PETROPAVLOVSK-KAMCHATSKY, August 25 (Itar-Tass) — The Shiveluch volcano on the Kamchatka Peninsula has spewed ash to a height of 8.2 kilometres above sea level. There is no danger to nearby populated localities, the Kamchatka Branch of the Geophysical Service of the Russian Academy of Sciences (RAS) reported on Thursday.
A series of seismic events lasting about 27 minutes was registered on the volcano. Based on these data, experts made a conclusion about the height of the volcanic ash eruption from the crater of the giant mount. There was no visible outburst because the volcano is covered by dense clouds. No ash fall has been registered in nearby populated localities, including the Klyuchi settlement (situated 50 km from the volcano).
According to the Kamchatka Volcanic Eruption Response Team (KVERT), Shiveluch retains high activity. The lava dome continues to grow in its active part. The “orange” aviation hazard code has been given to the giant mount. It warns about the threat to aircraft engines posed by volcanic gases and dust ejected into the atmosphere.
Shiveluch is the northernmost active volcano on the Kamchatka Peninsula. The absolute height of the giant mount is 3,283 metres. The highest point of the active part, called the Young Shiveluch has a height of 2,500 metres above sea level. The diameter of the crater is 1.5 kilometres. Young Shiveluch has been active since September 1980. Experts have been continuously monitoring the volcano for more than 30 years.
The volcano is characterised by weak and moderate eruptions lasting from several months to 2-3 years. Periods of Shiveluch’s activity intensification were recorded in 1980-1981 and 1993-1995. The most recent eruption of the volcano classified as catastrophic occurred in November 1964.
In 2001, the volcano intensified its activity. Since then, there has been extrusive dome growth in its crater (accumulation of viscous lava over the mouth of the volcano), bursts of activity, accompanied with ash falls, avalanches and mudflows from the slopes of the giant mount.
The 1964 eruption of Shiveluch was preceded by a long period of seismicity. A swarm of earthquakes occurred at the beginning of May 1964. There was a reduction in seismic activity during the second half of October. During the day before the eruption, 73 earthquakes were recorded, and in the 7-hour period immediately before the eruption began, earthquakes occurred almost continuously. The eruption began on 12th November 1964, at 07:05 (local time) with the destruction of the summit of the volcano and the formation of a crater, 1.5 x 3 km wide. The volume of directed-blast deposits was 1.5 cubic km. The volcano edifice was destroyed during the climactic stage of the eruption, possibly in a succession of smaller directed blasts rather than one explosion.
Shiveluch contains unusual rocks, similar to adakites. The eruptions are usually explosive. The volcano is noted for repeated large flank failures. Large flank failures occurred in 1964, 1970, 1995, 1999.
Another large eruption occurred at the Shiveluch volcano on 27-28 February 2005. Ash fell at Klyuchi, 46 km from the volcano. Satellite images showed ash deposits west of Shiveluch volcano covering an area of 24,800 sq km. From 25 February to 4 March 2005 ash fell in Ust'-Hairyuzovo, 250 km west of Shiveluch.
The large 2005 pyroclastic flow filled the valley and covered an area of about 25 square km, destroying the forest on low river terraces. The woodless part of the valley broadened from 100–200 to 1,000–2,000 m. Trees growing along the valley slopes died of burns inflicted by the hot surge spreading downward. Conifer forest die-off as a result of thermal impact from an eruption is a unique phenomenon for the Kuril–Kamchatka region.
A dome collapse occurred at the volcano in September 2008.
An eruption occurred at the Shiveluch volcano on 25th July 2009. Ash emissions reached height of 23,000 ft, and 170 earthquakes were measured in 24 hour period. Some earthquakes were followed by ash emissions and avalanches. Volcanic activity over the past 3 years has significantly altered the shape of the volcano, with the crater increasing in size by 50 percent and the slopes becoming steeper.
Explosive and effusive eruptions occurred at Shiveluch volcano in 2010. On 28th October ash emissions reached a height of 23,000 ft. Seismic activity began to increase on 26th October, and a strong paroxysmal explosive eruption at the volcano occurred from 14:00 until 20:40 UTC on 27th October. The ash column reached a height of 40,000 ft. Satellite images showed the ash plumes extending 2,500 km east from the volcano on 27-28 October. Ashfall occurred at Ust-Kamchatsk from 18:00 UTC on 27th October until 03:00 UTC on 28th October. The airport and road from Ust-Kamchatsk to Kluchi were closed. An eruption of the Shiveluch volcano occurred on 10th January. Ash emissions reached 21,000 ft altitude.
The Kamchatka Volcanic Eruption Response Team was established in 1993. KVERT has issued over 700 information releases regarding Kamchatka volcanic activity to all interested services including the largest airlines of the world, volcanic observatories and weather services. Every week, and in the case of strong eruptions several times a day, KVERT sends information regarding Kamchatka volcanic activity to the Federal Aviation Service (FAS) of Russia as well as the largest airlines of the world.