Increased rates of seismicity in the Delaware basin, Texas, accompanying unconventional petroleum development have created intensive interest in determining their cause. Detailed and accurate spatial distribution of seismicity and focal mechanisms are critical components for understanding the underlying industrial processes responsible for inducing seismicity. We focus on a highly seismically active area straddling the Reeves–Pecos County line where two TexNet stations sit atop the seismicity, which includes 21 ML 3+ events from 2017 to 2020 (Advanced National Seismic System Comprehensive Earthquake Catalog). Short epicentral distance enables us to reliably estimate the hypocentral depth using seismic phase picks and standard location methods. We use a deep-learning-based method to detect earthquakes and time the phase arrivals. Hypocentral locations computed in a velocity model constrained by local well data reveal that the seismicity concentrates between 1.5 and 2.5 km below ground in the Delaware Mountain Group, the primary wastewater disposal zone at this location. Waveform inversions for the moment tensor and focal depth independently confirm the shallow depths. The moment tensor solutions define critically stressed high-angle normal faults, suggesting a causal connection between injection and seismicity.

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The Delaware Basin is a giant oil and gas field in the Permian Basin, covering an extensive portion (22,000 km 2 ) of West Texas and southeastern New Mexico (Figure 1a inset). After being heavily exploited in the 20th century via conventional vertical production, 2009 brought a resurgence in oil and gas activity due to the development of organic rich shale beds using horizontal drilling and hydraulic fracturing (a.k.a. "unconventional") techniques. Similar to what has been observed in oil fields around the world, the Delaware Basin experienced an uptick in seismic activity coincident with unconventional development, leading many seismologists to infer those earthquakes were being induced by the development itself (e.g., Frohlich et al., 2016;Skoumal et al., 2020). Consequently, the state of Texas funded deployment of a regional seismic network, the TexNet array (Savvaidis et al., 2019), to better detect the regional seismicity and determine the underlying causes. The network has recorded thousands of small-to-moderate earthquakes in the Delaware Basin since its deployment in January 2017, including a M W 4.8 event on 26 March 2020 (Figure 1a). These events are mainly concentrated in the southeastern portion of the Delaware Basin in Reeves county, despite widespread oil and gas activity throughout the basin (Figure 1b).

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The 30 November 2022 earthquake near the town of Peace River (∼45 km ESE) is one of the largest documented (M L 5.6) in the history of Alberta (Figure 1), exceeded by the M W 5.4 14 March 2001 Dawson Creek event. The Peace River event was widely felt: ∼690 km SSE in the city of Calgary and ∼340 km WNW at Fort McMurray (NRCan ID: 20221130.0055; USGS ID: us6000j5n4). So far, no damage has been reported; likely because of the remote setting of the epicenter (Schultz et al., 2021b). Statements by the Alberta Energy Regulator (AER, 2022) asserted that this earthquake was not induced, but a natural tectonic event. This assertion was based on preliminary depth estimates and a presumed lack of nearby operations. Contrary to this, we argue that this event was most likely induced.Earthquakes induced by human activities are well documented (Ellsworth, 2013; and have been of growing concern. The Western Canada Sedimentary Basin (WCSB) has had a long history of seismicity related to petroleum development. First, an older history related to conventional resource exploitation techniques of production, secondary recovery (