The earth has more than 600 active volcanoes. Many of them are to be found on what is called the 'Ring of Fire' around the Pacific Ocean. The largest active volcano on the Earth today is the Mauna Lau, which is about 4168 metres (13,677 feet) high. It is situated in the Hawaiian islands. One volcanic explosion in Mauna Lau lasted for more than a year. Indonesia has more than 600 and Iceland has 200 volcanoes.