Paper No. 1
Presentation Time: 1:15 PM


TORFSTEIN, Adi, Institute of Earth Sciences, Hebrew University of Jerusalem, Edmond J. Safra Campus, Giva't Ram, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel, GOLDSTEIN, Steven L., Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, ENZEL, Yehouda, The Fredy and Nadine Harrmann Institute of Earth Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel, HAUG, Gerald, ETH Zürich, Geologisches Institut NO G 51.1, Sonneggstrasse 5, Zürich, 8092, Switzerland, KUSHNIR, Yochanan, Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9W, Palisades, NY 10964 and STEIN, Moti, Geological Survey of Israel, 30 Malkhe Israel St, Jerusalem, 95501,

The climate regime of the Levant during the last interglacial cycle played a primary role in modulating the dispersion of modern hominids out of Africa. Yet the nature of climate patterns during Marine Isotope Stage (MIS) 5 is ambiguous, with strong precession-timescale variations in regional hydrology and opposite influences of Northern Hemisphere (NH) and tropical climate systems. The limnological history of the Dead Sea is closely coupled to NH climate patterns, and thus serves as a primary proxy archive for regional hydro-climate conditions.

Here, we report on the limnological history of the Dead Sea hypersaline lakes, recorded in a continuous, 450-meter long sediment core recovered during the recent Dead Sea Deep Drilling Project (DSDDP). Accordingly, glacial and interglacial periods are characterized by extreme wetness and aridity, respectively. In particular, we report evidence for precession timescale catastrophic climate swings during the last interglacial, whose most extreme expression was the lake desiccation during MIS5.

The Levant climate was extremely hyperarid during the last interglacial. MIS5e was characterized by extreme water deprivation, which lead to massive deposition of salt (halite) from the lake. These conditions resulted in the near desiccation of the lake, which reached water levels of at least 300 meters below present Dead Sea water levels (ca. 423 meters below sea level). Although the hydrological conditions might have been less extreme during the subsequent MIS5d, ongoing arid conditions superimposed over the already exhausted water budget of the lake inhibited water level recovery until at least ca. 105-100 ka. Thereafter, the lake fluctuated between arid and hyperarid cycles, reflected by marl and halite cycles, respectively, until the transition into the last glacial cycle.

The Dead Sea limnological history during the last interglacial is modulated primarily by NH climate patterns, but is superimposed by episodic contributions of summer rain, reflecting an intensification and spatial northward shift of the African monsoon during times of maximum insolation. These perturbations had a limited effect on the overall hydrological balance of the lake, but are identified in the lake record as marl units sandwiched between massive halite intervals.