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Olga BORISOVA, KUDRYAVY VOLCANO [Электронный ресурс]: электрон. данные. - Москва: Научная цифровая библиотека PORTALUS.RU, 26 октября 2018. - Режим доступа: https://portalus.ru/modules/travelling/rus_readme.php?subaction=showfull&id=1540507431&archive=&start_from=&ucat=& (свободный доступ). – Дата доступа: 19.05.2024.

По ГОСТу РФ 2008 г. (ГОСТ 7.0.5—2008, "Библиографическая ссылка")

Olga BORISOVA, KUDRYAVY VOLCANO // Москва: Научная цифровая библиотека PORTALUS.RU. Дата обновления: 26 октября 2018. URL: https://portalus.ru/modules/travelling/rus_readme.php?subaction=showfull&id=1540507431&archive=&start_from=&ucat=& (дата обращения: 19.05.2024).

публикация №1540507431, версия для печати


Дата публикации: 26 октября 2018
Автор: Olga BORISOVA
Публикатор: Научная библиотека Порталус
Номер публикации: №1540507431 / Жалобы? Ошибка? Выделите проблемный текст и нажмите CTRL+ENTER!

by Olga BORISOVA, journalist

The NAUKA Publishing House has brought out a second revised edition of a book Face to Face With Active Volcano (Moscow, NAUKA, 2005). Its author is a geologist on the staff of the RAS Institute of Experimental Mineralogy (Chernogolovka, Moscow Region) Mikhail Korzhinsky, who describes his participation in 1990 - 2002 in expeditions to the Iturup, the biggest island of the Kuriles.

Let me point out right from the start that what we are dealing with is not a dry scientific report, couched in special terminology. It is a series of exciting descriptions of the extraordinary natural beauty of one of the unique islands of the Far Eastern Region, breath-taking descriptions of scientists risking their lives in extraordinary weather conditions (and on the active volcano!) and notes about their observations, finds, hypotheses and puzzling mysteries.

The studies focused on the Kudryavy volcano on the northern part of the Iturup Island. The name Kudryavy - curly, frizzly - mirrors clouds of smoke rising over the top of the hill - a reflection of the dan-

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gerous natural phenomena which are taking place inside the earth crust. Their observations help scientists to decide what natural transformations are going on at inaccessible depths. And of the greatest interest for us are processes involving fluids (water-gas substratum) and magmatic melts.

The Chernogolovka researchers went to the Kudryavy in the company of their colleagues from the RAS Institute of Marine Geology and Geophysics of the scientific center of the Far-Eastern Branch of RAS. The expedition was sent in 1993, when record temperatures of fumarole gases (gases released at great depths by molten magma) were recorded and extensive mineralization of rhenium (the most rare element on our planet). Members of the expedition included scientists from the Moscow RAS Institutes of Geology of Ore Deposits, Petrography, Mineralogy and Geochemisty, the Institute of Physics of the Earth named after O. Schmidt; and of the Institute of Mineralogy and Geochemistry of Rare Earths of the Ministry of Natural Resources of the Russian Federation.

Kudryavy volcano was formed by numerous discharges of molten rock from the bowels of the Earth, including lava flows. Researchers today see their upper layers-chaotic piles of bits and pieces of volcanic rock. An important feature of this particular volcano consists in the loss of its energy source - magmatic melt which activated it for a long time. This being so, the volcano ejects into the atmosphere some 30 thous. tons of hot gases a day. This is quite a lot, but there many other "fiery dragons" in the world which surpass the Iturup volcano by this parameter. The volcano consists of two closely located cones and a third one - volcano Sredniy.

What makes the Kudryavy so interesting to scientists? Above all - the top temperatures of its fumarole gases. They consist of water steam with admixtures of hydrogen, carbon dioxide, compounds of sulphur, small volumes of vapors of hydrochloric and other acids, and one can also trace, besides rhenium*, silver and bismuth. This is a very aggressive medium so that researchers have to wear gas masks and their jackets and footwear have to be often replaced. The same can be said of metals with the exceptions of gold and platinum. For example, a steel rod placed near the "hot zone" breaks up in about a week's time. And, believe it or not, the most "aggressively dangerous" are low-temperature gases of high density which cause skin burns.

1990 was a "reconnaissance" year and it was then that the scientists chose the Kudryavy for their experiments. When reaching its summit, the researchers were surprised to find the ruins of old sulphur pit built some time ago by the Japanese. They loaded the ore into trolleys of a 6 km-long cableway which carried the ore on the Medvezhya Bay. What remains of

* See: "Rhenium from Volcanic Gas", Science in Russia, No. 1, 2001. - Ed.

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the pit are stone-faced walls, traces of the cableway and a big iron wheel - the only metal object spared by the fumarole gases. This wheel still towers over the volcano as a symbol of the dedicated zeal of the people who managed, having no adequate technical equipment and working in difficult conditions, to build this impressive engineering facility.

Every season of the expedition scientists continued their manifold studies, measuring gas temperatures, collecting samples of sulphur and other substances, etc. In 1995 they were joined by their Swiss and American colleagues. The former studied the geochemistry of volcanic gases and their sublimates, and the latter measured the volumes of discharges using instruments with remote control.

Three years later Russian specialists used their new monitoring system for registration of manifestations of the Kudryavy activities. They chose for their tests one of the most active fumaroles with temperatures of the order of 900°C and inserted into it all kinds of sensors attached to computers. Over a period of several weeks, all round the clock and in an automatic regime, they were keeping an eye on the "respiration" of the volcano. Thanks to the new instruments, scientists were able to register some spontaneous outbreak during which the levels of explosive hydrogen components increased by 8 times in the gas discharges of the volcano. And the scientists also kept taking samples of liquid and volatile substances and volcanic rock. For studies of the sedimentation mechanisms they placed into some of the fumaroles quartz pipes in which the newly formed minerals settled.

In 1999 they decided to repeat such measurements in order to confirm the obtained results. Everything went on as planned when suddenly the Kudryavy... woke up and burst into action. They saw from the base camp clouds of black smoke rising to a height of 300 - 400 m and heard threatening roar. When the "beast" was examined next morning (it was only Korzhinsky - the author of the book - who saw the volcano "in all of its sinister beauty" at night). The scientists discovered in the old

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crater a funnel 35 - 40 m in diameter and up to 30 m deep. Thrown out onto the surface were broken fragments of 30 - 40 cm and an area of 3 to 5 km around was covered with ashes. An eruption of this kind belongs to the category of phreatic ones. Experts believe that after abundant rains, water seeps into the volcano, reaches the hot sediments and boils up. The pressure continues to grow, producing what they call a steam blast which explodes the rock layers on top. Such phenomena take place without the participation of the magnetic melt.

But what was the cause of it all? Heavy rains had ended 5 days before so that a small lake was formed in the crater. Could the seepage be a slow process which played its role "with delay"?

Another version of the event belongs to Dr. Korzhinsky: The lake in the crater prevented the free discharge of hydrogen, its concentration exceeded the critical level and this led to a spontaneous ignition. And there is one more - "anthropogenic" hypothesis. The ill-fated lake interfered with the work of specialists from Yuzhno-Sakhalinsk who conducted temperature measurements at the basis of the crater. They dug a hole and "drained" the crater. This must have broken up the thin layer of sand-and-clay sediments and water ruched into the volcano, causing the aforesaid process. And there are other puzzles connected with the Kudryavy activities.

The author of the book under review is clearly in love with the region, vividly describing its natural beauty, animal kingdom and his own experiences. He kind of takes us with him onto one of the main summits of Iturup and shows us the majestic panorama of major colors. When we approach in his company the active volcano, we see the walls of its new crater with blue streams of molten lava and down below-"the gates of Hell". It has shining-hot walls and bottom from which emanates a torrent of glowing volcanic gases. People who worked in the expedition and saw these wonders usually want to go there again to see the "dragon". And it could well be that the sight makes them feel stronger.

Опубликовано 26 октября 2018 года

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