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118-634: 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 (70 by 45 kilometers), and postcaldera lavas spill out a significant distance beyond

236-606: A ghost town ) and Fourpeaked Mountain in Alaska, which, before its September 2006 eruption, had not erupted since before 8000 BCE. Yellowstone Lake In winter, ice nearly 3 ft (0.91 m) thick covers much of the lake except where shallow water covers hot springs. The lake freezes over by early December and can remain frozen until late May or early June. The forest and valleys surrounding Yellowstone Lake had been populated with Native Americans since pre-historic times. Archeologists have found evidence of human presence in

354-484: A magma chamber below the surface. The process that forms volcanoes is called volcanism . On Earth, volcanoes are most often found where tectonic plates are diverging or converging , and because most of Earth's plate boundaries are underwater, most volcanoes are found underwater. For example, a mid-ocean ridge , such as the Mid-Atlantic Ridge , has volcanoes caused by divergent tectonic plates whereas

472-645: A subarctic climate ( Köppen Dfc ). Angling for Yellowstone cutthroat trout in Yellowstone Lake has been a popular pastime for both subsistence and recreation since the first explorers, surveyors and tourists visited the park. During the early days of fish stocking in Yellowstone (1890–1910), Atlantic Salmon , Mountain whitefish , and Rainbow trout were stocked in the lake; none of these introduced species survived. Today only native cutthroat and non-native lake trout and Longnose sucker exist in

590-404: A bit of which is excerpted below, Dr. Ferdinand V. Hayden described some of the explorations being conducted on the lake as follows: Yellowstone Lake, WY August 8th, 1871 - Dear Professor Baird, Your letters of June 6th and July 3rd were brought us from Fort Ellis by Lt. Doane who has just arrived to take command of our escort and accompany my party the remainder of the season ... We arrived at

708-462: A buffer that breaks apart the plume. Any heat from the plume that does make it to the surface is limited. Volcanic and tectonic actions in the region cause between 1,000 and 2,000 measurable earthquakes annually. Most are relatively minor, measuring magnitude 3 or weaker. Occasionally, numerous earthquakes are detected in a relatively short period of time, an event known as an earthquake swarm . In 1985, more than 3,000 earthquakes were measured over

826-437: A graduated spectrum, with much overlap between categories, and does not always fit neatly into only one of these three separate categories. The USGS defines a volcano as "erupting" whenever the ejection of magma from any point on the volcano is visible, including visible magma still contained within the walls of the summit crater. While there is no international consensus among volcanologists on how to define an active volcano,

944-422: A grasshopper bait. Two men could catch them faster than half a dozen could clean and get them ready for the frying pan. Caught in the open lake, their flesh was yellow; but in bays, where the water was strongly impregnated with chemicals, it was blood-red. Many of them were full of long white worms, woven across the interior of the body, and through to the skin on either side. These did not appear to materially affect

1062-534: A hundred or so lava extruding eruptions per million years, and "several to many" steam eruptions per century. The loosely defined term " supervolcano " has been used to describe volcanic fields that produce exceptionally large volcanic eruptions. Thus defined, the Yellowstone Supervolcano is the volcanic field that produced the latest three supereruptions from the Yellowstone hotspot; it also produced one additional smaller eruption, thereby creating

1180-417: A large caldera that was later partially filled by subsequent lava flows (see Yellowstone Caldera ). Part of this caldera is the 136 sq mi (350 km ) basin of Yellowstone Lake. The original lake was 200 ft (61 m) higher than the present-day lake, extending northward across Hayden Valley to the base of Mount Washburn . It is thought that Yellowstone Lake originally drained south into

1298-471: A magnitude 4.8 earthquake struck Yellowstone, the largest recorded there since February 1980. In February 2018, more than 300 earthquakes occurred, with the largest being a magnitude 2.9. The Lava Creek eruption of the Yellowstone Caldera, which occurred 640,000 years ago, ejected approximately 1,000 cubic kilometres (240 cu mi) of rock, dust and volcanic ash into the atmosphere. It

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1416-609: A magnitude of 3.9. Another swarm started in January 2010, after the Haiti earthquake and before the Chile earthquake . With 1,620 small earthquakes between January 17, 2010, and February 1, 2010, this swarm was the second-largest ever recorded in the Yellowstone Caldera. The largest of these shocks was a magnitude 3.8 that occurred on January 21, 2010. This swarm subsided to background levels by February 21. On March 30, 2014, at 6:34 AM MST ,

1534-443: A paper was published suggesting a new definition for the word 'volcano' that includes processes such as cryovolcanism . It suggested that a volcano be defined as 'an opening on a planet or moon's surface from which magma , as defined for that body, and/or magmatic gas is erupted.' This article mainly covers volcanoes on Earth. See § Volcanoes on other celestial bodies and cryovolcano for more information. The word volcano

1652-417: A period of several months. More than 70 smaller swarms were detected between 1983 and 2008. The USGS states these swarms are likely caused by slips on pre-existing faults rather than by movements of magma or hydrothermal fluids. In December 2008, continuing into January 2009, more than 500 earthquakes were detected under the northwest end of Yellowstone Lake over a seven-day span, with the largest registering

1770-580: A prismatic compass all around the Lake. A man stands on the shore with a compass and takes a bearing to the man in the Boat as he drops the lead, giving a signal at the time. Then a man in the Boat takes a bearing to the fixed point on the shore where the first man is located and thus the soundings will be located on the chart. Henry Elliot and Mr. Carrington have just left in our little boat, the Annie . [They] will make

1888-492: A serious decline in the cutthroat trout population and the National Park Service has an aggressive Lake trout eradication program on the lake. All lake trout caught by anglers must be killed. If the cutthroat trout isn’t protected from this invasive fish then ecologist predict that they could see a decline in surrounding birds and mammals that are natural predators to the cutthroat trout. The longnose sucker

2006-401: A substantial contribution to the development of geological sciences through history". The source of the Yellowstone hotspot is controversial. Some geoscientists hypothesize that the Yellowstone hotspot is the effect of an interaction between local conditions in the lithosphere and upper mantle convection . Others suggest an origin in the deep mantle ( mantle plume ). Part of the controversy

2124-499: A succession of explosive eruptions and less violent floods of basaltic lava . Together these eruptions have helped create the eastern part of the Snake River Plain (to the west of Yellowstone) from a once-mountainous region. At least a dozen of these eruptions were so massive that they are classified as supereruptions . Volcanic eruptions sometimes empty their stores of magma so swiftly that the overlying land collapses into

2242-524: A systematic sketch of the shore with all its indentations, with the banks down, indeed, making a complete topographical as well as a pictorial sketch of the shores as seen from the water, for a circuit--of at least 130 miles ... One of the islands has been explored. We have called it Stevenson's Island as he was undoubtedly the first human that ever set foot upon it ... Write at once. Yours Truly, F. V. Hayden, I will send you some Photographs soon. Between 1920 and 1937, multiple proposals were made to Congress and

2360-632: A volcano is largely determined by the composition of the lava it erupts. The viscosity (how fluid the lava is) and the amount of dissolved gas are the most important characteristics of magma, and both are largely determined by the amount of silica in the magma. Magma rich in silica is much more viscous than silica-poor magma, and silica-rich magma also tends to contain more dissolved gases. Lava can be broadly classified into four different compositions: Mafic lava flows show two varieties of surface texture: ʻAʻa (pronounced [ˈʔaʔa] ) and pāhoehoe ( [paːˈho.eˈho.e] ), both Hawaiian words. ʻAʻa

2478-555: A volcano is of a conical mountain, spewing lava and poisonous gases from a crater at its summit; however, this describes just one of the many types of volcano. The features of volcanoes are varied. The structure and behaviour of volcanoes depend on several factors. Some volcanoes have rugged peaks formed by lava domes rather than a summit crater while others have landscape features such as massive plateaus . Vents that issue volcanic material (including lava and ash ) and gases (mainly steam and magmatic gases) can develop anywhere on

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2596-465: A volcano that has experienced one or more eruptions that produced over 1,000 cubic kilometres (240 cu mi) of volcanic deposits in a single explosive event. Such eruptions occur when a very large magma chamber full of gas-rich, silicic magma is emptied in a catastrophic caldera -forming eruption. Ash flow tuffs emplaced by such eruptions are the only volcanic product with volumes rivalling those of flood basalts . Supervolcano eruptions, while

2714-532: A way that could be used as a geothermal power source. If enacted, the plan would cost about $ 3.46 billion. Brian Wilcox of the Jet Propulsion Laboratory observes that such a project could incidentally trigger an eruption if the top of the chamber is drilled into. Studies and analysis may indicate that the greater hazard comes from hydrothermal activity which occurs independently of volcanic activity. Over 20 large craters have been produced in

2832-739: Is a volcanic field of over 60 cinder cones. Based on satellite images, it has been suggested that cinder cones might occur on other terrestrial bodies in the Solar system too; on the surface of Mars and the Moon. Stratovolcanoes (composite volcanoes) are tall conical mountains composed of lava flows and tephra in alternate layers, the strata that gives rise to the name. They are also known as composite volcanoes because they are created from multiple structures during different kinds of eruptions. Classic examples include Mount Fuji in Japan, Mayon Volcano in

2950-441: Is an invasive fish that was believed to be introduced into the Yellowstone Lake in the late 1980s or early 1990s. With this foreign species in the Lake researchers have noticed a shift in the food chain. They have seen a rapid decline in the population of the cutthroat trout which in turn could cause other animal populations to start declining. One study found that the introduced longnose sucker competes with cutthroat trout for some of

3068-412: Is characterized by a rough, clinkery surface and is the typical texture of cooler basalt lava flows. Pāhoehoe is characterized by its smooth and often ropey or wrinkly surface and is generally formed from more fluid lava flows. Pāhoehoe flows are sometimes observed to transition to ʻaʻa flows as they move away from the vent, but never the reverse. More silicic lava flows take the form of block lava, where

3186-565: Is derived from the name of Vulcano , a volcanic island in the Aeolian Islands of Italy whose name in turn comes from Vulcan , the god of fire in Roman mythology . The study of volcanoes is called volcanology , sometimes spelled vulcanology . According to the theory of plate tectonics, Earth's lithosphere , its rigid outer shell, is broken into sixteen larger and several smaller plates. These are in slow motion, due to convection in

3304-430: Is exhibited via numerous geothermal vents scattered throughout the region, including the famous Old Faithful Geyser , plus recorded ground-swelling indicating ongoing inflation of the underlying magma chamber. The volcanic eruptions, as well as the continuing geothermal activity, are a result of a great plume of magma located below the caldera's surface. The magma in this plume contains gases that are kept dissolved by

3422-584: Is expressed using the volcanic explosivity index (VEI), which ranges from 0 for Hawaiian-type eruptions to 8 for supervolcanic eruptions. As of December 2022 , the Smithsonian Institution 's Global Volcanism Program database of volcanic eruptions in the Holocene Epoch (the last 11,700 years) lists 9,901 confirmed eruptions from 859 volcanoes. The database also lists 1,113 uncertain eruptions and 168 discredited eruptions for

3540-420: Is home to a large concentration of mammals. Whether that be large mammals such as bison, elk, or bighorn sheep there is a variety of different animals that are native to the Yellowstone area. On the other hand Yellowstone is also home to many smaller animals, and a few that are constantly around the lake are beavers, short tailed weasels, and river otters which have previously been mentioned. Yellowstone Lake has

3658-537: Is one of the several tuyas in the area of the Tuya River and Tuya Range in northern British Columbia. Tuya Butte was the first such landform analysed and so its name has entered the geological literature for this kind of volcanic formation. The Tuya Mountains Provincial Park was recently established to protect this unusual landscape, which lies north of Tuya Lake and south of the Jennings River near

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3776-407: Is opposite the channel of the river and five miles from the east shore; another is ten miles farther south, and two miles from the shore a mountain isle with a bold bluff all around to the water's edge. These islands doubtless have never been trodden by human footsteps, and still belong to the regions of the unexplored. We built a raft for the purpose of attempting to visit them, but the strong waves of

3894-522: Is the relatively sudden appearance of the hotspot in the geologic record. Additionally, the Columbia Basalt flows appeared at the same approximate time in the same place, prompting speculation that they share a common origin. As the Yellowstone hotspot traveled to the east and north, the Columbia disturbance moved northward and eventually subsided. An alternate theory to the mantle plume model

4012-471: Is typically low in silica, shield volcanoes are more common in oceanic than continental settings. The Hawaiian volcanic chain is a series of shield cones, and they are common in Iceland , as well. Lava domes are built by slow eruptions of highly viscous lava. They are sometimes formed within the crater of a previous volcanic eruption, as in the case of Mount St. Helens , but can also form independently, as in

4130-581: The 1980 Mount St. Helens eruption . The next biggest supereruption formed the Yellowstone Caldera (640,000 years ago) and produced the Lava Creek Tuff . The Henry's Fork Caldera (1.2 million years ago) produced the smaller Mesa Falls Tuff , but is the only caldera from the Snake River Plain–Yellowstone hotspot that is plainly visible today. Non-explosive eruptions of lava and less-violent explosive eruptions have occurred in and near

4248-617: The Cascade Volcanoes or the Japanese Archipelago , or the eastern islands of Indonesia . Hotspots are volcanic areas thought to be formed by mantle plumes , which are hypothesized to be columns of hot material rising from the core-mantle boundary. As with mid-ocean ridges, the rising mantle rock experiences decompression melting which generates large volumes of magma. Because tectonic plates move across mantle plumes, each volcano becomes inactive as it drifts off

4366-626: The Hawaiian hotspot is an example. Volcanoes are usually not created where two tectonic plates slide past one another. Large eruptions can affect atmospheric temperature as ash and droplets of sulfuric acid obscure the Sun and cool Earth's troposphere . Historically, large volcanic eruptions have been followed by volcanic winters which have caused catastrophic famines. Other planets besides Earth have volcanoes. For example, volcanoes are very numerous on Venus. Mars has significant volcanoes. In 2009,

4484-536: The International Union of Geological Sciences (IUGS) included "The Yellowstone volcanic and hydrothermal system" in its assemblage of 100 geological heritage sites around the world in a listing published in October 2022. The organization defines an IUGS Geological Heritage Site as "a key place with geological elements and/or processes of international scientific relevance, used as a reference, and/or with

4602-664: The Pacific Ocean via the Snake River . The lake currently drains north from its only outlet, the Yellowstone River , at Fishing Bridge. The elevation of the lake's north end does not drop substantially until LeHardy Rapids. Therefore, this spot is considered the actual northern boundary of Yellowstone Lake. Within a short distance downstream the Yellowstone River plunges first over the upper and then

4720-834: The landform and may give rise to smaller cones such as Puʻu ʻŌʻō on a flank of Kīlauea in Hawaii. Volcanic craters are not always at the top of a mountain or hill and may be filled with lakes such as with Lake Taupō in New Zealand. Some volcanoes can be low-relief landform features, with the potential to be hard to recognize as such and be obscured by geological processes. Other types of volcano include cryovolcanoes (or ice volcanoes), particularly on some moons of Jupiter , Saturn , and Neptune ; and mud volcanoes , which are structures often not associated with known magmatic activity. Active mud volcanoes tend to involve temperatures much lower than those of igneous volcanoes except when

4838-566: The lower falls and races north through the Grand Canyon of the Yellowstone . In the 1990s, geological research determined that the two volcanic vents, now known as " resurgent domes ", are rising again. From year to year, they either rise or fall, with an average net uplift of about one inch per year. During the period between 1923 and 1985, the Sour Creek Dome was rising. In the years since 1986, it has either declined or remained

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4956-474: The mantle rises toward the surface. The hotspot appears to move across terrain in the east-northeast direction, and is responsible for the eastern half of Idaho 's Snake River Plain , but in fact the hotspot is much deeper than the surrounding terrain and remains stationary while the North American plate moves west-southwest over it. Over the past 16.5 million years or so, this hotspot has generated

5074-761: The Department of the Interior to construct dams of various sizes at the Yellowstone Lake outlet or a few miles downstream. Montana and Wyoming politicians, the Army Corps of Engineers and lobbying groups in both states all had a variety of reasons to support the dams—flood control in the Yellowstone Valley, reclamation, or diversion of water over the continental divide to the Snake River. All the proposals and legislation were eventually defeated. In

5192-883: The Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes can also form where there is stretching and thinning of the crust's plates, such as in the East African Rift , the Wells Gray-Clearwater volcanic field , and the Rio Grande rift in North America. Volcanism away from plate boundaries has been postulated to arise from upwelling diapirs from the core–mantle boundary , 3,000 kilometres (1,900 mi) deep within Earth. This results in hotspot volcanism , of which

5310-622: The Philippines, and Mount Vesuvius and Stromboli in Italy. Ash produced by the explosive eruption of stratovolcanoes has historically posed the greatest volcanic hazard to civilizations. The lavas of stratovolcanoes are higher in silica, and therefore much more viscous, than lavas from shield volcanoes. High-silica lavas also tend to contain more dissolved gas. The combination is deadly, promoting explosive eruptions that produce great quantities of ash, as well as pyroclastic surges like

5428-613: The USGS defines a volcano as active whenever subterranean indicators, such as earthquake swarms , ground inflation, or unusually high levels of carbon dioxide or sulfur dioxide are present. The USGS defines a dormant volcano as any volcano that is not showing any signs of unrest such as earthquake swarms, ground swelling, or excessive noxious gas emissions, but which shows signs that it could yet become active again. Many dormant volcanoes have not erupted for thousands of years, but have still shown signs that they may be likely to erupt again in

5546-555: The West Thumb Geyser Basin. There is a "bulge" about 2,000 ft (610 m) long and 100 ft (30 m) high under a section of Yellowstone Lake, where there are a variety of faults, hot springs and small craters. Seismic imaging has recently shown that sediment layers are tilted, but how old this feature is has not yet been established. After the magma chamber under the Yellowstone area collapsed 640,000 years ago in its previous great eruption, it formed

5664-676: The West Thumb of Yellowstone Lake 174,000 years ago. The three supereruptions occurred 2.1 million, 1.3 million, and approximately 640,000 years ago, forming the Island Park Caldera , the Henry's Fork Caldera , and Yellowstone calderas, respectively. The Island Park Caldera supereruption (2.1 million years ago), which produced the Huckleberry Ridge Tuff , was the largest, and produced 2,500 times as much ash as

5782-582: The Yellowstone Caldera and the Lava Creek Tuff ). The caldera was the largest known until the discovery of Apolaki Caldera in 2019, which is more than twice as wide. Volcanism at Yellowstone is relatively recent, with calderas created by large eruptions that took place 2.1 million, 1.3 million, and 640,000 years ago. The calderas lie over the Yellowstone hotspot under the Yellowstone Plateau where light and hot magma (molten rock) from

5900-530: The Yellowstone River on September 24, 1869. They eventually followed the western shoreline to West Thumb before moving west to the geyser basins. Cook described the lake at Pelican Creek as follows: The main body is ten miles long from east to west and sixteen miles long from north to south, but at the south end it puts out two arms, one to the southeast and the other to the southwest, making the entire length about 30 miles ... There are three small islands which are also heavily timbered ... The shallow water in some of

6018-435: The Yellowstone caldera since the last supereruption. The most recent lava flow occurred about 70,000 years ago, while a violent eruption excavated the West Thumb of Lake Yellowstone 174,000 years ago. Smaller steam explosions occur as well. An explosion 13,800 years ago left a 5 km (3.1 mi) diameter crater at Mary Bay on the edge of Yellowstone Lake (located in the center of the caldera). Currently, volcanic activity

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6136-900: The Yellowstone hotspot. Progressively younger volcanic units, most grouped in several overlapping volcanic fields , extend from the Nevada – Oregon border through the eastern Snake River Plain and terminate in the Yellowstone Plateau. One such field, the Bruneau-Jarbidge volcanic field in southern Idaho , was formed between 10 and 12 million years ago, and the event dropped ash to a depth of one foot (30 cm) 1,000 miles (1,600 km) away in northeastern Nebraska and killed large herds of rhinoceroses , camels, and other animals at Ashfall Fossil Beds State Historical Park. The United States Geological Survey (USGS) estimates there are one or two major caldera-forming eruptions and

6254-464: The activity of many geysers and hot springs for several months afterward. In 2016, the USGS announced plans to map the subterranean systems responsible for feeding the area's hydrothermal activity. According to the researchers, these maps could help predict when another eruption occurs. Volcano 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

6372-479: The banks of the Yellow Stone Lake [ sic ] July 26th [actually July 28] and pitched our camp near the point where the river leaves the Lake. Hence we brought the first pair of wheels that ever came to the Lake with our Odometer. We launched the first Boat on the Lake, 4.5 feet wide and 11 feet long, with sails and oars ... A chart of this soundings will be made. Points have been located with

6490-406: The bottom of the lake, and the clear waters of the latter would roll 2,214 feet above its summit. With the single exception of Lake Titticaeca, Peru, it is the highest great body of water on the globe. No shells of any description are found on the lake shore, nor is there any evidence of the waters ever having stood at a much higher level than the present. Twenty-five feet will cover the whole range of

6608-510: The boundary with the Yukon Territory . Mud volcanoes (mud domes) are formations created by geo-excreted liquids and gases, although several processes may cause such activity. The largest structures are 10 kilometres in diameter and reach 700 meters high. The material that is expelled in a volcanic eruption can be classified into three types: The concentrations of different volcanic gases can vary considerably from one volcano to

6726-683: The caldera proper. The caldera formed during the last of three supereruptions over the past 2.1 million years: the Huckleberry Ridge eruption 2.1 million years ago (which created the Island Park Caldera and the Huckleberry Ridge Tuff ), the Mesa Falls eruption 1.3 million years ago (which created the Henry's Fork Caldera and the Mesa Falls Tuff ), and the Lava Creek eruption approximately 640,000 years ago (which created

6844-402: The case of Lassen Peak . Like stratovolcanoes, they can produce violent, explosive eruptions, but the lava generally does not flow far from the originating vent. Cryptodomes are formed when viscous lava is forced upward causing the surface to bulge. The 1980 eruption of Mount St. Helens was an example; lava beneath the surface of the mountain created an upward bulge, which later collapsed down

6962-426: The condition of the fish, which were apparently as active as the others. The Hayden Geological Survey of 1871 provided the most detailed and scientific descriptions of the lake in the pre-park era. The Hayden party, 34 men in all, encountered the lake at the outlet on July 28, 1871, spending two days there and returned to the lake at West Thumb on August 7, 1871. From West Thumb, the survey party took 15 days to explore

7080-676: The coves affords feeding ground for thousands of water fowl and we can take our choice of ducks, geese, trout, pelican or swan. The Washburn party was the first to describe the remote eastern and southern shorelines of the lake. From September 3, 1870, to September 17, 1870, the Washburn party traveled from the outlet of the lake around the northern, eastern, and southern shorelines to West Thumb 44°25′40″N 110°31′57″W  /  44.42778°N 110.53250°W  / 44.42778; -110.53250  ( West Thumb ) . The September 4, 1870 journal entry of Lieutenant Gustavus C. Doane ,

7198-507: The emptied magma chamber , forming a geographic depression called a caldera. The oldest identified caldera remnant straddles the border near McDermitt, Nevada–Oregon , although there are volcaniclastic piles and arcuate faults that define caldera complexes more than 60 km (37 mi) in diameter in the Carmacks Group of southwest-central Yukon , Canada, which are interpreted to have been formed 70 million years ago by

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7316-721: The enormous area they cover, and subsequent concealment under vegetation and glacial deposits, supervolcanoes can be difficult to identify in the geologic record without careful geologic mapping . Known examples include Yellowstone Caldera in Yellowstone National Park and Valles Caldera in New Mexico (both western United States); Lake Taupō in New Zealand; Lake Toba in Sumatra , Indonesia; and Ngorongoro Crater in Tanzania. Volcanoes that, though large, are not large enough to be called supervolcanoes, may also form calderas in

7434-698: The first detailed descriptions of the lake came in 1869, 1870 and 1871 as a result of the Cook–Folsom–Peterson Expedition , the Washburn-Langford-Doane Expedition and the Hayden Geological Survey of 1871 . Cook, Folsom and Peterson first encountered the lake near Pelican Creek 44°33′12″N 110°21′37″W  /  44.55333°N 110.36028°W  / 44.55333; -110.36028  ( Pelican Creek ) as they moved south along

7552-431: The flow is covered with angular, vesicle-poor blocks. Rhyolitic flows typically consist largely of obsidian . Tephra is made when magma inside the volcano is blown apart by the rapid expansion of hot volcanic gases. Magma commonly explodes as the gas dissolved in it comes out of solution as the pressure decreases when it flows to the surface . These violent explosions produce particles of material that can then fly from

7670-494: The foreseeable future. Recurrence intervals of these events are neither regular nor predictable." This conclusion was reiterated in December 2013 in the aftermath of the publication of a study by University of Utah scientists finding that the "size of the magma body beneath Yellowstone is significantly larger than had been thought". The Yellowstone Volcano Observatory issued a statement on its website stating: Although fascinating,

7788-610: The formation of a submarine volcano off the coast of Mayotte . Subglacial volcanoes develop underneath ice caps . They are made up of lava plateaus capping extensive pillow lavas and palagonite . These volcanoes are also called table mountains, tuyas , or (in Iceland) mobergs. Very good examples of this type of volcano can be seen in Iceland and in British Columbia . The origin of the term comes from Tuya Butte , which

7906-585: The future. In an article justifying the re-classification of Alaska's Mount Edgecumbe volcano from "dormant" to "active", volcanologists at the Alaska Volcano Observatory pointed out that the term "dormant" in reference to volcanoes has been deprecated over the past few decades and that "[t]he term "dormant volcano" is so little used and undefined in modern volcanology that the Encyclopedia of Volcanoes (2000) does not contain it in

8024-466: The glossaries or index", however the USGS still widely employs the term. Previously a volcano was often considered to be extinct if there were no written records of its activity. Such a generalization is inconsistent with observation and deeper study, as has occurred recently with the unexpected eruption of the Chaitén volcano in 2008. Modern volcanic activity monitoring techniques, and improvements in

8142-549: The hydrothermal explosion that formed Mary Bay. Further research shows that very distant earthquakes reach and have effects upon the activities at Yellowstone, such as the 1992 7.3 magnitude Landers earthquake in California 's Mojave Desert that triggered a swarm of quakes from more than 800 miles (1,300 km) away, and the 2002 7.9 magnitude Denali fault earthquake 2,000 miles (3,200 km) away in Alaska that altered

8260-450: The immense pressure under which the magma is contained. If the pressure is released to a sufficient degree by some geological shift, then some of the gases bubble out and cause the magma to expand. This can cause a chain reaction. If the expansion results in further relief of pressure, for example, by blowing crust material off the top of the chamber, the result is a very large gas explosion. According to analysis of earthquake data in 2013,

8378-492: The interior of a continent and lead to rifting. Early stages of rifting are characterized by flood basalts and may progress to the point where a tectonic plate is completely split. A divergent plate boundary then develops between the two halves of the split plate. However, rifting often fails to completely split the continental lithosphere (such as in an aulacogen ), and failed rifts are characterized by volcanoes that erupt unusual alkali lava or carbonatites . Examples include

8496-414: The lake dashed it to pieces in an hour. Numerous steam jets pour out from the bluffs on the shore at different points. The waters of the lake reflect a deep blue color, are clear as crystal, and doubtless of great depth near the center. The extreme elevation of this great body of water, 7,714 3/5 feet, is difficult to realize. Place Mount Washington, the pride of New England, with its base at the sea level, at

8614-417: The lake was probably visited by many trapping parties moving through the park region. In trapper Osborne Russell 's diary, he describes a visit to the lake in 1836 as follows: 16th [August] -Mr. Bridger came up with the remainder of the party. 18th-The whole camp moved down the east shore of the lake through thick pines and fallen timber about eighteen miles and encamped in a small prairie. 19th-continued down

8732-476: The lake with a Yellowstone Boating Permit. A Marina is operated at Bridge Bay and there is a boat ramp at Grant Village on the West Thumb. Areas in the southern arms of the lake are speed-restricted and/or no-motor zones to protect sensitive wildlife areas. Access to some of the lake's islands is also restricted. Xanterra Parks and Resorts at Bridge Bay Marina on Yellowstone Lake provides boat rentals and other boating services. Numerous outfitters operating outside

8850-533: The lake. Today, Yellowstone Lake is open for angling during the entire Yellowstone angling season (Memorial Day weekend thru Oct 31). All Cutthroat trout caught must be released. Recreational boating has been permitted on the lake in various forms since 1890 when the first permits for the Yellowstone Boat Company were issued to operate a ferry across the lake between road junctions. Today, powerboats, sailboats, canoes and kayaks are allowed on

8968-618: The land surface within the caldera moved upward as much as 8 inches (20 cm) at the White Lake GPS station. In January 2010, the USGS stated that "uplift of the Yellowstone Caldera has slowed significantly" and that uplift continues but at a slower pace. USGS, University of Utah and National Park Service scientists with the Yellowstone Volcano Observatory maintain that they "see no evidence that another such cataclysmic eruption will occur at Yellowstone in

9086-438: The leader of the U.S. Army escort during the expedition, describes the lake as follows: On the south side, these promontories project far into the lake in great numbers, dividing it into bays and channels. On the west side is a low bluff of the timbered ridges, with a sand beach in front along the margins of the waters. The greatest width of open water in any direction is about eighteen miles. Several islands are seen, one of which

9204-556: The magma chamber in two large influxes. An analysis of crystals from Yellowstone's lava showed that prior to the last supereruption, the magma chamber underwent a rapid increase in temperature and change in composition. The analysis indicated that Yellowstone's magma reservoir can reach eruptive capacity and trigger a super-eruption within just decades, not centuries as volcanologists had originally thought. In respect of it being "well-known for its past explosive volcanic eruptions and lava flows as well for its world class hydrothermal system",

9322-521: The magma chamber is 80 km (50 mi) long and 20 km (12 mi) wide. It also has 4,000 km (960 cu mi) underground volume, of which 6–8% is filled with molten rock. This is about 2.5 times bigger than scientists had previously imagined; however, scientists believe that the proportion of molten rock in the chamber is too low to allow for another supereruption. In October 2017, research from Arizona State University indicated prior to Yellowstone's last supereruption, magma surged into

9440-419: The mid-oceanic ridge is above sea level, volcanic islands are formed, such as Iceland . Subduction zones are places where two plates, usually an oceanic plate and a continental plate, collide. The oceanic plate subducts (dives beneath the continental plate), forming a deep ocean trench just offshore. In a process called flux melting , water released from the subducting plate lowers the melting temperature of

9558-492: The modelling of the factors that produce eruptions, have helped the understanding of why volcanoes may remain dormant for a long time, and then become unexpectedly active again. The potential for eruptions, and their style, depend mainly upon the state of the magma storage system under the volcano, the eruption trigger mechanism and its timescale. For example, the Yellowstone volcano has a repose/recharge period of around 700,000 years, and Toba of around 380,000 years. Vesuvius

9676-415: The most dangerous type, are very rare; four are known from the last million years , and about 60 historical VEI 8 eruptions have been identified in the geologic record over millions of years. A supervolcano can produce devastation on a continental scale, and severely cool global temperatures for many years after the eruption due to the huge volumes of sulfur and ash released into the atmosphere. Because of

9794-603: The most recent glacial retreat 13,000 years ago. Because the glacial till contains many different grain sizes, including clay and a thin layer of lake sediments, water cannot percolate readily into the ground. This is why the Hayden Valley is marshy and has little encroachment of trees. Non-native lake trout were discovered in Yellowstone Lake in 1994, and were believed to have been either accidentally or intentionally introduced as early as 1989 with fish taken from Lewis Lake . The introduction of Lake trout has caused

9912-438: The mud volcano is actually a vent of an igneous volcano. Volcanic fissure vents are flat, linear fractures through which lava emerges. Shield volcanoes, so named for their broad, shield-like profiles, are formed by the eruption of low-viscosity lava that can flow a great distance from a vent. They generally do not explode catastrophically but are characterized by relatively gentle effusive eruptions . Since low-viscosity magma

10030-534: The name Eustis Lake and the name Sublette 's Lake was also used to name the lake in the early 19th century. The name Yellowstone Lake appears formally first in the 1839 maps of the Oregon Territory by U.S. Army topographical engineer, Captain Washington Hood and has remained so since that time. Although many prospecting parties traversed the Yellowstone region throughout the 1850–60s,

10148-700: The new findings do not imply increased geologic hazards at Yellowstone, and certainly do not increase the chances of a 'supereruption' in the near future. Contrary to some media reports, Yellowstone is not 'overdue' for a supereruption. Media reports were more hyperbolic in their coverage. A study published in GSA Today , the monthly news and science magazine of the Geological Society of America , identified three fault zones where future eruptions are most likely to be centered. Two of those areas are associated with lava flows aged 174,000–70,000 years ago, and

10266-452: The next. Water vapour is typically the most abundant volcanic gas, followed by carbon dioxide and sulfur dioxide . Other principal volcanic gases include hydrogen sulfide , hydrogen chloride , and hydrogen fluoride . A large number of minor and trace gases are also found in volcanic emissions, for example hydrogen , carbon monoxide , halocarbons , organic compounds, and volatile metal chlorides. The form and style of an eruption of

10384-876: The north side of the mountain. Cinder cones result from eruptions of mostly small pieces of scoria and pyroclastics (both resemble cinders, hence the name of this volcano type) that build up around the vent. These can be relatively short-lived eruptions that produce a cone-shaped hill perhaps 30 to 400 metres (100 to 1,300 ft) high. Most cinder cones erupt only once and some may be found in monogenetic volcanic fields that may include other features that form when magma comes into contact with water such as maar explosion craters and tuff rings . Cinder cones may form as flank vents on larger volcanoes, or occur on their own. Parícutin in Mexico and Sunset Crater in Arizona are examples of cinder cones. In New Mexico , Caja del Rio

10502-549: The ocean surface as new islands or floating pumice rafts . In May and June 2018, a multitude of seismic signals were detected by earthquake monitoring agencies all over the world. They took the form of unusual humming sounds, and some of the signals detected in November of that year had a duration of up to 20 minutes. An oceanographic research campaign in May 2019 showed that the previously mysterious humming noises were caused by

10620-420: The ocean surface, due to the rapid cooling effect and increased buoyancy in water (as compared to air), which often causes volcanic vents to form steep pillars on the ocean floor. Hydrothermal vents are common near these volcanoes, and some support peculiar ecosystems based on chemotrophs feeding on dissolved minerals. Over time, the formations created by submarine volcanoes may become so large that they break

10738-471: The ocean's surface. In the deep ocean basins, the tremendous weight of the water prevents the explosive release of steam and gases; however, submarine eruptions can be detected by hydrophones and by the discoloration of water because of volcanic gases . Pillow lava is a common eruptive product of submarine volcanoes and is characterized by thick sequences of discontinuous pillow-shaped masses which form underwater. Even large submarine eruptions may not disturb

10856-468: The one that destroyed the city of Saint-Pierre in Martinique in 1902. They are also steeper than shield volcanoes, with slopes of 30–35° compared to slopes of generally 5–10°, and their loose tephra are material for dangerous lahars . Large pieces of tephra are called volcanic bombs . Big bombs can measure more than 1.2 metres (4 ft) across and weigh several tons. A supervolcano is defined as

10974-425: The overlying mantle wedge, thus creating magma . This magma tends to be extremely viscous because of its high silica content, so it often does not reach the surface but cools and solidifies at depth . When it does reach the surface, however, a volcano is formed. Thus subduction zones are bordered by chains of volcanoes called volcanic arcs . Typical examples are the volcanoes in the Pacific Ring of Fire , such as

11092-528: The park are licensed to provide boating services in the park. Several dozen backcountry campsites line the southern shoreline that is accessible only by boat. Two major hiking trails provide access to the lake shore away from the major road. The Nine Mile Post trail hugs the eastern shoreline into the Thorofare region and intersects with the Trail Creek and Heart Lake trails that touch the ends of both

11210-410: The park long before 1872. They found that Native Americans hunted bison and bighorn sheep , fished for cutthroat trout , and gathered bitterroot and camas bulbs for at least 11,000 years. Also 26 tribes claim cultural association with Yellowstone today. The first human of European descent to see the lake was trapper John Colter in the early 19th century. During the fur trading era of 1820–1840,

11328-418: The past 14,000 years, resulting in such features as Mary Bay, Turbid Lake , and Indian Pond, which was created in an eruption about 1300 BC. In a 2003 report, USGS researchers proposed that an earthquake may have displaced more than 77 million cubic feet (2,200,000 m; 580,000,000 US gal) of water in Yellowstone Lake, creating colossal waves that unsealed a capped geothermal system and led to

11446-619: The plume, and new volcanoes are created where the plate advances over the plume. The Hawaiian Islands are thought to have been formed in such a manner, as has the Snake River Plain , with the Yellowstone Caldera being part of the North American plate currently above the Yellowstone hotspot . However, the mantle plume hypothesis has been questioned. Sustained upwelling of hot mantle rock can develop under

11564-428: The same food sources. The declining population of cutthroat trout in the Yellowstone Lake can negatively impact fish predators. One in particular is the North American river otter which relies on the cutthroat fish as a prey. With a declining number of cutthroat trout in the spawning streams researchers saw a shift in the relationship between terrestrial and aquatic ecosystems that are linked together. Yellowstone

11682-435: The same time interval. Volcanoes vary greatly in their level of activity, with individual volcanic systems having an eruption recurrence ranging from several times a year to once in tens of thousands of years. Volcanoes are informally described as erupting , active , dormant , or extinct , but the definitions of these terms are not entirely uniform among volcanologists. The level of activity of most volcanoes falls upon

11800-492: The same way; they are often described as "caldera volcanoes". Submarine volcanoes are common features of the ocean floor. Volcanic activity during the Holocene Epoch has been documented at only 119 submarine volcanoes, but there may be more than one million geologically young submarine volcanoes on the ocean floor. In shallow water, active volcanoes disclose their presence by blasting steam and rocky debris high above

11918-482: The same. The resurgence of the Sour Creek dome, just north of Fishing Bridge is causing Yellowstone Lake to "tilt" southward. Larger sandy beaches can now be found on the north shore of the lake, and flooded areas can be found in the southern arms. The Hayden Valley was once filled by an arm of Yellowstone Lake. As a result, it contains fine-grained lake sediments that are now covered with glacial till left from

12036-401: The shore and on the west by a low bed of piney mountains. Its greatest width is about fifteen miles, lying in an oblong from south to north, or rather in the shape of a crescent. Near where we encamped were several hot springs which boiled perpetually. Near these was an opening in the ground about eight inches in diameter from which hot steam issued continually with a noise similar to that made by

12154-422: The shore to the outlet about twenty miles, and encamped in a beautiful plain { Hayden Valley } which extended along the northern extremity of the lake. This valley was interspersed with scattering groves of tall pines, forming shady retreats for the numerous elk and deer during the heat of the day. The lake is about 100 miles in circumference, bordered on the east by high ranges of mountains whose spurs terminate at

12272-622: The solidified erupted material that makes up the mantle of a volcano may be stripped away that its inner anatomy becomes apparent. Using the metaphor of biological anatomy , such a process is called "dissection". Cinder Hill , a feature of Mount Bird on Ross Island , Antarctica , is a prominent example of a dissected volcano. Volcanoes that were, on a geological timescale, recently active, such as for example Mount Kaimon in southern Kyūshū , Japan , tend to be undissected. Eruption styles are broadly divided into magmatic, phreatomagmatic, and phreatic eruptions. The intensity of explosive volcanism

12390-425: The southern and eastern flanks of the lake. On July 28, 1871, they launched Annie , the first European boat ever to sail on the lake and began exploring the islands and shoreline. Additionally, the first ever photographs of the lake were taken during this expedition by William Henry Jackson . In correspondence that was Hayden's Report No. 7 to Assistant Secretary of the Smithsonian Institution , Dr. Spencer Baird ,

12508-553: The southwest area of the lake, the West Thumb Geyser Basin is easily accessible to visitors. Geysers , fumaroles , and hot springs are found both alongside and in the lake. As of 2004, the ground under the lake has started to rise significantly, indicating increased geological activity, and limited areas of the national park have been closed to the public. As of 2005, no areas are currently off limits aside from those normally allowing limited access such as around

12626-410: The steam issuing from the safety valve of an engine, and could be heard five or six miles distant. The lake has been known by various names as depicted on early maps and in journals. Both fur trader David Thompson and explorer William Clark referred to the lake as Yellow Stone . Osborne Russell referred to the lake as Yellow Stone Lake in his 1834 journal. On some William Clark maps, the lake has

12744-406: The surrounding areas, and initially not seismically monitored before its unanticipated and catastrophic eruption of 1991. Two other examples of volcanoes that were once thought to be extinct, before springing back into eruptive activity were the long-dormant Soufrière Hills volcano on the island of Montserrat , thought to be extinct until activity resumed in 1995 (turning its capital Plymouth into

12862-434: The theory of plate tectonics. For example, some volcanoes are polygenetic with more than one period of activity during their history; other volcanoes that become extinct after erupting exactly once are monogenetic (meaning "one life") and such volcanoes are often grouped together in a geographical region. At the mid-ocean ridges , two tectonic plates diverge from one another as hot mantle rock creeps upwards beneath

12980-444: The thinned oceanic crust . The decrease of pressure in the rising mantle rock leads to adiabatic expansion and the partial melting of the rock, causing volcanism and creating new oceanic crust. Most divergent plate boundaries are at the bottom of the oceans, and so most volcanic activity on Earth is submarine, forming new seafloor . Black smokers (also known as deep sea vents) are evidence of this kind of volcanic activity. Where

13098-414: The third is a focus of present-day seismicity . In 2017, NASA conducted a study to determine the feasibility of preventing the volcano from erupting. The results suggested that cooling the magma chamber by 35 percent would be enough to forestall such an incident. NASA proposed introducing water at high pressure 10 kilometers underground. The circulating water would release heat at the surface, possibly in

13216-431: The underlying ductile mantle , and most volcanic activity on Earth takes place along plate boundaries, where plates are converging (and lithosphere is being destroyed) or are diverging (and new lithosphere is being created). During the development of geological theory, certain concepts that allowed the grouping of volcanoes in time, place, structure and composition have developed that ultimately have had to be explained in

13334-492: The volcano. Solid particles smaller than 2 mm in diameter ( sand-sized or smaller) are called volcanic ash. Tephra and other volcaniclastics (shattered volcanic material) make up more of the volume of many volcanoes than do lava flows. Volcaniclastics may have contributed as much as a third of all sedimentation in the geologic record. The production of large volumes of tephra is characteristic of explosive volcanism. Through natural processes, mainly erosion , so much of

13452-424: The volcanoes of the East African Rift . A volcano needs a reservoir of molten magma (e.g. a magma chamber), a conduit to allow magma to rise through the crust, and a vent to allow the magma to escape above the surface as lava. The erupted volcanic material (lava and tephra) that is deposited around the vent is known as a volcanic edifice , typically a volcanic cone or mountain. The most common perception of

13570-410: The water-marks. Its annual rise and falls are about two feet. Its waters abound with trout to such an extent that the fish at this season are in poor condition, for want of food. No other fish are seen; no minnows, and no small trout. There are also no clams, crabs, nor turtles -- nothing but full-grown trout. These could be caught in mule loads by wading out a few feet in the open waters at any point with

13688-513: Was Yellowstone's third and most recent caldera-forming eruption. Geologists closely monitor the elevation of the Yellowstone Plateau , which has been rising as quickly as 150 millimetres (5.9 in) per year, as an indirect measurement of changes in magma chamber pressure. The upward movement of the Yellowstone caldera floor between 2004 and 2008—almost 75 millimetres (3.0 in) each year—was more than three times greater than ever observed since such measurements began in 1923. From 2004 to 2008,

13806-421: Was described by Roman writers as having been covered with gardens and vineyards before its unexpected eruption of 79 CE , which destroyed the towns of Herculaneum and Pompeii . Accordingly, it can sometimes be difficult to distinguish between an extinct volcano and a dormant (inactive) one. Long volcano dormancy is known to decrease awareness. Pinatubo was an inconspicuous volcano, unknown to most people in

13924-521: Was proposed in 2018. It is suggested that the volcanism may be caused by upwellings from the lower mantle resulting from water-rich fragments of the Farallon plate descending from the Cascadia subduction region , sheared off at a subducted spreading rift. Others suggest that the mantle plume could not have been a dominant force in Yellowstone volcanism due to the sinking Farallon plate, as it acts as

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