:Mauna Kea

File:2003-3d-hawaiian-islands-usgs-i2809.jpg to submerge the top of Mauna Kea. Then slowly lower it again. The first thing to appear is the peak of Mauna Kea. Then Mauna Loa and peaks of the surrounding Hawaiian Islands will emerge from the ocean. If the ocean drains further, the island around Mauna Kea will grow and merge with the adjacent islands. Continue draining until a land bridge forms between the Hawaiian Islands and a continent so that it is possible to walk all the way there without getting wet. Stop draining at this point, and this bridge is the key col of a dry Mauna Kea, connecting it to Mount Everest. Mauna Kea's peak stands {{cvt|9,330|m|0}} above this key col.]]

Mauna Kea is unusually topographically prominent for its height, with a wet prominence fifteenth in the world among mountains, and a dry prominence second in the world, after only Mount Everest.{{cite book |last1=Helman |first1=Adam |title=The Finest Peaks - Prominence and Other Mountain Measures |date=2005 |publisher=Trafford Publishing |isbn=9781412059954}} It is the highest peak on its island, so its wet prominence matches its height above sea level, at {{cvt|4,207.3|m|0}}. Because the Hawaiian Islands slope deep into the ocean, Mauna Kea has a dry prominence of {{cvt|9,330|m|0}}. This dry prominence is taller than Mount Everest's height above sea level of {{cvt|8,848.86|m|0}}, so Everest would have to include whole continents in its foothills to exceed Mauna Kea's dry prominence.

Given how much Mauna Kea protrudes from the Hawaiian Trough, some authorities have called it the tallest (as opposed to highest) mountain in the world, as measured from base to peak.{{cite web |title=Mauna Kea |url=https://media.nationalgeographic.org/assets/file/maunakea-ngm-sept2012supp.pdf |website=National Geographic |access-date=October 10, 2021 |archive-date=August 12, 2021 |archive-url=https://web.archive.org/web/20210812233321/https://media.nationalgeographic.org/assets/file/maunakea-ngm-sept2012supp.pdf |url-status=live }}{{cite web |title=Tallest Mountain |url=http://www.guinnessworldrecords.com/world-records/tallest-mountain |website=Guinness World Records |access-date=January 21, 2015 |archive-date=January 21, 2015 |archive-url=https://web.archive.org/web/20150121193947/http://www.guinnessworldrecords.com/world-records/tallest-mountain |url-status=live }}{{cite book |authorlink=Hans-Ulrich Schmincke |first=Hans-Ulrich |last=Schmincke |title=Volcanism |publisher=Springer |year=2004 |isbn=978-3-540-43650-8 |page=71}}{{cite web |title=How High is Mauna Loa? |url=https://www.usgs.gov/center-news/volcano-watch-how-high-mauna-loa |website=U.S. Geological Survey |access-date=October 10, 2021 |archive-date=October 10, 2021 |archive-url=https://web.archive.org/web/20211010234959/https://www.usgs.gov/center-news/volcano-watch-how-high-mauna-loa |url-status=live }}{{Cite web |title=How Big Are Hawaiian Volcanoes? |url=https://www.usgs.gov/faqs/how-big-are-hawaiian-volcanoes |archive-url=https://web.archive.org/web/20220205034730/https://www.usgs.gov/faqs/how-big-are-hawaiian-volcanoes |archive-date=February 5, 2022 |publisher=U.S. Geological Survey}} Unlike prominence, base is loosely defined, which has resulted in numbers ranging from {{cvt|32,696|ft|0|order=flip}} (roughly to the deepest point in the Hawaiian Trough) to {{cvt|17,205|m|0}} (to the root of the mountain deep underground). Those calculations have produced rivaling claims for other mountains, such as higher climb from base for Mount Lamlam ({{cvt|37,820|ft|0|order=flip}}, starting from nearby Challenger Deep),{{cite web |title=How Do Scientists Determine the World's Tallest Mountain? |url=http://www.wisegeek.com/how-do-scientists-determine-the-worlds-tallest-mountain.htm |website=wisegeek|date=August 9, 2023 }}{{Cite web |title=Geography of Guam |url=http://ns.gov.gu/geography.html |access-date=2021-10-10 |url-status=dead |archive-url=https://web.archive.org/web/20200412084221/http://ns.gov.gu/geography.html |archive-date=12 April 2020 |website=Government of Guam}} and the tremendously deep roots of the Himalayan Mountains.{{cite web |title=Beneath the mountains |url=http://geoscience.wisc.edu/~chuck/Classes/Mtn_and_Plates/mtn_roots.html |access-date=January 21, 2015 |archive-date=February 21, 2015 |archive-url=https://web.archive.org/web/20150221122633/http://geoscience.wisc.edu/~chuck/Classes/Mtn_and_Plates/mtn_roots.html |url-status=dead }} Greater rises could be measured from the Atacama Trench to the Andes Mountains, for example, the bottom of Richard's Deep ({{cvt|8,065|m|0}} deep{{Cite web |title=Peru-Chile Trench {{!}} trench, Pacific Ocean |url=https://www.britannica.com/place/Peru-Chile-Trench |access-date=2021-10-11 |website=Encyclopedia Britannica |language=en |archive-date=May 14, 2015 |archive-url=https://web.archive.org/web/20150514164921/https://www.britannica.com/EBchecked/topic/453259/Peru-Chile-Trench |url-status=live }}) to the peak of the nearby Llullaillaco ({{cvt|6,739|m|0}} high{{Cite web |title=Llullaillaco |url=https://volcano.si.edu/volcano.cfm?vn=355110 |url-status=live |access-date=22 Nov 2021 |website=Global Volcanism Program |publisher=Smithsonian Institution |archive-date=November 18, 2021 |archive-url=https://web.archive.org/web/20211118204038/https://volcano.si.edu/volcano.cfm?vn=355110 }}) is {{cvt|14,804|m|0}}.{{cite book |last1=Abele |first1=Gerhard |title=The Southern Central Andes: Contributions to Structure and Evolution of an Active Continental Margin |date=1988 |publisher=Springer |isbn=978-3-540-45904-0 |page=153 |url=https://link.springer.com/chapter/10.1007/BFb0045180 |access-date=5 September 2024 |language=en |chapter=Geomorphological west-east-section through the north chilean andes near antofagasta}} Neither Mount Lamlam nor Llullaillaco have the dry prominence of Mauna Kea, because they do not extend into trenches in every direction.

File:Location Mauna Kea.svg|thumb|left|Clickable imagemap of Hawai{{okina}}i island showing the location of Mauna Kea, making up 22.8 percent of the island's surface area

poly 139 238 152 201 174 178 207 170 235 133 269 157 250 186 216 205 Kīlauea

poly 41 158 64 154 85 127 62 89 40 91 20 108 24 130 Hualālai

poly 66 55 107 55 119 33 63 2 53 8 51 28 Kohala

poly 65 65 97 105 138 126 229 113 236 134 207 171 174 180 151 201 139 237 121 259 97 286 57 261 48 240 56 197 39 159 60 157 85 127 63 90 47 90 54 74 Mauna Loa

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Mauna Kea is one of five volcanoes that form the island of Hawai{{okina}}i, the largest and youngest island of the Hawaiian–Emperor seamount chain.{{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 |archive-date=February 4, 2012 |archive-url=https://web.archive.org/web/20120204160200/http://pubs.usgs.gov/gip/dynamic/Hawaiian.html |url-status=live }} Of these five hotspot volcanoes, Mauna Kea is the fourth oldest and fourth most active. It began as a preshield volcano driven by the Hawai{{okina}}i hotspot around one million years ago, and became exceptionally active during its shield stage until 500,000 years ago.{{cite journal |title=Hawaiian hotspot dynamics as inferred from Hf and Pb isotope evolution of Mauna Kea volcano |journal=Geochemistry, Geophysics, Geosystems |publisher=American Geophysical Union |volume=4 |issue=2 |page=8704 |author1=Blichert-Toft, J. |author2=Weis, D. |author3=Maerschalk, C. |author4=Agranier, A. |author5=Albarède, F. |name-list-style=amp |url=http://perso.ens-lyon.fr/francis.albarede/JBT_Rev_text.pdf |doi=10.1029/2002GC000340 |date=February 19, 2003 |access-date=May 22, 2002 |bibcode=2003GGG.....4.8704B |doi-access=free |archive-date=December 10, 2015 |archive-url=https://web.archive.org/web/20151210215219/http://perso.ens-lyon.fr/francis.albarede/JBT_Rev_text.pdf |url-status=live }} Mauna Kea entered its quieter post-shield stage 250,000 to 200,000 years ago, and is currently active, having last erupted between 4,500 and 6,000 years ago. Mauna Kea does not have a visible summit caldera, but contains a number of small cinder and pumice cones near its summit. A former summit caldera may have been filled and buried by later summit eruption deposits.

Mauna Kea is over {{cvt|32000|km3|cumi|-1}} in volume, so massive that it and its neighbor, Mauna Loa, depress the ocean crust beneath it by {{cvt|6|km|mi|0}}.{{cite book |last=Wolfe |first=E.W. |author2=Wise, W.S. |author3=Dalrymple, G.B. |title=The geology and petrology of Mauna Kea volcano, Hawaii : a study of postshield volcanism |url=https://pubs.er.usgs.gov/djvu/PP/pp_1557.djvu |series=Professional Paper 1557 |year=1997 |publisher=United States Geological Survey |access-date=September 18, 2010 |archive-date=June 15, 2011 |archive-url=https://web.archive.org/web/20110615111115/http://pubs.er.usgs.gov/djvu/PP/pp_1557.djvu |url-status=live }}

File:Iotw2248a - Mauna Loa Lava and Light Pillar Caught on Camera from Gemini North.jpg

The volcano continues to slip and flatten under its own weight at a rate of less than {{cvt|0.2|mm|inch|2}} per year. Much of its mass lies east of its present summit. It stands {{cvt|4207.3|m|ft|0}} above sea level,{{cite web |title=Mauna Kea: Hawaiian Volcano Observatory |url=https://volcanoes.usgs.gov/volcanoes/mauna_kea/ |publisher=Hawaiian Volcano Observatory – United States Geological Survey |date=January 2, 2018 |access-date=February 24, 2020 |archive-url=https://web.archive.org/web/20200106015949/https://volcanoes.usgs.gov/volcanoes/mauna_kea/ |archive-date=January 6, 2020 |url-status=dead}} about {{cvt|38|m|ft|0}} higher than its neighbor Mauna Loa,[https://volcanoes.usgs.gov/volcanoes/mauna_loa/ "Mauna Loa, Hawaiian Volcano Observatory, Summary"] ([https://web.archive.org/web/20190203032210/https://volcanoes.usgs.gov/volcanoes/mauna_loa/ archive]). volcanoes.usgs.gov. United States Geological Survey. November 2, 2017. Retrieved February 12, 2019. and is the highest point in the state of Hawaii.{{cite web |title=Science In Your Backyard: Hawaii |url=http://www.usgs.gov/state/state.asp?State=HI |publisher=United States Geological Survey |access-date=October 25, 2010 |date=October 2, 2009 |url-status=dead |archive-url=https://web.archive.org/web/20101104233304/https://www.usgs.gov/state/state.asp?State=HI |archive-date=November 4, 2010}}

Like all Hawaiian volcanoes, Mauna Kea has been created as the Pacific tectonic plate has moved over the Hawaiian hotspot in the Earth's underlying mantle. The Hawaii island volcanoes are the most recent evidence of this process that, over 70 million years, has created the {{cvt|6000|km|mi}}-long Hawaiian Ridge–Emperor seamount chain. The prevailing, though not completely settled, view is that the hotspot has been largely stationary within the planet's mantle for much, if not all of the Cenozoic Era.{{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 |archive-date=January 16, 2012 |archive-url=https://web.archive.org/web/20120116023549/http://www.mantleplumes.org/Hawaii.html |url-status=live }} However, while Hawaiian volcanism is well understood and extensively studied, there remains no definite explanation of the mechanism that causes the hotspot effect.{{Cite book |year=1987 |title=Volcanism in Hawaii: papers to commemorate the 75th anniversary of the founding of the Hawaii Volcano Observatory |editor-link1=Robert W. Decker |editor1-first=Robert W. |editor1-last=Decker |editor2-first=Thomas L. |editor2-last=Wright |editor3-first=Peter H. |editor3-last=Straffer |chapter=The Hawaiian-Emperor Volcanic Chain – Geological Evolution |publisher=Volcano Hazards Team, United States Geological Survey, United States Government Printing Office |location=Washington, D.C. |volume=1 |series=Professional Paper 1350 |chapter-url=http://pubs.usgs.gov/pp/1987/1350/pdf/pp1350_vol1.pdf |page=32 |last1=Clague |first1=David A. |last2=Dalrymple |first2=G. Brent |access-date=April 5, 2015 |archive-date=October 23, 2014 |archive-url=https://web.archive.org/web/20141023002327/http://pubs.usgs.gov/pp/1987/1350/pdf/pp1350_vol1.pdf |url-status=live }}

Lava flows from Mauna Kea overlapped in complex layers with those of its neighbors during its growth. Most prominently, Mauna Kea is built upon older flows from Kohala to the northwest, and intersects the base of Mauna Loa to the south. The original eruptive fissures (rift zones) in the flanks of Mauna Kea were buried by its post-shield volcanism.{{cite web |title=Complete Report for Mauna Kea Volcano (Class B) No. 2601 |url=http://gldims.cr.usgs.gov/webapps/cfusion/sites/qfault/qf_web_disp.cfm?disp_cd=C&qfault_or=5107&ims_cf_cd=cf |archive-url=https://web.archive.org/web/20120305184251/http://gldims.cr.usgs.gov/webapps/cfusion/sites/qfault/qf_web_disp.cfm?disp_cd=C&qfault_or=5107&ims_cf_cd=cf |archive-date=March 5, 2012 |publisher=United States Geological Survey |access-date=August 9, 2010 |author1=Cannon, E.C. |author2=Bürgmann, R. Roland |date=October 26, 2009 |url-status=dead}} Hilo Ridge, a prominent underwater rift zone structure east of Mauna Kea, was once believed to be a part of the volcano; however, it is now understood to be a rift zone of Kohala that has been affected by younger Mauna Kea flows.{{cite web |title=What in the world is the Hilo Ridge? |url=http://hvo.wr.usgs.gov/volcanowatch/1998/98_01_08.html |publisher=Hawaii Volcano Observatory – United States Geological Survey |access-date=August 26, 2010 |date=January 8, 1998 |archive-date=October 22, 2011 |archive-url=https://web.archive.org/web/20111022135050/http://hvo.wr.usgs.gov/volcanowatch/1998/98_01_08.html |url-status=live }}

The shield-stage lavas that built the enormous main mass of the volcano are tholeiitic basalts, like those of Mauna Loa, created through the mixing of primary magma and subducted oceanic crust.{{cite journal |last=Herzberg |first=Claude |title=Petrology and thermal structure of the Hawaiian plume from Mauna Kea volcano |journal=Nature |publisher=Nature Publishing Group |volume=444 |issue=7119 |pages=605–9 |date=November 30, 2006 |pmid=17136091 |doi=10.1038/nature05254 |bibcode=2006Natur.444..605H |s2cid=4366221}} They are covered by the oldest exposed rock strata on Mauna Kea, the post-shield alkali basalts of the Hāmākua Volcanics, which erupted between 250,000 and 70–65,000 years ago. The most recent volcanic flows are hawaiites and mugearites: they are the post-shield Laupāhoehoe Volcanics, erupted between 65,000 and 4,000 years ago.{{cite web |url=http://pubs.usgs.gov/of/2007/1089/Hawaii_expl_pamphlet.pdf |title=Geological Map of the State of Hawaii |first1=David R. |last1=Sherrod |first2=John M. |last2=Sinton |first3=Sarah E. |last3=Watkins |first4=Kelly M. |last4=Brunt |year=2007 |publisher=United States Geological Survey |work=Open File report 2007-1089 |pages=44–48 |access-date=April 12, 2009 |archive-date=January 18, 2016 |archive-url=https://web.archive.org/web/20160118000515/http://pubs.usgs.gov/of/2007/1089/Hawaii_expl_pamphlet.pdf |url-status=live }}{{cite journal |last=Frey |first=F.A. |author2=Garcia, M. O. |author3=Wise, W. S. |author4=Kennedy, A. |author5=Gurriet, P. |author6=Albarede, F. |year=1991 |title=The Evolution of Mauna Kea Volcano, Hawaii: Petrogenesis of Tholeiitic and Alkalic Basalts |journal=Journal of Geophysical Research |volume=96 |issue=B9 |pages=14,347 |doi=10.1029/91JB00940 |bibcode=1991JGR....9614347F |s2cid=53070011 }} These changes in lava composition accompanied the slow reduction of the supply of magma to the summit, which led to weaker eruptions that then gave way to isolated episodes associated with volcanic dormancy. The Laupāhoehoe lavas are more viscous and contain more volatiles than the earlier tholeiitic basalts; their thicker flows significantly steepened Mauna Kea's flanks. In addition, explosive eruptions have built cinder cones near the summit. These cones are the most recent eruptive centers of Mauna Kea. Its present summit is dominated by lava domes and cinder cones up to {{cvt|1.5|km|mi|1}} in diameter and hundreds of meters tall.

{{multiple image|direction=vertical|width=250|image1=Mauna Kea Summit in Winter.jpg|caption1=Scoria and cinder cones on Mauna Kea's summit in winter|image2=Mauna Kea glaciation.jpg|caption2=Glacial evidence on Mauna Kea, outlining terminal moraines ("m") and till ("w")}}

Mauna Kea is the only Hawaiian volcano with distinct evidence of glaciation. Similar deposits probably existed on Mauna Loa, but have been covered by later lava flows. Despite Hawaii's tropical location, during several past ice ages a drop of a degree in temperature allowed snow to remain at the volcano's summit through summer, triggering the formation of an ice cap.{{cite web |last=Hon |first=Ken |title=GEOL205 – Fire and Ice – Mauna Kea: Lecture Notes |url=http://www.uhh.hawaii.edu/~kenhon/GEOL205/glaciers/default.htm |publisher=University of Hawaii at Hilo |access-date=September 17, 2010 |archive-date=July 28, 2011 |archive-url=https://web.archive.org/web/20110728021322/http://www.uhh.hawaii.edu/~kenhon/GEOL205/glaciers/default.htm |url-status=live }} There are three episodes of glaciation that have been recorded from the last 180,000 years: the Pōhakuloa (180–130 ka), Wāihu (80–60 ka) and Mākanaka (40–13 ka) series. These have extensively sculpted the summit, depositing moraines and a circular ring of till and gravel along the volcano's upper flanks. Subglacial eruptions built cinder cones during the Mākanaka glaciation,{{cite web |title=Hawaiian Volcano Observatory: Photo Information |url=http://hvo.wr.usgs.gov/volcanoes/maunakea/keasnow_caption.html |work=Photo description |publisher=United States Geological Survey |access-date=August 9, 2010 |date=March 13, 1998 |archive-date=May 28, 2010 |archive-url=https://web.archive.org/web/20100528020109/http://hvo.wr.usgs.gov/volcanoes/maunakea/keasnow_caption.html |url-status=live }} most of which were heavily gouged by glacial action. The most recent cones were built between 9,000 and 4,500 years ago, atop the glacial deposits,{{cite journal |title=Holocene Eruptions of Mauna Kea Volcano, Hawaii |journal=Science |date=April 23, 1971 |volume=172 |pmid=17756040 |issue=3981 |pages=375–7 |doi=10.1126/science.172.3981.375 |last=Porter |first=Stephen C. |bibcode=1971Sci...172..375P |s2cid=29652647}} although one study indicates that the last eruption may have been around 3,600 years ago.{{cite journal |last=Porter |first=Stephen C. |title=Stratigraphy and Chronology of Late Quaternary Tephra along the South Rift Zone of Mauna Kea Volcano, Hawaii |journal=GSA Bulletin |volume=84 |issue=6 |pages=1923–40 |date=June 1973 |doi=10.1130/0016-7606(1973)84<1923:SACOLQ>2.0.CO;2 |issn=0016-7606 |bibcode=1973GSAB...84.1923P}}

At their maximum extent, the glaciers extended from the summit down to between {{cvt|3200|and|3800|m|ft|-2}} of elevation.{{cite journal |journal=GSA Bulletin |title=General features and glacial geology of Mauna Kea, Hawaii |date=December 1937 |volume=47 |issue=12 |pages=1719–42 |doi=10.1130/gsab-48-1719 |last1=Gregory |first1=Herbert Ernest |last2=Wentworth |first2=Chester Keeler |bibcode=1937GSAB...48.1719G |url=https://www.jstage.jst.go.jp/article/grj1925/14/7/14_7_643/_pdf |access-date=February 27, 2022 |archive-date=November 2, 2018 |archive-url=https://web.archive.org/web/20181102183935/https://www.jstage.jst.go.jp/article/grj1925/14/7/14_7_643/_pdf |url-status=live |url-access=subscription }} A small body of permafrost, less than {{cvt|25|m|ft|-1}} across, was found at the summit of Mauna Kea before 1974, and may still be present. Small gullies etch the summit, formed by rain- and snow-fed streams that flow only during winter melt and rain showers.

On the windward side of the volcano, stream erosion driven by trade winds has accelerated erosion in a manner similar to that on older Kohala.{{cite web |title=Hawaiʻi: Hawaii's Comprehensive Wildlife Conservation Strategy |url=http://www.state.hi.us/dlnr/dofaw/cwcs/files/NAAT%20final%20CWCS/Chapters/CHAPTER%206%20hawaii%20NAAT%20final%20!.pdf |publisher=Hawaii Department of Land and Natural Resources |access-date=August 14, 2010 |date=October 1, 2005 |url-status=dead |archive-url=https://web.archive.org/web/20110615091612/http://www.state.hi.us/dlnr/dofaw/cwcs/files/NAAT%20final%20CWCS/Chapters/CHAPTER%206%20hawaii%20NAAT%20final%20!.pdf |archive-date=June 15, 2011}}

Mauna Kea is home to Lake Waiau, the highest lake in the Pacific Basin.{{cite book |last1=Stearns |first1=Harold Thornton |author-link2=Gordon A. Macdonald |last2=Macdonald |first2=Gordon Andrew |title=Geology and ground-water resources of the island of Hawaii |series=Bulletin |volume=9 |year=1946 |publisher=United States Geological Survey |page=245}} At an altitude of {{cvt|3969|m|ft|0}}, it lies within the Pu{{okina}}u Waiau cinder cone and is the only alpine lake in Hawaii. The lake is very small and shallow, with a surface area of {{cvt|0.73|ha|acre|2}} and a depth of {{cvt|3|m|ft|0}} when fullest. Radiocarbon dating of samples at the base of the lake indicates that it was clear of ice 12,600 years ago. Hawaiian lava types are typically permeable, preventing lake formation due to infiltration. Either sulfur-bearing steam altered the volcanic ash to low-permeability clays, or explosive interactions between rising magma and groundwater or surface water during phreatic eruptions formed exceptionally fine ash that reduced the permeability of the lake bed.{{cite web |title=Impermeable beds trap rain and snow at Mauna Kea's Lake Waiau |url=http://hvo.wr.usgs.gov/volcanowatch/2003/03_06_19.html |publisher=Hawaii Volcano Observatory – United States Geological Survey |access-date=August 9, 2010 |date=June 19, 2003 |archive-date=June 12, 2010 |archive-url=https://web.archive.org/web/20100612090649/http://hvo.wr.usgs.gov/volcanowatch/2003/03_06_19.html |url-status=live }}

No artesian water was known on the island of Hawai{{okina}}i until 1993 when drilling by the University of Hawai{{okina}}i tapped an artesian aquifer more than {{cvt|300|m}} below sea level, that extended more than {{cvt|100|m|ft}} of the borehole's total depth. The borehole had drilled through a compacted layer of soil and lava where the flows of Mauna Loa had encroached upon the exposed Mauna Kea surface and had subsequently been subsided below sea level. Isotopic composition shows the water present to have been derived from rain coming off Mauna Kea at higher than {{cvt|2000|m}} above mean sea level. The aquifer's presence is attributed to a freshwater head within Mauna Kea's basal lens. Scientists believe there may be more water in Mauna Kea's freshwater lens than current models may indicate.{{cite news |title=University plans to drill for water beneath Mauna Kea |url=http://www.bigislandvideonews.com/2012/07/26/university-plans-to-drill-for-water-beneath-mauna-kea/ |access-date=April 16, 2015 |agency=Big Island Video News |publisher=Big Island Video News |date=July 26, 2012 |archive-date=September 23, 2015 |archive-url=https://web.archive.org/web/20150923185103/http://www.bigislandvideonews.com/2012/07/26/university-plans-to-drill-for-water-beneath-mauna-kea/ |url-status=live }} Two more boreholes were drilled on Mauna Kea in 2012, with water being found at much higher elevations and shallower depths than expected. Donald Thomas, director of the University of Hawai{{okina}}i's Center for the Study of Active Volcanoes believes one reason to continue study of the aquifers is due to use and occupancy of the higher elevation areas, stating: "Nearly all of these activities depend on the availability of potable water that, in most cases, must be trucked to the Saddle from Waimea or Hilo — an inefficient and expensive process that consumes a substantial quantity of our scarce liquid fuels."{{cite news |last1=Miller |first1=Erin |title=Mauna Kea aquifers shallower than expected |url=http://westhawaiitoday.com/news/local-news/mauna-kea-aquifers-shallower-expected |access-date=April 16, 2015 |agency=West Hawaii Today |publisher=Oahu Publications, Inc. |date=February 18, 2014 |url-status=dead |archive-url=https://web.archive.org/web/20150805081528/http://westhawaiitoday.com/news/local-news/mauna-kea-aquifers-shallower-expected |archive-date=August 5, 2015}}

The last eruption of Mauna Kea was about 4,600 years ago (about 2600 BC); because of this inactivity, Mauna Kea is assigned a United States Geological Survey hazard listing of 7 for its summit and 8 for its lower flanks, out of the lowest possible hazard rating of 9 (which is given to the extinct volcano Kohala). Since 8000 BC lava flows have covered 20% of the volcano's summit and virtually none of its flanks.{{cite web |last=Watson |first=John |title=Lava Flow Hazard Maps: Kohala and Mauna Kea |url=http://pubs.usgs.gov/gip/hazards/maunakea-kohala.html |publisher=United States Geological Survey |access-date=August 9, 2010 |date=July 18, 1997 |url-status=dead |archive-url=https://web.archive.org/web/20090129201618/http://pubs.usgs.gov/gip/hazards/maunakea-kohala.html |archive-date=January 29, 2009}}

Despite its dormancy, Mauna Kea is expected to erupt again. Based on earlier eruptions, such an event could occur anywhere on the volcano's upper flanks and would likely produce long lava flows, mostly of {{okina}}a{{okina}}ā, {{cvt|15|-|25|km|mi|0}} long. Long periods of activity could build a cinder cone at the source. Although not likely in the next few centuries, such an eruption would probably result in little loss of life but significant damage to infrastructure.{{cite web |title=The next eruption of Mauna Kea |url=http://hvo.wr.usgs.gov/volcanowatch/2000/00_06_01.html |publisher=Hawaii Volcano Observatory – United States Geological Survey |access-date=August 10, 2010 |date=June 5, 2000 |archive-date=June 13, 2010 |archive-url=https://web.archive.org/web/20100613132905/http://hvo.wr.usgs.gov/volcanowatch/2000/00_06_01.html |url-status=live }}

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File:SaddleLele.JPG facing Mauna Kea, on Saddle Road between Mauna Kea and Mauna Loa]]

The first Ancient Hawaiians to arrive on Hawai{{okina}}i island lived along the shores, where food and water were plentiful. Settlement expanded inland to the Mauna Loa – Mauna Kea region in the 12th and early 13th centuries. Archaeological evidence suggests that these regions were used for hunting, collecting stone material, and possibly for spiritual reasons or for astronomical or navigational observations.{{cite web |title=Final Environmental Statement for the Outrigger Telescopes Project: Volume II |url=http://planetquest.jpl.nasa.gov/Outrigger/finalDocuments/fullDocument/OTP-FEIS-Volume-II.pdf |archive-url=https://web.archive.org/web/20090421000952/http://planetquest.jpl.nasa.gov/Outrigger/finalDocuments/fullDocument/OTP-FEIS-Volume-II.pdf |archive-date=April 21, 2009 |publisher=NASA |access-date=August 22, 2010 |page=C–9 |url-status=dead |date=February 2005}} The mountain's plentiful forest provided plants and animals for food and raw materials for shelter. Flightless birds that had previously known no predators became a staple food source.{{cite web |title=Culture: The First Arrivals: Native Hawaiian Uses |url=http://www.hawaii.edu/maunakea/5_culture.pdf |archive-url=https://web.archive.org/web/20121011113028/http://www.hawaii.edu/maunakea/5_culture.pdf |archive-date=October 11, 2012 |work=Mauna Kea Mountain Reserve Master Plan |publisher=University of Hawaii |access-date=August 17, 2010 |url-status=dead}}

Early settlement of the Hawaiian islands led to major changes to local ecosystems and many extinctions, particularly amongst bird species. Ancient Hawaiians brought foreign plants and animals, and their arrival was associated with increased rates of erosion.{{cite journal |last=Kirch |first=Patrick V. |title=The Impact of the Prehistoric Polynesians on the Hawaiian Ecosystem |journal=Pacific Science |date=January 1982 |volume=36 |issue=1 |pages=1–14 |url=http://scholarspace.manoa.hawaii.edu/handle/10125/406 |access-date=October 24, 2010 |publisher=University of Hawaiʻi Press |hdl=10125/406 |archive-date=June 11, 2010 |archive-url=https://web.archive.org/web/20100611095859/http://scholarspace.manoa.hawaii.edu/handle/10125/406 |url-status=live }}

The prevailing lowland forest ecosystem was transformed from forest to grassland; some of this change was caused by the use of fire, but the prevailing cause of forest ecosystem collapse and avian extinction on Hawai{{okina}}i appears to have been the introduction of the Polynesian (or Pacific) rat.{{cite journal |last=Athens |first=Stephen |author2=Tuggle, H. David |author3=Ward, Jerome V. |author4=Welch, David J. |year=2002 |title=Avifaunal Extinctions, Vegetation Change and Polynesian Impacts in Prehistoric Hawai'i |journal=Archaeology in Oceania |volume=37 |url=http://www2.hawaii.edu/~khayes/Journal_Club/spring2007/Athens_et_al_2002_Arch_Ocean.pdf |issue=2 |page=57 |doi=10.1002/j.1834-4453.2002.tb00507.x |access-date=April 5, 2015 |archive-date=April 14, 2015 |archive-url=https://web.archive.org/web/20150414014902/http://www2.hawaii.edu/~khayes/Journal_Club/spring2007/Athens_et_al_2002_Arch_Ocean.pdf |url-status=live }}

The five volcanoes of Hawai{{okina}}i are revered as sacred mountains; and Mauna Kea's summit, the highest, is the most sacred.{{citation needed|date=December 2022}} For this reason, a kapu (ancient Hawaiian law) restricted visitor rights to high-ranking aliʻi. Hawaiians associated elements of their natural environment with particular deities. In Hawaiian mythology, the summit of Mauna Kea was seen as the "region of the gods", a place where benevolent spirits reside. Poli{{okina}}ahu, deity of snow, also resides there. "Mauna Kea" is an abbreviation for Mauna a Wākea and means "white mountain," in reference to its seasonally snow-capped summit.{{cite book |last1=Pukui |first1=Mary Kawena |last2=Elbert |first2=Samuel H. |title=Hawaiian dictionary |year=1986 |publisher=University of Hawaii Press |isbn=0-8248-0703-0 |page=242}}

Around AD 1100, natives established adze quarries high up on Mauna Kea to extract the uniquely dense basalt (generated by the quick cooling of lava flows meeting glacial ice during subglacial eruptions) to make tools. Volcanic glass and gabbro were collected for blades and fishing gear, and māmane wood was preferred for the handles. At peak quarry activity after AD 1400, there were separate facilities for rough and fine cutting; shelters with food, water, and wood to sustain the workers; and workshops creating the finished product.

Lake Waiau provided drinking water for the workers. Native chiefs would also dip the umbilical cords of newborn babies in its water, to give them the strength of the mountain. Use of the quarry declined between this period and contact with Americans and Europeans. As part of the ritual associated with quarrying, the workers erected shrines to their gods; these and other quarry artifacts remain at the sites, most of which lie within what is now the Mauna Kea Ice Age Reserve.

This early era was followed by cultural expansion between the 12th and late 18th century. Land was divided into regions designed for the immediate needs of the populace. These ahupua{{okina}}a generally took the form of long strips of land oriented from the mountain summits to the coast. Mauna Kea's summit was encompassed in the ahupua{{okina}}a of Ka{{okina}}ohe, with part of its eastern slope reaching into the nearby Humu{{okina}}ula. Principal sources of nutrition for Hawaiians living on the slopes of the volcano came from the māmane–naio forest of its upper slopes, which provided them with vegetation and bird life. Bird species hunted included the {{okina}}ua{{okina}}u (Pterodroma sandwichensis), nēnē (Branta sandvicensis), and palila (Loxioides bailleui). The lower koa–{{okina}}ōhi{{okina}}a forest gave the natives wood for canoes and ornate bird feathers for decoration.

File:Mauna Kea from Mauna Loa Observatory, Hawaii - 20100913 (cropped).jpg]]

There are three accounts of foreigners visiting Hawai{{okina}}i before the arrival of James Cook, in 1778.{{cite book |author=William Mission Ellis |title=Narrative of a Tour Through Hawaii, Or, Owhyhee, with Observations on the Natural History of the Sandwich Islands |url=https://books.google.com/books?id=1glfAAAAcAAJ&pg=PA446 |year=1827 |publisher=H. Fisher, son, and P. Jackson |pages=446–448 |access-date=November 22, 2015 |archive-date=June 17, 2016 |archive-url=https://web.archive.org/web/20160617112818/https://books.google.com/books?id=1glfAAAAcAAJ&pg=PA446 |url-status=live }}{{cite book |author=Alton Pryor |title=Little Known Tales in Hawaii History |url=https://books.google.com/books?id=WFCewWiDeOwC&pg=PA145 |year=2004 |publisher=Stagecoach Pub. |isbn=978-0-9747551-1-3 |pages=144–147 |access-date=November 22, 2015 |archive-date=April 24, 2016 |archive-url=https://web.archive.org/web/20160424073407/https://books.google.com/books?id=WFCewWiDeOwC&pg=PA145 |url-status=live }}{{cite book |author=Daniel Ethan Chapman |title=Examining Social Theory: Crossing Borders/reflecting Back |url=https://books.google.com/books?id=ZgxDKYLG6eUC&pg=PA8 |year=2010 |publisher=Peter Lang |isbn=978-1-4331-0479-4 |page=8 |access-date=November 22, 2015 |archive-date=May 19, 2016 |archive-url=https://web.archive.org/web/20160519013151/https://books.google.com/books?id=ZgxDKYLG6eUC&pg=PA8 |url-status=live }} However, the earliest Western depictions of the isle, including Mauna Kea, were created by explorers in the late 18th and early 19th centuries. Contact with Europe and America had major consequences for island residents. Native Hawaiians were devastated by introduced diseases; port cities including Hilo, Kealakekua, and Kailua grew with the establishment of trade; and the adze quarries on Mauna Kea were abandoned after the introduction of metal tools.

In 1793, cattle were brought by George Vancouver as a tribute to King Kamehameha I. By the early 19th century, they had escaped confinement and roamed the island freely, greatly damaging its ecosystem. In 1809 John Palmer Parker arrived and befriended Kamehameha I, who put him in charge of cattle management on the island. With an additional land grant in 1845, Parker established Parker Ranch on the northern slope of Mauna Kea, a large cattle ranch that is still in operation today. Settlers to the island burned and cut down much of the lower native forest for sugarcane plantations and houses.

File:High, Dry and Covered in Snow (iotw2304a).jpg

The Saddle Road, named for its crossing of the saddle-shaped plateau between Mauna Kea and Mauna Loa, was completed in 1943, and eased travel to Mauna Kea considerably.

The Pohakuloa Training Area on the plateau is the largest military training ground in Hawai{{okina}}i. The {{cvt|108863|acre|ha|0|adj=on}} base extends from the volcano's lower flanks to {{cvt|2070|m|ft|-1}} elevation, on state land leased to the US Army since 1956. There are 15 threatened and endangered plants, three endangered birds, and one endangered bat species in the area.

Mauna Kea has been the site of extensive archaeological research since the 1980s. Approximately 27 percent of the Science Reserve had been surveyed by 2000, identifying 76 shrines, 4 adze manufacturing workshops, 3 other markers, 1 positively identified burial site, and 4 possible burial sites. By 2009, the total number of identified sites had risen to 223, and archaeological research on the volcano's upper flanks is ongoing. It has been suggested that the shrines, which are arranged around the volcano's summit along what may be an ancient snow line, are markers for the transition to the sacred part of Mauna Kea. Despite many references to burial around Mauna Kea in Hawaiian oral history, few sites have been confirmed. The lack of shrines or other artifacts on the many cinder cones dotting the volcano may be because they were reserved for burial.

File:David Douglass00.jpg, a Scottish botanist who died on Mauna Kea in 1834]]

In pre-contact times, natives traveling up Mauna Kea were probably guided more by landscape than by existing trails, as no evidence of trails has been found. It is possible that natural ridges and water sources were followed instead. Individuals likely took trips up Mauna Kea's slopes to visit family-maintained shrines near its summit, and traditions related to ascending the mountain exist to this day. However, very few natives reached the summit, because of the strict kapu placed on it.

In the early 19th century, the earliest notable recorded ascents of Mauna Kea included the following:

• On August 26, 1823, Joseph F. Goodrich, an American missionary, made the first recorded ascent in a single day; however, a small arrangement of stones he observed suggested he was not the first human on the summit. He recorded four ecosystems as he travelled from base to summit, and also visited Lake Waiau.{{cite journal |last1=Hartt |first1=Constance E |first2=Marie C. |last2=Neal |title=The Plant Ecology of Mauna Kea, Hawaii |journal=Ecology |date=April 1940 |volume=21 |issue=2 |pages=237–266 |doi=10.2307/1930491 |publisher=Ecological Society of America |jstor=1930491}} {{Subscription required}}
• On June 17, 1825, an expedition from HMS Blonde, led by botanist James Macrae, reached the summit of Mauna Kea. Macrae was the first person to record the Mauna Kea silversword (Argyroxiphium sandwicense), saying: "The last mile was destitute of vegetation except one plant of the Sygenisia tribe, in growth much like a Yucca, with sharp pointed silver coloured leaves and green upright spike of three or four feet producing pendulous branches with brown flowers, truly superb, and almost worth the journey of coming here to see it on purpose."
• In January 1834, David Douglas climbed the mountain and described extensively the division of plant species by altitude. On an unrelated traverse, from Kamuela to Hilo in July, he was found dead in a pit intended to catch wild cattle. Although murder was suspected, it was probably an accidental fall. The site, Ka lua kauka {{Coord|19|53|17|N|155|20|17|W|display=inline|type:landmark_region:US-HI |name=Kaluakauka }}, is marked by the Douglas fir trees named for him.{{cite journal |title=Kaluakauka Revisited: the Death of David Douglas in Hawaii |journal=Hawaiian Journal of History |year=1988 |publisher=Hawaiian Historical Society, Honolulu |volume=22 |pages=147–69 |hdl=10524/246}}
• In 1881, Queen Emma traveled to the peak to bathe in the waters of Lake Waiau during competition for the role of ruling chief of the Kingdom of Hawai{{okina}}i.
• On August 6, 1889, E.D. Baldwin left Hilo and followed cattle trails to the summit.
• In February 2021, Victor Vescovo and Clifford Kapono made the first ascent of Mauna Kea from its subaerial base 16,785 ft below sea level using the submersible Limiting Factor, then ocean kayaks from above the mountain base 27 miles to the shoreline, then bicycles to a camp at about 9000 ft altitude from which they then walked to the 13,802 ft summit (a total gain of 30,587 ft).{{cite news |url=https://www.sfgate.com/hawaii/article/Men-climb-Earths-tallest-mountain-16784886.php |title=Earth's tallest mountain is in Hawaii. Here's what it took to ascend it. |date=January 25, 2022 |work=SFGate |access-date=January 11, 2022 |archive-date=January 25, 2022 |archive-url=https://web.archive.org/web/20220125122414/https://www.sfgate.com/hawaii/article/Men-climb-Earths-tallest-mountain-16784886.php |url-status=live }}

In the late 19th and early 20th centuries trails were formed, often by the movement of game herds, that could be traveled on horseback. However, vehicular access to the summit was practically impossible until the construction of a road in 1964, and it continues to be restricted.{{cite web |title=Recreation: Enjoying Mauna Kea's Unique Natural Resources |url=http://www.hawaii.edu/maunakea/7_recreation.pdf |archive-url=https://web.archive.org/web/20090920101000/http://www.hawaii.edu/maunakea/7_recreation.pdf |archive-date=September 20, 2009 |work=Mauna Kea Mountain Reserve Master Plan |publisher=Institute for Astronomy – University of Hawaii |access-date=August 17, 2010 |url-status=dead}} Today, multiple trails to the summit exist, in various states of use.

Hawai{{okina}}i's geographical isolation strongly influences its ecology. Remote islands like Hawai{{okina}}i have a large number of species that are found nowhere else (see Endemism in the Hawaiian Islands).{{cite journal |last1=Sakai |first1=Ann K. |last2=Wagner |first2=Warren L. |last3=Mehrhoff |first3=Loyal A. |year=2002 |title=Patterns of Endangerment in the Hawaiian Flora |url=http://si-pddr.si.edu/dspace/bitstream/10088/7588/1/bot_Sakai_et_al_2002_endangerment.pdf |journal=Systematic Biology |pmid=12028733 |volume=51 |issue=2 |pages=276–302 |publisher=Oxford University Press |doi=10.1080/10635150252899770 |doi-access=free |access-date=October 14, 2010 |archive-date=March 12, 2012 |archive-url=https://web.archive.org/web/20120312041043/http://si-pddr.si.edu/dspace/bitstream/10088/7588/1/bot_Sakai_et_al_2002_endangerment.pdf |url-status=live }} The remoteness resulted in evolutionary lines distinct from those elsewhere and isolated these endemic species from external biotic influence, and also makes them especially vulnerable to extinction and the effects of invasive species. In addition the ecosystems of Hawai{{okina}}i are under threat from human development including the clearing of land for agriculture; an estimated third of the island's endemic species have already been wiped out. Because of its elevation, Mauna Kea has the greatest diversity of biotic ecosystems anywhere in the Hawaiian archipelago. Ecosystems on the mountain form concentric rings along its slopes due to changes in temperature and precipitation with elevation.{{cite journal |doi=10.2307/3673140 |last1=Juvik |first1=J. O |first2=S. P. |last2=Juvik |title=Mauna Kea and the Myth of Multiple Use: Endangered Species and Mountain Management in Hawaii |date=August 1984 |journal=Mountain Research and Development |volume=4 |issue=3 |pages=191–202 |publisher=International Mountain Society |jstor=3673140}} {{Subscription required}} These ecosystems can be roughly divided into three sections by elevation: alpine–subalpine, montane, and basal forest.

Contact with Americans and Europeans in the early 19th century brought more settlers to the island, and had a lasting negative ecological effect. On lower slopes, vast tracts of koa–{{okina}}ōhi{{okina}}a forest were converted to farmland. Higher up, feral animals that escaped from ranches found refuge in, and damaged extensively, Mauna Kea's native māmane–naio forest. Non-native plants are the other serious threat; there are over 4,600 introduced species on the island, whereas the number of native species is estimated at just 1,000.{{cite book |title=Alteration of native Hawaiian vegetation-Effects of humans, their activities and introductions |year=1990 |publisher=University of Hawaii Press |isbn=0-8248-1308-1 |url=https://books.google.com/books?id=u0RFAQAAIAAJ |first1=Charles P. |last1=Stone |first2=Linda W. |last2=Cuddihy |chapter=Alien Plants |access-date=November 22, 2015 |archive-date=June 17, 2016 |archive-url=https://web.archive.org/web/20160617104817/https://books.google.com/books?id=u0RFAQAAIAAJ |url-status=live }}

File:Mauna Kea silversword3.jpg (Argyroxiphium sandwicense sandwicense) growing near the volcano's summit]]

The summit of Mauna Kea lies above the tree line, and consists of mostly lava rock and alpine tundra. An area of heavy snowfall, it is inhospitable to vegetation, and is known as the Hawaiian tropical high shrublands. Growth is restricted here by extremely cold temperatures, a short growing season, low rainfall, and snow during winter months. A lack of soil also retards root growth, makes it difficult to absorb nutrients from the ground, and gives the area a very low water retention capacity.

Plant species found at this elevation include Styphelia tameiameiae, Taraxacum officinale, Tetramolopium humile, Agrostis sandwicensis, Anthoxanthum odoratum, Trisetum glomeratum, Poa annua, Sonchus oleraceus, and Coprosma ernodiodes. One notable species is Mauna Kea silversword (Argyroxiphium sandwicense var. sandwicense), a highly endangered endemic plant species that thrives in Mauna Kea's high elevation cinder deserts. At one stage reduced to a population of just 50 plants,{{cite journal |first=Lawrence R. |last=Walker |author2=Powell, Elizabeth Ann |title=Regeneration of the Mauna Kea silversword Argyroxiphium sandwicense (Asteraceae) in Hawaii |url=https://www.researchgate.net/publication/222036366 |journal=Biological Conservation |volume=88 |issue=1 |pages=61–70 |date=July 1999 |doi=10.1016/S0006-3207(98)00132-3 |access-date=September 4, 2017 |archive-date=February 27, 2022 |archive-url=https://web.archive.org/web/20220227225027/https://www.researchgate.net/publication/222036366_Regeneration_of_the_Mauna_Kea_silversword_Argyroxiphium_sandwicense_Asteraceae_in_Hawaii |url-status=live }} Mauna Kea silversword was thought to be restricted to the alpine zone, but in fact has been driven there by pressure from livestock, and can grow at lower elevations as well.

The Mauna Kea Ice Age Reserve on the southern summit flank of Mauna Kea was established in 1981. The reserve is a region of sparsely vegetated cinder deposits and lava rock, including areas of aeolian desert and Lake Waiau.{{cite web |title=Mauna Kea Ice Age |url=http://dlnr.hawaii.gov/ecosystems/nars/reserves/hawaii-island/mauna-kea-ice-age/ |publisher=Hawaii Department of Land and Natural Resources |access-date=August 13, 2010 |archive-date=October 30, 2014 |archive-url=https://web.archive.org/web/20141030055952/http://dlnr.hawaii.gov/ecosystems/nars/reserves/hawaii-island/mauna-kea-ice-age/ |url-status=live }} This ecosystem is a likely haven for the threatened {{okina}}ua{{okina}}u (Pterodroma sandwichensis) and also the center of a study on wēkiu bugs (Nysius wekiuicola).

File:Undescribed Mauna Kea Wolf Spider.jpg wolf spider endemic to the summit alpine desert on Mauna Kea]]

Wēkiu bugs feed on dead insect carcasses that drift up Mauna Kea on the wind and settle on snow banks. This is a highly unusual food source for a species in the genus Nysius, which consists of predominantly seed-eating insects. They can survive at extreme elevations of up to {{cvt|4200|m|ft|0}}{{cite journal |first1=Peter D. |last1=Ashlock |first2=Wayne C. |last2=Gagné |title=A Remarkable New Micropterous Nysius Species from the Aelion Zone of Mauna Kea, Hawaii island |journal=International Journal of Entomology |date=April 26, 1983 |volume=25 |issue=1 |pages=47–55 |url=http://hbs.bishopmuseum.org/pi/pdf/25%281%29-47.pdf |access-date=August 14, 2010 |archive-date=November 22, 2011 |archive-url=https://web.archive.org/web/20111122101710/http://hbs.bishopmuseum.org/pi/pdf/25%281%29-47.pdf |url-status=live }} because of natural antifreeze in their blood. They also stay under heated surfaces most of the time. Their conservation status is unclear, but the species is no longer a candidate for the Endangered Species List; studies on the welfare of the species began in 1980. The closely related Nysius aa lives on Mauna Loa. Wolf spiders (Lycosidae) and forest tent caterpillar moths have also been observed in the same Mauna Kea ecosystem; the former survive by hiding under heat-absorbing rocks, and the latter through cold-resistant chemicals in their bodies.{{cite web |title=Wekiu bugs-life on top of a volcano |url=http://hvo.wr.usgs.gov/volcanowatch/1999/99_05_20.html |work=Volcano Watch |publisher=Hawaiian Volcano Observatory – United States Geological Survey |access-date=August 14, 2010 |archive-date=June 14, 2010 |archive-url=https://web.archive.org/web/20100614020313/http://hvo.wr.usgs.gov/volcanowatch/1999/99_05_20.html |url-status=live }} Several native moths are also present near the summit including Agrotis helela and Agrotis kuamauna.

File:Starr 020221-0023 Sophora chrysophylla.jpg (Sophora chrysophylla) trees]]

The forested zone on the volcano, at an elevation of {{cvt|2000|-|3000|m|ft}}, is dominated by māmane (Sophora chrysophylla) and naio (Myoporum sandwicense), both endemic tree species, and is thus known as māmane–naio forest. Māmane seeds and naio fruit are the chief foods of the birds in this zone, especially the palila (Loxioides bailleui). The palila was formerly found on the slopes of Mauna Kea, Mauna Loa, and Hualālai, but is now confined to the slopes of Mauna Kea—only 10% of its former range—and has been declared critically endangered.

The largest threat to the ecosystem is grazing by feral sheep, cattle (Bos primigenius),{{cite journal |author=Scrowcroft, Paul G. |year=1983 |url=http://scholarspace.manoa.hawaii.edu/bitstream/10125/651/3/v37n2-109-119.pdf.txt |format=PDF |title=Tree Cover Changes in Mamane (Sophora chrysophylla) Forests Grazed by Sheep and Cattle |journal=Pacific Science |volume=37 |issue=2 |pages=109–20 |access-date=August 11, 2010 |archive-date=March 3, 2016 |archive-url=https://web.archive.org/web/20160303192837/http://scholarspace.manoa.hawaii.edu/bitstream/10125/651/3/v37n2-109-119.pdf.txt |url-status=live }} and goats (Capra hircus) introduced to the island in the late 18th century. Feral animal competition with commercial grazing was severe enough that a program to eradicate them existed as far back as the late 1920s, and continued through to 1949. One of the results of this grazing was the increased prevalence of herbaceous and woody plants, both endemic and introduced, that were resistant to browsing. The feral animals were almost eradicated, and numbered a few hundred in the 1950s. However, an influx of local hunters led to the feral species being valued as game animals, and in 1959 the Hawai{{okina}}i Department of Land and Natural Resources, the governing body in charge of conservation and land use management, changed its policy to a sustained-control program designed to facilitate the sport.

Mouflon (Ovis aries orientalis) was introduced from 1962 to 1964,{{cite web |author1=Hess, Steven |author2=Kawakami Jr, Ben |author3=Okita, David |author4=Medeiros, Keola |year=2006 |url=https://pubs.usgs.gov/of/2006/1193/ |title=A Preliminary Assessment of Mouflon Abundance at the Kahuku Unit of Hawaii Volcanoes National Park |publisher=United States Geological Survey |page=1 |access-date=February 23, 2018 |archive-date=February 24, 2018 |archive-url=https://web.archive.org/web/20180224112902/https://pubs.usgs.gov/of/2006/1193/ |url-status=live }} See: {{cite report |last=Giffin |first=J.G. |year=1982 |title=Ecology of mouflon sheep on Mauna Kea |publisher=Department of Land and Natural Resources, Division of Forestry and Wildlife |location=Honolulu, HI}} and a plan to release axis deer (Axis axis) in 1964 was prevented only by protests from the ranching industry, who said that they would damage crops and spread disease. The hunting industry fought back, and the back-and-forth between the ranchers and hunters eventually gave way to a rise in public environmental concern. With the development of astronomical facilities on Mauna Kea commencing, conservationists demanded protection of Mauna Kea's ecosystem. A plan was proposed to fence 25% of the forests for protection, and manage the remaining 75% for game hunting. Despite opposition from conservationists the plan was put into action. While the land was partitioned no money was allocated for the building of the fence. In the midst of this wrangling the Endangered Species Act was passed; the National Audubon Society and Sierra Club Legal Defense Fund filed a lawsuit against the Hawai{{okina}}i Department of Land and Natural Resources, claiming that they were violating federal law, in the landmark case Palila v. Hawaii Department of Land and Natural Resources (1978).{{cite court |litigants=Palila v. Hawaii Department of Land & Natural Resources |vol=639 F.2d 495 |pinpoint=79-4636 |court=United States Court of Appeals, Ninth Circuit |date=February 9, 1981 |url=https://scholar.google.com/scholar_case?case=8158542596159694344&hl=en&as_sdt=2&as_vis=1&oi=scholarr |access-date=August 29, 2010}}

The court ruled in favor of conservationists and upheld the precedence of federal laws before state control of wildlife. Having violated the Endangered Species Act, Hawai{{okina}}i state was required to remove all feral animals from the mountainside. This decision was followed by a second court order in 1981. A public hunting program removed many of the feral animals, at least temporarily. An active control program is in place, though it is not conducted with sufficient rigor to allow significant recovery of the māmane-naio ecosystem.Banko, Paul et al. Surveys reveal decline of the palila. Endangered Species Bulletin, Fall 2008. There are many other species and ecosystems on the island, and on Mauna Kea, that remain threatened by human development and invasive species.

The Mauna Kea Forest Reserve protects {{cvt|52500|acre|km2}} of māmane-naio forest under the jurisdiction of the Hawaii Department of Land and Natural Resources. Ungulate hunting is allowed year-round. A small part of the māmane–naio forest is encompassed by the Mauna Kea State Recreation Area.{{cite web |title=Mauna Kea State Recreation Area |url=http://www.hawaiistateparks.org/parks/hawaii/maunakea.cfm |url-status=usurped |archive-url=https://web.archive.org/web/20070419215525/http://www.hawaiistateparks.org/parks/hawaii/maunakea.cfm |archive-date=April 19, 2007 |work=Hawaii State Parks |publisher=Hawaii Department of Land and Natural Resources |access-date=August 15, 2010}}

File:Corvus hawaiiensis FWS.jpg or Hawaiian crow (Corvus hawaiiensis) is a bird in the crow family. It is extinct in the wild, with plans to reintroduce the species into the Hakalau Forest National Wildlife Refuge.]]

A band of ranch land on Mauna Kea's lower slopes was formerly Acacia koa – Metrosideros polymorpha (koa-{{okina}}ōhi{{okina}}a) forest. Its destruction was driven by an influx of European and American settlers in the early 19th century, as extensive logging during the 1830s provided lumber for new homes. Vast swathes of the forest were burned and cleared for sugarcane plantations. Most of the houses on the island were built of koa, and those parts of the forest that survived became a source for firewood to power boilers on the sugarcane plantations and to heat homes. The once vast forest had almost disappeared by 1880, and by 1900, logging interests had shifted to Kona and the island of Maui.{{cite book |title=Alteration of native Hawaiian vegetation-Effects of humans, their activities and introductions |year=1990 |publisher=University of Hawaii Press |isbn=0-8248-1308-1 |url=https://books.google.com/books?id=u0RFAQAAIAAJ |format=PDF |first1=Charles P. |last1=Stone |first2=Linda W. |last2=Cuddihy |chapter=Changes in Vegetation Since 1850 |access-date=November 22, 2015 |archive-date=June 17, 2016 |archive-url=https://web.archive.org/web/20160617104817/https://books.google.com/books?id=u0RFAQAAIAAJ |url-status=live }} With the collapse of the sugar industry in the 1990s, much of this land lies fallow but portions are used for cattle grazing, small-scale farming and the cultivation of eucalyptus for wood pulp.{{cite web |title=Economic Impact of Shutting Down Hawaii's Sugar Industry |url=http://www.ctahr.hawaii.edu/oc/freepubs/pdf/EI-6.pdf |work=Economic Issues |publisher=College of Tropical Agriculture and Human Resources |access-date=September 27, 2010 |first1=Junning |last1=Cai |first2=Ping Sun |last2=Leung |date=April 2004 |archive-date=June 11, 2010 |archive-url=https://web.archive.org/web/20100611230248/http://www.ctahr.hawaii.edu/oc/freepubs/pdf/EI-6.pdf |url-status=live }}

The Hakalau Forest National Wildlife Refuge is a major koa forest reserve on Mauna Kea's windward slope. It was established in 1985, covering {{cvt|32733|acre|ha|0}} of ecosystem remnant. Eight endangered bird species, twelve endangered plants, and the endangered Hawaiian hoary bat (Lasiurus cinereus semotus) have been observed in the area, in addition to many other rare biota. The reserve has been the site of an extensive replanting campaign since 1989.{{cite web |title=Welcome to Hakalau Forest National Wildlife Refuge |url=http://www.fws.gov/hakalauforest/ |publisher=US Fish and Wildlife Service |access-date=August 16, 2010 |date=April 6, 2010 |archive-date=September 13, 2010 |archive-url=https://web.archive.org/web/20100913002327/http://www.fws.gov/hakalauforest/ |url-status=live }} Parts of the reserve show the effect of agriculture on the native ecosystem, as much of the land in the upper part of the reserve is abandoned farmland.

Bird species native to the acacia koa–{{okina}}ōhi{{okina}}a forest include the Hawaiian crow (Corvus hawaiiensis), the {{okina}}akepa (Loxops coccineus), Hawaii creeper (Oreomystis mana), ʻakiapōlāʻau (Hemignathus munroi), and Hawaiian hawk (Buteo solitarius), all of which are endangered, threatened, or near threatened; the Hawaiian crow in particular is extinct in the wild, but there are plans to reintroduce the species into the Hakalau reserve.

{{Main|Mauna Kea Observatories|Opposition to the Mauna Kea Observatories}}

File:Mauna Kea observatory.jpg. From left to right: the Subaru Telescope, the twin Keck I and II telescopes, and the NASA Infrared Telescope Facility.]]

Mauna Kea's summit is one of the best sites in the world for astronomical observation due to favorable observing conditions. The arid conditions are important for submillimeter and infrared astronomy for this region of the electromagnetic spectrum. The summit is above the inversion layer, keeping most cloud cover below the summit and ensuring the air on the summit is dry, and free of atmospheric pollution. The summit atmosphere is exceptionally stable, lacking turbulence for some of the world's best astronomical seeing. The very dark skies resulting from Mauna Kea's distance from city lights are preserved by legislation that minimizes light pollution from the surrounding area; the darkness level allows the observation of faint astronomical objects.{{cite web |title=About Mauna Kea Observatories |url=http://www.ifa.hawaii.edu/mko/about_maunakea.shtml |publisher=Institute for Astronomy – University of Hawaii |access-date=August 19, 2010 |archive-date=June 10, 2010 |archive-url=https://web.archive.org/web/20100610142632/http://www.ifa.hawaii.edu/mko/about_maunakea.shtml |url-status=live }} These factors historically made Mauna Kea an excellent spot for stargazing.

In the early 1960s, the Hawai{{okina}}i Island Chamber of Commerce encouraged astronomical development of Mauna Kea, as economic stimulus; this coincided with University of Arizona astronomer Gerard Kuiper's search for sites to use newly improved detectors of infrared light. Site testing by Kuiper's assistant Alika Herring in 1964 confirmed the summit's outstanding suitability. An intense three-way competition for NASA funds to construct a large telescope began between Kuiper, Harvard University, and the University of Hawai{{okina}}i (UH), which only had experience in solar astronomy. This culminated in funds being awarded to the "upstart" UH proposal.{{cite web |title=Timeline of Astronomy in Hawai'i |url=http://mkooc.org/css-timeline.html |publisher=Mauna Kea Observatories Outreach Committee |access-date=October 2, 2010 |first=Andrew |last=Pickles |year=2003 |url-status=dead |archive-url=https://web.archive.org/web/20110727090520/http://mkooc.org/css-timeline.html |archive-date=July 27, 2011}} UH rebuilt its small astronomy department into a new Institute for Astronomy, and in 1968 the Hawai{{okina}}i Department of Land and Natural Resources gave it a 65-year lease for all land within a {{cvt|4|km|mi|1}} radius of its telescope, essentially that above {{cvt|11500|ft|m|0}}. On its completion in 1970, the UH88 was the seventh largest optical/infrared telescope in the world.

File:Mauna Kea.jpg on Maui, approximately {{cvt|78|mi|km}} away]]

By 1970, two {{cvt|24|in|m|1}} telescopes had been constructed by the US Air Force and Lowell Observatory. In 1973, Canada and France agreed to build the 3.6 m CFHT on Mauna Kea. However, local organisations started to raise concerns about the environmental impact of the observatory. This led the Department of Land and Natural Resources to prepare an initial management plan, drafted in 1977 and supplemented in 1980. In January 1982, the UH Board of Regents approved a plan to support the continued development of scientific facilities at the site. In 1998, {{cvt|2033|acre|ha|0}} were transferred from the observatory lease to supplement the Mauna Kea Ice Age Reserve. The 1982 plan was replaced in 2000 by an extension designed to serve until 2020: it instituted an Office of Mauna Kea Management,{{cite web |title=Mauna Kea Science Reserve Astronomy Development Plan 2000–2020 – Summary |url=http://www.hawaii.edu/maunakea/appendix_a.pdf |archive-url=https://web.archive.org/web/20090920100909/http://www.hawaii.edu/maunakea/appendix_a.pdf |archive-date=September 20, 2009 |publisher=Institute for Astronomy – University of Hawaii |access-date=August 19, 2010 |date=August 1999 |url-status=dead}} designated {{cvt|525|acre|ha|0}} for astronomy, and shifted the remaining {{cvt|10763|acre|ha|0}} to "natural and cultural preservation". This plan was further revised to address concern expressed in the Hawaiian community that a lack of respect was being shown toward the cultural values of the mountain.{{cite web |title=Mauna Kea Comprehensive Management Plan: UH Management Areas |url=http://archive.jan2013.hawaii.gov/dlnr/occl/mauna-kea-management-plan/comprehensive-management-plan |format=PDF |last=Institute for Astronomy – University of Hawaii |publisher=Hawai'i State Department of Land and Natural Resources |access-date=August 19, 2010 |date=January 2009 |url-status=dead |archive-url=https://web.archive.org/web/20160304045751/http://archive.jan2013.hawaii.gov/dlnr/occl/mauna-kea-management-plan/comprehensive-management-plan |archive-date=March 4, 2016}}

Today the Mauna Kea Science Reserve has 13 observation facilities, each funded by as many as 11 countries.{{cite web |url=http://archive.jan2013.hawaii.gov/dlnr/occl/random-files/mauna-kea-files/Mauna_Kea_CMP-Sect5-7.pdf |title=Mauna Kea Comprehensive Management Plan |last=University of Hawai`i |date=January 2009 |publisher=Hawai'i State Department of Land and Natural Resources |pages=6–1 |access-date=January 18, 2012 |url-status=dead |archive-url=https://web.archive.org/web/20160304071537/http://archive.jan2013.hawaii.gov/dlnr/occl/random-files/mauna-kea-files/Mauna_Kea_CMP-Sect5-7.pdf |archive-date=March 4, 2016}} There are nine telescopes working in the visible and infrared spectrum, three in the submillimeter spectrum, and one in the radio spectrum, with mirrors or dishes ranging from {{cvt|0.9|to|25|m|ft|0}}. In comparison, the Hubble Space Telescope has a {{cvt|2.4|m|ft|1}} mirror, similar in size to the UH88, now the second smallest telescope on the mountain.{{cite web |title=Mauna Kea Telescopes |url=http://www.ifa.hawaii.edu/mko/telescope_table.shtml |publisher=Institute for Astronomy – University of Hawaii |access-date=August 29, 2010 |archive-date=July 2, 2010 |archive-url=https://web.archive.org/web/20100702044615/http://www.ifa.hawaii.edu/mko/telescope_table.shtml |url-status=live }}

A "Save Mauna Kea" movement believes development of the mountain to be sacrilegious.{{cite book |author=Robert F. Oaks |title=Hawaii:: A History of the Big Island |url=https://books.google.com/books?id=HDVNJ5wzcisC&pg=PA131 |date=November 1, 2003 |publisher=Arcadia Publishing |isbn=978-1-4396-1403-7 |page=131}} Native Hawaiian non-profit groups such as Kahea, concerned with cultural heritage and the environment, also oppose development for cultural and religious reasons.{{cite book |author=Ned Kaufman |title=Place, Race, and Story: Essays on the Past and Future of Historic Preservation |url=https://books.google.com/books?id=5fCTAgAAQBAJ&pg=PA14 |date=September 11, 2009 |publisher=Routledge |isbn=978-1-135-88972-2 |page=14 |access-date=November 22, 2015 |archive-date=May 2, 2016 |archive-url=https://web.archive.org/web/20160502010211/https://books.google.com/books?id=5fCTAgAAQBAJ&pg=PA14 |url-status=live }} The multi-telescope "outrigger" proposed in 2006 was eventually canceled.{{cite news |title=Ruling could block Mauna Kea projects |url=http://www.bizjournals.com/pacific/stories/2006/08/07/daily18.html?jst=b_ln_hl |access-date=November 4, 2010 |newspaper=Pacific Business News |date=August 8, 2006 |archive-date=February 4, 2011 |archive-url=https://web.archive.org/web/20110204220924/http://www.bizjournals.com/pacific/stories/2006/08/07/daily18.html?jst=b_ln_hl |url-status=live }} A planned new telescope, the Thirty Meter Telescope (TMT), has attracted controversy and protests.{{cite web |title=Thirty Meter Telescope Selects Mauna Kea |url=http://www.tmt.org/news-center/thirty-meter-telescope-selects-mauna-kea |work=Press release |publisher=Caltech, University of California, and the Association of Canadian Universities for Research in Astronomy |access-date=August 29, 2010 |date=August 21, 2009 |url-status=dead |archive-url=https://web.archive.org/web/20100810235601/http://www.tmt.org/news-center/thirty-meter-telescope-selects-mauna-kea |archive-date=August 10, 2010}}{{cite web |title=University of Hawaii Develop New Telescope for "Killer" Asteroid Search |url=http://www.ifa.hawaii.edu/~kaiser/pan-starrs/pressrelease/ |work=Press release |publisher=Institute for Astronomy – University of Hawaii |date=October 8, 2002 |access-date=August 29, 2010 |archive-url=https://web.archive.org/web/20160323020630/http://www.ifa.hawaii.edu/%7Ekaiser/pan-starrs/pressrelease/ |archive-date=March 23, 2016 |url-status=dead}} The TMT was approved in April 2013.{{cite news |url=http://www.3news.co.nz/Massive-telescope-to-be-built-in-Hawaii/tabid/1160/articleID/294296/Default.aspx |work=3 News NZ |title=Massive telescope to be built in Hawaii |date=April 15, 2013 |access-date=April 15, 2013 |archive-date=October 8, 2014 |archive-url=https://web.archive.org/web/20141008070749/http://www.3news.co.nz/environmentsci/massive-telescope-to-be-built-in-hawaii-2013041512 |url-status=live }} In October 2014, the groundbreaking ceremony for the telescope was interrupted by protesters causing the project to temporarily halt.{{cite news |last1=Kelleher |first1=Jennifer Sinco |title=Protesters halt Mauna Kea telescope groundbreaking |url=http://www.staradvertiser.com/news/breaking/20141007_Groundbreaking_delayed_for_Hawaii_telescope.html?id=278448831 |access-date=April 4, 2015 |agency=Honolulu Star Advertiser |work=Star Advertiser |date=October 7, 2014 |archive-date=April 17, 2015 |archive-url=https://web.archive.org/web/20150417012339/http://www.staradvertiser.com/news/breaking/20141007_Groundbreaking_delayed_for_Hawaii_telescope.html?id=278448831 |url-status=live }} In late March 2015, demonstrators blocked access of the road to the summit again.{{cite news |last1=Davis |first1=Chelsea |title=Thirty Meter Telescope protesters continue to block construction on Mauna Kea |url=http://www.hawaiinewsnow.com/story/28619239/thirty-meter-telescope-protesters-continue-to-block-construction-on-mauna-kea |access-date=April 4, 2015 |agency=KHNL |publisher=WorldNow and KHNL |date=March 26, 2015 |archive-date=April 3, 2015 |archive-url=https://web.archive.org/web/20150403071928/http://www.hawaiinewsnow.com/story/28619239/thirty-meter-telescope-protesters-continue-to-block-construction-on-mauna-kea |url-status=live }} On April 2, 2015, 300 protestors were gathered near the visitor center when 12 people were arrested with 11 more arrested at the summit.{{cite news |title=Clash in Hawaii Between Science and Sacred Land |url=https://www.usnews.com/news/science/news/articles/2015/04/03/clash-over-telescope-at-sacred-hawaiian-site-intensifies |access-date=April 4, 2015 |agency=Associated Press |work=AP/U.S. News & World Report |date=April 3, 2015 |archive-date=April 11, 2015 |archive-url=https://web.archive.org/web/20150411070747/http://www.usnews.com/news/science/news/articles/2015/04/03/clash-over-telescope-at-sacred-hawaiian-site-intensifies |url-status=live }}{{cite news |title=Police, TMT Issue Statements on Mass Arrests on Mauna Kea |url=http://www.bigislandvideonews.com/2015/04/02/police-tmt-issue-statements-on-mass-arrests-on-mauna-kea/ |access-date=April 4, 2015 |agency=Big Island Video News |publisher=Big Island Video News |date=April 2, 2015 |archive-date=April 7, 2015 |archive-url=https://web.archive.org/web/20150407003405/http://www.bigislandvideonews.com/2015/04/02/police-tmt-issue-statements-on-mass-arrests-on-mauna-kea/ |url-status=live }} Among the concerns of the protest groups are the land appraisals and Native Hawaiians consultation. Construction was halted on April 7, 2015, after protests expanded over the state.{{cite web |url=https://www.usnews.com/news/science/news/articles/2015/04/07/amid-controversy-construction-of-telescope-in-hawaii-halted |title=Amid controversy, construction of telescope in Hawaii halted - US News |access-date=April 7, 2015 |archive-date=April 14, 2015 |archive-url=https://web.archive.org/web/20150414101526/http://www.usnews.com/news/science/news/articles/2015/04/07/amid-controversy-construction-of-telescope-in-hawaii-halted |url-status=live }} After several halts, the project has been voluntarily postponed. Governor Ige announced substantial changes to the management of Mauna Kea in the future but stated the project can move forward.{{cite news |title=Gov: Hawaii has 'failed' Mauna Kea; telescope can continue |url=http://www.kitv.com/news/gov-hawaii-has-failed-mauna-kea-telescope-can-continue/33231448 |access-date=July 24, 2015 |agency=Associated Press/KITV |publisher=Hearst Stations Inc. on behalf of KITV-TV |date=May 26, 2015 |url-status=dead |archive-url=https://web.archive.org/web/20150725013933/http://www.kitv.com/news/gov-hawaii-has-failed-mauna-kea-telescope-can-continue/33231448 |archive-date=July 25, 2015}} The Supreme Court of Hawai{{okina}}i approved the resumption of construction on October 31, 2018.[https://www.bbc.com/news/world-us-canada-46046864 Hawaii top court approves controversial Thirty Meter Telescope] {{Webarchive|url=https://web.archive.org/web/20190811175530/https://www.bbc.com/news/world-us-canada-46046864 |date=August 11, 2019 }} BBC News, October 31, 2018. Protestors have posted online petitions as a reaction against the Thirty Meter Telescope. The online petition titled "The Immediate Halt to the Construction of the TMT Telescope" was posted to Change.org on July 14, 2019. The online petition has currently gathered over 278,057 signatures worldwide.{{cite news |url=https://www.staradvertiser.com/2019/07/18/breaking-news/online-petition-demands-immediate-halt-to-thirty-meter-telescope-project/ |title=Online petition demanding halt to Thirty Meter Telescope project collects 100K signatures |last=Wu |first=Nina |date=July 18, 2019 |work=Honolulu Star-Advertiser |access-date=December 11, 2019 |archive-date=December 7, 2019 |archive-url=https://web.archive.org/web/20191207215752/https://www.staradvertiser.com/2019/07/18/breaking-news/online-petition-demands-immediate-halt-to-thirty-meter-telescope-project/ |url-status=live }} Some protesters have also called for the impeachment of Hawaiian Governor David Ige because of his support for the Thirty Meter Telescope. On July 18, 2019, an online petition titled "Impeach Governor David Ige" had been posted to Change.org and has currently gathered over 62,562 signatures.{{cite news |url=https://www.kitv.com/story/40814201/petition-on-changeorg-calls-for-impeachment-of-governor-david-ige |title=Petition on change.org calls for impeachment of Governor David Ige |date=July 19, 2019 |work=KITV |access-date=December 11, 2019 |archive-date=December 11, 2019 |archive-url=https://web.archive.org/web/20191211234043/https://www.kitv.com/story/40814201/petition-on-changeorg-calls-for-impeachment-of-governor-david-ige |url-status=live }}

As of late 2021, construction plans are currently on hold due to the ongoing effects of the COVID-19 pandemic and a shift in funding for the project that may see federal funds made available through the National Science Foundation.{{cite news |url=https://www.civilbeat.org/2021/11/national-panel-recommends-federal-funding-for-the-thirty-meter-telescope/ |title=National Panel Recommends Federal Funding For The Thirty Meter Telescope |first=Blaze |last=Lovell |date=Nov 4, 2021 |work=Honolulu Civil Beat |access-date=November 14, 2021 |archive-date=November 14, 2021 |archive-url=https://web.archive.org/web/20211114220323/https://www.civilbeat.org/2021/11/national-panel-recommends-federal-funding-for-the-thirty-meter-telescope/ |url-status=live }} The controversy surrounding construction of the Thirty Meter Telescope continues. Independent polls commissioned by local media organizations{{cite news |url=https://www.civilbeat.org/2019/08/civil-beat-poll-strong-support-for-tmt-but-little-love-for-ige/ |title=Strong Support for TMT |last=Blair |first=Chad |date=August 7, 2019 |work=Honolulu Civil Beat |access-date=November 14, 2021 |archive-date=August 12, 2019 |archive-url=https://web.archive.org/web/20190812043510/https://www.civilbeat.org/2019/08/civil-beat-poll-strong-support-for-tmt-but-little-love-for-ige/ |url-status=live }}{{cite news |url=https://www.westhawaiitoday.com/2020/05/28/hawaii-news/ward-research-shows-citizens-2-to-1-favor-of-telescope/ |title=Poll shows majority support for TMT |last=Staff |date=May 28, 2020 |work=West Hawaii Today |access-date=November 14, 2021 |archive-date=November 14, 2021 |archive-url=https://web.archive.org/web/20211114220323/https://www.westhawaiitoday.com/2020/05/28/hawaii-news/ward-research-shows-citizens-2-to-1-favor-of-telescope/ |url-status=live }} show consistent support for the project in the islands with over two thirds of local residents supporting the project. These same polls indicate Native Hawaiian community support remains split with about half of Hawaiian respondents supporting construction of the new telescope.

A July 2022 state law responds to the protests by shifting control over the master land lease from the University of Hawaii to the new Mauna Kea Stewardship and Oversight Authority (MKSOA).[https://www.capitol.hawaii.gov/measure_indiv.aspx?billtype=HB&billnumber=2024&year=2022 HB2024 HD1 SD2 CD1] The MKSOA is a 12-member board (11 voting members and 1 non-voting member) which includes representatives from the university, astronomers and native Hawaiians[https://www.npr.org/2022/07/31/1114314076/hawaii-mauna-kea-telescope-space-observatory On a stunning Hawaiian mountain, the fight over telescopes is nearing a peaceful end] and it was created with the aim of finding a balance between the conflicting interests of astronomers and native Hawaiians. It is placed within the Hawaii department of land and natural resources and will be the principal authority for the management of state-managed lands within the Mauna Kea lands after a 5-year transition period from the university starting on July 1, 2023.{{Cite web |title=Hawaii Revised Statutes {{!}} Chapter 195H - MAUNA KEA STEWARDSHIP AND OVERSIGHT AUTHORITY {{!}} Casetext |url=https://casetext.com/statute/hawaii-revised-statutes/division-1-government/title-12-conservation-and-resources/subtitle-6-general-and-miscellaneous-programs/chapter-195h-mauna-kea-stewardship-and-oversight-authority |access-date=2023-02-23 |website=casetext.com}} During the transition period, the MKSOA and the university will jointly manage the land while the authority develops a management plan to govern land uses, human activities, and overall operations. Once the transition period is up in 2028, the authority's responsibilities will include issuing new land use permits which will be important as the current master lease ends in 2033, and any observatories which don't come up with new leases by the time of its expiration will be decommissioned.{{Cite web |title=A New Stewardship Paradigm for Maunakea |url=https://aas.org/posts/news/2022/08/new-stewardship-paradigm-maunakea |access-date=2023-03-01 |website=aas.org |language=en}}

Mauna Kea has an alpine climate (ET). Due to the influence of its tropical latitude, temperature swings are very low. Frosts are common year round, but the average monthly temperature remains above freezing throughout the year.

Snow may fall at an altitude of {{cvt|11,000.|ft|m}} and above in any month, but occurs most often from October to April.{{Cite web|url=https://www.weather.gov/hfo/faq|title=Frequently Asked Questions|access-date=September 15, 2020|archive-date=September 16, 2020|archive-url=https://web.archive.org/web/20200916212459/https://www.weather.gov/hfo/faq|url-status=live}}

A weather station was operated from 1972 to 1982; however, only 33 months within this period have temperature records; many years only have data for two months. The temperatures presented below are smoothed averages, not the raw numbers recorded by NOAA.

{{Weather box |location=Mauna Kea Observatory, elevation: {{cvt|13,800.|ft|m}}

|single line=y

|Jan record high F=55

|Feb record high F=56

|Mar record high F=54

|Apr record high F=55

|May record high F=59

|Jun record high F=58

|Jul record high F=75

|Aug record high F=57

|Sep record high F=60

|Oct record high F=59

|Nov record high F=54

|Dec record high F=55

|Jan record low F=19

|Feb record low F=12

|Mar record low F=18

|Apr record low F=18

|May record low F=12

|Jun record low F=23

|Jul record low F=22

|Aug record low F=17

|Sep record low F=23

|Oct record low F=20

|Nov record low F=20

|Dec record low F=17

|Jan high F=42.0

|Feb high F=42.5

|Mar high F=40.3

|Apr high F=41.4

|May high F=47.5

|Jun high F=49.3

|Jul high F=50.9

|Aug high F=49.9

|Sep high F=50.5

|Oct high F=43.8

|Nov high F=45.1

|Dec high F=42.7

|Jan low F=26.3

|Feb low F=26.1

|Mar low F=24.9

|Apr low F=26.2

|May low F=29.0

|Jun low F=29.4

|Jul low F=30.3

|Aug low F=30.9

|Sep low F=31.3

|Oct low F=29.5

|Nov low F=27.8

|Dec low F=27.6

|Jan precipitation inch=0.81

|Feb precipitation inch=0.24

|Mar precipitation inch=1.05

|Apr precipitation inch=0.50

|May precipitation inch=0.92

|Jun precipitation inch=0.14

|Jul precipitation inch=0.29

|Aug precipitation inch=0.77

|Sep precipitation inch=0.51

|Oct precipitation inch=0.58

|Nov precipitation inch=1.04

|Dec precipitation inch=0.52

|source 1=[http://www.wrcc.dri.edu/ Western Regional Climate Center]{{cite web |author=WRCC |title=Western U.S. Climate Historical Summaries Weather |url=http://www.wrcc.dri.edu/cgi-bin/cliMAIN.pl?hi6183 |publisher=Western Regional Climate Center |access-date=September 15, 2020 |archive-date=May 16, 2019 |archive-url=https://web.archive.org/web/20190516134916/https://wrcc.dri.edu/cgi-bin/cliMAIN.pl?hi6183 |url-status=live }}

|date=September 2020}}

File:A173, Hawaii, USA, Mauna Kea, from outskirts of Hilo, 2007.JPG near Hilo]]

Mauna Kea's coastline is dominated by the Hamakua Coast, an area of rugged terrain created by frequent slumps and landslides on the volcano's flank.{{cite book |last1=Juvik |first1=Sonia P. |last2=Juvik |first2=James O. |last3=Paradise |first3=Thomas R. |title=Atlas of Hawaii |edition=3rd |year=1998 |publisher=University of Hawaii Press |location=Hilo |isbn=0-8248-2125-4 |page=71}} The area includes several recreation parks including Kalopa State Recreation Area, Wailuku River State Park and Akaka Falls State Park.{{cite web |title=Hawaii Island |publisher=Hawaii Department of Land and Natural Resources |url=http://dlnr.hawaii.gov/dsp/parks/hawaii/ |access-date=July 27, 2017 |archive-date=July 26, 2017 |archive-url=https://web.archive.org/web/20170726122232/http://dlnr.hawaii.gov/dsp/parks/hawaii/ |url-status=live }}

There are over 3,000 registered hunters on Hawaii island, and hunting, for both recreation and sustenance, is a common activity on Mauna Kea. A public hunting program is used to control the numbers of introduced animals including pigs, sheep, goats, turkey, pheasants, and quail. The Mauna Kea State Recreation Area functions as a base camp for the sport. Birdwatching is also common at lower levels on the mountain. A popular site is Kīpuka Pu{{okina}}u Huluhulu, a kīpuka on Mauna Kea's flank that formed when lava flows isolated the forest on a hill.{{cite book |title=Hawai'i: The big island |publisher=Lonely Planet |isbn=978-1-74059-691-6 |pages=[https://archive.org/details/lonelyplanethawa00luci/page/145 145–46]|chapter-url=https://books.google.com/books?id=T83kOvN6aTYC&q=Pu%E2%80%99u%20Huluhulu%20Native%20Tree%20Refuge&pg=PA145 |first1=Alan |last1=Tarbell |first2=Luci |last2=Yamamoto |chapter=Around Mauna Kea |date=August 1, 2005 |url-access=registration |url=https://archive.org/details/lonelyplanethawa00luci/page/145}}

File:A152, Hawaii, USA, Mauna Kea observatories, from summit, 2007.JPG, UH88, Gemini North, and CFHT]]

Mauna Kea's great height and the steepness of its flanks provide a better view and a shorter hike than the adjacent Mauna Loa. The height with its risk of altitude sickness, weather concerns, steep road grade, and overall inaccessibility make the volcano dangerous and summit trips difficult. Until the construction of roads in the mid-20th century, only the hardy visited Mauna Kea's upper slopes; hunters tracked game animals, and hikers traveled up the mountain. These travelers used stone cabins constructed by the Civilian Conservation Corps in the 1930s as base camps, and it is from these facilities that the modern mid-level Onizuka Center for International Astronomy telescope support complex is derived. The first Mauna Kea summit road was built in 1964, making the peak accessible to more people.

Today, multiple hiking trails exist, including the Mauna Kea Trail, and by 2007 over 100,000 tourists and 32,000 vehicles were going each year to the Visitor Information Station (VIS) adjacent to the Onizuka Center for International Astronomy. The Mauna Kea Access Road is paved up to the Center at {{cvt|2804|m|ft|0}}. One study reported that around a third of visitors and two-thirds of professional astronomers working on the mountain have experienced symptoms of acute altitude sickness.{{cite journal |doi=10.1089/ham.2007.8307 |author1=Onopa, J. |author2=Haley, A. |author3=Yeow, M. E. |title=Survey of acute mountain sickness on Mauna Kea |journal=High Altitude Medicine & Biology |volume=8 |issue=3 |pages=200–5 |year=2007 |pmid=17824820}} Visitors to the mountain should prepare ahead of time by acclimating at a lower elevation or using a prescription medicine like Diamox.{{cite journal |last1=Dziezynski |first1=James |title=Hike Mauna Kea: The Expert Guide to Hiking Hawaii’s Highest Point |journal=Backpacker Magazine |date=October 25, 2023 |url=https://www.backpacker.com/trips/trips-by-state/hawaii-trails/hike-mauna-kea/ |access-date=26 October 2023}} It is strongly recommended to use a four-wheel drive vehicle to drive all the way to the top. Brakes often overheat on the way down and there is no fuel available on Mauna Kea.{{cite web |title=Mauna Kea Hazards: Please Read Before Travelling Above Hale Pohaku |url=http://irtfweb.ifa.hawaii.edu/observing/safety/MK_Hazards.pdf |work=Safety Leaflet |publisher=Institute for Astronomy – University of Hawaii |access-date=August 28, 2010 |archive-url=https://web.archive.org/web/20100609215514/http://irtfweb.ifa.hawaii.edu/observing/safety/MK_Hazards.pdf |archive-date=June 9, 2010 |url-status=dead}} A free Star Gazing Program was previously held at the VIS every night from 6-10 pm, with the program canceled due to both a change in operating hours and closure due to the ongoing COVID-19 pandemic.{{cite web |title=Star Gazing Program |publisher=Mauna Kea Support Services |url=http://www.ifa.hawaii.edu/info/vis/visiting-mauna-kea/star-gazing-program.html |access-date=September 18, 2014 |archive-url=https://web.archive.org/web/20140820032021/http://www.ifa.hawaii.edu/info/vis/visiting-mauna-kea/star-gazing-program.html |archive-date=August 20, 2014 |url-status=dead}}{{cite web |title=Maunakea Visitor Information Station |publisher=Mauna Kea Support Services |url=http://www.ifa.hawaii.edu/info/vis/ |access-date=June 11, 2020 |archive-date=February 11, 2015 |archive-url=https://web.archive.org/web/20150211034901/http://www.ifa.hawaii.edu/info/vis/ |url-status=live }} Between 5,000 and 6,000 people visit the summit of Mauna Kea each year, and to help ensure safety, and protect the integrity of the mountain, a ranger program was implemented in 2001.

{{Portal|Oceania|United States|Hawaii|Mountains|Volcanoes}}

• Evolution of Hawaiian volcanoes
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{{Notelist}}

{{Reflist}}

• Ciotti, Joseph E. (2011). [https://evols.library.manoa.hawaii.edu/items/9d28969e-058a-475a-9f61-e51f5ac36d8d "Historical Views of Mauna Kea: From the Vantage Points of Hawaiian Culture and Astronomical Research]". Hawaiian Journal of History. 45, 147–66.

{{Commons and category}}

; Geology

• http://hvo.wr.usgs.gov/volcanoes/maunakea/ {{Webarchive |url=https://web.archive.org/web/20061021204300/http://hvo.wr.usgs.gov/volcanoes/maunakea/|date=October 21, 2006 }}
• [http://www.volcano.si.edu/world/volcano.cfm?vnum=1302-03- Mauna Kea Summary]—Global Volcanism Program
• [http://www.soest.hawaii.edu/GG/HCV/maunakea.html Mauna Kea]. Hawaii Center for Volcanology.

; Astronomy and culture

• [http://www.ifa.hawaii.edu/mko/ Mauna Kea Observatories]. Tour of Mauna Kea's summit facilities.
• [http://www.ifa.hawaii.edu/info/vis/ Mauna Kea Visitor Information]. Information pertaining to visiting the summit telescopes.

; Ecology and management

• [http://www.malamamaunakea.org/ Office of Mauna Kea Management]. Plan for land management.
• [http://dlnr.hawaii.gov/ecosystems/nars/reserves/hawaii-island/mauna-kea-ice-age/ Mauna Kea Ice Age Reserve]. Department of Land and Natural Resources.

{{Hawaii highest}}

{{Hawaiian volcanism}}

{{U.S. State Highest Points}}

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