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Biomarker and stable isotopic composition of terrestrial and aquatic organic matter as proxies for environmental changes during selected time slides over the last 200,000 years at Lake Van (Turkey)

English title Biomarker and stable isotopic composition of terrestrial and aquatic organic matter as proxies for environmental changes during selected time slides over the last 200,000 years at Lake Van (Turkey)
Applicant Schubert Carsten
Number 156110
Funding scheme Project funding
Research institution Biogeochemie EAWAG
Institution of higher education Swiss Federal Institute of Aquatic Science and Technology - EAWAG
Main discipline Other disciplines of Earth Sciences
Start/End 01.01.2016 - 31.01.2018
Approved amount 228'200.00
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Keywords (10)

Environmental reconstruction; Climate change; Biomarkers; organisch-geochemisch; isotopen-geochemisch; Landpflanzen; Algen; Temperatur; Niederschlag; Salzgehalt

Lay Summary (German)

Lead
Die Region des Vansees ist ein Schlüsselgebiet um die Entwicklung des quartären Klimas zu erforschen. Es liegt an einer Kreuzung des Sibirischen Hochdruckgebietes mit dem nördlichen Ausläufer des subtropischen Hochs und markiert damit ein auf Klimaschwankungen sehr sensibel reagierendes System. Die Untersuchung von Biomarkern (organische Moleküle von Pflanzen) soll aufzeigen, wie sich das Klimasystem in Bezug auf Temperatur/Niederschlag und Eisbedeckung geändert hat.
Lay summary
Inhalt und Ziel des Forschungsprojekts

In 2009 wurden zwei Sedimentkerne am Vansee erfolgreich vom Paleovan-Team gebohrt. Bis jetzt konnte ein erfolgreiches Altersmodell mit Hilfe von 14C, Be, Einzelkristall 40Ar/39Ar Altern und einem Vergleich zu den marinen Sauerstoffphasen etabliert werden und ein Grund-verständnis der Sedimentation basierend auf organischen/inorganischen Kohlenstoffgehalten und einer Kernradiographie erlangt werden. Zwei Biomarkerstudien an 60 ausgewählten Proben zeigten, dass es innerhalb der letzten 600 Jahre zu dramatischen Klimaänderungen gekommen ist. Diese Untersuchungen zeigten aber auch, dass die zeitliche Auflösung zu gering ist. In diesem Projekt versuchen wir die klima-gesteuerten (Niederschlag/Temperatur/Eisbedeckung) Vegetationsänderungen zu erfassen. Wir haben drei grundlegende Fragen:

1.         Was war die Temperatur in den letzten 200.000 Jahren im Gebiet um den Vansee?

2.         Wie hat sich die Vegetation in den betrachteten Zeiträumen geändert?

3.         Wie hat sich der Salzgehalt im Vansee geändert und kann man hieraus Niederschlagsänderungen ableiten?

Wir messen organische Moleküle von Land- und Seepflanzen, sogenannte Biomarker, um Verschiedenheit oder Gemeinsamkeit dieser Marker herauszuarbeiten. Hierfür benutzen wir organisch-geochemische und isotopen-geochemische Techniken der neuesten Entwicklung.  Diese Untersuchungen werden an besonders ausgewählten Kernsegmenten, welche besonders starke Kalt-Warmschwankungen auf längeren oder Millenium-Zeitskalen (sogenannte Dansgaard-Oeschger Ereignisse) aufweisen.

Wissenschaftlicher und gesellschaftlicher Kontext des Forschungsprojekts

Unsere Arbeit wird neue und wichtige Informationen über drastische Klimaschwankungen in einer Schlüsselregion liefern. Die Ergebnisse werden es erlauben, Politikerinnen und Politiker einen Eindruck im Hinblick auf klimatisch bedingte mögliche Änderungen in der Zukunft zu geben und diesen mit Vorkehrungen gegen Schäden zu begegnen.

Direct link to Lay Summary Last update: 14.12.2014

Responsible applicant and co-applicants

Employees

Name Institute

Publications

Publication
Paleoenvironmental and paleoclimatic variations around Lake Van (Eastern Turkey) recorded by sedimentary source specific biomarkers 250–130 ka (MIS7 and MIS6)
Guillemot T., Stockhecke M., Bechtel A., Ladd S.N., Nelson D.B., Schubert C.J. (2019), Paleoenvironmental and paleoclimatic variations around Lake Van (Eastern Turkey) recorded by sedimentary source specific biomarkers 250–130 ka (MIS7 and MIS6), in Quaternary Science Reviews, 225, 105997-105997.
Biomarkers in Lake Van sediments reveal dry conditions in eastern Anatolia during 110.000-10.000 years B.P.
Randlett Marie-Eve, Bechtel Achim, van der Meer Marcel T. J., Peterse Francien, Litt Thomas, Pickarski Nadine, Kwiecien Ola, Stockhecke Mona, Wehrli Bernhard, Schubert Carsten J. (2017), Biomarkers in Lake Van sediments reveal dry conditions in eastern Anatolia during 110.000-10.000 years B.P., in Geochemistry, Geophysics, Geosystems, 18(2), 571-583.

Collaboration

Group / person Country
Types of collaboration
Prof. Litt/University of Bonn Germany (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Dr. Mona Stockhecke/Eawag/ETHZ Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Prof. Rolf Kipfer/Eawag Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
Prof. Anselmetti/University of Bern Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Exchange of personnel
Namik Çagatay/Technical University Istanbul Turkey (Europe)
- in-depth/constructive exchanges on approaches, methods or results
Prof. Kwiecien/University Bochum Germany (Europe)
- in-depth/constructive exchanges on approaches, methods or results
Prof. Eglinton/ETHZ Switzerland (Europe)
- Research Infrastructure
Prof. Püttmann/University Frankfurt Germany (Europe)
- in-depth/constructive exchanges on approaches, methods or results

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
Swiss Geoscience Meeting Poster Paleo-humidity reconstruction around Lake Van (Turkey) between MIS 5 to 7 based on alkenones assemblages and δD measurements 17.11.2017 Davos, Switzerland Guillemot Typhaine; Bechtel Achim; Schubert Carsten;
Réunion des Sciences de la Terre (RST) Poster Variations hydrologiques des 6 derniers cycles glaciaires/interglaciaires en Anatolie Est à partir du D mesuré sur des stérols et alcénones présents au sein des sédiments du lac Van 24.10.2017 Caen, France Guillemot Typhaine; Schubert Carsten; Bechtel Achim;
International Meeting of Organic Geochemistry Poster PALEOCLIMATE RECONSTRUCTION FROM LAKE VAN SEDIMENTS DURING DASGAARD-OESCHGER EVENTS AND LAST GLACIAL TERMINATIONS 17.09.2017 Florenz, Italy Schubert Carsten; Bechtel Achim; Guillemot Typhaine;
International Meeting of Organic Geochemistry Poster PALAEO-CLIMATIC RECONSTRUCTIONS AROUND LAKE VAN DURING THE LAST 600 KA BP USING MOLECULAR BIOMARKERS AND δD MEASUREMENTS 17.09.2017 Florenz, Italy Guillemot Typhaine; Bechtel Achim; Schubert Carsten;
EGU General Assembly 2016 (Vienna, Austria) Poster Temperature and precipitation reconstruction in correspondance to Dansgaard-Oeschger events and glacial terminations from Turkey 23.04.2017 Vienna, Austria Schubert Carsten; Bechtel Achim;


Associated projects

Number Title Start Funding scheme
143340 The Swiss contribution to the ICDP Lake Van Drilling Project: Linking modern seismic and biogeochemical signatures to 500,000 years of environmental history 01.01.2013 Project funding
124981 The Swiss contribution to the Lake Van Drilling Project: 500000 years of environmental and climate change in Eastern Anatolia (Science Part) 01.01.2010 Project funding

Abstract

In 2009 two sediment cores from Lake Van were successfully recovered by the Paleovan-Team. This endeavour was only possible due to the involvement of a large group of scientist from Switzerland and co-funding by the Swiss National Science foundation. After 4 years we have: first of all a reliable age model based on 14C, Be, single crystal 40Ar/39Ar ages, and a comparison with marine oxygen isotope records, a basic understanding of factors controlling the sedimentation in Lake Van based on bulk parameters (e.g. TOC, TIC, XRF core scanning), and numerous sediment samples that are ready for further analysis. Two biomarker studies were already performed on 60 samples and led to the conclusion that dramatic biological/climatical changes in the 600 kyr old lake history occurred (Randlett et al. in review, Randlett et al. in prep.). Although these results are important and give new insights into the history of this climatically important region, the resolution of the samples is not sufficient. We hence, in this proposal, lay out several lines of ideas in how to further use the outstanding sediment record of Lake Van to understand climatically controlled variations in vegetation changes based on changes in precipitation/ temperature/ ice cover to only mention few possibilities. We have three basic questions:1.What was the temperature in the Lake Van region over the investigated time periods?2.How did the vegetation changed over these periods?3.How did salinity changed in Lake Van over those time periods and can this be linked to precipitation?Our studies will include measurements of terrestrial plants as well as algal biomarkers to decipher differences or commonalities in the catchment and in the lake itself. For this, we will use state-of-the-art organic geochemistry and isotope geochemistry tools. We propose to do numerous biomarker investigation on specifically selected core regions, i.e., with a special focus on terminations I and II, and on glacials characterized by millennial-scale hydroclimate variability known as Dansgaard Oeschger events. Since this project is embedded in the Paleovan-Team it will have the support and knowledge gained during the first 4 years of all researchers based mainly in Switzerland, Germany, and Turkey. With this proposal we make full use of the already available data and further justify the prior financial commitment of SNF to the Lake Van project.
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