THE CONCEPT OF MAPPING THE CRYOGENIC DYNAMICS TENDENCY OF THE COASTAL ZONE (BY THE EXAMPLE OF EAST SIBERIAN ARCTIC SECTOR)

https://doi.org/10.24057/2414-9179-2017-1-23-418-427

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About the Authors

A. V. Gavrilov

Lomonosov Moscow State University
Russian Federation

Faculty of Geology,

119991, Moscow, Leninskie Gory, 1

E. I. Pizhankova

Lomonosov Moscow State University
Russian Federation

Faculty of Geology,

119991, Moscow, Leninskie Gory, 1

Abstract

We have proposed a conceptual model of dynamics of frozen and cooled below 0°С rocks of the coastal zone. The map shows the areas of degradation, formation, and a stable state of permafrost. The basis of mapping is the type assignment of the coastal zone based on the transformation factors. This geological structure is characterized by ground ice occurrence, ice-bearing rocks, modern vertical movements, hydrodynamic processes, and solid runoff. Depending on the combination of these factors, in some cases sedimentation, accompanied by syngenetic freezing of rocks occurs in the coastal zone. In other cases, the seashores retreat, and the frozen deposits of the underwater coastal slope thaw. In other cases, the banks retreat, and the permafrost sediments of the underwater coastal slope are thawed. This happens due to intensive salinization at the sea depths of 0- 2 m, where sea ice adfreezes with a bottom, as well as due to summer warming of near-bottom water. In the third case, under stable shores, the bottom rocks in the depth interval 0-2 m basical remain frozen and only in the interval from 2 to 3-5 m they are cooled. Alluvial-marine sedimentation in the mouths of rivers depends on a ratio of the volume of solid runoff and vertical tectonic movements. This can lead to formation of new permafrost or to submersion of sediments under the sea level and following thawing.

Mapping of the tendency of the cryogenic dynamics of the coastal zone is based on its typing, the regional permafrost, aerospace and cartographic data. Such a map has been compiled for the eastern part of the Laptev Sea and for the western part of the East Siberian Sea. It shows the types of frozen and cooled rocks—degrading, aggradating, stable—and their subtypes. The basis for identifying the rock types has been provided by the factors that determined the dynamics of the state of frozen and cooled rocks. Selected subdivisions have been characterized by a cryogenic structure, the presence of ground ice, bulk ice content, neotectonics and cryogenic processes. 

Keywords

permafrost and chilled rocks, subaerial and submarine permafrost, coastal erosion, coastalmarine and alluvial-marine sedimentation, permafrost degradation and aggradation.

References

  1. Are F.E. Razrushenie beregov arkticheskikh primorskikh nizmennostej [Coastal erosion of the Arctic lowlands], Novosibirsk: Geo, 1912, 291 p. (in Russian).
  2. Gavrilov A.V., Tumskoy V.E. Sovremennye processy kriolitogeneza vostochnogo poberezhya morya Laptevykh [Modern cryolithogenesis processes on the eastern coast of the Laptev Sea], Kriosfera Zemli, 2002, T. VI, No 1, pp. 35–48 (in Russian).
  3. Geokriologia SSSR. Vostochnaya Sibir i Dalnij Vostok. Pod red. Ershova E.D. [Geocryology of the USSR. Eastern Siberia and the Far East]. Moscow: Nedra, 1989. 515 p. (in Russian).
  4. Grigorev M.N. Kriomorfogenez i litodinamica pribrezhno-shelfovoj zony morej Laptevykh i Vostochno-Sibirskogo [Cryomorphogenesis and lithodynamic coastal-shelf zone of the seas of Eastern Siberia]. Avtoreferat ... diss. doct. geogr. n., Yakutsk, 2008, 38 p. (in Russian).
  5. Grigorev N.F. Mnogoletnemerzlye porody Primorskoj zony Yakutii [Permafrost of the coastal zone of Yakutia], Moscow: Nauka, 1966, 180 p. (in Russian).
  6. Gukov A.Yu. Ostrov, otkrytyj v XXI veke [The Island discovered in the twenty-first century], 2014, No 2, pp. 14–18 (in Russian).
  7. Zhigarev L.A. Zakonomernosti razvitiya kriolitozony arkticheskogo bassejna [The patterns of the development of the Arctic basin permafrost zone], Criolitozona arcticheskogo shelfa, 1981, Yakutsk: IM SO AN USSR, pp. 4–17 (in Russian).
  8. Pizhankova E. I., Dobrynina M. S. Dinamica poberezhya Lyakhovskikh ostrovov (resultaty deshifrirovaniya aerokosmicheskikh snimkov) [The dynamics of the Lyakhovsky Islands coastline (results of aerospace image interpretation)], Criosfera Zemli, T. XVI, No. 4, pp. 66–79 (in Russian).
  9. Pizhankova E. I. Sovremennye izmeneniya klimata vysokikh shirot i ikh vliyanie na dinamiku beregov rajona Dmitriya Lapteva [Modern climate change at high latitudes and their influence on the coastal dynamics of the Dmitry Laptev Strait area], Criosfera Zemli, 2016, T. XX, No. 1, pp. 51–64 (in Russian).
  10. Romanovskiy N.N., Eliseeva A.A., Gavrilov A.V. i dr. Mnogoletnyaya dinamika tolshch merzlykh porod i zony stabilnosti gazovykh gidratov v riftovykh strukturakh Arkticheskogo shelfa Vostochnoj Sibiri (Soobshchenie 2). Rezultaty chislennogo modelirovaniya [The long-term dynamics of the permafrost and gas hydrate stability zone on rifts of the Eastern Siberian Arctic shelf (Report 2). The results of numerical modeling], Criosfera Zemli, 2006, T. X, No. 1, pp. 29–38 (in Russian).
  11. Sekretov S.B. Petroleum potential of Laptev Sea basins: geological, tectonic and geodynamic factors // Polarforschung 69, 1999 (erschienen 2001), 259 p.

For citation: Gavrilov A.V., Pizhankova E.I. THE CONCEPT OF MAPPING THE CRYOGENIC DYNAMICS TENDENCY OF THE COASTAL ZONE (BY THE EXAMPLE OF EAST SIBERIAN ARCTIC SECTOR). Proceedings of the International conference “InterCarto. InterGIS”. 2017;23(1):418-427. https://doi.org/10.24057/2414-9179-2017-1-23-418-427