HR: 09:45h
AN: U21F-08    [Abstracts]
TI: Persistent Atlantic cold-water spells into the Mediterranean caused abrupt aridities in the late Quaternary Levant
AU: * Stein, M
EM: motis@vms.huji.ac.il
AF: Geological Survey of Israel, 30 Malkhe Israel St., Jerusalem, 95501, Israel
AU: Bartov, Y
EM: ybartov@mines.edu
AF: Colorado school of mines, Golden Colorado, Golden, 80401, United States
AU: Enzel, Y
EM: yenzel@vms.huji.ac.il
AF: The Hebrew University of Jerusalem, Givat Ram, Jerusalem, 91904, Israel
AU: Goldstein, S L
EM: steveg@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory, Palisades, New York, 10964, Israel
AU: Torfstein, A
EM: aditorf@pob.huji.ac.il
AF: Geological Survey of Israel, 30 Malkhe Israel St., Jerusalem, 95501, Israel
AU: Torfstein, A
EM: aditorf@pob.huji.ac.il
AF: Colorado school of mines, Golden Colorado, Golden, 80401, United States
AU: Waldmann, N
EM: Nicolas.Waldmann@terre.unige.ch
AF: University of Geneva, Rue des Maraichers 13, Geneva, 1205, Switzerland
AB: The late Quaternary Levant paleohydrology and paleoclimate were recorded in the sedimentary and level history of lakes that occupied the tectonic depressions along the Dead Sea rift. The region was characterized by cold – wet climate conditions during glacials and warm-dry conditions during interglacials. This pattern was punctuated by abrupt arid events (< 200 y) that are correlated with intrusions of cold Atlantic-water into the east Mediterranean. Important examples are the abrupt falls of Lake Lisan during the Heinrich events, the catastrophic falls of Lake Lisan at the 14 and 11th millennium BP that were linked to "melt water pulses" MWP1-A and B. The Allerod fall marked the severest catastrophic aridity that prevailed in the late Quaternary Levant where the intruding cold waters enhanced the post-glacial warming - aridification trend. Subsequently, during the YD, the North Atlantic-cooling imposed a strong deviation from the post-Glacial warming-aridification trend of the Levant leading to enhanced-rain precipitation (return to the "glacial mode"). Bartov et al. (2003) proposed that the intruding cold water stopped the cyclonic uptake of vapor from the Mediterranean to the atmosphere, shutting the Levant rains. It seems that the YD cooling was associated with atmospheric changes, probably stronger effects of the Polar fronts and Westerlies that brought more rains to the Levant. Similar effects of cold seawater intrusions on the regional climate can be detected throughout the Holocene causing possibly the significant aridities of ca. 8.1, 3.5 and possibly the Medieval warming. The rapidity of the response of the regional hydrological systems to the global climate changes and the sensitivity of past human cultures to these changes (e.g. the collapse of the Natufian culture during the Allerod aridity) are certainly important lessons and alarming signals for our human society.
DE: 1105 Quaternary geochronology
DE: 1605 Abrupt/rapid climate change (4901, 8408)
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1637 Regional climate change
DE: 1641 Sea level change (1222, 1225, 4556)
SC: Union [U]
MN: 2007 Fall Meeting