BIOLOGIYA MORYA, 2017, Vol. 43, No. 4, pp. 246-255

Late Holocene environmental changes in the southwestern Chukchi Sea inferred from diatom analysis

© 2017 I. B. Tsoy¹, M. S. Obrezkova¹, K. I. Aksentov¹, A. N. Kolesnik1, V. S. Panov²

¹V.I. Ilyichev Pacific Oceanological Institute, Far Eastern Branch, Russian Academy of Sciences, Vladivostok 690041;
²Institute of Archeology and Ethnography, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090

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The environmental changes in the southern part of the Chukchi Sea over the last 2300 years (two warmings during the periods ~262 BC-630 AD and ~630-1300 AD and 1 cooling ~1300-1840 AD) were inferred from changes in the content of diatoms in sediments (per gram), the ratio of dominant species and the ecological structure of diatom assemblages. The sediment age was assessed based on the sedimentation rates (0.43 mm/yr) that were determined by ²¹⁰Pb and radiocarbon dating of mollusk shells. The environmental changes in the southern Chukchi Sea that were inferred from the diatom analysis correlate with global climate changes, viz., the warming events of the early (Roman) and the middle (Medieval) Subatlantic and the cooling of the late (Little Ice Age) Subatlantic.

Key words: diatoms, paleoenvironmental change, late Holocene, Subatlantic, Chukchi Sea, Arctic.