Seismic Swarm S20230602.1 Near Cold Springs, Nevada

A notable earthquake swarm, designated S20230602.1, occurred 6 km south of Cold Springs, Nevada, from 12:42 on 1 June 2023 until 18:05 on 4 June 2023. Over 77 hours and 23 minutes, the sequence produced 45 events. The largest shock reached magnitude 3.7 at a depth of 7 km early on 2 June, followed by a magnitude 3.1 event minutes later at 6 km depth. Subsequent activity remained modest, with most events between magnitude 0.5 and 2.5 and focal depths clustered between 5 km and 9 km.

The swarm unfolded in distinct phases. Initial low-magnitude events on 1 June gave way to the two largest shocks shortly after midnight on 2 June. Activity then declined gradually, punctuated by occasional magnitude-2 events on 2 and 3 June, before tapering to a final magnitude-1.1 event on 4 June. Depths remained consistent with shallow crustal faulting typical of the region.

Cold Springs lies within the western Basin and Range province, where crustal extension along north-striking normal faults drives contemporary seismicity. The Reno–Carson City corridor sits near the transition between the Sierra Nevada and the Walker Lane belt, a zone of distributed dextral shear that accommodates a portion of Pacific–North America plate motion. This tectonic setting produces frequent earthquake swarms, often linked to fluid migration or aseismic slip on favorably oriented faults.

Historical records compiled since 1 January 2000 document 32 swarms in the immediate vicinity. Notable years include 2008 and 2013, each hosting seven and eight swarms respectively. Earlier clusters occurred in 2004, 2005, 2010, 2012, 2014–2016, 2018, and 2019. These recurrent swarms illustrate the persistent, low-level strain release characteristic of the northern Walker Lane.

The June 2023 sequence fits this established pattern. No damage or injuries were reported, consistent with the modest magnitudes and rural location. Continued monitoring by regional seismic networks remains essential for tracking strain accumulation along the active faults that bound the Sierra Nevada frontal system and adjacent basins.

References

Nevada Seismological Laboratory, University of Nevada, Reno.
U.S. Geological Survey Earthquake Hazards Program.
Nevada Bureau of Mines and Geology.