The Earth has about five thousand active underwater volcanoes. Some are really small, only the size of the average car. Others are larger and some have burst through the surface and have become islands. Hawaii is the best known example of a volcanic island created from an underwater volcano. The submerged part of the Hawaiian Islands is the largest volcanic ridges on Earth. It is more than 1,500 miles (2,400 kilometers) long. The entire volcanic ridge was created by a hot spot under the crust, probably as deep as 2000 miles underground. This "hot spot" is formed by magma (molten lava) punching through the crutal plate and erupting continuously for at least 70 million years to create the islands.
The Big Island of Hawaii is constructed of five shield volcanoes: Kilauea, Mauna Loa, Mauna Kea, Hualalai, and Kohala. Mauna Loa is the largest active volcano and most massive mountain on earth occupying an area of 10,000 cubic miles. Mauna Kea at 13,796 feet is the highest. Kilauea (4093 feet) is the youngest and one of the world's most active.
The Big Island of Hawaii is constructed of five shield volcanoes: Kilauea, Mauna Loa, Mauna Kea, Hualalai, and Kohala. Mauna Loa is the largest active volcano and most massive mountain on earth occupying an area of 10,000 cubic miles. Mauna Kea at 13,796 feet is the highest. Kilauea (4093 feet) is the youngest and one of the world's most active.