MAUNA LOA VOLCANO (VNUM #332020)
19°28'30" N 155°36'29" W, Summit Elevation 13681 ft (4170 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW
ACTIVITY SUMMARY
Mauna Loa Volcano is not erupting. A small swarm of shallow seismicity, that began at 1:00 a.m. HST this morning, is occurring beneath the upper Ka‘ōiki seismic zone, under Mauna Loa’s southeast flank and northwest of Kīlauea's summit. Other Mauna Loa monitoring data streams remain stable and show no signs of increased activity.
OBSERVATIONS
On March 18, 2021, the U.S. Geological Survey’s Hawaiian Volcano Observatory (HVO) has recorded over 40 earthquakes beneath the upper Ka‘ōiki seismic zone, about 21 km (13 mi) WNW of Volcano. These earthquakes are occurring in a cluster about 2 km (1 mi) wide and 0.5–6 km (0.5–4 mi) below the surface.
The largest event in the sequence, so far, was a magnitude-3.5 earthquake, with the bulk of the events being less than magnitude-2 and not widely reported by residents. Reported felt events were described as weak shaking, with a maximum Intensity of II on the Modified Mercalli Intensity Scale.
Clustering of shallow earthquakes in this region does not mean an eruption is imminent. HVO has recorded shallow earthquakes in this area for many decades across several eruptive cycles at both Kīlauea and Mauna Loa. These earthquakes do not show any signs of magmatic involvement and are part of normal re-adjustments of the volcano due to changing stresses within it. Other monitoring data streams for Kīlauea and Mauna Loa, including ground deformation, gas, and imagery, show no signs of increased activity.
HVO continues to closely monitor geologic changes, seismicity, deformation, and gas emissions at Kīlauea and Mauna Loa Volcano’s. HVO will issue additional messages and alert level changes as warranted by changing activity.
For more information on earthquakes in the Kaʻōiki Pali area, please see the Volcano Watch article titled, “Why do swarms of earthquakes occur around the Ka‘ōiki Pali?” published by HVO scientists on March 1, 2012: https://www.usgs.gov/center-news/volcano-watch-why-do-swarms-earthquakes-occur-around-ka-iki-pali.
For information on recent earthquakes in Hawaii and eruption updates, visit the USGS Hawaiian Volcano Observatory website at https://www.usgs.gov/observatories/hawaiian-volcano-observatory.
MORE INFORMATION:
Mauna Loa activity summary also available by phone: (808) 967-8866
Other Hawaiian volcanoes summary also available by phone: (808) 967-8877
Subscribe to these messages: https://volcanoes.usgs.gov/vns2/
Mauna Loa webcam images: https://www.usgs.gov/volcanoes/mauna-loa/webcams
Mauna Loa photos/video: https://www.usgs.gov/volcanoes/mauna-loa/photo-video-chronology
Mauna Loa FAQs: https://volcanoes.usgs.gov/observatories/hvo/faq_maunaloa.html
Summary of volcanic hazards from eruptions: https://volcanoes.usgs.gov/observatories/hvo/hawaii_hazards.html
Recent earthquakes in Hawaiʻi (map and list): https://www.usgs.gov/observatories/hawaiian-volcano-observatory/earthquakes
Explanation of Volcano Alert Levels and Aviation Color Codes: https://www.usgs.gov/natural-hazards/volcano-hazards/about-alert-levels
CONTACT INFORMATION:
The Hawaiian Volcano Observatory is one of five volcano observatories within the U.S. Geological Survey and is responsible for monitoring volcanoes and earthquakes in Hawaiʻi.