Great Sitkin volcan
Mise à jour: 31 janv.. 2023 21:30 GMT -
Stratovolcano 1740+ m / 5,709 ft
United States, Aleutian Islands, 52.08°N / -176.13°W
Condition actuelle: Activité petite ou avertissement éruption imminente (3 sur 5)
United States, Aleutian Islands, 52.08°N / -176.13°W
Condition actuelle: Activité petite ou avertissement éruption imminente (3 sur 5)
Last update: 25 janv. 2023 (Smithsonian / USGS Weekly Volcanic Activity Report)
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Eruptions du volcan Great Sitkin: 2021, 1974
Derniers séismes proches
| Heure | Mag. / Profondeur | Distance/Lieu | ||
| vendredi, 20 janvier 2023 GMT (1 séisme) | ||||
| 20 janv. 2023 11:08 (GMT -10) (20 janv.. 2023 21:08 GMT) | 1.4 9.2 km | 21 km (13 mi) 30 Km E of Adak, Alaska | ||
Introduction
Constructed within the caldera of an older shield volcano forming the northern half of Great Sitkin Island, 1740-m-high Great Sitkin volcano contains a small, 0.8 x 1.2 km ice-filled summit caldera. Deep glacial valleys radiate from the summit, which lies at the eastern rim of the caldera, which was formed by massive edifice failure that produced a submarine debris avalanche that traveled more than 40 km to the north. The entire island is blanketed with a light-brown to black pumice layer up to 6 m thick. This deposit is overlain over much of the NW side of the island by ash deposits from a subsidiary vent NW of the caldera. Hot springs, mud pots, and fumaroles occur near the head of Big Fox Creek, south of the volcano. Historical eruptions have been recorded since the late-19th century. In 1945, a 400-600 m wide, flat-topped lava dome was emplaced through a glacier filling the steep-sided, 180-m-deep summit caldera.---
Smithsonian / GVP volcano information
See also: Sentinel hub | Landsat 8 | NASA FIRMS
