Mauna Loa is the largest subaerial and second largest overall volcano in the world (behind Tamu Massif), covering a land area of 5,271 km 2 (2,035 sq mi) and spans a maximum width of 120 km (75 mi). Mokuʻāweoweo, Mauna Loa's summit caldera, covered in snow. At 1 million to 600,000 years of age, Mauna Loa is the second youngest of the five volcanoes on the island, making it the third youngest volcano in the Hawaiian – Emperor seamount chain, a chain of shield volcanoes and seamounts extending from Hawaii to the Kuril–Kamchatka Trench in Russia. Kamaʻehuakanaloa (formerly Lōʻihi) on the island's flank is even younger, but has yet to breach the surface of the Pacific Ocean. The oldest volcano on the island, Kohala, is more than a million years old, and Kīlauea, the youngest, is believed to be between 210,000 and 280,000 years of age. Mauna Loa is one of five subaerial volcanoes that make up the island of Hawaiʻi. However, while the Hawaiian mantle plume is well understood and extensively studied, the nature of hotspots themselves remains fairly enigmatic. The prevailing view states that the hotspot has been largely stationary within the planet's mantle for much, if not all of the Cenozoic Era. The Hawaii island volcanoes are the most recent evidence of this process that, over 70 million years, has created the 3,700 mi (6,000 km)-long Hawaiian–Emperor seamount chain. Like all Hawaiian volcanoes, Mauna Loa was created as the Pacific tectonic plate moved over the Hawaii hotspot in the Earth's underlying mantle. Landsat mosaic recent lava flows appear in black Hawaii Volcanoes National Park covers the summit and portions of the southeastern and southwestern flanks of the volcano, and also incorporates Kīlauea, a separate volcano. Observations of the atmosphere are undertaken at the Mauna Loa Observatory, and of the Sun at the Mauna Loa Solar Observatory, both located near the mountain's summit. Mauna Loa has been monitored intensively by the Hawaiian Volcano Observatory since 1912. Because of the potential hazards it poses to population centers, Mauna Loa is part of the Decade Volcanoes program, which encourages studies of the world's most dangerous volcanoes. No recent eruptions of the volcano have caused fatalities, but eruptions in 19 destroyed villages, and the city of Hilo is partly built on lava flows from the late 19th century. Mauna Loa's most recent eruption occurred from March 24 to April 15, 1984. The slow drift of the Pacific Plate will eventually carry Mauna Loa away from the hotspot within 500,000 to one million years from now, at which point it will become extinct. The volcano's magma comes from the Hawaii hotspot, which has been responsible for the creation of the Hawaiian island chain over tens of millions of years. The oldest-known dated rocks are not older than 200,000 years. Mauna Loa has probably been erupting for at least 700,000 years, and may have emerged above sea level about 400,000 years ago. Lava eruptions from Mauna Loa are silica-poor and very fluid, and they tend to be non-explosive. It is an active shield volcano with relatively gentle slopes, with a volume estimated at 18,000 cubic miles (75,000 km 3), although its peak is about 125 feet (38 m) lower than that of its neighbor, Mauna Kea. The largest subaerial volcano (as opposed to subaqueous volcanoes) in both mass and volume, Mauna Loa has historically been considered the largest volcano on Earth, dwarfed only by Tamu Massif. ə/ Hawaiian: English: Long Mountain ) is one of five volcanoes that form the Island of Hawaii in the U.S.

Hawaii mauno loa