Volcano Caldera - John Seach

Calderas are large volcanic depressions, roughly circular in shape, from 1 to 250 km in diameter.
Structures less than 1 km diameter are termed  maars, and those over 250 km volcanic depressions.

Ambrym volcano caldera is 12 km across. This photo shows Benbow
crater degassing from the edge of the caldera. The crater is 5 km away.

Examples of Calderas
Krakatau (Indonesia), Batur (Indonesia), Deception Island (Antarctica), Ambrym (Vanuatu).
 

Caldera
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