For months after an eruption, dark skies, heavy rain and strong winds may be present90. Geysers rely on volcanic heat to heat trapped groundwater, which they then expel into the air91. Only 20-30 volcanoes erupt every year92. The Hawaiian goddess of fire and volcanoes, Pele, was said to have a terrible temper and would throw lava at anyone who angered her. It was said to live in the crater of the Kilauea volcano93. Stratovolcanoes are the most common type of volcanoes. Mount Fuji in Japan and Mount Rainer in Washington state are examples of stratovolcanoes94. About 20% of all existing volcanoes are underwater95. Black beaches, such as those in Hawaii and Iceland, have sand composed of basalt; formed when the lava cools it is broken into sand particles96. Geothermal energy uses the heat energy of magma to run power plants and heat water in some volcanic areas97. 10% of the world's active volcanoes are located in Japan98. The newest land mass on earth, Sutsey Island, was created in 1963 by an underwater volcano99. In Japan it is believed that illnesses can be cured by bathing in hot volcanic sand100. In 1865, the term "magma" was first used geologically to describe melting