Krubera Cave : the first 2000m+ cave on Earth

Cave profile

Arabika Massif, Western Caucasus Ukrainian Speleological Association “The Call of the Abyss” Project "The Call of the Abyss" Project

Arabika (flash)

"The Call of the Abyss" Project is a multi-year project aimed to the exploration and study of deep caves in the two outstanding limestone massifs: Aladaglar massif in the Eastern Taurus ( Turkey) and Arabika massif in the Western Caucasus (Abkhasia). An ultimate goal of the Project, officially adopted in 2000, was to discover, explore and study the first 2000m+ deep cave on Earth.The project is run by the Ukrainian Speleological Association, and involves institutions, individual cavers and karst scientists from Ukraine, Turkey, Britain, France, Spain, Moldova, Russia and Abkhazia.

The expeditions of the Project this summer have been supported by the National Geographic Society, USA. The Leica Geosystems Company of Switzerland kindly sponsored laser distometers used for topographic surveys in the explored caves. Help with caving equipment had been provided by the Ukrainian "Traverse", "Atlantida", and "Megacom" companies and the Slovak "Meander" company. The official carrier of the project expedition to Turkey was the "Motor-Sich" company of Ukraine. Their sponsorship and help is greatly acknowledged.

Arabika Massif, Western Caucasus:
August 2004 expedition news

Arabika is an outstanding alpine karst massif in the Western Caucasus, were many deep cave explorations have been made since 1980, including Krubera-Voronja (-1710m) and the nearby Arabikskaja system (Kujbyshevskaja-Genrikhova Bezdna; -1110 m) in the Ortobalagan Valley.

Other prominent caves in various sectors of the massif are Iljukhina system (-1240 m), Dzou Cave (-1080 m), Moskovskaja Cave (-970 m) and the Sarma Cave (-1530m). The hydrogeological potential of Arabika had been proven to be over 2300m by dye tracing tests conducted in 1984-85. The exploration of the Krubera cave to -1710m by theUkrainian Speleological Association had established a world depth record in the beginning of 2001.

Besides the core of the Ukrainian cavers, the Arabika expedition in August 2004 was composed of explorers from Moldova, Spain, France, the United States, Britain, Russia and Abkhazia.

In the summer of 2003, the expedition of the Cavex team found a new branch behind a siphon at -1440m in a small passage that diverges from the main route to the -1710 bottom. This July, immediately before the Ukr.S.A. expedition, the expedition of Moscow cavers briefly explored the post-siphon section and ended at another siphon at the depth which they estimated to be –1830m. This figure had been claimed as the new world's record.

The Ukr.S.A expedition in August re-explored and thoroughly surveyed this part, and found the second siphon to be at –1775m instead of –1830m. The attempt has been made to dive the second siphon, the deepest diving operation ever made in caves. By reaching a squeeze at a depth of 10m under water the depth of this branch was established at -1780 m. The siphon continues down almost vertically behind the squeeze.

Meantime, the detailed investigation of side passages through the whole deep section between the two siphons gave the most important discovery. On August 24 the explorers broke through a nasty side passage to a large new section, which bypassed the siphon at –1770m and steeply led to a still greater depth. On August 25 the team of four Ukrainians, one French and one Spanish (Gennadiy Samokhin, Denis Kurta, Dmitry Fedotov, Julia Timoshevskaja, Bernard Tourte and Sergio Garcia Dils) reached another siphon at -1840m, establishing the new world’s record for deep caves. The newly discovered section has many promising side leads still to be fully explored. It gives a good perspective for further depth advance.

The explorers used four underground camps (at –700m, -1200m, -1400m and –1637m) to support various works through the main part of this immensely deep and complex cave. Some cavers spent continuously two weeks underground in the course of the expedition. Twelve cavers took part in explorations behind the siphon at –1440m.

The expedition has made several discoveries and new explorations in some other parts of the Krubera Cave, provided for detailed topographic, photo- and video documentation of all new sections and conducted a considerable body of scientific research.

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Arabika Massif, Western Caucasus:
October 2004 expedition news

The Ukrainian Speleological Association is happy to inform speleologists around the world about a historic accomplishment: the first 2000m+ cave on Earth became a reality. The 2000m milestone in deep cave explorations has been vanquished in Krubera Cave, Arabika Massif, Abkhazia, during the third expedition of "The Call of the Abyss" project in the year of 2004, conducted between October 1-28.

The expedition led by Yury Kasjan was composed of nine Ukrainian cavers representing caving clubs of Yalta, Kiev, Kharkov and Uzhgorod (Igor Ishchenko, Sergey Bogutsky, Dmitry Furnik, Kyryl Gostev, Ilja Lapa, Ekaterina Medvedeva, Emil Vash and Shantor Chervits). The main goal was to continue exploring the new section discovered by the previous Ukr.S.A. expedition in August.

Based in the camp at –1645m behind the first sifon, the group of five cavers explored a lead deviating from the main branch some 55m above the terminal sifon. The newly explored part, named “Windows”, consist of a series of inclined passages and vertical pits (up to 40m deep), which form a complex structure in plan and profile of the total length of 1070m and depth of 290m. No big stream (active collector) has been encountered so far. The new part ended with a dry chamber (named “Game Over”) plugged with sandy and silt sediments. There are many side openings through the Windows series suggesting good possibilities for further exploration, including advance in depth.

Based on a standard topographic survey made during the August and October expeditions (Suunto compass & clinometer and DisoLite laser distometer; BCRA Grade 3-4) of the post-sifon section below -1440m, added to the previous Ukr.S.A. survey for the whole cave, the total depth of the cave is found to be of –2080m. The 2000m mark and the lowest point were reached on October 19.

With the entrance located at the altitude of about 2250m, the deepest point of the cave has reached the altitude of 170m above sea level, but it has not reached the top of the phreatic zone yet. The system is hydrologically linked to major springs located at 1 to 50m altitudes at the Black Sea coast at the distance of 12-16km, and also to submarine springs. Such a low gradient (less than 170m/13.000m) suggests the low hydraulic resistance of the deep sections of the massif, which is probably because the well developed conduit porosity had formed during Pleistocene periods of low sea level stands, when the drainage level was at much lower position than at present.

The world’s depth record in Krubera Cave was first established at –1710m by the Ukr.S.A. expedition in January 2001. During this year the advance in 370m has been made, unparalleled in the history of deep cave explorations.

The "The Call of the Abyss" Project will continue exploring Krubera Cave to its ultimate limits, and will seek to “grow up” another 2000m+ cave in the Aladaglar Massif in Turkey, yet another project study area where Kuzgun Cave has been explored to –1400m this July.

Alexander Klimchouk, Yury Kasjan and Nikolaj Solovjev
”The Call of the Abyss” Project coordinators,
Ukrainian Speleological Association

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Arabika Massif, Western Caucasus:
February-March 2005 expedition news

The next regular expedition of the Ukrainian Speleological Association to Krubera (Voronja) Cave has been carried out between February 9 – March 16, 2005. The expedition, led by Yury Kasjan and composed of cavers from Kiev (N. Solovjev and M.Bondarenko) and Novaja Kakhovka (D.Fedotov and E.Kononov), was the part of the ongoing "Call of the Abyss" project, run by the Ukr.S.A since the year of 2000. For more information about recent explorations in the Krubera Cave visit http://www.speleogenesis.info/spotlights/krubera.php.

The main goal of the expedition was to systematically explore the deepest section of the cave discovered during the previous Ukr.S.A. expeditions in August and October 2004. There were many open side leads left unchecked in the Windows Series between the Big Junction at –1790m and the Game Over Chamber, the deepest point at –2080m (see the cave profile http://www.speleogenesis.info/img/werbung/krubera_profile_large.gif).

The expedition has been brought to the cave by a helicopter on February 14.

The team have continuously worked in the cave during 19 days, since February 16. After return to the surface on March 6, the team had to wait out bad weather in the mountains during six days to be picked up by a helicopter.

During descend and ascent the team used established camps at –700, -1215, -1410 and –1640m. It took eight days to restore and improve all the rigging through the cave and to transport materials and supplies to the lowest camp set at the Big Junction at –1790m. Six days were spent for the work in the lower section, and it took five days to get back to the surface.

The results of current explorations in the lower section of the cave can be briefly summarized as follows:

1) Many windows and side leads have been checked within the –1700m - -2080m interval. Almost all of them have looped to the known passages and pits, while some ended by impenetrable squeezes. The only window in the bottom chamber (Game Over), visible in the wall at some ten meters above the floor, has been also checked (dead-ended).

2) The siphon ("Kvitochka") in a side passage at –1980m has been dived through by Nikolay Solovjev. The siphon 10m long and 4m deep gave a continuation explored to a next vertical pitch. This is now the main direction for the further exploration. The dive was the deepest diving operation ever made in caves.

3) Two siphons in side passages near the Big Junction (around –1800m) have been tested.

One of them has been dived for 7m in length and 3m in depth; it continues by an ascending leg. Another siphon (6m long, 2m deep) has connected to the known passage. The terminal siphon at –1840m, which stopped the exploration in August 2004, has not been attempted as it apparently connects to a known passage in the "Windows" series.

4) The temperature measurements have been carried out through the cave to study temperature gradients. The air temperature rises through the cave from 2.1 grad C at –90m to 7.7 grad C at –2080m, giving the overall gradient of 0.28 grad C/100m.

During 2005 the Ukrainian Speleological Association will continue systematic explorations in Krubera Cave and other caves of the Ortobalagan valley in Arabika in August and September-October. Another expedition of the "Call of the Abyss" project is planned for July to the Aladaglar massif in Turkey (see http://www.speleogenesis.info/spotlights/kuzgun.php).

Alexander Klimchouk, Yury Kasjan and Nikolaj Solovjev
The "Call of the Abyss" Project coordinators,
Ukrainian Speleological Association