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Спелеоперспективы Камчатки: W. Halliday

Автор: Andrei Filippov
Дата: 02 Jun 2002

Всем привет!
Многие сейчас интересуются лавовыми пещерами Камчатки.
В России трудно, иногда почти невозможно найти иностранные публикации по
ним. Ниже помещаю кпаткую заметку знаменитого Уильяма Холидея (с его
разрешения), опубликованную в Geo, 1996, vol. 21, p. 21.
С уважением,
Андрей Филиппов

Speleological Potential of Kamchatka Oblast
William R. Halliday

In September 1996, I spent eight days in Kamchatka Oblast of Siberia
speaking at the Institute of Volcanic Geology and Geochemistry in
Petropavlovsk and participating in a field excursion to the 1740 and 1975
lava beds of Tolbachik volcano. By international standards, the caves of
these flows are small. But recently it has appeared that variations in
chemistry and gas content of pahoehoe basalts makes profound variations in
their lava tube caves. Thus it is important to look at as many
speleoliferous regions as possible. This trend continued at Tolbachik.
Although the longest cave to date has only about five hundred meters of
passages in a straight line distance of two hundred meters, it is unusual in
several ways and contains a type of feature I have not seen before. This
consists of wafer-thin, irregularly rounded blades of grainy lava many
inches in diameter hanging down in parallel rows along the axis of flow.
Especially they are present in constricted areas downslope from spacious
sections. I could not determine whether they are lava stalactites or
eroded/ablated bedrock remnants. The cave's pattern is braided, with small
tubular cutarounds at floor and ceiling level. The main corridor is up to
twenty meters high (?) and four meters wide, although most of it is much
smaller. The cave is an important water source in a pseudokarst which is
very arid in summer and autumn despite up to twenty feet of snow each
winter. Sections of its arched ceiling are especially interesting because of
innumerable little flattened tubes of lava, recurved or straight like tiny
grey cigarettes evidently blasted upward by innumerable molten bubbles
bursting in molten lava close below. The cave is believed to have been
mapped three times: in 1975 by Yurii Slezin (now the Russian member of the
IUS Commission on Volcanic Caves), in 1995 by a Japanese team headed by
Takanori Ogawa, and a few days before our coming by a Swiss team led by Yvo
Weidmann. Only the 1975 map has been published to date. In the next year,
fuller descriptions will appear in several countries.
Several other caves are known in the 1740 and 1975 flows. The longest is
about sixty meters long but some of these are of interest because they
resemble boundary ridge caves in Kilauea volcano. Most of these flows remain
uninvestigated for caves. The 1975 flow was studied very thoroughly during
its emplacement and caves found here will be of special interest. The Swiss
found several caves here but they were only a few meters long, and the
blocky lava
does not appear especially promising for long caves. A pit cave with a
24-foot overhanging entrance-located a few km farther north, near Gora
Vysokaja (High Mountain), may be a tectonic feature rather than rheogenic.
It consists of a single chamber with extensive snow and ice accululations.
On the ridgeline south of the Zvesda (Star) vent of the 1740 flows is a
hornito with an apparent window in its side. Apparently it has not been
looked into; on Hualalai volcano, HI, similar hornitos are atop open
vertical volcanic conduits up to fifty meters deep.
On the west side of the northern group of 1975 "New Tolbachik volcanoes" is
a long chain of closed depressions, evidently along the course of a major
lava tube. They are said to be closed by rubble and no one has attempted to
dig through it. Similarly, in a lightly-forested flow perhaps 500 or 600
years old about 5 km east of the main Tolbachik cave is a large collapse
sink which no one has tried to dig. Slezin reported that in winter, with the
temperature about minus 25 °C, considerable air above the freezing point was
emerging from the rocks. Also, just after the flank eruption of 1975 on
Klyuchevskoy volcano farther north, Yurti looked down the shaft of a red-hot
open vertical volcanic conduit perhaps sixty meters deep. He could not
determine what lay at the bottom. Now it may or may not be blocked with
rubble, or by snow and ice. It was at the 3000 meter level. He also has
reported caves on Gorely volcano.
Back in Petropavlovsk, Yurii showed me slides of a larga geo-thermal firn
cave at least 200 meters long, in the crater of Ushkovskii volcano. Entry
requires a fifteen meter rappel. This is the fifth such cave on record; the
others in the craters of Mounts Rainier and Baker in Washington, on the side
of Mt. Erebus, in Antarctica, and beneath a glacier in Iceland. Yurii's
co-worker, Aleksey Tsyurupa, wants to investigate some lava flows far north
in eastern Siberia.
In terms of caves as much as of climates, Kamchatka and nearby Siberia will
never be another Hawaii. But the future here is truly intriguing. And even
if another cave is never found, the Tolbachik area is one of the world's
most spectacular volcanic regions. I am very happy to have had a view of it.
Submitted to: Cascade Caver, Hawaii Grotto News, Geo, Speleograph.
Information copy to Volcano Quarterly, and IUS Commission on Volcanic Caves.




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