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Mauna Loa: a Sleepy Giant

In Hawaiian, Mauna Loa means Long Mountain. Mauna Loa is the largest volcano on earth. It extends nearly 56,000 feet from the base of the ocean. Scientists have recorded eruptions from Mauna Loa 33 times since 1843, making it one of the most active volcanoes in the world. Five of those eruptions reached the west coast of Hawaii, and one lava flow reached the sea on the southwest side of Hawaii in less than three hours.

Its most recent eruption was from March 24 to April 15 in 1984. Mauna Loa is due to erupt again. Scientists predict another eruption in the next few decades, possibly within the next few years. A United States Geological Scientist has said that evidence suggests Mauna Loa is, “on the verge of shifting to a period of long-lived l

Mauna Loa Monitoring

The United States Geological Survey Department publishes a bi-weekly report on the current status of Mauna Loa. You can read current and past conditions on the mountain at http://volcano.wr.usgs.gov/maunaloastatus.php.

To help limit the amount of damage and save lives during an eruption, scientists monitor four factors during an eruption- the location of the lava eruption, the rate of lava production, the lay of the land (specifically the steepness of the terrain), and the duration of the eruption.

Mauna Loa Facts and History

The lava produced by Mauna Loa is comprised of mostly basalt and very little silicon. This means that the lava flows are very fluid and less likely to erupt into the sky. The trickling lava contributes to the volcano’s gently sloping sides.

Every eruption elongates the Long Mountain. The most recent lava eruptions from Mauna Loa have not caused any loss of life, but in 1926 and again in 1950, Mauna Loa erupted and the lava destroyed several villages and villagers caught in the path of the lava. The modern day city of Hilo is built on top of old lava flows from this period.

In 1935, an eruption threatened the city of Hilo and five United States Air Force bombers dropped bombs in the lava’s path to help divert the lava flow away from Hilo. The eruption stopped just four miles short of reaching the city. About half of the eruptions occur from the volcano’s summit, while others emerge from fissures in the rift lines along the side of mountain.

Volcanologists, geologists, and scientists monitor Mauna Loa very closely for signs of an impending eruption. Because of Mauna Loa’s previous history of eruptions, it is very unlikely that anyone will be harmed during a future eruption, but property damage is unavoidable.