Lake Billyakh, Verkhoyansk Mountains, Eastern Siberia
Funding
Alfred Wegener Institute for Polar and Marine Research
Field Team
• Bernhard Diekmann (AWI Potsdam)
• Andrei Andreev (AWI Potsdam)
• Gerald Müller (AWI Potsdam)
• Hermann Lüpfert (Humboldt University Berlin / AWI Potsdam)
• Luidmilla Petryakova (Yakutsk State University)
• Dmitry Subetto (Limnological Institute, St. Petersburg)
• Dmitry Grusznykh (Local Field Guide)
Background
The study of Lake Billyakh (see map here) was stimulated through foregoing Russian-German expeditions in the central Verkhoyansk Mountains during the summer seasons 2002 and 2003. Palaeolimnological studies, so far, were concentrated on Holocene thermokarst lakes in the Central Yakutian low lands. Holocene lacustrine records were not available until the expedition. The former studies in the Verkhoyansk Mountains have confirmed the presence of repeated glacial advances. It became evident that mountain glaciers did not reach the Lake Billyakh area after 80 ka BP. Therefore, it was expected that Lake Billyakh may provide a continuous lacustrine sediment section spanning the mid- to late Weichselian cold climate stage and the Holocene. The objective of the expedition was the retrieval of long sediment cores for later multi-proxy palaeolimnological analyses in connection with a survey of lake hydrology and bathymetry and georadar measurements of the sedimentary basin infill. The study is designed to contribute to a better understanding of late Quaternary regional palaeoenvironmental changes at high temporal resolution.
The lake is of tectonic origin and was sculptured by former glacial advances. Mean depth is 8 m, with a central profundal depocentre at 25 m water depth. Sediment coring with an UWITEC piston corer system was concentrated at one site in the central part of the lake and on a depth transect near the northern shore. In summary, a total of 35 m sediment cores were taken. In the part of the lake, five overlapping core sections provided a 9.4 m long sediment sequence, dominated by green-greyish silty clays that are partly laminated. The upper 1.5 m of the section include an increased concentration of fine-grained organic gyttya in the siliciclastic muds. First radiocarbon dates indicates a Holocene age of the upper section. The lower part is older than at least 25 ka BP. The near-shore sites yielded up to more than five metre long Holocene sections and penetrated underlying basal sands.
Further information
• Diekmann et al. (2007). Expedition 'Verkhoyansk 2005' - Limnogeological studies at Lake Billyakh, Verkhoyansk Mountains, Yakutia. In: Schirrmeister, L. (ed.): Expeditions in Sibiria in 2005, Reports on Polar and Marine Research, 550: 247-258.
Outcomes
• Müller, S., Tarasov, P., Andreev, A., Diekmann, B. (2009). Late Glacial to Holocene environments in the present-day coldest region of the Northern Hemisphere infrerred from a pollen record of Lake Billyakh, Verkhoyansk Mts., NE Siberia. Climate of the Past, 5: 73-84.
