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Holocene to Late-Pleistocene Paleoclimatic Changes in Turkey and the Eastern Mediterranean Recorded in Speleothems

English title Holocene to Late-Pleistocene Paleoclimatic Changes in Turkey and the Eastern Mediterranean Recorded in Speleothems
Applicant Fleitmann Dominik
Number 130450
Funding scheme SNSF Professorships
Research institution
Institution of higher education University of Berne - BE
Main discipline Geology
Start/End 01.10.2010 - 30.09.2012
Approved amount 527'765.00
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All Disciplines (4)

Discipline
Geology
Climatology. Atmospherical Chemistry, Aeronomy
Geochronology
Geochemistry

Keywords (9)

Paleoclimate; Turkey; Eastern Mediterranean climate; Uranium-series dating; stable isotopes; trace elements; fluid inclusions; North Atlantic Oscillation; Indian Monsoon

Lay Summary (German)

Lead
Lay summary
Es gibt bislang zu wenig Information über die Schwankungen im Wasserkreislauf in der Vergangenheit. Mit Hilfe von Stalagmiten aus der Türkei sollen Niederschlagsschwankungen während der letzten 600000 Jahre mit einer sehr hohen zeitlichen Auflösung rekonstruiert werden.HINTERGRUNDEin wichtiges Ziel der heutigen Klimaforschung ist es den Wasserkreislauf auf regionaler bis zu globaler Ebene besser zu verstehen. Bis heute gibt es jedoch kaum Informationen über Niederschlagsschwankungen in der Vergangenheit, da der Fokus eher auf der Rekonstruktion von Temperaturschwankungen lag. Das ist erstaunlich, da in vielen Gebieten der Erde gerade das Wasser von grösserer Bedeutung für Ökosysteme und Gesellschaften ist. Dies trifft ganz besonders auf das östliche Mittelmeer zu, wo es bis heute nur sehr ungenaue Informationen über Niederschlagsschwankungen vor der Zeit der instrumentellen Daten gibt. Die wenigen vorhandenen Niederschlagszeitreihen beruhen entweder auf der Auswertung von Seesedimenten oder Baumringen. Diese Rekonstruktionen sind entweder kurz und erfassen nur wenige Jahrhunderte oder zeitlich schlecht aufgelöst und ungenau datiert. Das Fehlen genauer Daten führt dazu dass die Ursachen und Verlauf von Niederschlagsschwankungen im östlichen Mittelmeer unzureichend erforscht sind.DAS ZIELDas Projekt hat zum Ziel, Niederschlagsschwankungen in der Türkei anhand von Stalagmiten zu untersuchen. Mit Hilfe von sehr genauen Altersdatierungen (Uran-Thorium Datierungsmethode), stabilen Isotopen (Wasserstoff, Kohlenstoff und Sauerstoff) und Spurenelementen sollen Zeitreihen erstellt werden, welche Niederschlagsschwankungen mit einer bislang unerreichten Genauigkeit aufzeigen. Diese Zeitreihen geben dann Auskunft über die Ursachen von Niederschlagsschwankungen, wie zum Beispiel die Häufigkeit und Dauer von Dürren.BEDEUTUNGDas Projekt soll dazu beitragen, den Wasserkreislauf im östlichen Mittelmeer wesentlich besser zu verstehen und wichtige Datengrundlagen zu liefern um Klimamodelle zu verifizieren. Die Mittelmeerregion ist dicht bevölkert und die Landwirtschaft ist eine wichtige Einkommensquelle. Es ist daher offensichtlich dass wir die Ursachen für extreme Niederschlagsschwankungen in dieser komplexen Region verstehen müssen um genauere Vorhersagen für die Zukunft treffen zu können. Hierbei spielen Paläoklimadaten eine zentrale Rolle.
Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Employees

Associated projects

Number Title Start Funding scheme
119966 Determination of paleotemperatures from fluid inclusion liquid-vapour homogenization in speleothems 01.04.2008 Project funding (Div. I-III)
132646 STALCLIM - Multi-proxy climatic and environmental reconstructions from stalagmites from Switzerland, Turkey, Arabia and India 01.01.2011 Sinergia

Abstract

An important task of current and future paleoclimate research is the characterization of variations in the hydrological cycle on a regional to global scale. Yet, however, there is a clear misbalance between temperature and precipitation records, as past climate research was focused rather on temperature than precipitation. This tendency neglects the arguably much greater importance of water availability to society and ecosystem functioning. As a result, well-dated and highly resolved (1-10 year resolution) precipitation records are either scarce or not available in most parts of the globe. This is particularly true for the Eastern Mediterranean and Turkey respectively. In this area, published paleoclimate reconstructions are almost exclusively based on lake sediment and tree ring records. However, long and precisely-dated records documenting changes of the hydrological cycle on all time-scales have not yet been retrieved from both climate archives. This gap of knowledge can be filled by speleothems from caves in Turkey. A particular strength of speleothem records are their potential for constructing long (103-104 years) and highly resolved records with very precise chronologies.Results obtained during the first stage of this project clearly reveal that stalagmites from western Turkey can provide precipitation records of unsurpassed quality, particularly in terms of dating precision, temporal coverage and resolution. Within three years of research, several “master” palaeorecords were constructed, some of shich go back to 330,000 years before present (BP). However, there are still spatial and temporal gaps in our reconstructions. For instance, there is only one stalagmite record from the Black Sea coast in Turkey that covers the Holocene and Late Glacial period continuously. Such a single record is not sufficient to fully explain the pattern and causes of hydrological changes in entire western Turkey. Furthermore, there are still gaps in a stacked stalagmite record from Sofular Cave, which covers several glacial-interglacial cycles. A continuous 400,000 year-long precisely dated and highly-resolved (~40 year resolution) paleoclimate record from Sofular Cave would be truly unique as there are currently less than a handful terrestrial paleoclimate records of comparable quality worldwide. Furthermore, most of our speleothem-based paleoclimate reconstructions are almost entirely based on oxygen and stable isotope measurements of speleothem calcite. Thus, an additional and important aspect of this follow-up proposal is to measure additional parameters, such as trace elements, noble gas concentrations in speleothem fluid inclusions, fluid inclusion liquid-vapour homogenization temperatures and stable isotopes in fluid inclusion water. This comprehensive approach will allow us to retrieve detailed information on precipitation, temperature and ecosystem from the same sample. Importantly, the use of multiple proxies allows assessing the factors that can alter or even mask climatic and environmental signals along the pathway from precipitation to speleothem calcite. Such a multi-proxy approach would improve our interpretation skills significantly. Conclusively, the requested research will produce high-quality and more quantitative paleoclimate records which can be used for benchmarking the same models that are used for climate projections. The statement “Palaeo-data and models have the potential for a truly symbiotic relationship” by the climate modeller Gerrit Lohmann (AWI, Bremerhafen, Germany) underlines the importance of such paleodata. Constructing near-instrumental records covering long periods from natural climate archives is thus a key-objective of ongoing and future palaeoclimate research.
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