A volcanic crater lake is a lake in a crater that was formed by explosive activity or a collapse during a volcanic eruption .
41-630: Lake Albano (Italian: Lago Albano or Lago di Castel Gandolfo ) is a small volcanic crater lake in the Alban Hills of Lazio , at the foot of Monte Cavo , 20 km (12 mi) southeast of Rome . Castel Gandolfo , overlooking the lake, is the site of the Papal Palace of Castel Gandolfo . It hosted the canoeing and rowing events of the 1960 Summer Olympic Games that were held in Rome. The lane marking system developed for these events
82-409: A caldera, possibly an ash-flow caldera. The volcanic activity of Mars is concentrated in two major provinces: Tharsis and Elysium . Each province contains a series of giant shield volcanoes that are similar to what we see on Earth and likely are the result of mantle hot spots . The surfaces are dominated by lava flows, and all have one or more collapse calderas. Mars has the tallest volcano in
123-400: A diameter of 290 km (180 mi). The average caldera diameter on Mars is 48 km (30 mi), smaller than Venus. Calderas on Earth are the smallest of all planetary bodies and vary from 1.6–80 km (1–50 mi) as a maximum. The Moon has an outer shell of low-density crystalline rock that is a few hundred kilometers thick, which formed due to a rapid creation. The craters of
164-471: A magma chamber whose magma is rich in silica . Silica-rich magma has a high viscosity , and therefore does not flow easily like basalt . The magma typically also contains a large amount of dissolved gases, up to 7 wt% for the most silica-rich magmas. When the magma approaches the surface of the Earth, the drop in confining pressure causes the trapped gases to rapidly bubble out of the magma, fragmenting
205-601: A noticeable drop in temperature around the world. Large calderas may have even greater effects. The ecological effects of the eruption of a large caldera can be seen in the record of the Lake Toba eruption in Indonesia . At some points in geological time , rhyolitic calderas have appeared in distinct clusters. The remnants of such clusters may be found in places such as the Eocene Rum Complex of Scotland,
246-583: A permanent crater lake about 100 m (330 ft) in diameter at an elevation of 6,390 m (20,965 ft) on its eastern side. This is most likely the highest lake of any kind in the world. Due to their unstable environments, some crater lakes exist only intermittently. Caldera lakes in contrast can be quite large and long-lasting. For instance, Lake Toba ( Indonesia ) formed after its eruption around 75,000 years ago. At around 100 kilometres (62 mi) by 30 kilometres (19 mi) in extent and 505 metres (1,657 ft) deep at its deepest point, Lake Toba
287-453: A prophecy that illustrated the relationship between the level of its waters and either the safety or the fall of the town to the Romans. It foretold that as long as the waters of the lake remained high, Veii would be impregnable to the Romans. If the waters of the lake were scattered in an inland direction, Veii would fall; but if they were to overflow through the usual streams or channels toward
328-549: Is 1350 m long, 1.20 m wide and 2 m high. Five vertical access shafts are known and it runs 128 m below the surface. The exit was originally 13 m below the level of the lake, but today it is higher due to the lowering of the level. It begins about 500 m beyond the nymphaeum of Bergantino, and comes out on the other side in the Mole di Castel Gandolfo locality, where the water flow drove multiple watermills . According to Titus Livius , this feat of engineering
369-410: 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
410-516: Is commonly referred to as the Albano buoy system . In Roman times , it was known as Albanus Lacus and lay not far from the ancient city of Alba Longa . With a depth of about 170 m (560 ft), Lake Albano is the deepest in Lazio. The lake is 3.5 km (2.2 mi) long by 2.3 km (1.4 mi) wide, and was formed by the overlapping union of two volcanic craters, an origin indicated by
451-405: Is ejected, the emptied chamber is unable to support the weight of the volcanic edifice above it. A roughly circular fracture , the "ring fault", develops around the edge of the chamber. Ring fractures serve as feeders for fault intrusions which are also known as ring dikes . Secondary volcanic vents may form above the ring fracture. As the magma chamber empties, the center of the volcano within
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#1732772002676492-416: Is reached between the rates of incoming and outgoing water. Sources of water loss singly or together may include evaporation , subsurface seepage, and, in places, surface leakage or overflow when the lake level reaches the lowest point on its rim. At such a saddle location, the upper portion of the lake is contained only by its adjacent natural volcanic dam ; continued leakage through or surface outflow across
533-540: Is relatively young (1.25 million years old) and unusually well preserved, and it remains one of the best studied examples of a resurgent caldera. The ash flow tuffs of the Valles caldera, such as the Bandelier Tuff , were among the first to be thoroughly characterized. About 74,000 years ago, this Indonesian volcano released about 2,800 cubic kilometres (670 cu mi) dense-rock equivalent of ejecta. This
574-606: Is the largest crater lake in the world. While many crater lakes are picturesque, they can also be deadly. Gas discharges from Lake Nyos in Cameroon suffocated 1,800 people in 1986, and crater lakes such as Mount Ruapehu 's (New Zealand) often contribute to destructive lahars . Certain bodies of water, although their formation is directly related to volcanic activity, are not usually referred to as crater lakes, including: Caldera A caldera ( / k ɔː l ˈ d ɛr ə , k æ l -/ kawl- DERR -ə, kal- )
615-508: The San Juan Mountains of Colorado , where the 5,000 cubic kilometres (1,200 cu mi) Fish Canyon Tuff was blasted out in eruptions about 27.8 million years ago. The caldera produced by such eruptions is typically filled in with tuff, rhyolite , and other igneous rocks . The caldera is surrounded by an outflow sheet of ash flow tuff (also called an ash flow sheet ). If magma continues to be injected into
656-417: The Earth's volcanic activity (the other 40% is attributed to hotspot volcanism). Caldera structure is similar on all of these planetary bodies, though the size varies considerably. The average caldera diameter on Venus is 68 km (42 mi). The average caldera diameter on Io is close to 40 km (25 mi), and the mode is 6 km (3.7 mi); Tvashtar Paterae is likely the largest caldera with
697-683: The English term cauldron is also used, though in more recent work the term cauldron refers to a caldera that has been deeply eroded to expose the beds under the caldera floor. The term caldera was introduced into the geological vocabulary by the German geologist Leopold von Buch when he published his memoirs of his 1815 visit to the Canary Islands , where he first saw the Las Cañadas caldera on Tenerife , with Mount Teide dominating
738-514: The Moon have been well preserved through time and were once thought to have been the result of extreme volcanic activity, but are currently believed to have been formed by meteorites, nearly all of which took place in the first few hundred million years after the Moon formed. Around 500 million years afterward, the Moon's mantle was able to be extensively melted due to the decay of radioactive elements. Massive basaltic eruptions took place generally at
779-678: The San Juan Mountains of Colorado (formed during the Oligocene , Miocene , and Pliocene epochs) or the Saint Francois Mountain Range of Missouri (erupted during the Proterozoic eon). For their 1968 paper that first introduced the concept of a resurgent caldera to geology, R.L. Smith and R.A. Bailey chose the Valles caldera as their model. Although the Valles caldera is not unusually large, it
820-726: The Solar System, Olympus Mons , which is more than three times the height of Mount Everest, with a diameter of 520 km (323 miles). The summit of the mountain has six nested calderas. Because there is no plate tectonics on Venus , heat is mainly lost by conduction through the lithosphere . This causes enormous lava flows, accounting for 80% of Venus' surface area. Many of the mountains are large shield volcanoes that range in size from 150–400 km (95–250 mi) in diameter and 2–4 km (1.2–2.5 mi) high. More than 80 of these large shield volcanoes have summit calderas averaging 60 km (37 mi) across. Io, unusually,
861-411: The base of large impact craters. Also, eruptions may have taken place due to a magma reservoir at the base of the crust. This forms a dome, possibly the same morphology of a shield volcano where calderas universally are known to form. Although caldera-like structures are rare on the Moon, they are not completely absent. The Compton-Belkovich Volcanic Complex on the far side of the Moon is thought to be
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#1732772002676902-403: The bottom of the lake and gradually building up until suddenly releasing, causing the water to overflow. Around 395 BC, during the wars between Rome and Veii , a discharge tunnel was built crossing the crater walls. It served as an emissary to control flooding of the lake, and was a gigantic work given the modest means of the time. It is said that it was built by 30,000 men. The tunnel
943-587: The caldera atop Fernandina Island collapsed in 1968 when parts of the caldera floor dropped 350 metres (1,150 ft). Since the early 1960s, it has been known that volcanism has occurred on other planets and moons in the Solar System . Through the use of crewed and uncrewed spacecraft, volcanism has been discovered on Venus , Mars , the Moon , and Io , a satellite of Jupiter . None of these worlds have plate tectonics , which contributes approximately 60% of
984-413: The collapse of a volcano during an eruption. Lakes in maars fill medium-sized craters where an eruption deposited debris around a vent. Crater lakes form as the created depression, within the crater rim , is filled by water. The water may come from precipitation , groundwater circulation (often hydrothermal fluids in the case of volcanic craters) or melted ice . Its level rises until an equilibrium
1025-676: The collapsed magma chamber, the center of the caldera may be uplifted in the form of a resurgent dome such as is seen at the Valles Caldera , Lake Toba , the San Juan volcanic field, Cerro Galán , Yellowstone , and many other calderas. Because a silicic caldera may erupt hundreds or even thousands of cubic kilometers of material in a single event, it can cause catastrophic environmental effects. Even small caldera-forming eruptions, such as Krakatoa in 1883 or Mount Pinatubo in 1991, may result in significant local destruction and
1066-545: The dam can erode its included material, thus lowering lake level until a new equilibrium of water flow, erosion, and rock resistance is established. If the volcanic dam portion erodes rapidly or fails catastrophically, the occurrence produces a breakout or outburst flood. With changes in environmental conditions over time, the occurrence of such floods is common to all natural dam types. These lakes may become soda lakes , many of which are associated with active tectonic and volcanic zones. A well-known crater lake, which bears
1107-403: The emptied or partially emptied magma chamber, leaving a large depression at the surface (from one to dozens of kilometers in diameter). 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,
1148-498: The fact had been digging channels for a long time as recent archaeological finds confirm. There is a temporal coincidence between the conjuration of the prodigy and the works of derivation recommended by Palladius and Columella at the time of the canicula , when the waters are at their lowest. 41°45′0″N 12°39′54″E / 41.75000°N 12.66500°E / 41.75000; 12.66500 Volcanic crater lake Lakes in calderas fill large craters formed by
1189-464: 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". The term caldera comes from Spanish caldera , and Latin caldaria , meaning "cooking pot". In some texts
1230-467: The human species was reduced to approximately 5,000–10,000 people. There is no direct evidence, however, that either theory is correct, and there is no evidence for any other animal decline or extinction, even in environmentally sensitive species. There is evidence that human habitation continued in India after the eruption. Some volcanoes, such as the large shield volcanoes Kīlauea and Mauna Loa on
1271-429: The island of Hawaii , form calderas in a different fashion. The magma feeding these volcanoes is basalt , which is silica poor. As a result, the magma is much less viscous than the magma of a rhyolitic volcano, and the magma chamber is drained by large lava flows rather than by explosive events. The resulting calderas are also known as subsidence calderas and can form more gradually than explosive calderas. For instance,
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1312-484: The landscape, and then the Caldera de Taburiente on La Palma . A collapse is triggered by the emptying of the magma chamber beneath the volcano, sometimes as the result of a large explosive volcanic eruption (see Tambora in 1815), but also during effusive eruptions on the flanks of a volcano (see Piton de la Fournaise in 2007) or in a connected fissure system (see Bárðarbunga in 2014–2015). If enough magma
1353-561: The magma to produce a mixture of volcanic ash and other tephra with the very hot gases. The mixture of ash and volcanic gases initially rises into the atmosphere as an eruption column . However, as the volume of erupted material increases, the eruption column is unable to entrain enough air to remain buoyant, and the eruption column collapses into a tephra fountain that falls back to the surface to form pyroclastic flows . Eruptions of this type can spread ash over vast areas, so that ash flow tuffs emplaced by silicic caldera eruptions are
1394-476: The only volcanic product with volumes rivaling those of flood basalts . For example, when Yellowstone Caldera last erupted some 650,000 years ago, it released about 1,000 km of material (as measured in dense rock equivalent (DRE)), covering a substantial part of North America in up to two metres of debris. Eruptions forming even larger calderas are known, such as the La Garita Caldera in
1435-450: The ridge in its center, which rises to a height of 70 m (230 ft). Plutarch reports that in 406 BC the lake surged over the surrounding hills, despite there being no rain nor tributaries flowing into the lake to account for the rise in water level. The ensuing flood destroyed fields and vineyards before eventually pouring into the sea. It is thought to have been a limnic eruption caused by volcanic gases, trapped in sediment at
1476-462: The ring fracture begins to collapse. The collapse may occur as the result of a single cataclysmic eruption, or it may occur in stages as the result of a series of eruptions. The total area that collapses may be hundreds of square kilometers. Some calderas are known to host rich ore deposits . Metal-rich fluids can circulate through the caldera, forming hydrothermal ore deposits of metals such as lead, silver, gold, mercury, lithium, and uranium. One of
1517-613: The same name as the geological feature, is Crater Lake in Oregon . It is located in the caldera of Mount Mazama . It is the deepest lake in the United States with a depth of 594 m (1,949 ft). Crater Lake is fed solely by falling rain and snow, with no inflow or outflow at the surface, and hence is one of the clearest lakes in the world. The highest volcano in the world, 6,893-m (22,615-ft) Ojos del Salado in Chile , has
1558-551: The sea, this would be unfavourable to the Romans as well. Dumézil ascribed this story to the Roman custom of projecting religious legendary heritage onto history, considering it to be a festival myth aimed at giving relevance to an exceptional event which would have happened during the Neptunalia . This legend showed the scope of the powers hidden in waters and the religious importance of their control by man: Veientans too knowing
1599-653: The world's best-preserved mineralized calderas is the Sturgeon Lake Caldera in northwestern Ontario , Canada, which formed during the Neoarchean era about 2.7 billion years ago. In the San Juan volcanic field , ore veins were emplaced in fractures associated with several calderas, with the greatest mineralization taking place near the youngest and most silicic intrusions associated with each caldera. Explosive caldera eruptions are produced by
1640-452: Was incited by the Oracle of Delphi : the Roman victory against Veii would be possible only when the lake waters were channeled and used for irrigation. During Rome's war with Veii in 393 BC, the level of Lake Albano rose to an unusual height even in the absence of rain. This prodigy was believed to be relevant to the siege of Veii because a haruspex from Veii recited some lines of
1681-464: Was the largest known eruption during the ongoing Quaternary period (the last 2.6 million years) and the largest known explosive eruption during the last 25 million years. In the late 1990s, anthropologist Stanley Ambrose proposed that a volcanic winter induced by this eruption reduced the human population to about 2,000–20,000 individuals, resulting in a population bottleneck . More recently, Lynn Jorde and Henry Harpending proposed that