Permafrost conditions are assumed to be stable in the Siberian Arctic since probably 2.5 million years. The permafrost deposits of the Siberian lowlands are excellent climate and environmental archives and important links between marine records of the Pacific, Atlantic, Arctic Ocean, glacial records from Greenland as well as the high-resolution lacustrine records. The abundance of well-preserved bioindicators (pollen, plant macrofossils, rhizopods, chironomids, beetles, ostracods, diatoms, mammal bones) in permafrost deposits allows multiproxy paleoenvironmental reconstructions. Ground ice data and sedimentological characteristics reflect the conditions of permafrost formation and transformation. These records are also suitable datasets for climate reconstructions. Although, they are not always as highly resolved as other archives, permafrost deposits are widely distributed in Siberia and contain data of several climate stages. Moreover, they are the only available records for the validation of climate models in high latitudes of Siberia. The investigations will be focused on the New Siberian Archipelago and the Yana-Kolyma lowland, wherefrom the oldest deposits, and the most diverse stratigraphic, and facial permafrost sequences are reported. Neotectonics play an important role for the Quaternary environmental changes in this region. Moreover, the region between 130° and 150°E is assumed to be influenced by both, the Pacific and the Atlantic Ocean, and thus be sensitive for changes in atmospheric circulation patterns.The main objectives of studies on selected locations are Dating and characterization of the first tracks of permafrost in the Arctic Correlation of Pliocene/Early Pleistocene marine deposits exposed along the coasts with marine records Distribution and characterization of Saalian ice-rich deposits in Arctic shelf areas The Eemian in the Arctic and the degradation of permafrost Periglacial landscapes on the dry arctic shelf during the LGM The Holocene Arctic flood and modern patterns of coastal landscape extreme environmental transformations of Arctic landscapesThe response of the permafrost dominated Arctic landscapes to global climate changes and their feedback on the climate are still poorly understood. A set of paleodata equally covering the Arctic is required for reliable environmental reconstructions. The proposed project will help to reconstruct or estimate: Paleogeographic patterns of Arctic shelf areas (e.g. transgression-regression, extreme freshwater runoff, thermokarst processes) during the Quaternary vegetation and faunal changes, Paleotemperature and precipitation Greenhouse gas emission from thawing permafrost mainly during warm periodsIn summer 2007 field-work should be realized along the Dimitrii Laptev Strait between Bolshoy Lyakhovsky Island and the mainland coast of Oygossky Yar. The main goal of the expedition is multidisciplinary study of middle and late Quaternary permafrost sequences exposed on both coasts. These sequences are the largest and most extended Arctic permafrost archive containing traces of two or three glacial-interglacial-cycles. Large coastal sections must be studied in order to produce a comprehensive picture of the Quaternary landscape dynamics and to understand the complex stratigraphy. This work is based on previous studies in 1999 and 2004 on Bolshoy Lyakhovsky Island and Cape Svyatoy Nos as well as in 2002 on Oygossky Yar by teams from AWI-Potsdam, Moscow State University (MGU), and Permafrost Institute Yakutsk (PIY).
Helmholtz Research Programs > MARCOPOLI (2004-2008) > POL6-Earth climate variability since the Pliocene