Geologic Background:
Karymsky, the most active volcano of east
Kamchatka, is located approx. 130 km north of
Petropavlovsk-Kamchatsky, near the trans-Kamchatka air
route. It is a symmetrical stratovolcano constructed
within a 5-km-wide caldera that formed during the early
Holocene. The last eruptive period began about 500 years
ago, following a 2,300 year quiescence. Much of the cone
is mantled by lava flows less than 200 years old. Eleven
eruptions were recorded between 1945 and 1970, but since
1982 relative calm has prevailed.
Karymsky and Akademia Nauk are part of the 50 x 35 km
Karymsky Volcanic Center (sometimes referred to as the
Zhupanovky volcano-tectonic depression). Located in the
Eastern Kamchatka volcanic belt, 30 km from the Kronotsky
Gulf and Pacific Ocean, this center contains 21 volcanic
edifices, six calderas, and two historically active
stratovolcanoes, Karymsky and Maly Semiachik.
The 5-km-diameter Karymsky Caldera formed 7,600-7,700
radiocarbon years ago and the Karymsky cone has been
growing in the center of the caldera about 2,000 years
later, ejecting andesitic and dacitic materials.
Akademia Nauk caldera, which was named by the famous
Russian volcanologist Vladimir Vlodavetz in 1939, is
located imediately to the south in the SW part of the
Karymsky Volcanic Center. Its activity began about 50,000
years ago. The north part of the caldera is occupied by
Karymsky Lake (4 km wide, 12.5 sq km in area, and 80 m
deep).
Historic Activity:
- Historical reports on Karymsky's eruptions have been
available sine 1771. During that period of time, more
than 20 prolonged eruptions were separated by quiet
periods as long as 10 years. The most recent previous
eruption continued from 1970 to1982.
- Eruptions in 1771, 1830, 1852, 1854, 1908, 1911,
1912, 1915, 1921, 1923, 1925, 1929, 1932-1935, 1938,
1940, 1943, 1945-1947, 1952, 1953, 1955- 1957, 1960-1967,
1970-1973, 1975, 1976, 1979, and 1982.
Recent Activity:
- Karymsky's most recent reported eruption lasted from
1970 until October 1982, generating moderate explosions,
pyroclastic flows, lahars, lava flows, and lava dome
extrusion from the summit crater. Small lava flow was
photographed by Space Suttle astronauts on May 3, 1985.
Small steam emissions were reported at the summit in
August 1993.
- Increased seismicity was reported in April 1995.
- An eruption began on Jan 2, 1996 from the summit of
Karymsky and from the lake (Karymsky Lake) within the
Akademia Nauk caldera, previously considered to be
extinct. Ash and gas clouds from the summit vent on
Karymsky fed a plume rising to 1 km above the crater.
Violent subaqueous explosions occurred several times per
hour at Akademia Nauk caldera lake with an eruption cloud
rising to 8 km. Major activity was finished by Jan. 5 but
minor activity continued through December.
- 1997 began with ongoing low-level Strombolian
eruptions which continued through August 1999 and then
began to decline and end in December.
- Activity resumed in Feb. 2000. Pyroclastic flow in
late June.
- Increased seismicity from December 2000 through
September 2001.
Data Sources
- Smithsonian's SEAN Bulletin (V. 1, No. 7 to V. 10,
No. 4)
- Global Volcanism Network (V. 15, No. 3 to V. 26, No.
8).
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