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Mauna Kea



         


Mauna Kea is a dormant volcano in the Hawaiian Islands, one of five volcanic peaks that together form the Island of Hawaii. In Hawaiian mauna kea means "white mountain", a reference to the fact that it is regularly snow or frost capped in the northern hemisphere winter. The top of the mountain peaks out at 4,205 m (13,796 ft) on Pu'u Wēkiu (one of numerous cinder cones on the summit), the highest point in the Hawaiian Islands. It is also the tallest mountain in the world when measured from the base under the surface of the Pacific Ocean to the summit.

Although snow and ice occur now mostly in the period from November through March, Mauna Kea had permanent (year-round) ice caps 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.

The elevation and location of Mauna Kea have made it an important location for atmospheric and astronomical observations. The summit is above approximately 40% of Earth's atmosphere and 90% of the water vapor, allowing for exceptionally clear images. Additionally, the peak is well above the inversion layer, allowing up to 300 clear nights per year. Also, at 20°N latitude, much of both the northern and southern skies are visible. The summit is widely known for its observatories built by many nations, the best seeing disk with a measurement of ~0.2 arcseconds.

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