Mauna Kea with its seasonal snowcap, viewed from Kohala Mountain
|Elevation||13,803 ft (4,207.2 m) NAVD 88 |
|Prominence||13,803 ft (4,207.2 m) Ranked 15th|
U.S. state high point
|Range||Hawaiian-Emperor seamount chain|
|Topo map||USGS Mauna Kea|
|Age of rock||About one million years|
|Volcanic arc/belt||Hawaiian-Emperor seamount chain|
|Last eruption||About 2460 BC ± 100 years|
Mauna Kea (pronounced /ˌmɔːnə ˈkeɪ.ə/ or /ˌmaʊnə ˈkeɪ.ə/ in English, [ˈmounə ˈkɛjə] in Hawaiian) is an inactive volcano in the U.S. state of Hawaii, one of five volcanoes which together form the island of Hawaii. Mauna Kea, according to some etymologists is a contraction of Mauna-o-Wakea, meaning in English, "Mountain of the deity Wakea." The modern form, "Mauna Kea," means "white mountain" in the Hawaiian language, a reference to its summit being regularly covered by snow in winter.
The peak of Mauna Kea is 13,803 feet (4,207 m) above mean sea level, about 100 feet (30 m) taller than neighboring Mauna Loa and about 30,000 feet (9,100 m) above its base on the floor of the Pacific Ocean. By this measurement, Mauna Kea is the world's tallest mountain, taller than Mount Everest, which is the highest mountain above sea level.
Pu'u Wekiu, traditionally known as Pu‘u o Kukahau‘ula, is the highest of the numerous cinder cones on the summit plateau. It is also the highest point in the state. Mauna Kea can be reached via the Saddle Road.
Mauna Kea is in the post-shield stage of volcanic evolution, having made the transition from the shield stage about 200,000 to 250,000 years ago. At that time, its appearance was probably quite similar to that of its neighbor Mauna Loa today, a smooth shield volcano with a large summit caldera. Following the transition, eruptions became more explosive in character, resulting in the formation of numerous overlapping cinder cones which eventually filled and completely obscured the caldera. These cinder cones now form the peaks at the summit of Mauna Kea, with several of them exceeding 13,500 feet (4,100 m) in elevation. After several hundred thousand years of slowly building itself up by volcanic activity, the mountain's height is slowly decreasing now as its massive weight depresses the Pacific seafloor beneath it.
The summit of Mauna Kea was entirely covered by a massive ice cap during the Pleistocene ice ages. The summit shows evidence of four periods of glaciation over the last 200,000 years, the last ending about 11,000 years ago, at the end of the most recent glacial period. The dense rock at the Mauna Kea Adz Quarry near the summit is believed to have been formed when lava erupted under a glacier.
The summit plateau of Mauna Kea is entirely above timberline, with a landscape of mostly lava rock with patches of alpine tundra. Snowfall often occurs at elevations above 11,000 feet (3,400 m) during the period from November through March. During particularly cold and wet winters, which are usually linked to La Niña, a snowpack several feet (1 m) deep may remain in the summit region above 13,000 feet (4,000 m) for weeks or months. This permits skiing and other snowplay activities on the slopes of the cinder cones.
A bit lower is the area where the endemic Mauna Kea silversword can be found.
Between 5,200 and 8,000 feet (1,600 and 2,400 m) there is a band of ranch land which was formerly koa-mamane forest but has been almost entirely converted to pasture. This area has suffered from heavy infestations of gorse, an invasive species in Hawaii. Most of the north and west slopes are also pasture. The palila, an endangered finch-like honeycreeper, feeds almost exclusively on mamane seeds and lives in mamane-naio forest on the west slope. Large numbers of feral sheep inhabit the upper elevations, and have had a severe impact on the native vegetation.
The windward (eastern) slopes are covered in Hawaiian tropical rainforests between about 1,500 and 5,200 feet (460 and 1,600 m). Lower on the mountain are extensive agricultural lands that formerly included vast areas of sugarcane. 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 summit of Mauna Kea has been a celestial observatory since ancient times and is considered to be one of the best astronomical sites in the world. For this reason it is home to many of the world's leading astronomical observatories. The summit is above approximately 40% of Earth's atmosphere and 90% of the water vapor, allowing for exceptionally clear images of the night sky. Additionally, the peak is well above the inversion layer, which leads to approximately 300 clear nights per year. Also, at 20°N latitude, all of the northern sky and most of the southern sky is visible. The fact that it is a shield volcano has meant that road transportation to the summit is relatively easy. The low population density of the Island of Hawaii means that there is little light pollution from man-made sources. All of these factors have made Mauna Kea an ideal location for state-of-the-art astronomy.
Construction of telescopes on Mauna Kea has been a source of intense legal and political controversy in recent years. Due to the qualities listed above, it is a highly favored location and the summit area is now home to over a dozen telescopes. Native Hawaiians and environmental groups have protested that construction of additional telescopes would cause considerable environmental damage and further desecrate a site of great cultural importance. According to legend, the summit of Mauna Kea is the home of the snow goddess, Poliahu, and many other deities. It is also an important site for prayer, burials, consecration of children, and traditional celestial observation. In addition, the summit area is home to a unique insect, the wēkiu bug, which feeds on insects blown to the summit by updrafts. The insect itself is a major point of debate. Mercury spills (before 1995) and sewage dumps have also occurred at the existing telescopes; these are of particular concern because of the unique and otherwise-pristine underground water systems in the area.
Over the past decade, major legal battles have raged through Hawaii's court system over these issues. On January 19, 2007, the Third Circuit Court reaffirmed its decision to halt all further development on Mauna Kea until an appropriate Management Plan that sufficiently addresses the environmental damage and cultural impacts posed by astronomical development has been fully approved. The CMP was approved by the state board of Land and Natural Resources on April 9, 2009.
Plans for two additional telescopes have been moving forward. The Thirty Meter Telescope (TMT) project, the single largest optical/infrared telescope ever built on Earth, is currently being proposed by a partnership including The University of California, Caltech, and The Gordon and Betty Moore Foundation. Mauna Kea was selected as the site for the TMT in July, 2009, with design and legal approvals moving forward. Several science institutes, in collaboration with the United States Air Force are planning to build Pan-STARRS, a major telescope project. The California Institute of Technology has announced that the CalTech Submillimeter Observatory will be decommissioned in 2016, with the facility entirely removed and the site restored to a natural state.
Mauna Kea is a dormant volcano in the Hawaiian Islands. It is the highest point in Hawaii at 4,205 meters. If measured from top to bottom, below sea level, it is 10,200 meters high and would be the tallest mountain in the world. It is around 1,000,000 years old. Mauna Kea means 'white mountain' because in winter it often has snow at the summit.
Mauna Kea is an important site for astronomy, with many different countries or institutions having an observatory there.
It is an important site for its high altitudes and clear skies.
High altitude is important because atmosphere causes an effect called seeing, which limits the quality of images by blurring them. By having a high altitude, there is less atmosphere between the observatories and space and this lessens the effect.