Seismic Swarm S20130113.1: Analysis of Activity Near Volcano, Hawaii

A seismic swarm designated S20130113.1 occurred 8 km south-southeast of Volcano, Hawaii, on the Big Island. The sequence began at 03:12 on 13 January 2013 and concluded at 07:01 on 17 January 2013, lasting 99 hours and 48 minutes. During this period, 63 earthquakes were recorded.

The events were characterized by low to moderate magnitudes, with the largest reaching 3.1. Depths remained predominantly shallow, between 0 and 7 km, consistent with volcanic processes in the region. The swarm exhibited a typical pattern of clustered microseismicity, including multiple events exceeding magnitude 2.0 on 13, 14, 15, and 16 January. Notable peaks included a 3.1 magnitude quake at 14:28 on 13 January and several magnitude 2.8 events on 15 January. Overall, the activity reflected a gradual buildup and subsequent decline in event frequency and energy release.

This swarm took place within the tectonically active setting of Kilauea volcano, part of the Hawaiian hotspot chain. The Hawaiian Islands formed through prolonged volcanic activity as the Pacific plate moves over a mantle plume. Kilauea, one of the most active volcanoes on Earth, experiences frequent earthquake swarms driven by magma movement, dike propagation, and flank instability along its south flank. Such swarms commonly occur at depths of 1–5 km and serve as indicators of subsurface volcanic unrest rather than purely tectonic faulting.

Historical records maintained since 2000 document 33 similar swarms in the area. These occurred in the following yearly counts: three in 2000, one in 2001, eight in 2003, five in 2004, one in 2005, two in 2006, four in 2007, one in 2008, four in 2011, and four in 2012. This pattern underscores the recurrent nature of swarm activity linked to Kilauea’s persistent eruptive behavior and associated seismic hazards.

The 2013 swarm aligns with established volcanic seismicity models for the region. Shallow focal depths and a maximum magnitude below 4.0 suggest the events resulted from fluid migration or minor crustal adjustments rather than a major tectonic rupture. No significant surface deformation or eruptive activity was directly associated with this specific sequence based on contemporaneous monitoring.

References

USGS Hawaiian Volcano Observatory, Volcano Hazards Program reports on Kilauea seismicity.
Smithsonian Institution Global Volcanism Program, Kilauea volcano background and activity summaries.
USGS Earthquake Catalog for Hawaii region event verification.