A caldera is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcanic eruption. An eruption that ejects large volumes of magma over a short period of time can cause significant detriment to the structural integrity of such a chamber, greatly diminishing its capacity to support its own roof, and any substrate or rock resting above. The ground surface then collapses into the emptied or partially emptied magma chamber, leaving a large depression at the surface. 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 over the course of a century, the formation of a caldera is a rare event, occurring only a few times within a given window of 100 years. Only eight caldera-forming collapses are known to have occurred between 1911 and 2018, with a caldera collapse at Kīlauea, Hawaii in 2018. Volcanoes that have formed a caldera are sometimes described as "caldera volcanoes".
A supervolcano is a volcano that has had an eruption with a volcanic explosivity index (VEI) of 8, the largest recorded value on the index. This means the volume of deposits for such an eruption is greater than 1,000 cubic kilometers.
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. The process that forms volcanoes is called volcanism.
Long Valley Caldera is a depression in eastern California that is adjacent to Mammoth Mountain. The valley is one of the Earth's largest calderas, measuring about 20 mi (32 km) long (east-west), 11 mi (18 km) wide (north-south), and up to 3,000 ft (910 m) deep.
A fumarole is a vent in the surface of the Earth or another rocky planet from which hot volcanic gases and vapors are emitted, without any accompanying liquids or solids. Fumaroles are characteristic of the late stages of volcanic activity, but fumarole activity can also precede a volcanic eruption and has been used for eruption prediction. Most fumaroles die down within a few days or weeks of the end of an eruption, but a few are persistent, lasting for decades or longer. An area containing fumaroles is known as a fumarole field.
The Taupō Volcanic Zone (TVZ) is a volcanic area in the North Island of New Zealand. It has been active for at least the past two million years and is still highly active.
The Valles Caldera is a 13.7-mile (22.0 km) wide volcanic caldera in the Jemez Mountains of northern New Mexico. Hot springs, streams, fumaroles, natural gas seeps, and volcanic domes dot the caldera landscape. The highest point in the caldera is Redondo Peak, an 11,254-foot (3,430 m) resurgent lava dome located entirely within the caldera and surrounded by moat-like flows of rhyolitic solidified lavas.Located within the caldera are several grass valleys, or valles, the largest of which is Valle Grande, the only one accessible by a paved road. In 1975, Valles Caldera was designated as a National Natural Landmark by the National Park Service with much of the caldera being within the Valles Caldera National Preserve, a unit of the National Park System. The area has a varied history involving cultural significance, economic resources, scientific studies, and complex geological setting.
Extrusive rock refers to the mode of igneous volcanic rock formation in which hot magma from inside the Earth flows out (extrudes) onto the surface as lava or explodes violently into the atmosphere to fall back as pyroclastics or tuff. In contrast, intrusive rock refers to rocks formed by magma which cools below the surface.
The Yellowstone Caldera, sometimes referred to as the Yellowstone Supervolcano, is a volcanic caldera and supervolcano in Yellowstone National Park in the Western United States. The caldera and most of the park are located in the northwest corner of the state of Wyoming. The caldera measures 43 by 28 miles, and postcaldera lavas spill out a significant distance beyond the caldera proper.
The Rotorua Caldera is a large rhyolitic caldera that is filled by Lake Rotorua. It was formed by an eruption 240,000 years ago that produced extensive pyroclastic deposits. Smaller eruptions have occurred in the caldera since, the most recent less than 25,000 years ago. It is one of several large volcanoes in the Taupō Volcanic Zone on the North Island of New Zealand.
The Yellowstone hotspot is a volcanic hotspot in the United States responsible for large scale volcanism in Idaho, Montana, Nevada, Oregon, and Wyoming, formed as the North American tectonic plate moved over it. It formed the eastern Snake River Plain through a succession of caldera-forming eruptions. The resulting calderas include the Island Park Caldera, Henry's Fork Caldera, and the Bruneau-Jarbidge caldera. The hotspot currently lies under the Yellowstone Caldera. The hotspot's most recent caldera-forming supereruption, known as the Lava Creek Eruption, took place 640,000 years ago and created the Lava Creek Tuff, and the most recent Yellowstone Caldera. The Yellowstone hotspot is one of a few volcanic hotspots underlying the North American tectonic plate; another example is the Anahim hotspot.
The Lava Creek Tuff is a voluminous sheet of ash-flow tuff located in Wyoming, Montana and Idaho, United States. It was created during the Lava Creek eruption around 630,000 years ago, which led to the formation of the Yellowstone Caldera. This eruption is considered the climactic event of Yellowstone's third volcanic cycle. The Lava Creek Tuff covers an area of more than 7,500 km2 (2,900 sq mi) centered around the caldera and has an estimated magma volume of 1,000 km3 (240 cu mi).
La Garita Caldera is a large caldera and extinct supervolcano in the San Juan volcanic field in the San Juan Mountains around the town of Creede in southwestern Colorado, United States. It is west of La Garita, Colorado. The eruption that created the La Garita Caldera is among the largest known volcanic eruptions in Earth's history, as well as being one of the most powerful known supervolcanic events.
This timeline of volcanism on Earth includes a list of major volcanic eruptions of approximately at least magnitude 6 on the Volcanic explosivity index (VEI) or equivalent sulfur dioxide emission during the Quaternary period. Other volcanic eruptions are also listed.
Calabozos is a Holocene caldera in central Chile's Maule Region. Part of the Chilean Andes' volcanic segment, it is considered a member of the Southern Volcanic Zone (SVZ), one of the three distinct volcanic belts of South America. This most active section of the Andes runs along central Chile's western edge, and includes more than 70 of Chile's stratovolcanoes and volcanic fields. Calabozos lies in an extremely remote area of poorly glaciated mountains.
The Tengchong Volcanic Field (TVF) is a Cenozoic volcanic field located in the Southeastern margin of the Tibetan Plateau around 40 km from the Chinese border with Myanmar. The TVF is uniquely the only region affected by Quaternary volcanism that is part of the Himalayan Geothermal Belt caused by the Indo-Asian continent-continent collision. The TVF is characterized by hydrothermal activity and large-scale eruptions last recorded in 1609CE. Although the volcanoes themselves are considered extinct, several geothermal fields geographically linked to the TVF are still highly active. Evidence for geothermal activity can be linked to several prevalent active hot-springs located predominantly within the vicinity of the volcanoes in the TVF. Holocene eruptions occurred predominantly in the three largest volcanoes in the TVF named the Dayingshan, Maa'nshan and Heikongshan, the highest of which (Dayingshan) reaches 2865 meters above sea level. The volcanoes are distributed in a string-like pattern clustered from North to South in the middle on the Tengchong basin and are characterized by post-collisional high-Potassium (K) calc-alkaline series eruptions. The TVF provides unique geographical and geological knowledge as understanding the geological processes of creation provides insight into aspects such as the history of volcanism during the Quaternary Era in the region and as well as compositional information of its source and crustal assimilants. The TVF can be visited in the Tengchong Volcanic Geothermal National Geological Park.`
Much of the volcanic activity in the northern portions of the North Island of New Zealand is recent in geological terms and has taken place over the last 30 million years. This is primarily due to the North Island's position on the boundary between the Indo-Australian and Pacific Plates, a part of the Pacific Ring of Fire, and particularly the subduction of the Pacific Plate under the Indo-Australian Plate. The activity has included some of the world's largest eruptions in geologically recent times and has resulted in much of the surface formations of the North Island being volcanic as shown in the map.
