Total Recorded Eruptions of Mauna Loa
Mauna Loa has erupted 34 times since its first well-documented eruption in 1843, according to the newest available public data from the U.S. Geological Survey. This makes it one of the most active volcanoes on Earth in terms of frequency and volume of lava output.
The 34 eruptions span nearly two centuries of systematic observation, with events ranging from relatively gentle lava flows to larger-scale episodes that have reached the coast. Each eruption is cataloged by the Hawaiian Volcano Observatory, which tracks seismic and ground-deformation data in real time.
Key Eruption Dates and Patterns
The most recent eruption began on November 27, 2022, and lasted about two weeks, marking the first eruption since 1984. Prior to that, Mauna Loa had erupted in 1975, 1950, 1940, and 1935, showing a pattern of intervals that vary from a few years to several decades.
Historical records indicate that eruptions have occurred at both the summit and the volcano's extensive rift zones. The 1950 eruption produced lava flows that reached the ocean within hours, while the 1984 event sent lava toward Hilo but stopped short of the city.
Monitoring, Data Sources, and Future Outlook
The USGS Hawaiian Volcano Observatory continuously monitors Mauna Loa using seismic networks, GPS stations, and satellite imagery. Data from these systems feed into public alert levels and eruption forecasts, helping officials and residents prepare for future events.
For the latest official updates, visit the USGS Mauna Loa page USGS Mauna Loa Volcano Updates. Additional scientific context on volcano monitoring and risk assessment can be found on the Global Volcanism Program site Smithsonian Global Volcanism Program.