Seismic Swarm S20240313.1: Analysis of Activity Near Volcano, Hawaii
Seismic swarm S20240313.1 was recorded 10 km south-southwest of Volcano, Hawaii, beginning at 15:05 on 12 March 2024 and concluding at 07:19 on 19 March 2024. Over 160 hours and 14 minutes, the sequence produced 103 earthquakes. This event occurred in a region long recognized for recurrent seismic swarms driven by volcanic processes on the Big Island.
The Hawaiian Islands owe their existence to the Hawaiian hotspot, a mantle plume that has generated the archipelago over millions of years as the Pacific Plate moves northwestward. Volcano lies on the southeast flank of Kīlauea, one of the world's most active volcanoes. Magma movement, crustal stress changes, and occasional dike intrusions commonly trigger earthquake swarms in this setting. Depths in the provided events range from surface levels to approximately 36 km, with notable clusters near 0–5 km and 28–36 km, reflecting both shallow volcanic-tectonic activity and deeper processes associated with the volcanic system.
Analysis of the first 100 events shows magnitudes between 1.1 and 3.3. The strongest shocks reached 3.3 on 16 March at 31 km depth, followed by events of 3.2 and 2.9 later that day and on 15 March. Shallow events (depths of 0–7 km) dominated the initial phase on 12–13 March, while deeper events (28–36 km) became more frequent from 14 March onward. Multiple events occurred within seconds of each other on several occasions, indicating rapid stress release typical of swarm sequences rather than mainshock-aftershock patterns.
Historical records document 108 swarms in the region since 1 January 2000. Annual counts have varied, with notable increases in recent years: 14 swarms in 2020, 11 in 2021, 22 in 2023, and two already recorded in 2024. Earlier decades showed lower frequencies, such as three in 2000 and six each in 2003 and 2004. This long-term pattern underscores the persistent volcanic-tectonic environment around Kīlauea.
The March 2024 swarm fits within established geological behavior of the area, where swarms often reflect magma migration or pressure changes without necessarily leading to surface eruptions. Continued monitoring by seismic networks remains essential for interpreting future activity in this dynamic volcanic setting.
References
- SeismoSight internal swarm classification data (S20240313.1 parameters and event list)
- U.S. Geological Survey Hawaiian Volcano Observatory summaries on Kīlauea seismicity and regional tectonics