A caldera is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcanic eruption. When large volumes of magma are erupted over a short time, structural support for the rock above the magma chamber is lost. The ground surface then collapses downward into the emptied or partially emptied magma chamber, leaving a massive depression at the surface (from one to dozens of kilometers in diameter).[1] Although sometimes described as a crater, the feature is actually a type of sinkhole, as it is formed through subsidence and collapse rather than an explosion or impact. Compared to the thousands of volcanic eruptions that occur each century, the formation of a caldera is a rare event, occurring only a few times per century.[2] Only seven caldera-forming collapses are known to have occurred between 1911 and 2016.[2] More recently, a caldera collapse occurred at Kīlauea, Hawaii in 2018.[3]

Mount Mazama's eruption timeline, an example of caldera formation

Share this article:

This article uses material from the Wikipedia article Caldera, and is written by contributors. Text is available under a CC BY-SA 4.0 International License; additional terms may apply. Images, videos and audio are available under their respective licenses.