I have a very interesting book on volcanoes. This book is written by Jeremy Caplan. He is a reporter for “Time” magazine. A volcano erupts when pressure builds up underground. Volcanoes can be active, dormant or extinct. Scientists who study volcanoes are called volcanologists. After years at rest volcanoes sometimes explode with sudden violence. The biggest volcano in the world is Mauna Loa in Hawaii. The mountain rises 30,000 feet above the ocean floor. The word volcano comes from Vulcan – the Roman God of fire. A volcano under the sea or ocean can lead to a Tsunami. And I know that much about my book of volcanoes.