DATE2019-01-08 12:44:22
IDABSTRACT2014/106
CONTACTzanchetta@dst.unipi.it
PRESENTATIONORAL
INVITED0
IDSESSION1
TITLECOEVAL DRY EVENTS IN THE CENTRAL AND EASTERN MEDITERRANEAN BASIN AT 5.2 AND 5.6 KA RECORDED IN CORCHIA (ITALY) AND SOREQ CAVE (ISRAEL) SPELEOTHEMS
AUTHORSGiovanni Zanchetta (1)|Bar-Matthews Mira (2)|Drysdale Russell (3)|Lionello Piero (4)|Ayalon Avner (2)|Hellstrom John (3)|Isola Ilaria (4)|Regattieri Eleonora (1)
AFFILIATIONS
  1. University of Pisa, Pisa, Italy
  2. Geological Survey of Israel, Jerusalem, Israel
  3. University of Melbourne, Melbourne, Australia
  4. Università del Salento, Lecce, Italy
  5. Geological Survey of Israel, Jerusalem, Israel
  6. University of Melbourne, Melbourne, Australia
  7. INGV, Pisa, Italy
  8. University of Pisa, Pisa, Italy
ABSTRACTSoreq (Israel) and Corchia (central Italy) Caves are located 2500 km far apart along the Mediterranean winter-storm track and are ideally suited for investigating past variations of winter rainfall in the Mediterranean region. Analyses of speleothem d18O records from both caves for the period between ca. 7 to 4 ka BP show some striking similarities for the ca. 6 and 4 ka interval, but lack agreement between ca. 7 to 6 ka BP. Two prominent isotopic excursions, argued to reflect relatively drier conditions, are centred at ca. 5.6 and ca. 5.2 ka BP. The 5.2 ka event lasts less than a century, whereas the 5.6 ka event extends from ca. 5.7 to 5.4 ka BP. A period of progressive drying is also apparent from ca. 5 to 4 ka. Another prominent event, reflecting wetter conditions, is recorded in both records at ca. 5.8 ka and seems to last several decades. The 5.6 and 5.2 ka events occurred within a period of higher deposition of haematite-stained grains in cores of the sub-polar North Atlantic, suggesting that rainfall reduction was related to a southward shift of the polar front, which reduced vapour advection from Atlantic towards the Mediterranean. A comparison with Alpine records, including the Spannagel Cave isotope record, suggests that dry events recorded at Soreq and Corchia Caves may correspond to wetter (lake high stands) and cooler (glacier expansion) conditions in the Alpine region, indicating complex regional climate re-organization
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