Kamchatkan and Northern Kurile Volcanic Activity
INFORMATION RELEASE 15-05
Tuesday, March 01, 2005, 10:45 KST (22:45 UTC on February 28)

The Alaska Volcano Observatory (AVO) received the following release via
e-mail from KVERT (Kamchatkan Volcanic Eruptions Response Team). Kamchatkan
Standard Time (KST) is 21 hours ahead of Alaska Standard Time. All time and
dates are UTC, if not marked specifically.

SHEVELUCH VOLCANO: 56 38'N, 161 19'E; Elevation 3,283 m, the dome elevation
~2,500 m.
CURRENT LEVEL OF CONCERN COLOR CODE IS ORANGE.
PREVIOUS LEVEL OF CONCERN COLOR CODE WAS RED.

Unrest at the volcano continues. According to seismic data, the large
eruption occurred from 6:25 to 13:00 UTC on February 27.

Seismic activity abruptly increased on February 27 consisting of
spasmodic volcanic tremor of 1.14 x10-6 mps. According to satellite
data from Russia (TERRA MODIS at 00:05 UTC on February 28), ash
deposits covered an area of Kamchatka of 24,800 square kilometer to
the west from the volcano. A linear thermal anomaly of 10-25-pixels
was observed on AVHRR imagery at 10:22 UTC on February 28 (AVO, USA).
A resuspended ash cloud covering >360 km centered over western half
Kamchatka and Sea of Okhotsk was also observed (AVHRR) at 04:17 UTC.

Seismic activity was above background levels on February 24-26. Weak
shallow earthquakes at a depth of 0-5 km beneath the active dome were
constantly registered. Intermittent spasmodic volcanic tremor of 0.24-0.35
x10-6 mps was recorded on February 24-26. According to seismic data,
possible ash-gas explosions up to 4,700 m (or 15,400 ft.) ASL occurred at
22:43 UTC on February 25. According to video data, a gas-steam plume rose
up to 300 - 1,000 m above the dome (9,200 - 11,500 ft ASL) on February
24-25 extending to the north-east on February 24, for > 10 km (or 6.2 mi)
and to the north-west west on February 25. Clouds obscured the volcano at
other times. According to satellite data from the USA and Russia, a
2-6-pixel thermal anomaly was registered at the dome on February 24-26.

Olga Girina
Kamchatkan Volcanic Eruptions Response Team
IVS FED RAS, Piip Blvd, 9
Petropavlovsk-Kamchatsky, 683006 RUSSIA
E-mail: girina@kcs.iks.ru
Tel. (41522) 58627

Svetlana Droznina
Kamchatkan Volcanic Eruptions Response Team
KEMSD GS RAS, Piip Blvd, 9
Petropavlovsk-Kamchatsky, 683006 RUSSIA
E-mail: ssl@emsd.iks.ru
Tel. (41522) 59523

John Power, Acting Scientist-in-Charge, Alaska Volcano Observatory
4200 University Drive
Anchorage, Alaska 99508 USA
E-mail: jpower@usgs.gov
Tel. 907-786-7497

The Kamchatkan Volcanic Eruption Response Team is a cooperative program of
the Alaska Volcano Observatory (USA), the Institute of Volcanology and
Seismology FED RAS and the Kamchatkan Experimental and Methodical
Seismological Department GS RAS (Russia).