The Kuril Islands and the Kamchatka Peninsula are one of the most active volcanic arcs in our country.
The history of Russian volcanology began on Kamchatka. On September 1, 1935, the first volcanological station in the USSR was opened on the peninsula, later it was transformed into the Volcanology Laboratory of the USSR Academy of Sciences.
The reason for the establishment of the Volcanologist Day was the following event. Kamchatka Bezymianny (Nameless) volcano emerged from a thousand-year period of quiescence. It was considered extinct and absolutely did not attract the attention of scientists. However, on October 22, 1955, a medium size eruption occurred, and until March 29, 1956, the seismic activity of the volcano was accompanied by a dense ash fall. And on March 30, 1956, at 5:10 p.m. an explosion of monstrous power split the snow-covered top of Bezymianny, which had previously risen to a height of 3,048 meters above sea level. A catastrophic explosion completely destroyed the top and part of the eastern part of the volcanic structure; a crater with a diameter of 1.5 kilometers was formed in their place, and the height of volcano decreased by 250 meters.
Ash cloud of the Bezymyanny Volcano, 1956
Georgy Stepanovich Gorshkov, volcanologist, who was nearby, in the village of Klyuchi, described the scene: «The cloud strongly curled and quickly changed its outlineЕ.. It seemed very to be dense and almost tangibly heavy. Together with the cloud, a thunder roar emerged and intensified, accompanied by incessant lightning flashes. Around 5:40 p.m., when the cloud had already passed the zenith, ashes began to fall … and by 6:20 p.m. it was so dark that it was impossible to see your own hand even if you brought it close to your face. People returning from work wandered around the village in search of their homes. Rolling thunder roared with a deafening force, non-stopping. We saw a lot of electrical activity during the eruption, phones rang spontaneously, speakers burned out in the radio networkЕ There was a strong smell of sulfur».
The hot layer of ash, covering an area of 482 square kilometers, melted the snow and formed fast-moving mud flows in the valley of the river Sukhaya Hapitsa and valleys located on the slopes of adjoining volcanoes. These streams washed huge rocks weighing hundreds of tons and carried them through the valley, sweeping away everything in its path. The trees were torn up or burnt.
It was the first catastrophic eruption, studied in detail by specialists. «In the evening, sitting in the tent, we, mostly young specialists, discussed the event, excitedly exchanging opinions,» recalls Henry Semenovich Shteinberg, one of the oldest Russian volcanologists, Doctor of Science and an Academician of the Russian Academy of Natural Sciences. « One of the guys suggested And lets celebrate this date as the Day of the volcanologist!»
Bezymianny Volcano threw a column of ash to a height of up to over 40 km. The Kamchatka River was filled with volcanic debris. At the eastern foot of the volcano, in an area of about 500 square kilometers, trees and shrubs were broken and felled in the direction from the volcano, and the ash from Bezymianny entered into the atmosphere and eventually covered the entire globe. In connection with this type of exceptional activity, the international volcanological community introduced a term to describe a new kind of eruption «directed blast» or «Bezymianny type eruption» .
That is why the Day of Volcanologist is celebrated on March 30 in Russia.
There are more than 300 volcanoes in Kamchatka, and about 30 of them are active.
On the Kuril Islands arc, there are 105 land volcanoes, about 40 of which are active. The activity of the volcanoes of the Kurile Islands, intensive in the geological past, continues even now: according to the Laboratory of Volcanology of the Institute of Marine Geology and Geophysics, FEB RAS, large eruptions occur here on average every 33 years, moderately large every 22 years, moderate eruptions every 11 years, weak eruptions every 15 years.
One of the most active volcanoes of the Kuril chain is the Sarychev volcano on Matua island.
The eruption at Sarychev Peak volcano in June 2009. The photo was taken by astronauts from the ISS orbit, published by NASA
Volcanoes of the Kuril Islands are characterized by eruptions of the most dangerous, explosive type, in which the radius of the affected zone can reach 2530 km. Such eruptions are often accompanied by scorching clouds, as well as pyroclastic and mud flows which can extend several kilometers.
Information on active volcanoes of the Kuril Islands can be obtained in the «Geologic History of Sakhalin and the Kuril Islands» exposition hall of the Sakhalin Regional Museum. The «Geological Map of the Kuril Islands» exhibits a collection of volcanic activity: volcanic bombs of various types (ribbon-like, spindle-shaped, shell-like type, bread crust type), samples of lava, pumice, volcanic glass, raw sulfur, a large sample of a new mineral Ц Rheniite discovered at Kudryavy volcano in the north of Iturup Island. Due to the unique physicochemical conditions existing on this volcano, in particular long-lived superheated fumaroles having high-temperatures, unique minerals are formed which cannot be found anywhere else.
According to the temperatures of volcanic gases that reach 940 degrees Celsius, Kudryavy volcano is referred to the hottest volcanoes of the Earth in a quasi-steady state.
Young phreatic crater of Kudryavy volcano. Rhenium high temperature field in the background. Photo by I. Chaplygin
At present, there are 1545 active volcanoes worldwide. Scientists define an „active volcano“ as one that has erupted in the last 10,000 years.
There are about 80 volcanic eruptions occurring every year on the Earth, with 1720 volcanoes which have been erupting constantly. There are 15 volcanoes that are known to have been erupting for over 30 years without interruptions.
Prepared by: A.V. Solovyov, Researcher