Volcano Learning zone > Volcano Glossary
A Caldera is the near circular depression caused when a magma chamber is emptied by a volcanic eruption and collapses. If a large shallow magama chamber under the volcano dramatially erupts then the roof of the chamber will collapse forming a caldera. Crater Lake,Yellowstone and Santorini are good examples. An often rounded depression with a flat bottom and steep cliff sides will be left. A lake or sea may fill the depression. The volcano may grow to fill the caldera by forming a new cone or dome.