CALDERAS

In rare occasions composite volcanoes can erupt so violently that the entire mountain can be destroyed. These eruptions form a hugh depression called a cadera. Caldera can reach a diameter of more than 25 kilometers and a depth of several kilometers. This is what geologists believe happened to form Crater Lake in Oregon. For a more detailed description of calderas you can click onto http://vulcan.wr.usgs.go...description_caldera.html.