The shoreline formations of Stolbovoy Island. Note the polygons on the lower left and the conical mounds along the seashore.

Baydzharakh (Russian: Байджарах; Yakut: Бадьараах, Baçaraakh) is a term based in the Yakut language, referring to a roughly cone-shaped natural rock formation. They are usually composed of siltstone, silty peat or loam.

Description

Baydzharakhs form owing to thermokarst activity in periglacial areas. They are the result of a cryolithological process by which polygonal ice-wedges thaw within the permafrost.[1] These formations usually reach a height between 5 meters (16 ft) and 10 meters (33 ft) with an area at the base between 15 square meters (160 sq ft) to 20 square meters (220 sq ft).[2]

In the first phase of the ice melting process baydzharakhs have a pillar-like shape. When the ice mass in the surrounding rocks is high, they swell and form rounded depressions known as alas (Алаас) in Yakut. These depressions are usually between 8 meters (26 ft) to 12 meters (39 ft) in depth, but exceptionally may be 30 meters (98 ft) deep. Baydzharakhs come often combined with alas depressions.[3][4]

Baydzharakh formations are found in different places across the East Siberian Lowland, such as Muostakh Island, Stolbovoy Island, Kotelny Island and the Ulakhan-Sis Range, as well as in scattered places of the Yana-Indigirka Lowland.[5] In 1950 a baydzharakh was the last vestige of now disappeared Semyonovsky Island in the Laptev Sea. They often occur together with Yedoma (Едома) complexes and in areas with ice-wedges of considerable thickness.[6]

See also

References

  1. ↑ Andreev, A. A., D. M. Peteet, P. E. Tarasov, F. A. Romanenko, L. V. Filimonova and L. D. Sulerzhitsky, 2001, Late Pleistocene Interstadial Environment on Faddeyevskiy Island, East-Siberian Sea, Russia . Arctic, Antarctic, and Alpine Research. vol. 33, no. 1, pp. 28–35,
  2. ↑ V.A. Kudryavtseva, ed. General Permafrost Science (Geocryology). 1978 pp. 227-228.
  3. ↑ Baydzharakh - Russian Geodictionary (VSEFEI)
  4. ↑ S.V. Kalesnik, ed.Encyclopedic dictionary of geographical terms. Moscow. 1968
  5. ↑ Russian Academy of Sciences, Geology Bulletin. (Izvestiya Akademii Nauk. Seriya Geologicheskaya), Issues 1-7. p. 55
  6. ↑ The concept of territorial protection of the New Siberian Islands, Bulletin of the Orenburg Scientific Center of the Ural Branch of the Russian Academy of Sciences - 2017
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