An integrated study of the upper 1283 cm of sediment from El'gygytgyn Lake, which formed nearly 4 million years ago following a meteorite impact in northern Chukotka, revealed the first continuous record of extreme changes in Beringian climate and vegetation from the middle portion of the Middle Pleistocene to present (MIS 1-7 and upper MIS 8). Climate was warmer than modern between 8600 and 10700 ¹⁴C years BP and during the Late Pleistocene interglaciation (MIS 5e, 116-128 kyr ago). In 2003, an international expedition (Germany-Russia-U.S.A.) obtained a deeper core from El'gygytgyn Lake. The subsequent study of these sediments has provided new data about changes in vegetation cover during the Middle Pleistocene and the first information about Middle Pleistocene interglaciation (MIS 9; 297-347 kyr ago). The pollen spectra associated with this Middle Pleistocene interglaciation are similar to spectra from the early stages of the Late Pleistocene interglaciation and to the climatic optimum that occurred during the transition from the Pleistocene to Holocene.

The climatic history of El'gygytgyn Lake forms the basis for stratigraphic correlations and environmental reconstructions in the eastern sector of the Arctic. These data also improve understanding of climatic change for international projects «Pole-Equator-Pole Paleoclimate Project», «Past Global Changes Project» and others.

The works are supported by the Russian Foundation for Fundamental Research (Project 06-05-64129), Far East Branch of RAS (Project 05-III-B-09-009), National Science Foundation (USA) (Projects ATM 99-05813, ATM 00-117406).

Reference:

Lozhkin A.V., Anderson P.M., Matrosova T.V. Pleistocene and Holocene climates of northeastern Siberia. Correlation of Pleistocene Events in the Russian North. International Workshop Abstracts. 4-6 December 2006. Saint-Petersburg, 2006, p. 58.