From Freepedia
<tr><td style="border-top:1px solid #999966; border-right:1px solid #999966" bgcolor=#e7dcc3 width=85>
Coordinates:
<td style="border-top:1px solid #999966" width=220>
19°49′15.7″ N 155°28′06.0″ W
<tr><td style="border-top:1px solid #999966; border-right:1px solid #999966" bgcolor=#e7dcc3 width=85>
Topo map:
<td style="border-top:1px solid #999966" width=220>
USGS Mauna Kea
<tr><td style="border-top:1px solid #999966; border-right:1px solid #999966" bgcolor=#e7dcc3 width=85>
Type:
<td style="border-top:1px solid #999966" width=220>
Shield volcano
<tr><td style="border-top:1px solid #999966; border-right:1px solid #999966" bgcolor=#e7dcc3 width=85>
Age of rock:
<td style="border-top:1px solid #999966" width=220>0.4
Ma
<tr><td style="border-top:1px solid #999966; border-right:1px solid #999966" bgcolor=#e7dcc3 width=85>
Last eruption:
<td style="border-top:1px solid #999966" width=220>~2460 BC ± 100 years
</table>
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 during the northern hemisphere winter. Its highest point, Pu'u Wēkiu (one of numerous
cinder cones on the summit), is the highest point in the state of
Hawaii at 4,207 m (13,803 ft). Mauna Kea is also the tallest mountain in the world when measured from base to peak, its base being some 5,000 m (over 16,000 ft) under the surface of the
Pacific Ocean. After millions of years of building itself up by volcanic activity, the mountain's height is slowly decreasing as it is being crushed under its own massive weight into the Pacific seafloor.
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. (Woodcock
et al., 1970) 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. Finally, the fact that it's a
shield volcano has meant that road transportation to the summit is relatively easy. All of these factors have made Mauna Kea a prime target for state-of-the-art astronomy, and the summit is home to many different
observatories.
See also
References
- Woodcock AH, Furumoto AS, Woollard GP (1970). Fossil ice in hawaii?. Nature 226 (5248): 873. PMID 16057558
External links
