Mauna Loa

Mauna Loa is the largest volcano on planet Earth. Its summit – the caldera of which is named Moku`aweoweo – extends 4 km above sea level. Below the water, its long submarine flanks descend another 5 km to the sea floor, which in turn is depressed by Mauna Loa’s great mass another 8 km. Scientists say this makes the volcano’s summit about 56,000 feet above its base. The massive volcano covers half of the Island of Hawai`i. 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. [USGS HVO]