Caldera Mount Mazama 's eruption timeline, an example of caldera formation A caldera (/ kɔːlˈdɛrə, kæl -/ [1] kawl-DERR-ə, kal-) is a large cauldron -like hollow that forms shortly after the emptying of a magma chamber in a volcanic eruption. Caldera (noun, “Kal-DER-ah”) A caldera is a type of crater. It forms when a volcano collapses after a massive eruption. When volcanoes erupt, material bursts from underground cavities. That material could be lava. It could also be vapor, dust and gases. Either way, the blast leaves empty pockets underground. Sometimes, those pockets cave in. Here's a detailed explanation of their differences: Craters and calderas are both volcanic features, but they are formed in very different ways. A crater is a bowl-shaped depression at the top of a volcano, while a caldera is a much larger basin-shaped depression formed by the collapse of a volcano. A caldera is a large depression formed when a volcano erupts and collapses. During a volcanic eruption , magma present in the magma chamber underneath the volcano is expelled, often forcefully. When the magma chamber empties, the support that the magma had provided inside the chamber disappears. As a result, the sides and top of the volcano collapse inward. Calderas vary in size from one to. Calderas are both landforms that are parts of other volcanoes and a type of volcano in their own right. Resurgent calderas, the largest type of caldera, are not associated with any individual volcanic edifice, but are characterized by broad volcanic plateaus with voluminous ash-fall and pyroclastic-flow deposits (ignimbrites). Yellowstone Caldera Chronicles is a weekly column written by scientists and collaborators of the Yellowstone Volcano Observatory. This week's contribution is from Michael Poland, geophysicist with the U.S. Geological Survey and Scientist-in-Charge of the Yellowstone Volcano Observatory. What is a Caldera? Calderas are some of the most spectacular features on Earth. They are large volcanic craters that form by two different methods: 1) an explosive volcanic eruption; or, 2) collapse of surface rock into an empty magma chamber. The accompanying image is a satellite view of one of the most famous calderas - Crater Lake in Oregon. Crater Lake was formed about 7700 years ago when. Campi Flegrei, a volcanic caldera near Naples, is speeding toward a transition, a new study suggests, but there are still a lot of questions as to whether it will erupt in the near future. The meaning of CALDERA is a volcanic crater that has a diameter many times that of the vent and is formed by collapse of the central part of a volcano or by explosions of extraordinary violence. Did you know? Caldera, large bowl-shaped volcanic depression more than one kilometre in diameter and rimmed by infacing scarps. Calderas usually, if not always, form by the collapse of the top of a volcanic cone or group of cones because of removal of the support formerly furnished by an underlying body of magma.