The U.S. Geological Survey’s Hawaiian Volcano Observatory (HVO) reports that a small seismic swarm is ongoing beneath the summit of Mauna Loa volcano. Since 2 a.m. HST on Sept. 23, 2022, HVO has recorded over 38 earthquakes beneath the summit caldera region with most earthquakes in a cluster about 3.1 mi (5 km) wide and -1.2 to 0.6 mi (-2 to 1 km) below the surface. These earthquakes may result from changes in the magma storage system and/or may be part of normal re-adjustments of the volcano due to changing stresses within it. HVO continues to monitor Hawaiian volcanoes for any changes.
According to HVO Scientist-in-Charge Ken Hon, “Seismic activity beneath Mauna Loa has been gradually increasing over the past two months. Small earthquake swarms are considered a normal part of this increase in activity. Currently there are no indications that magma is moving toward the surface and other monitoring systems are displaying normal behavior. Levels of seismicity and deformation remain below those recorded during the winter of 2021. HVO will continue to closely monitor this activity and report any significant changes.”
EARTHQUAKE SWARM DESCRIPTION
- Magnitude Range: up to 2.7, https://earthquake.usgs.gov/earthquakes/eventpage/hv73149507
- Date and Time: Starting at 2 a.m. HST on September 23, 2022, and ongoing
- Location: beneath summit caldera region of Mauna Loa
- Depth: -1.2 to 0.6 mi (-2 to 1 km) below sea level
- Number of detected events: Over 38
INTENSITY OF EARTHQUAKES AND AFFECTED AREAS
- Potential Damage: No damage to buildings or infrastructure expected based on earthquake intensity
- Maximum Modified Mercalli Scale Intensity: I – Not felt except by a very few under especially favorable conditions. (https://www.usgs.gov/natural-hazards/earthquake-hazards/science/modified-mercalli-intensity-scale)
- Felt Reports: No felt reports for swarm (http://earthquake.usgs.gov/dyfi/)
- Felt Area: N/A
EARTHQUAKE MAPS AND ADDITIONAL INFORMATION
- USGS National Earthquake Information Center Latest Earthquakes Map website: https://earthquake.usgs.gov/earthquakes/map/
- USGS-HVO Interactive Earthquake Map of Hawaiʻi: https://www.usgs.gov/observatories/hawaiian-volcano-observatory/earthquakes
FIVE MOST RECENT MAGNITUDE 4 OR GREATER EARTHQUAKES IN HAWAII
- 2022 September 5—Magnitude 4.0—7 mi ( 12 km) ENE of Pāhala, Island of Hawaiʻi (https://earthquake.usgs.gov/earthquakes/eventpage/hv73132252)
- 2022 August 22—Magnitude 4.0— 6 mi (9 km) E of Pāhala, Island of Hawaiʻi (https://earthquake.usgs.gov/earthquakes/eventpage/hv73118317)
- 2022 July 27—Magnitude 4.6—27 mi (43 km) ESE of Nāʻālehu, Island of Hawaiʻi (https://earthquake.usgs.gov/earthquakes/eventpage/hv73089052/executive)
- 2022 May 22—Magnitude 4.7—2 mi (3 km) NW of Hōlualoa, Island of Hawaiʻi (https://earthquake.usgs.gov/earthquakes/eventpage/hv73019747/executive)
- 2022 April 15—Magnitude 4.6—6 mi (9 km) E of Pāhala, Island of Hawaiʻi (https://earthquake.usgs.gov/earthquakes/eventpage/hv72984552/executive)