Editing Mauna Loa (section)

===Setting===
{{multiple image | direction = horizontal | align=left| width1 = 187 | width2 = 200 |image1=Mauna Loa map.gif|caption1=Position of Mauna Loa on [[Hawaii (island)|Hawaiʻi island]]|image2=Island of Hawai'i - Landsat mosaic.jpg|caption2=[[Landsat]] mosaic; recent lava flows appear in black}}

Like all Hawaiian volcanoes, Mauna Loa was created as the [[Pacific Plate|Pacific tectonic plate]] moved over the [[Hawaii hotspot]] in the Earth's underlying [[mantle (geology)|mantle]].<ref name=usgs-map>{{cite web|title=Geologic Map of the State of Hawai'i|url=http://pubs.usgs.gov/of/2007/1089/Hawaii_expl_pamphlet.pdf|work=Open-File Report 2007–1089|publisher=[[United States Geological Survey]]|access-date=December 9, 2012|pages=50–51|year=2007|author1=David R. Sherrod |author2=John M. Sinton |author3=Sarah E. Watkins |author4=Kelly M. Brunt |name-list-style=amp}}</ref> The Hawaii island volcanoes are the most recent evidence of this process that, over 70&nbsp;million years, has created the {{convert|3700|mi|km|abbr=on}}-long [[Hawaiian–Emperor seamount chain]].<ref name="Watson">{{cite web|last=Watson|first=Jim|title=The long trail of the Hawaiian hotspot|url=http://pubs.usgs.gov/gip/dynamic/Hawaiian.html|publisher=United States Geological Survey|access-date=August 26, 2010|date=May 5, 1999}}</ref> The prevailing view states that the hotspot has been largely stationary within the planet's mantle for much, if not all of the [[Cenozoic]] Era.<ref name="Watson"/><ref>{{cite web|url=http://www.mantleplumes.org/Hawaii.html|title=The Emperor and Hawaiian Volcanic Chains: How well do they fit the plume hypothesis?|author1=Foulger, G.R |author2=Anderson, Don L.
|publisher=MantlePlumes.org|date=March 11, 2006|access-date=April 1, 2009}}</ref> However, while the Hawaiian [[mantle plume]] is well understood and extensively studied, the nature of hotspots themselves remains fairly enigmatic.<ref>{{Cite book|year=1987 |title=Volcanism in Hawaii: papers to commemorate the 75th anniversary of the founding of the Hawaii Volcano Observatory |chapter=The Hawaiian-Emperor Volcanic Chain – Geological Evolution |publisher=United States Geological Survey |volume=1 |series=Professional Paper 1350 |chapter-url=https://pubs.usgs.gov/pp/1987/1350/pdf/chapters/pp1350_ch1.pdf |page=32 |author1=Clague, David A. |author2=Dalrymple, G. Brent}}</ref>

Mauna Loa is one of five [[subaerial]]{{efn|occurring on or near the Earth's land surface as opposed to submarine (below the sea), sub-glacial (below a glacier), etc.}} volcanoes that make up the island of [[Hawaii (island)|Hawaiʻi]].<ref>{{cite book |editor1-last=Juvik |editor1-first=Sonia P. |editor2-last=Juvik |editor2-first=James O. |title=Atlas of Hawaiʻi |date=1998 |publisher=University of Hawaiʻi Press |isbn=0-8248-2125-4 |page=44 |edition=3rd |quote=Hawaiʻi Island. Hawaiʻi consists of five coalescent, subaerial (above sea level) volcanoes...}}</ref> The oldest volcano on the island, [[Kohala (mountain)|Kohala]], is more than a million years old,<ref>{{cite web |last1=Sherrod |first1=David R. |last2=Sinton |first2=James M. |last3=Watkins |first3=Sarah E. |last4=Brunt |first4=Kelly M. |title=Geologic Map of the State of Hawaiʻi |date=2007 |publisher=United States Geological Survey |location=Reston, Virginia |page=41 |url=https://pubs.usgs.gov/of/2007/1089/Hawaii_expl_pamphlet.pdf}}</ref> and [[Kīlauea]], the youngest, is believed to be between 210,000 and 280,000 years of age.<ref>{{cite web |title=Kīlauea: Geology and History |url=https://www.usgs.gov/volcanoes/kilauea/geology-and-history |website=U.S. Geological Survey |access-date=December 25, 2021}}</ref> [[Kamaʻehuakanaloa Seamount|Kamaʻehuakanaloa]] (formerly Lōʻihi) on the island's flank is even younger, but has yet to breach the surface of the Pacific Ocean.<ref>{{cite book |author1=David A. Clague |author2=David R. Sherrod |editor1-last=Poland |editor1-first=Michael P. |editor2-last=Takahashi |editor2-first=T. Jane |editor3-last=Landowski |editor3-first=Claire M. |title=Characteristics of Hawaiian volcanoes, Professional Paper 1801 |date=2014 |publisher=U.S. Geological Survey |location=Reston, VA |chapter=Growth and degradation of Hawaiian volcanoes|page=104|url=https://pubs.usgs.gov/pp/1801/downloads/pp1801_Chap3_Clague.pdf}}</ref> At 1&nbsp;million to 600,000 years of age,<ref name="USGS-Mauna Loa history">{{cite web|title=Mauna Loa: Earth's Largest Volcano|url=https://www.usgs.gov/volcanoes/mauna-loa/geology-and-history|publisher=Hawaiian Volcano Observatory – [[United States Geological Service]]|access-date=January 29, 2022}}</ref> Mauna Loa is the second youngest of the five volcanoes on the island, making it the [[List of volcanoes in the Hawaiian – Emperor seamount chain|third]] youngest volcano in the [[Hawaiian – Emperor seamount chain]], a chain of [[shield volcano]]es and [[seamount]]s extending from [[Hawaii]] to the [[Kuril–Kamchatka Trench]] in [[Russia]].<ref name="USGS Hotspots">{{cite book|url=http://pubs.usgs.gov/gip/dynamic/hotspots.html|title="Hotspots": Mantle thermal plumes|publisher=United States Geological Survey|edition=1.14|year=1996|isbn=978-0-16-048220-5|author1=W. J. Kious |author2=R. I. Tilling |name-list-style=amp |access-date=December 9, 2012}}</ref>

[[File:mauna loa from hilo bay.JPG|thumb|Mauna Loa from Hilo Bay, December 2017]]

Following the [[Evolution of Hawaiian volcanoes|pattern]] of Hawaiian volcano formation, Mauna Loa would have started as a [[submarine volcano]], gradually building itself up through underwater eruptions of [[alkali]] [[basalt]] before emerging from the sea through a series of [[surtseyan eruption]]s<ref name=hov-evolution>{{cite web|title=Evolution of Hawaiian Volcanoes|url=https://www.usgs.gov/news/volcano-watch-evolution-hawaiian-volcanoes|publisher=Hawaiian Volcano Observatory – United States Geological Survey|access-date=January 29, 2022|date=March 26, 1998}}</ref> about 400,000 years ago. Since then, the volcano has remained active, with a history of [[Hawaiian eruption|effusive]] and [[explosive eruption|explosive]] eruptions, including 34 eruptions since the first well-documented eruption in 1843.<ref name="hvo-loa">{{cite web |title=Mauna Loa |url=https://www.usgs.gov/volcanoes/mauna-loa |website=US Geological Survey |access-date=January 29, 2022}}</ref>