A super volcano is a volcano that has the potential of creating more than 1,000 cubic kilometers of ash, pumice, and lava during a single eruption. Super volcanoes erupt very rarely and may go hundreds of thousands of years between eruptions.
Unlike smaller volcanoes, which form a cone, super volcanoes form a depression known as a caldera. The most recent eruption of a super volcano is thought to have occurred 27,000 years ago near the center of New Zealand's north island. Other super volcanoes can be found in Indonesia, Eastern California and Yellowstone National Park, which is thought to have had three eruptions in the past three million years.