Popular volcanic mountain names are Mount St. Helens in the United States mainland, Mauna Loa in Hawaii, Mount Rainier in Washington, Mount Edziza in British Columbia and Hoodoo Mountain in Canada. Many of the highest volcanoes are located in Chile and Argentina, such as Ojos del Salado, Tacora, Tromen, Copahue and Risco Plateado.Know More
Earth is not the only planet with volcanoes. The planet Venus has too many volcanoes to name. Planetary bodies like Mercury and the Moon have volcanoes that have not been active for billions of years. Several satellites of the giant planets Jupiter and Saturn have volcanoes. The largest volcano in the Solar System is Olympus Mons on the planet Mars. It stands three times higher than the tallest mountain on Earth.
Volcanoes form when liquid rock from the Earth's mantle wells up and explodes in a shower of gas and lava. Over geological timescales, this lava solidifies and builds up to ever-increasing heights. Every time the pent-up gases in the mantle become too much, the rock melts and wells up to the surface in another explosion. On Earth, the sizes of volcanoes are limited by plate tectonics. On Mars, which has no moving continental plates, a volcano like Olympus Mons just keeps growing taller.Learn more about Volcanoes
Mount St. Helens has erupted numerous times in its 300,000-year history, most notably on May 18, 1980. While much of its early history remains a mystery, geologic studies have concluded that Mount St. Helens is the most active volcano in the Pacific Northwest.Full Answer >
Mauna Loa is the world's largest volcano and is located on the Big Island of Hawaii. While considered dormant, the volcano has erupted 33 times since its first recorded eruption in 1843, according to the U.S. Geological Survey, with the last eruption occurring in 1984.Full Answer >
Lava eruptions, from a plume of magma known as the Hawaiian hot spot, began the formation of Hawaii's Mauna Loa 600,000 to 1 million years ago. This plume of magma is responsible for the formation of the entire chain of Hawaiian islands. Continuously monitored as a potential threat to lives and property, Mauna Loa's last eruption was in 1984, when the lava flow came within four miles of the city of Hilo.Full Answer >
Mount Rainier's lava is either andesitic or basaltic. These lavas have formed features such as hexagonal columns and ridges and are mostly light to dark gray, although some areas are black or red.Full Answer >