Western Beringia and beyond - three decades of German-Russian paleoenvironmental research on Siberian permafrost

With first joint fieldwork on Taymyr Peninsula during mid-1990s, a successful cooperation of German, Russian, and further international partners on permafrost and Quaternary palaeoenvironments in Siberia was started and resulted in extensive joint research for 3 decades. Studies of permafrost deposits and ground ice provided insights on past environmental and climatic changes, covering several hundreds of thousands of years into the past. They provide multi-proxy evidence for multiple glacial/interglacial cycles and different periods of past climate change or stability in Arctic land environments. Study objects were natural permafrost exposures along coastal sections, thaw slumps, and river banks, studied mostly during summers, complemented by permafrost cores from land, lake and sea ground drilled mostly in spring. Exposure geometry and stratigraphic horizon thickness have been surveyed using laser tachymetry, other measuring equipment, and drones. Based on multi-proxy analyses, mid- and late Quaternary periods were studied, resulting in >300 scientific papers. The approach includes geomorphic studies, various geochronological analyses, analysis of frozen sediments (for ice, carbon, nitrogen, and carbonate contents, grain-size parameters, magnetic susceptibility, heavy mineral compositions), ground ice (stable water isotopes, major ions) and of numerous fossil bioindicators, to reconstruct the Quaternary paleoenvironmental change. Oldest permafrost horizons were dated from the Batagay mega-thaw-slump (Yana Uplands) to about 650 ky with luminescence dating. Here and elsewhere, records of Eemian and Holocene interglacial periods, and environmental conditions associated with it were targeted. Many sites with late Pleistocene Yedoma Ice Complex have been explored. Lateglacial and Holocene warming induced enormous periglacial landscape changes by widespread permafrost degradation and substantial paleoecological changes. For vast Siberian areas where glacial records are not available, we aim on the establishment of permafrost as paleoclimatic archive, emphasizing peculiarities of permafrost age control and record resolution and stressing the great potential for understanding climate variability on glacial-interglacial timescales in Western Beringia