Environmental Changes in the Eastern Arctic during Marine Isotope Stages 80 and 81

Abstract

Palynological analysis of a 317-m-long sediment core obtained from Lake El'gygytgyn (67° 30' N, 172° 05' E) located in the Eastern Arctic documents the changes in vegetation between 2.103 and 2.146 Ma. This interval encompasses marine isotope stages (MIS) 80 and 81 and includes the Reunion paleomagnetic event, an important chronological event within MIS 81. Seven pollen zones depict the varying plant communities associated with interglacial, interstadial, and glacial intervals. The warmest climatic conditions occurred during MIS 81 (pollen zone E2) when coniferous forests dominated the landscape. These forests also included moderately thermophilous broadleaf trees and shrubs. The interstade (MIS 81, pollen zone E3) is characterized by open larch forests and forest-tundra. During the period of deepest climatic cooling, which occurred at the end of MIS 80 (pollen zone E7), larch forest-tundra and shrub tundra were present across the region. The palynological analysis of sediments from Lake El'gygytgyn illustrates the varying responses of vegetation to a wide range of climatic conditions and suggests that modern Arctic communities may disappear in the future as a result of global warming.