Editing Yellowstone National Park (section)

===Geysers and the hydrothermal system===
{{see also|List of Yellowstone geothermal features}}
{{Multiple image|total_width=330|align=right|direction=horizontal
|image1= Old faithful geyser 2015.jpg|caption1= [[Old Faithful]] erupts approximately every 90 minutes.
|image2= Steamboat Geyser Major Eruption in 2005.jpg|caption2= [[Steamboat Geyser]] is the world's largest active geyser.
}}

The most famous [[geyser]] in the park, and perhaps the world, is [[Old Faithful]] geyser, located in [[Upper Geyser Basin]]. [[Castle Geyser]], [[Lion Geyser]], [[Beehive Geyser]], [[Grand Geyser]] (the world's tallest predictable geyser), [[Giant Geyser]] (the world's most voluminous geyser), [[Riverside Geyser]] and numerous other geysers are in the same basin. The park contains the tallest active geyser in the world—[[Steamboat Geyser]] in the [[Norris Geyser Basin]]. A study that was completed in 2011 found that at least 1,283 geysers have erupted in Yellowstone. Of these, an average of 465 are active in a given year.<ref>{{cite conference |last1=Cross |first1=Jeff |title=How many geysers are found in Yellowstone? |conference=The 11th Biennial Scientific Conference on the Greater Yellowstone Ecosystem |date=October 8–10, 2012 |location=Mammoth Hot Springs Hotel, Yellowstone National Park, Wyoming }}</ref><ref>{{cite news |last=Lundquist |first=Laura |title=Dormant Yellowstone geyser erupts |newspaper=The Bozeman Daily Chronicle |date=August 2, 2013 |url=https://www.bozemandailychronicle.com/news/environment/dormant-yellowstone-geyser-erupts/article_b92f45b8-fb07-11e2-b4ea-0019bb2963f4.html |access-date=August 6, 2018 |archive-date=August 2, 2021 |archive-url=https://web.archive.org/web/20210802222245/https://www.bozemandailychronicle.com/news/environment/dormant-yellowstone-geyser-erupts/article_b92f45b8-fb07-11e2-b4ea-0019bb2963f4.html |url-status=live }}</ref> Yellowstone contains at least 10,000 [[Geothermal activity|geothermal features]] altogether, including [[geyser]]s, [[hot spring]]s, [[mudpot]]s, and [[fumarole]]s.<ref>{{cite web |url=https://pubs.usgs.gov/sir/2014/5137/pdf/sir2014-5137.pdf |title=Provisional Maps of Thermal Areas in Yellowstone National Park, based on Satellite Thermal Infrared Imaging and Field Observations |id=Scientific Investigations Report 2014–5137 |publisher=U.S. Department of the Interior, U.S. Geological Survey |first1=R. Greg |last1=Vaughan |first2=Henry |last2=Heasler |first3=Cheryl |last3=Jaworowski |first4=Jacob B. |last4=Lowenstern |first5=Laszlo P. |last5=Keszthely |year=2014 |page=6 |access-date=August 9, 2018 |archive-date=March 1, 2021 |archive-url=https://web.archive.org/web/20210301024440/https://pubs.usgs.gov/sir/2014/5137/pdf/sir2014-5137.pdf |url-status=live }}</ref> Over half of the world's geysers and hydrothermal features are concentrated in Yellowstone.<ref name="un">{{cite web |url=https://whc.unesco.org/en/list/28 |title=Yellowstone National Park |website=World Heritage Sites |publisher=UNESCO World Heritage Centre |date=April 23, 2007 |access-date=April 23, 2007 |url-status=live |archive-url=https://web.archive.org/web/20170224234321/https://whc.unesco.org/en/list/28 |archive-date=February 24, 2017 }}</ref><ref name=britannica/>

In May 2001, the [[U.S. Geological Survey]], Yellowstone National Park, and the [[University of Utah]] created the Yellowstone Volcano Observatory (YVO), a partnership for long-term monitoring of the geological processes of the Yellowstone Plateau volcanic field, for disseminating information concerning the potential hazards of this geologically active region.<ref name="yvo">{{cite web |url=http://volcanoes.usgs.gov/yvo/yvo.html |title=Information about the Yellowstone Volcano Observatory |website=Yellowstone Volcano Observatory |publisher=U.S. Geological Survey |date=February 2, 2007 |access-date=March 12, 2007 |url-status=live |archive-url=https://web.archive.org/web/20080514160440/http://volcanoes.usgs.gov/yvo/yvo.html |archive-date=May 14, 2008 }}</ref>
[[File:Albert_Bierstadt_-_Geysers_in_Yellowstone_(c.1881).jpg|alt=Geysers erupting vertically. Sunlight illuminating the one in the foreground and the breeze is blowing the steam and spray to the left.|thumb|[[Albert Bierstadt]], ''Geysers in Yellowstone'', 1881]]
In 2003, changes at the Norris Geyser Basin resulted in the temporary closure of some trails in the basin. New [[fumarole]]s were observed, and several geysers showed enhanced activity and increasing water temperatures. Several geysers became so hot that they were transformed into purely steaming features; the water had become superheated and they could no longer erupt normally.<ref name="geyserbasin">{{cite web |url=http://volcanoes.usgs.gov/yvo/2003/NorrisTherm03.html |title=Notable Changes in Thermal Activity at Norris Geyser Basin Provide Opportunity to Study Hydrothermal System |website=Yellowstone Volcano Observatory |publisher=U.S. Geological Survey |date=March 16, 2005 |access-date=March 12, 2007 |url-status=live |archive-url=https://web.archive.org/web/20120118013707/http://volcanoes.usgs.gov/yvo/2003/NorrisTherm03.html |archive-date=January 18, 2012 }}</ref> This coincided with the release of reports of a multiple year United States Geological Survey research project which mapped the bottom of Yellowstone Lake and identified a structural dome that had uplifted at some time in the past. Research indicated that these uplifts posed no immediate threat of a volcanic eruption, since they may have developed long ago, and there had been no temperature increase found near the uplifts.<ref name="uplift2">{{cite web |title=Frequently asked questions about recent findings at Yellowstone Lake |url=http://volcanoes.usgs.gov/yvo/new.html |url-status=live |archive-url=https://web.archive.org/web/20120204035350/http://volcanoes.usgs.gov/yvo/new.html |archive-date=February 4, 2012 |access-date=March 12, 2007 |website=Yellowstone Volcano Observatory |publisher=U.S. Geological Survey }}</ref> Most recently, in July 2024, a hydrothermal explosion occurred in Biscuit Basin.<ref>{{Cite web |date=July 24, 2024 |title=Surprise Yellowstone geyser eruption highlights little known hazard at popular park |url=https://apnews.com/article/yellowstone-park-hydrothermal-explosion-geyser-basin-17e575de4b9a22823d50f08086478a5b |access-date=September 10, 2024 |website=AP News |language=en |archive-date=September 10, 2024 |archive-url=https://web.archive.org/web/20240910234502/https://apnews.com/article/yellowstone-park-hydrothermal-explosion-geyser-basin-17e575de4b9a22823d50f08086478a5b |url-status=live }}</ref>

On March 10, 2004, a biologist discovered 5 dead bison which apparently had inhaled toxic geothermal gases trapped in the Norris Geyser Basin by a seasonal atmospheric inversion. This was closely followed by an upsurge in earthquake activity in April 2004.<ref name="news">{{cite web |url=http://volcanoes.usgs.gov/yvo/NewsArchive.html |title=Archive of Stories About the Yellowstone Volcanic System |website=Yellowstone Volcano Observatory |publisher=U.S. Geological Survey |date=February 2, 2007 |access-date=March 12, 2007 |archive-url=https://web.archive.org/web/20070210050433/http://volcanoes.usgs.gov/yvo/NewsArchive.html |archive-date=February 10, 2007 }}</ref> In 2006, it was reported that the Mallard Lake Dome and the Sour Creek Dome—areas that have long been known to show significant changes in their ground movement—had risen at a rate of {{convert|1.5|to|2.4|in|cm}} per year from mid–2004 through 2006. As of late 2007, the uplift has continued at a reduced rate.<ref>{{cite news |title=Earthquake Swarms at Yellowstone Continue |publisher=Inland Park News |date=December 19, 2008 |url=http://www.islandparknews.com/atf.php?sid=5600&current_edition=2008-12-19 |access-date=August 24, 2011 |url-status=dead |archive-url=https://web.archive.org/web/20130520181706/http://www.islandparknews.com/atf.php?sid=5600&current_edition=2008-12-19 |archive-date=May 20, 2013 }}</ref><ref>{{cite news |last=Smith |first=Robert B. |author2=Wu-Lung Chang |author3=Lee Siegel |title=Yellowstone rising: Volcano inflating with molten rock at record rate |work=Press release, University of Utah Public Relations |publisher=EurekAlert! (American Association for the Advancement of Science) |date=November 8, 2007 |url=http://www.eurekalert.org/pub_releases/2007-11/uou-yr103007.php |access-date=November 9, 2007 |url-status=live |archive-url=https://web.archive.org/web/20071115095510/http://www.eurekalert.org/pub_releases/2007-11/uou-yr103007.php |archive-date=November 15, 2007 }}</ref> These events inspired a great deal of media attention and speculation about the geologic future of the region. Experts responded to the conjecture by informing the public that there was no increased risk of a volcanic eruption in the near future.<ref>{{cite journal |last=Lowenstern |first=Jake |title=Truth, fiction and everything in between at Yellowstone |journal=Geotimes |date=June 2005 |url=http://www.agiweb.org/geotimes/june05/feature_supervolcano.html |access-date=March 12, 2007 |archive-date=February 3, 2019 |archive-url=https://web.archive.org/web/20190203211435/http://www.agiweb.org/geotimes/june05/feature_supervolcano.html |url-status=live }}</ref> These changes demonstrate the dynamic nature of the Yellowstone hydrothermal system.