Seismic Swarm Near Carson City, Nevada: Analysis of the June 2013 Event

A seismic swarm designated S20130605.1 was recorded 6 km southeast of Carson City, Nevada. The sequence began at 03:08 on 5 June 2013 and concluded at 03:39 on 7 June 2013, spanning 48 hours and 31 minutes. During this period, 56 earthquakes were registered, with magnitudes ranging from -0.4 to 2.9 and focal depths primarily between 5 and 11 km.

The swarm exhibited typical characteristics of clustered microseismicity, featuring a rapid onset followed by a gradual decline in event frequency. The largest event reached magnitude 2.9 at 12:59 on 5 June at a depth of 9 km. Subsequent activity included multiple events between magnitudes 0.0 and 1.5, concentrated within the first 24 hours. Depths remained consistent across the sequence, indicating a shallow crustal source zone.

Carson City lies within the Basin and Range Province, where active extensional tectonics drive normal faulting and distributed seismicity. The region experiences ongoing crustal stretching between the stable Sierra Nevada block to the west and the Colorado Plateau to the east. This tectonic setting produces frequent small-magnitude earthquakes along range-front faults associated with the Carson Range.

Historical records maintained by SeismoSight indicate that only one prior swarm has occurred in the area since 1 January 2000, with the previous episode documented in 2005. The 2013 swarm aligns with this infrequent pattern, underscoring the episodic nature of seismic clustering in this portion of western Nevada.

No damage or felt reports were associated with the 2013 events, consistent with their low magnitudes. Such swarms provide valuable data for refining local fault models and improving understanding of strain accumulation in the northern Walker Lane belt.

References

SeismoSight internal swarm classification database.
Prompt data for Swarm S20130605.1.