Seismic Swarm S20140110.1 Near Spanish Springs, Nevada

Seismic swarm S20140110.1 was recorded beginning at 03:22 on 10 January 2014 and concluding at 12:54 on 15 January 2014. The events occurred 2 km NNE of Spanish Springs, Nevada, with a total of 169 earthquakes registered over 129 hours and 32 minutes.

Analysis of the first 100 events reveals predominantly low-magnitude activity concentrated at depths between 8 km and 13 km. Initial events on 10 January included magnitudes ranging from -0.4 to 2.2, with the majority below 1.0. A notable increase in activity occurred around 16:09 on 10 January, featuring several events above magnitude 1.0. The largest magnitude recorded in this subset reached 2.7 at 02:20 on 11 January, followed by continued small-magnitude events through the morning of 11 January. Depths remained consistent in the upper crust, suggesting activity along shallow fault structures without significant migration.

This swarm aligns with the broader seismic character of the region. Spanish Springs lies within the Basin and Range Province of western Nevada, where extensional tectonics produce numerous normal faults. The area experiences recurrent earthquake swarms due to fluid migration and stress interactions along these faults. Historical records indicate 15 swarms in the vicinity since 1 January 2000, with notable clusters in 2008 (6 events), 2012 (1 event), and 2013 (8 events). Such swarms typically consist of low-magnitude events that pose minimal surface hazard but provide valuable data on subsurface fault dynamics.

The consistent depth range observed supports models of brittle failure in the shallow crust typical of the northern Walker Lane belt. Ongoing monitoring by regional networks continues to track similar sequences, contributing to refined hazard assessments for the Reno-Sparks metropolitan area.

References

SeismoSight internal swarm classification records.
USGS Earthquake Hazards Program regional fault database.
Nevada Seismological Laboratory historical earthquake catalog.