BackgroundThe large Gorely volcano has a very complex structure: The edifice fills a large 9 x 13.5 km caldera occupied by 3 closely spaced overlapping stratovolcanoes with 11 summit craters and more than 30 flank craters. The lavas of Gorely are mainly basalt and basaltic andesite and the volcano developed along a WNW-ESE line within the caldera. It is cut by 3 rift zones. Some of the craters contain acid or freshwater crater lakes.
The caldera formed after a giant plinian eruption that produced about 100 cubic miles of tephraabout 38,000-40,000 years ago.
Historic activity of Gorely volcano can be traced since the 19th century. 4 explosive eruptions from summit craters occured in 1828, 1832, 1855, and 1869. The first historic eruptions in 1929-30 produced several strong eruptions which ejected ash and larger fragments of rock, and ash plumes that reached the Pacific coast, Petropavlovsk-Kamchatsky, and the village of Nachiki at 150 km from the volcano.
In the 20th century, seven eruptions occured in 1929, 1930, 1931, 1947, 1961, 1980-1981, and 1984-1986. During the last 1984-1986 eruption, the ash plumes reached 3.5 km height and a crater was formed that is now filled with a lake.
A cinder cone on Gorely's NE flank. (Photo: Tom Pfeiffer)
Crater of Gorely volcano, Kamchatka (Photo: AndreyNikiforov)
The crater lake of the central summit crater of Gorely is partially frozen. (Photo: Tom Pfeiffer)
Vilyuchik volcano is always visible behind as we decide to climb Gorely in the afternoon. (Photo: Tom Pfeiffer)
Gorely volcano tours:Kamchatka - Land of Colors (volcano expedition to Kamchatka)
See also: Sentinel hub | Landsat 8 | NASA FIRMS