U.S. Geological Survey - Hawaiian Volcano Observatory
Mauna Loa - Current Activity - Hazards - History
Mauna Loa is among Earth's most active volcanoes, having erupted 33 times since its first well-documented historical eruption in 1843. Its most recent eruption was in 1984. Mauna Loa is certain to erupt again, and we carefully monitor the volcano for signs of unrest. See current activity for a summary of our monitoring efforts.
| Hazards | Eruptive History |
Hawaiian Meaning
The Hawaiian name "Mauna Loa" means "Long Mountain." This name is
apt, for the subaerial part of Mauna Loa extends for about 120 km
from the southern tip of the island to the summit caldera and then
east-northeast to the coastline near Hilo.
Elev. Above Sea Level
4,170 m
13,680 ft
Area
5,271 km2
2,035 mi2
(50.5% of Hawai`i)
Volume
80,000 km3
19,000 mi3
Most Recent Eruption
March 24-April 15, 1984
Number of Historical Eruptions
33
Summit Caldera
Name: Moku`aweoweo, "Moku" refers to a coastal land section or
islet; "`aweoweo" is a type of red Hawaiian fish. Literal translation
is fish section (the red of the fish suggests red lava).
Estimated Age of Earliest Subaerial Eruptions
About 400,000 years ago
Estimated Age of First Eruption of Mauna Loa
Between 1,000,000 and 700,000 years before present
Hawaiian Volcano Stage
Shield-forming stage