Yellowstone Caldera 1

Yellowstone Caldera

Yellowstone Caldera

The northeastern part of Yellowstone Caldera, with the Yellowstone River flowing through Hayden Valley and the calderarim in the distance

Elevation 10,308 ft (3,142 m) at Mount Sheridan

Location

Location Yellowstone National Park, Wyoming, USA

Range Rocky Mountains

Coordinates 44°24′N 110°42′W [1]Coordinates: 44°24′N 110°42′W [1]

Topo map USGS Yellowstone National Park

Geology

Type Caldera and supervolcano

Age of rock 640,000 years

Last eruption 1350 BC ± 200 years

Climbing

Easiest route Hike/auto/bus

The Yellowstone Caldera is the volcanic caldera and supervolcano located in Yellowstone National Park in theUnited States, sometimes referred to as the Yellowstone Supervolcano. The caldera is located in the northwestcorner of Wyoming, in which the vast majority of the park is contained. The major features of the caldera measureabout 34 by 45 miles (55 by 72 km).[2] The caldera formed during the last of three supereruptions over the past 2.1million years. First came the Huckleberry Ridge eruption 2.1 million years ago, which created the Island ParkCaldera and the Huckleberry Ridge Tuff. Next came the Mesa Falls eruption 1.3 million years ago, which created theHenry's Fork Caldera and the Mesa Falls Tuff. Finally came the Lava Creek eruption 640,000 years ago, whichcreated the Yellowstone Caldera and the Lava Creek Tuff.

Yellowstone Caldera 2

Volcanism

Yellowstone sits on top of four overlapping calderas. (US NPS)

Volcanism at Yellowstone is relativelyrecent with calderas that were created duringlarge eruptions that took place 2.1 million,1.3 million, and 640,000 years ago. Thecalderas lie over a hotspot where light, hot,molten rock from the mantle rises towardthe surface. While the Yellowstone hotspotis now under the Yellowstone Plateau, itpreviously helped create the eastern SnakeRiver Plain (to the west of Yellowstone)through a series of huge volcanic eruptions.The hotspot appears to move across terrainin the east-northeast direction, but in fact thehotspot is much deeper than terrain andremains stationary while the NorthAmerican Plate moves west-southwest overit.

Over the past 18 million years or so, this hotspot has generated a succession of violent eruptions and less violentfloods of basaltic lava. Together these eruptions have helped create the eastern part of the Snake River Plain from aonce-mountainous region. At least a dozen of these eruptions were so massive that they are classified assupereruptions. Volcanic eruptions sometimes empty their stores of magma so swiftly that they cause the overlyingland to collapse into 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 arevolcaniclastic piles and arcuate faults that define caldera complexes more than 60 km (37 mi) in diameter in theCarmacks Group of southwest-central Yukon, Canada, which is interpreted to have formed 70 million years ago bythe Yellowstone hotspot. Progressively younger caldera remnants, most grouped in several overlapping volcanicfields, extend from the Nevada-Oregon border through the eastern Snake River Plain and terminate in theYellowstone Plateau. One such caldera, the Bruneau-Jarbidge caldera in southern Idaho, was formed between 10 and12 million years ago, and the event dropped ash to a depth of one foot (30 cm) 1,000 miles (1,600 km) away innortheastern Nebraska and killed large herds of rhinoceros, camel, and other animals at Ashfall Fossil Beds StateHistorical Park. The USGS estimates there are one or two major caldera-forming eruptions and 100 or so lavaextruding eruptions per million years, and "several to many" steam eruptions per century.[3]

The loosely defined term 'supervolcano' has been used to describe volcanic fields that produce exceptionally largevolcanic eruptions. Thus defined, the Yellowstone Supervolcano is the volcanic field which produced the latest threesupereruptions from the Yellowstone hotspot; it also produced one additional smaller eruption, thereby creating WestThumb Lake[4] 174,000 years ago. The three super eruptions occurred 2.1 million, 1.3 million, and 640,000 yearsago, forming the Island Park Caldera, the Henry's Fork Caldera, and Yellowstone calderas, respectively.[5] TheIsland Park Caldera supereruption (2.1 million years ago), which produced the Huckleberry Ridge Tuff, was thelargest and produced 2,500 times as much ash as the 1980 Mount St. Helens eruption. The next biggest supereruptionformed 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 RiverPlain-Yellowstone (SRP-Y) hotspot that is plainly visible today.[6]

Non-explosive eruptions of lava and less-violent explosive eruptions have occurred in and near the Yellowstone caldera since the last supereruption. The most recent lava flow occurred about 70,000 years ago, while a violent

Yellowstone Caldera 3

eruption excavated the West Thumb of Lake Yellowstone around 150,000 years ago. Smaller steam explosions occuras well; an explosion 13,800 years ago left a 5 km (3.1 mi) diameter crater at Mary Bay on the edge of YellowstoneLake (located in the center of the caldera). Currently, volcanic activity is exhibited via numerous geothermal ventsscattered throughout the region, including the famous Old Faithful Geyser, plus recorded ground swelling indicatingongoing inflation of the underlying magma chamber.The volcanic eruptions, as well as the continuing geothermal activity, are a result of a great cove of magma locatedbelow the caldera's surface. The magma in this cove contains gases that are kept dissolved only by the immensepressure that the magma is under. If the pressure is released to a sufficient degree by some geological shift, thensome of the gases bubble out and cause the magma to expand. This can cause a runaway reaction. If the expansionresults in further relief of pressure, for example, by blowing crust material off the top of the chamber, the result is avery large gas explosion.According to the analysis of earthquake data in 2013, the magma chamber is 80 km (50 mi) long and 20 km (12 mi)wide, and is shaped like 4,000 km3 (960 cu mi) underground mass, of which 6–8% is filled with molten rock. This isabout 2.5 times bigger than scientists had previously imagined it to be.

Earthquakes

Number of earthquakes in Yellowstone NationalPark region (1973 – Sep 29, 2012)

Due to the volcanic and tectonic nature of the region, the YellowstoneCaldera experiences between 1000 and 2000 measurable earthquakes ayear. Most are relatively minor, measuring a magnitude of 3 or weaker.Occasionally, numerous earthquakes are detected in a relatively shortperiod of time, an event known as an earthquake swarm. In 1985, morethan 3000 earthquakes were measured over several months. More than70 smaller swarms have been detected between 1983 and 2008. TheUSGS states that these swarms could be caused more by slips onpre-existing faults than by movements of magma or hydrothermalfluids.

In December 2008, continuing into January 2009, more than 500quakes were detected under the northwest end of Yellowstone Lakeover a seven day span, with the largest registering a magnitude of 3.9.The most recent swarm started in January 2010 after the Haitiearthquake and before the Chile earthquake. With 1620 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 amagnitude 3.8 on January 21, 2010 at 11:16 PM MST. This swarm reached the background levels by 21 February.On March 30, 2014, at 6:34 AM MST, a magnitude 4.8 earthquake struck Yellowstone, the largest recorded theresince February 1980.

Volcanic hazards

Diagram of the Yellowstone Caldera

The last full-scale eruption of the Yellowstone Supervolcano, the LavaCreek eruption which happened nearly 640,000 years ago, ejectedapproximately 240 cubic miles (1,000 km3) of rock, dust and volcanicash into the sky.

Geologists are closely monitoring the rise and fall of the YellowstonePlateau, which measures on average 0.6 inches (1.5 cm) yearly, as anindication of changes in magma chamber pressure.

Yellowstone Caldera 4

The upward movement of the Yellowstone caldera floor between 2004 and 2008 — almost 3 inches (7.6 cm) eachyear — was more than three times greater than ever observed since such measurements began in 1923.[7] Frommid-summer 2004 through mid-summer 2008, the land surface within the caldera moved upward as much as 8inches (20 cm) at the White Lake GPS station. By the end of 2009, the uplift had slowed significantly and appearedto have stopped.[8] In January 2010, the USGS stated that "uplift of the Yellowstone Caldera has slowedsignificantly"[9] and that uplift continues but at a slower pace.[10] The U.S. Geological Survey, University of Utahand National Park Service scientists with the Yellowstone Volcano Observatory maintain that they "see no evidencethat another such cataclysmic eruption will occur at Yellowstone in the foreseeable future. Recurrence intervals ofthese events are neither regular nor predictable." This conclusion was reiterated in December 2013 in the aftermathof the publication of a study by University of Utah scientists finding that the "size of the magma body beneathYellowstone is significantly larger than had been thought." The Yellowstone Volcano Observatory issued astatement on its website stating,

Although fascinating, the new findings do not imply increased geologic hazards at Yellowstone, and certainlydo not increase the chances of a 'supereruption' in the near future. Contrary to some media reports,Yellowstone is not 'overdue' for a supereruption.

Other media reports were more hyperbolic in their coverage.A study published in GSA Today identified three fault zones that future eruptions are most likely to be centered on.Two of those areas are associated with lava flows aged 174,000–70,000 years, and the third area is a focus ofpresent-day seismicity.

Hydrothermal explosion hazard

Path of the Yellowstone hot spot over the past 16million years

Studies and analysis may indicate that the greater hazard comes fromhydrothermal activity which occurs independently of volcanic activity.Over 20 large craters have been produced in the past 14,000 years,resulting in such features as Mary Bay, Turbid Lake, and Indian Pondwhich was created in an eruption about 1300 BCE.In a 2003 report, USGS researchers proposed that an earthquake mayhave displaced more than 77 million cubic feet (2,200,000 m3)(576,000,000 US gallons) of water in Yellowstone Lake, creatingcolossal waves that unsealed a capped geothermal system leading intothe hydrothermal explosion that formed Mary Bay.

Further research shows that earthquakes from great distances do reach and have effects upon the activities atYellowstone, such as the 1992 7.3 magnitude Landers earthquake in California’s Mojave Desert that triggered aswarm of quakes from more than 800 miles (1,300 km) away and the 2002 7.9 magnitude Denali fault earthquake2,000 miles (3,200 km) away in Alaska that altered the activity of many geysers and hot springs for several monthsafterward.

Yellowstone hotspot originThe source of the Yellowstone hotspot is controversial. Some geoscientists hypothesize that the Yellowstone hotspotis the effect of an interaction between local conditions in the lithosphere and upper mantle convection. Otherssuggest a deep mantle origin (mantle plume).[11] Part of the controversy is due to the relatively sudden appearance ofthe hotspot in the geologic record. Additionally, the Columbia Basalt flows appeared at the same approximate time,causing speculation about their origin.

Yellowstone Caldera 5

References[1] http:/ / tools. wmflabs. org/ geohack/ geohack. php?pagename=Yellowstone_Caldera&

params=44_24_N_110_42_W_type:mountain_region:US& title=Yellowstone+ Caldera[2] as determined by geological field work conducted by Bob Christiansen of the United States Geological Survey in the 1960s and 1970s.[3] Yellowstone Volcanic Hazards, USGS (http:/ / volcanoes. usgs. gov/ volcanoes/ yellowstone/ yellowstone_hazard_42. html).

Volcanoes.usgs.gov (2012-03-01). Retrieved on 2013-12-31.[4] West Thumb Lake is not to be confused with West Thumb Geyser Basin. The caldera created West Thumb Lake, and the underlying

Yellowstone hotspot keeps West Thumb Geyser Basin active. See Fig. 22 (http:/ / www. cr. nps. gov/ history/ online_books/ geology/publications/ bul/ 1347/ sec3. htm). See also File:Yellowstone Caldera map2.JPG.

[5] Newhall, Christopher G.; Dzurisin, Daniel (1988) Historical Unrest at Large Calderas of the World (http:/ / pubs. er. usgs. gov/ publication/b1855): U.S. Geological Survey Bulletin 1855

[6][6] This qualitative statement is easily verified by reviewing the Yellowstone area in Google Earth[7] Molten Rock Fills Yellowstone Volcano at Record Rate (http:/ / newswise. com/ articles/ view/ 534941/ ) Newswise, Retrieved on September

2, 2008.[8] Alert Archive Search (http:/ / volcanoes. usgs. gov/ yvo/ activity/ archive/ 2009. php). volcanoes.usgs.gov[9] Current Alerts for U.S. Volcanoes (http:/ / volcano. wr. usgs. gov/ yvostatus. php). volcano.wr.usgs.gov[10] GPS Station: WLWY – Data Products – Time Series Plots (http:/ / web. archive. org/ web/ 20090405033306/ http:/ / pboweb. unavco. org/

shared/ scripts/ stations/ ?checkkey=WLWY& sec=timeseries_plots& timeseries=raw). unavco.org[11] See list of off-line references in mantleplumes.org/CRB.html (http:/ / www. mantleplumes. org/ CRB. html)

Further reading• Breining, Greg (2007). Super Volcano: The Ticking Time Bomb beneath Yellowstone National Park. St. Paul,

MN: Voyageur Press. ISBN 978-0-7603-2925-2. "A popularized scientific look at the Yellowstone area'sgeological past and potential future"

• Vazquez, J.A.; Reid, M.R. (2002). "Time scales of magma storage and differentiation of voluminous rhyolites atYellowstone caldera". Contributions to Mineralogy & Petrology (Wyoming) 144 (3): 274–285. Bibcode:2002CoMP..144..274V (http:/ / adsabs. harvard. edu/ abs/ 2002CoMP. . 144. . 274V). doi:10.1007/s00410-002-0400-7 (http:/ / dx. doi. org/ 10. 1007/ s00410-002-0400-7).

• Sutherland, Wayne; Sutherland, Judy (2003). Yellowstone Farewell. Spur Ridge. "A novel looking at an eruptionin the Yellowstone Caldera written by a practicing Wyoming geologist. Contains a wealth of technical details onthe geology of western Wyoming"

External links• The Snake River Plain and the Yellowstone Hot Spot (http:/ / volcano. oregonstate. edu/ vwdocs/ volc_images/

north_america/ yellowstone. html)• Yellowstone Volcano Observatory (http:/ / volcanoes. usgs. gov/ yvo/ )

• YVO FAQ relating to Supervolcano (http:/ / volcanoes. usgs. gov/ yvo/ about/ faq/ faqsupervolcano. php)• Supervolcano documentary (http:/ / www. bbc. co. uk/ sn/ tvradio/ programmes/ supervolcano/ index. shtml) from

BBC• Interactive: When Yellowstone Explodes (http:/ / ngm. nationalgeographic. com/ 2009/ 08/ yellowstone/

yellowstone-interactive) from National Geographic

Article Sources and Contributors 6

Article Sources and ContributorsYellowstone Caldera  Source: http://en.wikipedia.org/w/index.php?oldid=602514174  Contributors: A. di M., Adam Bishop, Aim Here, Alansohn, AlexiusHoratius, Anders Feder, AndroidMouse, Animum, Anthony Appleyard, Arctic Night, Arthena, Ary29, AstroHurricane001, Atif.t2, August Dominus, Avenue, Avoided, Awickert, Baa, Backspace, Bemoeial, Ben12345678910,BenKovitz, Bender235, Bennyboy 154, Bentley4, Bgwhite, BigDwiki, Blahblahblahblah25, Blu3d, Boing! said Zebedee, Bryan Derksen, Budelberger, Burntnickel, Burpen, CRGreathouse,Calabe1992, CanadianLinuxUser, Canderson7, CannedLizard, Capricorn42, CharlesC, Chris the speller, Chris.urs-o, Chrislk02, Chrono951, Corcs999, Cosmic Latte, CosmicPenguin, Courcelles,Craigsjones, Cst17, D6, DMacks, David Newton, DavidLeighEllis, Dawnseeker2000, Delirium, Delldot, Deluxejaylewis, Deor, DerHexer, Dermar130, Dfjdejulio, Djr xi, Dmarquard, Donner60,Download, Droll, Durin, Dycedarg, Eeekster, Ellenheather, Engelhardt, Epbr123, Epolk, Eras-mus, Ericoides, Escape Orbit, Etacar11, Eve Hall, Excirial, Exoplanetaryscience, Farry,Fauxcouture, Feline Hymnic, FourthAve, Fredrik, FreeKresge, Fxer, Fæ, GWhitewood, Gatemansgc, Geege0r, GeoGreg, Geogene, Geologyguy, George The Dragon, GeorgeBarnick, Ghdjb,Gilgamesh, GorillaWarfare, Grahamdubya, GregorB, Gro-Tsen, Gråbergs Gråa Sång, Guanlongwucaii, Gubernatoria, Gurch, HAl, HamburgerRadio, Hephaestos, Here, Hike395, Hmains,Horation12, Hydrogen Iodide, Hydrox, I was always all ways, IanOsgood, Icseaturtles, Illegitimate Barrister, Ivan Štambuk, Ixfd64, J.Voss, J.delanoy, JCDenton2052, JDspeeder1, Jackelfive,Jackfork, Jafeluv, Jaroslavleff, Jim1138, Jllm06, Jncraton, JoanneB, JohnMatzen, Jpopcon123321, Jrt989, Juanmantoya, Juliancolton, Julius Sahara, Jumbledupwords, K6ka, Kbh3rd, KelvinCase, Kerry7374, Kibi78704, Kielsky, Kkken, Krm500, Ktr101, Kyoko, Layth888, LibLord, LightandDark2000, Lightmouse, Liltman5424, LittleOldMe, Look2See1, MER-C, MONGO, Mahats, Malcolm, Malljaja, Marek69, Markunator, Materialscientist, Mathpianist93, Mav, Melba1, Mentifisto, Metrodyne, Michael Hardy, Mike Cline, Mike Rosoft, Mike Schwartz, Mikenorton,Mmcannis, Mojo Hand, MorrieD, Mplsbf, Mysteriosum, NCDane, NSK Nikolaos S. Karastathis, Neitherday, Neurolysis, Norm230395, NorthernFire, Npnunda, OlEnglish, Olan7allen, Pasado,Paulbat, Persian Poet Gal, PeterSymonds, Petrim, Peyre, Philip Trueman, Piano non troppo, Pinethicket, Polopolo1, Professor marginalia, R77xu, Radagast83, RadicalOne, Radon210, Raj 2 da k,Razorflame, RedWolf, Rickterp, Rjwilmsi, RobertMfromLI, Rockdoc63, Ronhjones, Rotational, Rrburke, Rwflammang, RyanGerbil10, Rémih, SEWilco, Safalra, Sam Hocevar,Satsriakaalpernji1, Scarian, Sceptre, Scott.wheeler, Sean.hoyland, Seanrowley132, Seaphoto, Seattle Skier, Senor Cuete, Serveux, Shawn in Montreal, Sidewinder666666, Skizzik, SkoreKeep,Snowolf, Sophie, Sozclarkey, SpellingGuru, Sstteevvee, StaticGull, Strickyn, Stwalkerster, SummerPhD, SuperLuigi31, Team4Technologies, Thatguyflint, The Thing That Should Not Be, Thewub, TheFeds, Theda, Theopolisme, Thetrellan, Tiddly Tom, Tide rolls, Tolly4bolly, Tom Morris, Tommy2010, Tr1290, Tristan Shale-Hester, Trollteck, Trusilver, TwoTwoHello, Tyleranstey,Ugog Nizdast, Uncle Dick, Useight, Vanished user 39948282, Veryhuman, Volcanoguy, Vranak, Vsmith, WBardwin, Wachholder0, Wadems, Wayne Slam, Wayward, Wetman, White Ash,Whoop whoop pull up, Widefox, Wiedemann, Wikipelli, Wombatcat, Woohookitty, Woozycorrection, Wsiegmund, WurmWoode, Xanzzibar, Xetrov znt, Xx3nvyxx, Xzildiln, Yellowdesk,Yintan, Youtube84, Zafiroblue05, Zarcadia, Zephalis, 769 anonymous edits

Image Sources, Licenses and ContributorsFile:Yellowstone River in Hayden Valley.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Yellowstone_River_in_Hayden_Valley.jpg  License: Public Domain  Contributors: EdAustin/Herb JonesImage:Yellowstone Caldera map2.JPG  Source: http://en.wikipedia.org/w/index.php?title=File:Yellowstone_Caldera_map2.JPG  License: Public Domain  Contributors: National Park Service.Image:Yellowstone earthquakes.JPEG  Source: http://en.wikipedia.org/w/index.php?title=File:Yellowstone_earthquakes.JPEG  License: Creative Commons Attribution 3.0  Contributors:Kelvin Case (talk)File:Yellowstone Caldera.svg  Source: http://en.wikipedia.org/w/index.php?title=File:Yellowstone_Caldera.svg  License: Public Domain  Contributors: Kbh3rdImage:HotspotsSRP.JPG  Source: http://en.wikipedia.org/w/index.php?title=File:HotspotsSRP.JPG  License: Creative Commons Attribution 3.0  Contributors: Kelvin Case (talk)

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