CalderasCaldera are subcircular depressions in volcanic areas, with a diameter of between about two and several tens of kilometres. The term has a late Latin origin, meaning ‘a pot for boiling’ (Shorter Oxford Dictionary), and was first introduced into the geological vocabulary (‘a deep cauldron-like cavity on the summit of a volcano’) when Leopold von Buch published his 1815 memoir of his visit to the Canary Islands. Large calderasCaldera types (basaltic shield, summit of composite cones, ash-flow or ignimbrite) are impressive volcanicVulcano volcano, Aeolian Islands, Italy landforms due to their size: 10–30 km in diameter, 500–1000 m in depth, surrounded by extensive aprons of ignimbrite covering hundreds to thousands of km2, as seen in satellite images.