Seismic Swarm S20250510.1: Prague, Oklahoma Region

A seismic swarm designated S20250510.1 occurred 8 km northwest of Prague, Oklahoma, from 06:53 on 9 May 2025 to 13:35 on 15 May 2025. Over 150 hours and 42 minutes, the sequence produced 113 earthquakes. Analysis of the first 100 events shows magnitudes ranging from -2.0 to 3.1, with the largest event recorded at 3.1 on 10 May 2025 at a depth of 3 km. Most events clustered at depths of 4–7 km, though isolated events reached 13 km. The majority registered below magnitude 1.0, indicating predominantly microseismic activity consistent with swarm behavior rather than a mainshock-aftershock sequence. The temporal distribution revealed an initial peak in activity on 10 May, followed by a gradual decline through 13 May. Shallow focal depths align with regional basement faulting in central Oklahoma, where fluid migration along pre-existing structures can trigger slip. No events exceeded magnitude 3.1 in the initial 100, suggesting limited energy release during the early phase. Central Oklahoma lies within the stable continental interior but has experienced elevated seismicity since the early 2000s, largely linked to wastewater injection associated with oil and gas production. The Prague area sits near mapped faults of the Nemaha Uplift and Wilzetta fault system, where induced events have historically occurred at depths of 3–8 km. Historical records document 13 swarms in the region since 1 January 2000, with notable increases in frequency during 2024 (10 swarms) compared to earlier isolated episodes in 2011, 2020, and 2023. This pattern reflects broader trends in induced seismicity across the Anadarko Basin and surrounding platforms. The May 2025 swarm fits within this established framework of episodic, low-magnitude clustering. Depths and magnitudes remain typical for fluid-induced events, with no indication of deeper tectonic involvement. Continued monitoring supports improved characterization of swarm recurrence in areas of ongoing subsurface fluid management. References:
USGS Earthquake Catalog (historical Oklahoma seismicity)
Oklahoma Geological Survey annual reports on induced seismicity
SeismoSight internal swarm classification S20250510.1