The difference in the altitude of the cave's entrance and its deepest explored point is 2,191 ± 20 metres (7,188 ± 66 ft). It became the deepest-known cave in the world in 2001 when the expedition of the Ukrainian Speleological Association reached a depth of 1,710 m (5,610 ft) which exceeded the depth of the previously deepest cave, Lamprechtsofen, in the Austrian Alps, by 80 m. In 2004, for the first time in the history of speleology, the Ukrainian Speleological Association expedition reached a depth greater than 2,000 m, and explored the cave to −2,080 m (−6,824 ft). The current maximum depth of 2,191 m was reached during a 46 m dive by Gennadiiy Samokhin into the terminal sump during the expedition of the Ukrainian Speleological Association in August–September 2007. The cave remains the only known cave on Earth deeper than 2,000 metres.
Location And Background
The Arabika Massif, the home of Krubera (Voronya) Cave, is one of the largest high-mountain limestone karst massifs in the Western Caucasus. It is composed of Lower Cretaceous and Upper Jurassic limestones that dip continuously southwest to the Black Sea and plunge below the modern sea level.
Among several hundred caves known in the Arabika Massif, fifteen have been explored deeper than 400 m and five deeper than 1,000 m (shown in Figure 1).
Krubera Cave is located at 2,256 m asl in the Ortobalagan Valley, a perfectly shaped, relatively shallow, glacial trough of the sub-Caucasian stretch, which holds the advanced position in the Arabika's central sector relative to the seashore. Since 1980, Ukrainian cavers have been undertaking systematic efforts in exploring deep caves in the Ortobalagan Valley, resulting in exploration of the Krubera Cave to its current depth and of the Arabikskaja System to depth of −1,110 m (−3,641.7 ft). The latter consists of Kuybushevskaya Cave (also spelled as Kujbyshevskaja; −1,110 m) and Genrikhova Bezdna Cave (−965 m to the junction with Kujbyshevskaja). Another deep cave in the valley, located in its very upper part and explored by Moldavian and Ukrainian cavers is Berchilskaya Cave, 500 m (1,600 ft) deep. All large caves of the Ortobalagan Valley likely belong to a single hydrological system, connected to large springs at the Black Sea shore. The direct physical connection of Krubera Cave with the Arabikaskaja System is a sound possibility, although not yet physically realized.