was finally reactivated on the northern subfault with two more M4 events.

Raton Basin Induced Seismicity Is Hosted by Networks of Short Basement Faults and Mimics Tectonic Earthquake Statistics

“…However, ruptures may span multiple nearby fault segments (e.g., Landers earthquake, Li et al., 1994; and Hector Mine earthquake, Treiman et al., 2002) such that the maximum fault length is not a reliable predictor of the maximum earthquake magnitude. Such co‐slipping of en‐echelon fault systems has been observed for induced seismicity in Alberta, Canada (M W 4.1, Wang et al., 2018) and east Texas (M 4.8, Wang, Ellsworth et al., 2020). Within the Raton Basin, the largest earthquake since the beginning of injection was the M W 5.3 Trinidad event with a geodetically estimated rupture length of ∼8–10 km (Barnhart et al., 2014), which is shorter than the ∼14 km total length of the Trinidad zone of seismicity (Meremonte et al., 2002; Rubinstein et al., 2014).…”

Prediction of Pressure Increase during Waste Water Injection to Prevent Seismic Events

“…Although the rate has declined since 2015, there were still 130 M3+ earthquakes recorded in the same region in 2019. Some of them were particularly strong and damaging such as the M5.8 Pawnee and M5.0 Cushing Oklahoma earthquakes that occurred in 2016 [15][16][17].…”

“…Although earthquakes can be induced in many ways such as the filling up subsurface reservoirs, oil and gas production, fluid injection, mining, geothermal energy extraction, and other operations, each of these activities fundamentally causes earthquakes due to the same mechanism: a sudden release of stored elastic strain energy by frictional sliding along preexisting faults due to the change of their stress conditions [14]. Observations and numerical modeling showed that increased fluid pressure within faults is the main risk factor whether injection well will trigger earthquakes [12][13][14][15][16][17][18]. A case history of injectioninduced seismicity demonstrated that elevating the pore pressure by hundreds of psi could cause a previously quiescent area to become seismically active when the regions are sufficiently prestressed [13,38].…”

SeismoGen: Seismic Waveform Synthesis Using GAN With Application to Seismic Data Augmentation

“…In the seismology community, there have been several recent works studying the importance of the model generalization (Chai et al., 2020; Liu et al., 2020; Mousavi et al., 2020; Park et al., 2020; K. Wang, Ellsworth, & Beroza, 2020; R. Wang, Schmandt, et al., 2020). As demonstrated in most of these recent studies, DNN‐based models yield some generalization ability that would allow for a model being trained on one data set to then be applied to a different study region.…”

“…In the seismology community, there have been several recent works studying the importance of the model generalization (Chai et al, 2020;Liu et al, 2020;Mousavi et al, 2020;Park et al, 2020;K. Wang, Ellsworth, & Beroza, 2020; R. Wang, Schmandt, et al, 2020).…”