Mauna Kea

of a dry Mauna Kea, connecting it to Mount Everest. Mauna Kea's peak stands 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. It is the highest peak on its island, so its wet prominence matches its height above sea level, at . Unlike prominence, base is loosely defined, which has resulted in numbers ranging from and the Himalayan Mountains have tremendously deep roots. The climb between parts of the Atacama Trench and Andes Mountains has been described as "the highest slope on earth": the bottom of Richard's Deep ( deep) to the peak of the nearby Llullaillaco ( high) is . Neither Mount Lamlam nor Llullaillaco have the dry prominence of Mauna Kea, because they do not extend into trenches in every direction. ==Geology==

File:Location Mauna Kea.svg|thumb|left|Clickable imagemap of Hawaii island showing the location of Mauna Kea, making up 22.8 percent of the island's surface area Of these five hotspot volcanoes, Mauna Kea is the fourth oldest and fourth most active. Mauna Kea entered its quieter post-shield stage 250,000 to 200,000 years ago, The volcano continues to slip and flatten under its own weight at a rate of less than per year. Much of its mass lies east of its present summit. It stands above sea level, about higher than its neighbor Mauna Loa, and is the highest point in the state of Hawaii. 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. However, while Hawaiian volcanism is well understood and extensively studied, there remains no definite explanation of the mechanism that causes the hotspot effect. 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. 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. 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. 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. 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. 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. 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, although one study indicates that the last eruption may have been around 3,600 years ago. At their maximum extent, the glaciers extended from the summit down to between of elevation. A small body of permafrost, less than across, was found at the summit of Mauna Kea before 1974, and may still be present. Mauna Kea is home to Lake Waiau, the highest lake in the Pacific Basin. At an altitude of , it lies within the Puu Waiau cinder cone and is the only alpine lake in Hawaii. The lake is very small and shallow, with a surface area of and a depth of 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. No artesian water was known on the island of Hawaiʻi until 1993 when drilling by the University of Hawaiʻi tapped an artesian aquifer more than below sea level, that extended more than 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 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. 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 Hawaiʻi'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." Future activity The last eruption of Mauna Kea was about 4,600 years ago (about 2600 BC); 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 aā, 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. ==Human history==

Native history '' facing Mauna Kea, on Saddle Road between Mauna Kea and Mauna Loa The first Ancient Hawaiians to arrive on Hawaiʻi 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. 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. 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. 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 Hawaiʻi appears to have been the introduction of the Polynesian (or Pacific) rat. The five volcanoes of Hawaiʻi are revered as sacred mountains. 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. Poliahu, deity of snow, also resides there. Wākea is also the Hawaiian sky god. 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. 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. • 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 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 Hawaiʻi. In the late 19th and early 20th centuries trails were formed, often by the movement of game herds, that could be traveled on horseback. Today, multiple trails to the summit exist, in various states of use. ==Ecology==

Background Hawaiʻi's geographical isolation strongly influences its ecology. Remote islands like Hawaiʻi have a large number of species that are found nowhere else (see Endemism in the Hawaiian Islands). 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 Hawaiʻi 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. These ecosystems can be roughly divided into three sections by elevation: alpine–subalpine, montane, and basal forest. Alpine environment (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. 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. This ecosystem is a likely haven for the threatened uau (Pterodroma sandwichensis) and also the center of a study on wēkiu bugs (Nysius wekiuicola). 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. Several native moths are also present near the summit including Agrotis helela and Agrotis kuamauna. Māmane–naio forest (Sophora chrysophylla) trees The forested zone on the volcano, at an elevation of , 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. 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 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 Hawaiʻi 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). 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, Hawaiʻi state was required to remove all feral animals from the mountainside. There are many other species and ecosystems on the island, and on Mauna Kea, that remain threatened by human development and invasive species. Lower environment 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-ōhia) forest. 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. The Hakalau Forest National Wildlife Refuge is a major koa forest reserve on Mauna Kea's windward slope. It was established in 1985, covering 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. 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–ōhia forest include the Hawaiian crow (Corvus hawaiiensis), the 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. ==Summit observatories==

. 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. These factors historically made Mauna Kea an excellent spot for stargazing. UH rebuilt its small astronomy department into a new Institute for Astronomy, and in 1968 the Hawaiʻi Department of Land and Natural Resources gave it a 65-year lease for all land within a radius of its telescope, essentially that above . designated for astronomy, and shifted the remaining 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. Today the Mauna Kea Science Reserve has 13 observation facilities, each funded by as many as 11 countries. 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 . A "Save Mauna Kea" movement believes development of the mountain to be sacrilegious. Native Hawaiian non-profit groups such as Kahea, concerned with cultural heritage and the environment, also oppose development for cultural and religious reasons. The multi-telescope "outrigger" proposed in 2006 was eventually canceled. A planned new telescope, the Thirty Meter Telescope (TMT), has attracted controversy including the Thirty Meter Telescope protests. The TMT was approved in April 2013. In October 2014, the groundbreaking ceremony for the telescope was interrupted by protesters causing the project to temporarily halt. In late March 2015, demonstrators blocked access of the road to the summit again. On April 2, 2015, 300 protestors were gathered near the visitor center when 12 people were arrested with 11 more arrested at the summit. Among the concerns of the protest groups are the land appraisals and Native Hawaiians consultation. 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. The Supreme Court of Hawaiʻi approved the resumption of construction on 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. 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. 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. The controversy surrounding construction of the Thirty Meter Telescope continues. Independent polls commissioned by local media organizations 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 Hawaiʻi to the new Mauna Kea Stewardship and Oversight Authority (MKSOA). 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 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. 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. ==Climate==

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 and above in any month, but occurs most often from October to April. 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: ==Recreation==

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. The area includes several recreation parks including Kalopa State Recreation Area, Wailuku River State Park and Akaka Falls State Park. 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. , UH88, Gemini North, and the Canada–France–Hawaii Telescope 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. Visitors to the mountain should prepare ahead of time by acclimating at a lower elevation or using a prescription medicine like Diamox. 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. 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. 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. ==See also==