Grand Prismatic Spring
{{Use mdy dates|date=September 2024}}
{{Use American English|date=September 2024}}
{{Short description|Largest hot spring in the United States}}{{Infobox hot spring
| name = Grand Prismatic Spring
| photo = Aerial image of Grand Prismatic Spring (view from the south).jpg
| photo_width =
| photo_caption = Aerial view of the Grand Prismatic Spring
| location = Midway Geyser Basin, Yellowstone National Park, Teton County, Wyoming
| coordinates = {{Wikidatacoord|Q1422831|region:US-WY_type:waterbody|display=inline,title}}
| coords_ref = {{cite rcn|5748|Grand Prismatic Spring }}
| elevation = {{cvt|7270|ft}}{{cite gnis|1609256|Grand Prismatic Spring }}
| hot_spring_type = Hot spring
| height =
| duration =
| frequency =
| discharge = {{cvt|560|USgal|L|-2}} per minute
| temperature = {{cvt|160|F|C|-1}}
| depth = {{cvt|160|ft|m|-1}}
}}
The Grand Prismatic Spring in Yellowstone National Park is the largest hot spring in the United States, and the third largest in the world,{{cite web |title=Steam Explosions, Earthquakes, and Volcanic Eruptions—What's in Yellowstone's Future? |publisher=U.S. Geological Survey |url=http://pubs.usgs.gov/fs/2005/3024/ |access-date=September 14, 2005 |archive-date=July 23, 2018 |archive-url=https://web.archive.org/web/20180723093212/https://pubs.usgs.gov/fs/2005/3024/ |url-status=live }} after Frying Pan Lake in New Zealand and Boiling Lake in Dominica. It is located in the Midway Geyser Basin.
Grand Prismatic Spring was noted by geologists working in the Hayden Geological Survey of 1871, and named by them for its striking coloration. Its colors match most of those seen in the rainbow dispersion of white light by an optical prism: red, orange, yellow, green, and blue.{{Cite web |url=http://www.lpi.usra.edu/education/fieldtrips/2007/explorations/grand_prismatic/index.html |title=Grand Prismatic Spring |author1=Traci Bryan |author2=Leslie Machen |author3=Joyce Heinsz |author4=Peggy McCracken |publisher=Lunar and Planetary Institute |access-date=December 4, 2015 |archive-date=March 3, 2016 |archive-url=https://web.archive.org/web/20160303214633/http://www.lpi.usra.edu/education/fieldtrips/2007/explorations/grand_prismatic/index.html |url-status=live }}
History
The first records of the spring are from early European explorers and surveyors. In 1839, a group of four trappers from the American Fur Company crossed the Midway Geyser Basin and made note of a "boiling lake", most likely the Grand Prismatic Spring,{{cite book |chapter="The Fire Hole": Era of the American Fur Company, 1833-1840 |title=Colter's Hell & Jackson's Hole |chapter-url=http://www.cr.nps.gov/history/online_books/grte1/chap7.htm |publisher=National Park Service |url-status=dead |archive-url=https://web.archive.org/web/20050312032047/http://www.cr.nps.gov/history/online_books/grte1/chap7.htm |archive-date=March 12, 2005 }} with a diameter of {{convert|300|ft|m|-1}}. In 1870 the Washburn–Langford–Doane Expedition visited the spring, noting a {{convert|50|ft|m|adj=on}} geyser nearby (later named Excelsior).{{cite book |chapter=Notes |title=Yellowstone National Park: Its Exploration and Establishment |chapter-url=http://www.cr.nps.gov/history/online_books/haines1/ieee.htm#2146 |publisher=National Park Service |url-status=dead |archive-url=https://web.archive.org/web/20060208011441/http://www.cr.nps.gov/history/online_books/haines1/ieee.htm#2146 |archive-date=February 8, 2006 }}{{cite book |chapter=Part II: Definitive Knowledge - The Washburn Party (1870) |title=Yellowstone National Park: Its Exploration and Establishment |publisher=National Park Service |chapter-url=http://www.cr.nps.gov/history/online_books/haines1/iee2d.htm |url-status=dead |archive-url=https://web.archive.org/web/20041213044126/http://www.cr.nps.gov/history/online_books/haines1/iee2d.htm |archive-date=December 13, 2004 }}
Color
The bright, vivid colors in the spring are the result of microbial mats of thermophilic bacteria around the edges of the mineral-rich water. The mats produce colors ranging from green to red; the amount of color in the microbial mats depends on the ratio of chlorophyll to carotenoids and on the temperature gradient in the runoff. In the summer, the mats tend to be orange and red, whereas in the winter the mats are usually dark green.{{cite web |author=Thomas D. Brock |author-link=Thomas D. Brock |title=Colorful Yellowstone |work=Life at High Temperature |url=http://www.bact.wisc.edu/bact303/b4 |archive-url=https://web.archive.org/web/20051125213458/http://www.bact.wisc.edu/bact303/b4 |archive-date=November 25, 2005 }} The center of the pool is sterile due to extreme heat.
The deep blue color of the water in the center of the pool results from the intrinsic blue color of water. The effect is strongest in the center of the spring, because of its sterility and depth.
Physical structure
The spring is approximately {{convert|370|ft|m|-1}} in diameter and is {{convert|160|ft|m|-1}} deep. The spring discharges an estimated {{convert|560|USgal|L|-2}} of {{convert|160|F|C|-1}} water per minute.{{cite web |last1=Geiling |first1=Natasha |title=The Science Behind Yellowstone's Rainbow Hot Spring |url=http://www.smithsonianmag.com/travel/science-behind-yellowstones-rainbow-hot-spring-180950483/?no-ist |website=Smithsonian.com |publisher=Smithsonian Institution |access-date=August 17, 2015 |archive-date=August 7, 2015 |archive-url=https://web.archive.org/web/20150807201143/http://www.smithsonianmag.com/travel/science-behind-yellowstones-rainbow-hot-spring-180950483/?no-ist |url-status=live }}{{cite gosa|GRANDPRISMATIC|Grand Prismatic Spring }}
{{gallery
|width = 250
|File:Grand Prismatic Springs in July.jpg|Grand Prismatic Spring|4=Aerial view of spring|5=File:Grand Prismatic Spring, Yellowstone NP.jpg|6=Microbial mat|7=File:Grand_Prismatic_Spring_(timelapse).webm|8=Timelapse video of the Grand Prismatic Spring}}
References
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{{Portal|Volcanoes|Geology|Wyoming|United States}}
{{Reflist}}
{{Lower Midway}}
{{Wyoming}}
Category:Geothermal features of Yellowstone National Park
Category:Hot springs of Wyoming