1. Clima en España: Pasado, Presente y Futuro – Madrid, 11-13 February 2009 Decoding Mediterranean climate variability using lake sediments Decoding Mediterranean climate variability using lake sediments Daniel Ariztegui Section of Earth and Environmental Sciences University of Geneva Switzerland daniel.ariztegui@unige.ch Daniel Ariztegui Section of Earth and Environmental Sciences University of Geneva Switzerland daniel.ariztegui@unige.ch

2. Clima en España: Pasado, Presente y Futuro – Madrid, 11-13 February 2009 Decoding

3. Clima en España: Pasado, Presente y Futuro – Madrid, 11-13 February 2009 A NATURALIST'S VOYAGE ROUND THE WORLD First Edition - May 1860

4. The Great Drought was very well described by Darwin …During this time so little rain fell, that the vegetation failed; the brooks were dried up, and the whole country assumed the appearance of a dusty high-road… …Very great numbers of birds, wild animals, cattle, and horses perished from the want of food and water… The smaller streams in the Pampas were paved with a breccias of bones… …What would be the opinion of a geologist, viewing such an enormous collection of bones, of all kinds of animals and of all ages, thus embedded in one thick earthy mass?... Clima en España: Pasado, Presente y Futuro – Madrid, 11-13 February 2009

5. Decode : verb(trans.) convert (a coded message) into intelligible language Decode : verb(trans.) convert (a coded message) into intelligible language PROXY

6. modern atmospheric circulation North Atlantic

7. Climate The North Atlantic Oscillation (NAO) negative (-)positive (+) The NAO index is defined as the anomalous difference between the polar low and the subtropical high during the winter season (December through March) www.ldeo.columbia.edu/NAO/ modern atmospheric circulation

8. Climate The North Atlantic Oscillation (NAO) The NAO index is defined as the anomalous difference between the polar low and the subtropical high during the winter season (December through March) www.ldeo.columbia.edu/NAO/ modern atmospheric circulation 18601880190019201940196019802000 (+) dry in the Mediterranean (-) moist air into the Mediterranean

9. The North Atlantic Oscillation (NAO) in the Mediterranean realm How far west can be tracked ? modern atmospheric circulation Was this modern climate feature active during glacial intervals?

10. modern atmospheric circulation Lake Albano North Atlantic

11. Lake Albano seismo-stratigraphy and core location after Chondrogianni et al., 2004 high-resolution window into the LGM

12. core correlation and chronology after Chondrogianni et al., 2004 Lake Albano high-resolution window into the LGM

13. Lake Albano high-resolution window into the LGM Lithology

14. after Chondrogianni et al., 2004 Lake Albano high-resolution window into the LGM

15. after Chondrogianni et al., 2004 North Atlantic Oscillation (NAO) Lake Albano high-resolution window into the LGM periodical changes in productivity/sedimentation during LGM

16. after Chondrogianni et al., 2004 Centennial-millennial changes four alternating cold and warm intervals between H1 and H2 Decadal-interdecadal changes moisture fluctuations associated with NAO and/or ENSO like mechanisms Lake Albano high-resolution window into the LGM

17. The North Atlantic Oscillation (NAO) in the Mediterranean realm atmospheric circulation How far west can be tracked ? Was this modern climate feature active during glacial intervals?

18. modern atmospheric circulation Lake Butrint North Atlantic

19. Lake Butrint high-resolution window into the last three centuries Lake Butrint Albania Greece Corfu Italy Mediterranean Sea

20. Lake Butrint high-resolution window into the last three centuries Corfu Albania Lake Butrint Ionian Sea 1 km

21. Lake Butrint high-resolution window into the last three centuries sedimentary cores reference core

22. Lake Butrint high-resolution window into the last three centuries B 00-2B 00-3 Excellent core to core correlation laminated facies homogeneous facies

23. Lake Butrint high-resolution window into the last three centuries Depth (cm) 30 20 10 0 Magnetic susceptibility 0 60 120 Cs-137 (mBq/g) 196319861917187218111794 Years AD 0102030405060708090100110120130140150160 1.6 1.4 1.2 1.0 Density (g/cm 3 ) 1741 Ariztegui et al., in review

24. Lake Butrint high-resolution window into the last three centuries 1 cm one year 1 µm 1 mm gray layer dark brown layer white layer Spring Autumn Summer Winter Pennate diatoms centric diatoms carbonate crystals allochthonous OM autochthonous OM star-shaped aragonite sediment cycle one year 1905 1893

25. Lake Butrint high-resolution window into the last three centuries Ariztegui et al., in reviewDepth (cm) 0 2 4 TOC (%) 19631986 -30.0 - 24.0 - 26.0 - 28.0  13 C (OM) (‰) 1917187218111794 Years AD 0 Oxygen Index (mgCO 2 g -1 TOC) 200 400 C/N 9 11 13  15 N (OM) (‰)  15 N (OM) (‰) 4.0 6.0 2.0 1741 0 100 Hydrogen Index (mgHC g -1 TOC) Hydrogen Index (mgHC g -1 TOC) 200 50 150 0 - 4.0 - 8.0  18 O (carbonate) (‰) - 4.0 0 - 2.0  13 C (carbonate) (‰)  13 C (carbonate) (‰) - 6.0 020406080100120 140 160 sedimentary organic matter authigenic carbonates

26. Lake Butrint high-resolution window into the last three centuries Depth (cm) 10 20 30 40 50 2000 1917 1 µm aragonite low Mg calcite 1943 1986 1947 1929 1913 1 µm 0 Ariztegui et al., in review

27. Lake Butrint high-resolution window into the last three centuries number of lamina 0 0.4 0.8 data analyzed raw data mobile mean thickness (cm) 204060801001201401601802002202402600 - 0.4 Climate Thickness of the gray lamina year 2000 year 1740

28. Lake Butrint high-resolution window into the last three centuries period (calendar years) Climate Spectral analyses 100200 0 0.14 0.04 0.10 0.08 1015 spectral density 3.5 years = NAO

29. Lake Butrint high-resolution window into the last three centuries The land-sea interface influence of the NAO index increasing evaporation for the last part of the 20 century (positive index) but… anthropogenic impact trigger the most recent changes in salinity

30. The North Atlantic Oscillation (NAO) in the Mediterranean realm atmospheric circulation How far west can be tracked ? Was this modern climate feature active during glacial intervals? YES shifting temperature, wind directions and source of moisture The Ionian and Adriatic Sea

31. THANKS EU-Project PALICLAS Swiss National Science Foundation Albanian Geological Survey Université de Genève ETH Zürich Clima en España: Pasado, Presente y Futuro – Madrid, 11-13 February 2009

32. Lake Butrint high-resolution window into the last three centuries