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A high resolution Late Glacial and Holocene Stalagmite Stable Isotope Record from the Southern Black Sea Coast

Ozan Mert GöktürkInstitute of Geosciences, University of BernOeschger Centre for Climate Change Research

2. April 2009

A high-resolution Late Glacial and Holocene Stalagmite Stable Isotope Record ...

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Motivation and Study Sites

> Turkey: influenced by / exhibiting a variety of climate patterns> Very few climate proxy data available> Highly sensitive to global warming (IPCC reports)> Peculiar location in the historical context> Hosting thousand of caves with stalagmites!

Ovacik CaveSofular Cave

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Study Site – Climate Characteristics

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What we measured

> Stalagmite So-1> δ13C and δ18O, last 50000 years > ~ 8 years of temporal resolution (late glacial and Holocene)> 99 U-Th dates, errors <= 1 %

> Stalagmite O-1> δ13C and δ18O, last 10000 years > At the moment: Lower temporal resolution,

looser age control> Analyses ongoing

So-1

O-1

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Questions

> The response of vegetation during big warmings / coolings ? (Bolling/Allerod , Younger Dryas, Holocene ...)

> Did shorter stadials (Older / Oldest Dryas, Gerzensee) really exist?

> Effect of meltwater inputs ?> Flooding of Black Sea ?> Holocene climate

patterns ?

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δ13C : relation to climate

> More negative δ13C in stalagmites when the vegetation is up and running!

> Microbial activity> C4 plants> Abundant rainfall> Moderate temperatures

> More positive δ13C in stalagmites when the vegetation is less active

> C3 plants> Drought> Extreme heat / cold> Human impact (land use change)

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δ18O: relation to climate

> More positive δ18O in stalagmites in case of :

> Generally warmer climate

> More summer rainfall (relative to winter)

— More negative δ18O in stalagmites in case of:

> Generally cooler climate

> More winter rainfall

> Source effects: Input from melting ice

> Amount effect:Heavier rain

> Continental rain-out:Rainfall source far away

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Vegetation response

YDKotthoff et al (2008)BA

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Meltwater – Black Sea effect

MeltWater

Deep sea coreBahr et al, 2008

North Greenland

Ice Core

Greenland Ice Core

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Meltwater – detailed look

North Greenland

Ice Core

Greenland Ice Core

Deep sea coreBahr et al, 2008

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Black Sea flooding?

? ?

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Holocene climate patterns

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Conclusions

> Very rapid vegetation response on the Black Sea coast> Shorter stadials identifiable> Meltwater pulses clear> Rapid Holocene events unclear (8.2, 4.2 kyr events)> Big changes after mid-Holocene

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Outlook

> Results to be reproduced> Trace elements to be incorporated> What was different in the Early to Mid-Holocene?

Teleconnections? Rainfall regime? Seasonality?> Late Holocene Climate?

OvacikUzuntarla

Kocain

Sofular

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Thanks

> Dominik Fleitmann> Seraina Badertscher, Robyn Pickering> Okan Tuysuz

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