Mount Katmai
| Mount Katmai | |
|---|---|
Mount Katmai and its crater lake in September 1980.
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| Highest point | |
| Elevation | 6,716 ft (2,047 m) |
| Coordinates | 58°16′43.0″N 154°57′24.9″W / 58.278611°N 154.956917°W |
| Geography | |
| Location | Katmai National Park and Preserve, Alaska, United States |
| Parent range | Aleutian Range |
| Topo map | USGS Mount Katmai B-3 |
| Geology | |
| Mountain type | Stratovolcano |
| Volcanic arc/belt | Aleutian Arc |
| Last eruption | June to July 1912 |
| Climbing | |
| Easiest route | basic snow/ice climb |
Mount Katmai is a large stratovolcano (composite volcano) on the Alaska Peninsula in southern Alaska, located within Katmai National Park and Preserve. It is about 6.3 miles (10 km) in diameter with a central lake-filled caldera about 3 by 2 mi (4.5 by 3 km) in area, formed during the Novarupta eruption of 1912. The caldera rim reaches a maximum elevation of 6,716 feet (2,047 m). In 1975 the surface of the crater lake was at an elevation of about 4,220 feet (1,286 m), and the estimated elevation of the caldera floor is about 3,400 ft (1,040 m). The mountain is located in Kodiak Island Borough, very close to its border with Lake and Peninsula Borough.
Mount Katmai is one of five vents encircling the Novarupta volcano, source of the VEI 6 eruption and associated voluminous pyroclastic flows in 1912. The volcano has caused ten known fatalities due to gas exposure. Katmai consists chiefly of lava flows, pyroclastic rocks, and non-welded to agglutinated air fall. The Quaternary volcanic rocks at Katmai and adjacent cones are less than 5,000 ft (1,500 m) thick. Much of the volcano is mantled by snow and ice and several valley glaciers radiate out from the flanks.
Katmai volcano is built on the sedimentary rocks of the Naknek Formation of Late Jurassic age, which are exposed just west of the caldera rim at an elevation of about 5,000 feet (1,520 m), as well as north and southeast of the crater. Sedimentary rocks have been reported at an elevation of over 6,000 feet (1,830 m) in the west wall of the caldera and near the bottom of the eastern wall near 3,400 ft (1,040 m).
Little is known about the historical activity of Katmai volcano before the great 1912 eruption. Early U.S. Coast and Geodetic Survey maps suggest a pre-caldera summit elevation of about 7,500 ft (2,300 m), and local villagers reported in 1898 that one of the volcanoes in the general area "smoked" occasionally.
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Wikipedia