@phdthesis{Chapligin2011, author = {Chapligin, Bernhard}, title = {From method develoment to climate reconstruction - oxygen isotope analysis of biogenic silica from Lake El'gygytgyn, NE Siberia}, address = {Potsdam}, pages = {195 S.}, year = {2011}, language = {en} } @article{KaempfPlessenLauterbachetal.2019, author = {K{\"a}mpf, Lucas and Plessen, Birgit and Lauterbach, Stefan and Nantke, Carla and Meyer, Hanno and Chapligin, Bernhard and Brauer, Achim}, title = {Stable oxygen and carbon isotopes of carbonates in lake sediments as a paleoflood proxy}, series = {Geology / the Geological Society of America}, volume = {48}, journal = {Geology / the Geological Society of America}, number = {1}, publisher = {American Institute of Physics}, address = {Melville, NY}, issn = {1943-2682}, doi = {10.1130/G46593.1}, pages = {3 -- 7}, year = {2019}, abstract = {Lake sediments are increasingly explored as reliable paleoflood archives. In addition to established flood proxies including detrital layer thickness, chemical composition, and grain size, we explore stable oxygen and carbon isotope data as paleoflood proxies for lakes in catchments with carbonate bedrock geology. In a case study from Lake Mondsee (Austria), we integrate high-resolution sediment trapping at a proximal and a distal location and stable isotope analyses of varved lake sediments to investigate flood-triggered detrital sediment flux. First, we demonstrate a relation between runoff, detrital sediment flux, and isotope values in the sediment trap record covering the period 2011-2013 CE including 22 events with daily (hourly) peak runoff ranging from 10 (24) m(3) s(-1) to 79 (110) m(3) s(-1). The three- to ten-fold lower flood-triggered detrital sediment deposition in the distal trap is well reflected by attenuated peaks in the stable isotope values of trapped sediments. Next, we show that all nine flood-triggered detrital layers deposited in a sediment record from 1988 to 2013 have elevated isotope values compared with endogenic calcite. In addition, even two runoff events that did not cause the deposition of visible detrital layers are distinguished by higher isotope values. Empirical thresholds in the isotope data allow estimation of magnitudes of the majority of floods, although in some cases flood magnitudes are overestimated because local effects can result in too-high isotope values. Hence we present a proof of concept for stable isotopes as reliable tool for reconstructing flood frequency and, although with some limitations, even for flood magnitudes.}, language = {en} } @article{BiskabornNazarovaPestryakovaetal.2019, author = {Biskaborn, Boris and Nazarova, Larisa B. and Pestryakova, Luidmila Agafyevna and Syrykh, Liudmila and Funck, Kim and Meyer, Hanno and Chapligin, Bernhard and Vyse, Stuart Andrew and Gorodnichev, Ruslan and Zakharov, Evgenii and Wang, Rong and Schwamborn, Georg and Bailey, Hannah L. and Diekmann, Bernhard}, title = {Spatial distribution of environmental indicators in surface sediments of Lake Bolshoe Toko, Yakutia, Russia}, series = {Biogeosciences}, volume = {16}, journal = {Biogeosciences}, number = {20}, publisher = {Copernicus}, address = {G{\"o}ttingen}, issn = {1726-4170}, doi = {10.5194/bg-16-4023-2019}, pages = {4023 -- 4049}, year = {2019}, abstract = {Rapidly changing climate in the Northern Hemisphere and associated socio-economic impacts require reliable understanding of lake systems as important freshwater resources and sensitive sentinels of environmental change. To better understand time-series data in lake sediment cores, it is necessary to gain information on within-lake spatial variabilities of environmental indicator data. Therefore, we retrieved a set of 38 samples from the sediment surface along spatial habitat gradients in the boreal, deep, and yet pristine Lake Bolshoe Toko in southern Yakutia, Russia. Our methods comprise laboratory analyses of the sediments for multiple proxy parameters, including diatom and chironomid taxonomy, oxygen isotopes from diatom silica, grain-size distributions, elemental compositions (XRF), organic carbon content, and mineralogy (XRD). We analysed the lake water for cations, anions, and isotopes. Our results show that the diatom assemblages are strongly influenced by water depth and dominated by planktonic species, i.e. Pliocaenicus bolshetokoensis. Species richness and diversity are higher in the northern part of the lake basin, associated with the availability of benthic, i.e. periphytic, niches in shallower waters. delta O-18(diatom) values are higher in the deeper south-western part of the lake, probably related to water temperature differences. The highest amount of the chironomid taxa underrepresented in the training set used for palaeoclimate inference was found close to the Utuk River and at southern littoral and profundal sites. Abiotic sediment components are not symmetrically distributed in the lake basin, but vary along restricted areas of differential environmental forcing. Grain size and organic matter are mainly controlled by both river input and water depth. Mineral (XRD) data distributions are influenced by the methamorphic lithology of the Stanovoy mountain range, while elements (XRF) are intermingled due to catchment and diagenetic differences. We conclude that the lake represents a valuable archive for multiproxy environmental reconstruction based on diatoms (including oxygen isotopes), chironomids, and sediment-geochemical parameters. Our analyses suggest multiple coring locations preferably at intermediate depth in the northern basin and the deep part in the central basin, to account for representative bioindicator distributions and higher temporal resolution, respectively.}, language = {en} }