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Mauna Loa
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Mauna Loa
green NORMAL, 2026-04-02 18:36:46 UTC
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Rising gradually to more than 4 km (13,100 ft) above sea level, Mauna Loa is the largest active volcano on our planet.
Mauna Loa 2022 Eruption
Quick Facts
Location:
Island of Hawai‘i
Latitude:
19.475° N
Longitude:
155.608° W
Elevation:
4,169 (m) 13,679 (f)
Volcano type:
Shield
Composition:
Basalt
Most recent eruption:
Began Nov. 27, 2022
Nearby towns:
Hilo, Waikōloa, Ocean View, Captain Cook, Miloli‘i, Nā‘ālehu, Pāhala
Threat Potential:
Very High*
*based on the
National Volcano Early Warning System
Summary
Its long submarine flanks descend to the seafloor an additional 5 km (16,400 ft), and the seafloor in turn is depressed by Mauna Loa's great mass another 8 km (26,200 ft). This makes the volcano's summit about 17 km (55,700 ft) above its base! The enormous volcano covers half of the Island of Hawai‘i and by itself amounts to about 85 percent of the area of all the other Hawaiian Islands combined.
The Hawaiian name "Mauna Loa" means "Long Mountain." This name is apt, for the subaerial part of Mauna Loa extends for about 120 km (74 mi) from the southern tip of the island to the summit caldera and then east-northeast to the coastline near Hilo.
Mauna Loa is among Earth's most active volcanoes, having erupted 34 times since its first well-documented historical eruption in 1843. It has produced large, voluminous flows of basalt that have reached the ocean eight times since 1868. During the 1984 eruption, a lava flow came within 7.2 km (4.5 mi) of Hilo, the largest population center on the island. During the most recent eruption, in 2022, lava flows came to within 1.7 miles (2.8 kilometers) of the Daniel K. Inouye Highway (Saddle Road). Mauna Loa is certain to erupt again, and with such a propensity to produce large flows, we carefully monitor the volcano for signs of unrest.
Read our
Frequently Asked Questions about Mauna Loa
See the geonarrative,
Mauna Loa: Preparing for the next eruption of Earth's largest active volcano
Download Video
Sources/Usage: Public Domain.
View Media Details
Mauna Loa is Earth's largest active volcano and covers just over half of the Island of Hawaiʻi. It erupted most recently in November-December 2022, and it will erupt again. This video describes general hazards associated with Mauna Loa eruptions and how different areas on the Island of Hawaiʻi can be impacted by Mauna Loa lava flows on different timescales.
New open access articles on Mauna Loa 2022 eruption
April 8, 2026
New open access articles on Mauna Loa 2022 eruption
Volcano Watch — Mauna Loa has lessons to teach during quiet times
February 26, 2026
Volcano Watch — Mauna Loa has lessons to teach during quiet times
Photo & Video Chronology — December 23, 2025 — Mauna Loa overflight and Kīlauea episode 39
January 5, 2026
Photo & Video Chronology — December 23, 2025 — Mauna Loa overflight and Kīlauea episode 39
View All
October 22, 2018
2018 update to the U.S. Geological Survey national volcanic threat assessment
2018 update to the U.S. Geological Survey national volcanic threat assessment
When erupting, all volcanoes pose a degree of risk to people and infrastructure, however, the risks are not equivalent from one volcano to another because of differences in eruptive style and geographic location. Assessing the relative threats posed by U.S. volcanoes identifies which volcanoes warrant the greatest risk-mitigation efforts by the U.S. Geological Survey and its partners...
Authors
John W. Ewert, Angela K. Diefenbach, David W. Ramsey
By
Volcano Hazards Program
Volcano Science Center
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Weekly Update
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August 2, 2024
How are lava flows mapped in Hawaii?
Lava flow mapping provides situational awareness of volcanic eruptive hazards in Hawaii. During eruptions, USGS Hawaiian Volcano Observatory (HVO) scientists employ a variety of techniques to collect and disseminate map data depicting key eruptive features, especially lava flows.
By
Volcano Hazards Program
Volcano Science Center
Hawaiian Volcano Observatory
Kīlauea
Mauna Loa
How are lava flows mapped in Hawaii?
August 2, 2024
How are lava flows mapped in Hawaii?
Lava flow mapping provides situational awareness of volcanic eruptive hazards in Hawaii. During eruptions, USGS Hawaiian Volcano Observatory (HVO) scientists employ a variety of techniques to collect and disseminate map data depicting key eruptive features, especially lava flows.
July 8, 2024
1926 Eruption
Mauna Loa's recognized eruptive pattern is a summit eruption followed—within hours, days, or months—by a flank eruption. In 1926, there was a brief summit eruption, followed by 14 days of eruption on the Southwest Rift Zone.
By
Hawaiian Volcano Observatory
Mauna Loa
1926 Eruption
July 8, 2024
1926 Eruption
Mauna Loa's recognized eruptive pattern is a summit eruption followed—within hours, days, or months—by a flank eruption. In 1926, there was a brief summit eruption, followed by 14 days of eruption on the Southwest Rift Zone.
November 27, 2023
Monitoring Data for Mauna Loa
For more information on how electronic tiltmeters and GPS receivers help monitor the deformation of Kīlauea Volcano, see the HVO Deformation page.
By
Hawaiian Volcano Observatory
Mauna Loa
Monitoring Data for Mauna Loa
November 27, 2023
Monitoring Data for Mauna Loa
For more information on how electronic tiltmeters and GPS receivers help monitor the deformation of Kīlauea Volcano, see the HVO Deformation page.
View All
Quick Facts
Location:
Island of Hawai‘i
Latitude:
19.475° N
Longitude:
155.608° W
Elevation:
4,169 (m) 13,679 (f)
Volcano type:
Shield
Composition:
Basalt
Most recent eruption:
Began Nov. 27, 2022
Nearby towns:
Hilo, Waikōloa, Ocean View, Captain Cook, Miloli‘i, Nā‘ālehu, Pāhala
Threat Potential:
Very High*
*based on the
National Volcano Early Warning System
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