Mauna Loa is the largest volcano on Earth in terms of volume and area covered and one of five volcanoes that form the Island of Hawaii in the U.S. state of Hawai?i in the Pacific Ocean. It is an active shield volcano, with a volume estimated at approximately 18,000 cubic miles, although its peak is about 120 feet (37 m) lower than that of its neighbors.The volcano has probably been erupting for at least 700,000 years. Mauna Loa’s most recent eruption occurred from March 24, 1984, to April 15, 1984. In view of the hazards it poses to population centers, Mauna Loa is part of the Decade Volcanoes program, which encourages studies of the most dangerous volcanoes.Mauna Loa is the world’s largest shield volcano in terms of area covered. Mauna Loa is shaped like a shield, because its lava is extremely fluid (it has low viscosity), and therefore although the eruptions are not so explosive, the fluidity speeds up the lava causing more fires and threat to the population.