Oceans and seas

East Siberian Sea

May 14, 2013, 2:09 pm
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Icy East Siberian Sea in winter. Source: NASA

The East Siberian Sea is a saline marine body, which is a southern marginal sea of the Arctic Ocean.

To the east is found the Chukchi Sea and to the west beyond the New Siberian Islands is the Laptev Sea. This relatively shallow sea resides in a polar climate, with November through March weather dominated by cold continental air masses moving northwestward from Siberia; this results in prevailing East Siberian Basin winter air temperatures attaining minus thirty degrees Celsius in this cold season.

caption Source: Creative Commons

This sea is classified as an area of low marine biological productivity, with principal biomass generation occurring in the months of Juty through September. Salinity is less than average compared to the seas of the world, since precipation exceeds evaporation and there is a moderate amount of freshwater influx from the Sibarian mainland.

Hydrology

The surface water temperature of the East Siberian Sea generally is warmest in the south. In winter the surface marine temperature ranges from  minus 0.2 to minus 0.6 ° Celsius (C) on the river deltas; in the northern sea realm the winter surface temperature varies between –1.7 to –1.8 °C. Salinity is lowest at the deltas of the large Siberian rivers that efflux to the East Siberian Sea; the deep reaches of this sea also display some of the highest salinity levels.

Seabed topography generally manifests as an epipelagic plain, sloping from southwest to northeast; this benthic floor is chiefly covered with a mixture of silt, sand and stone, absent of major depressions. The majority of the East Siberian Sea exhibits a depth of approximately twenty to twenty-five meters. Northeast of the mouths of the Kolyma River and Indigirka River, one finds relatively deep trenches excised on the seabed, a product of prehistoric river valleys, submerged as recent as the Holocene.

Marine ecology

See main article: East Siberian Sea large marine ecosystem

Ice cover on the East Siberian Sea varies appreicbly inter-annually. Ice cover for a major portion of the year prevents sunlight from penetrating deeply into the water column and thus limits biological production for several months. Increased primary production occurs after the ice melt of summer months. The formation and melting of ice, which supplies freshwater and chemical nutrients, complicates the thermal, chemical, sedimentological and biological processes in the Siberian polynya.

The East Siberian Sea is considered a Class III, low productivity (less than 150 grams of carbon per square meters per year) ecosystem. The phytoplankton cycle occurs during the short Arctic summer. The chief basis for interannual differences in the biological seasons are the meteorological, hydrological and glacial conditions. Zooplankton population size and biomass can vary widely in July and august, The copepod group being dominant. Much of the East Siberian Sea is influenced by Pacific marine species. An issue of special importance is the relationship between shelf circulation and nutrient fluxes. Coastal erosion and river discharges provide a major source of suspended matter and nutrients. Major Siberian rivers, such as the Kolyma River, discharge millions of tons of nutrients into the East Siberian Sea annually.

Terrestrial ecology

See main article: Northeast Siberian coastal tundra

The Northeast Siberian coastal tundra is a terrestrial ecoregion lying along the southern edge of the East Siberian Sea. This stretch of coastal subarctic tundra between the Yana and Kolyma Rivers is among the most productive Arctic tundra wetlands in northeastern Russia.

Plant association characteristics of the region are typical for dwarf shrub Arctic and typical tundra, but some sparse patches of larch forest are present along the southern border of the region. Permafrost underlies the entire region and plays a large role in landscape formation and botanical distribution. Common plant species include cotton grass (Eriophorum sp.), dryas (Dryas punctata), willows (Salix sp.), crowberry (Empetrum sp.), cranberry (Vaccinium vitis-idea), and mosses.

The Kolyma region is notable for keeping dormant seeds viable for over 30,000 years; the wildflower species Silene stenophylla was brought to life from these ancient seeds preserved in the permafrost of this Arctic Circle habitat.

References

  • G.A.Baskakov and A.O.Shpaikher. 1978. The boundary and the main morphometric characteristics of the Siberian shelf. Proc. of the AARI, v. 349
  • William Elliott Butler. 1978. Northeast arctic passage. ISBN 90-286-0498-7
  • International Hydrographic Organization. 1953. Limits of Oceans and Seas, 3rd edition./files/192001_192100/192095/S23_1953.pdf
  • S.Kurnaev. 1990. Forest regionalization of the USSR (1:16,000,000) Moscow: Dept. of Geodesy and Cartography. 
  • D.V.Nalivkin D. V. 1960. The geology of the U.S.S.R. A short outline. Pergamon Press. Oxford, U.K.

See also

Glossary

Citation

Hogan, C. (2013). East Siberian Sea. Retrieved from http://www.eoearth.org/view/article/151879

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