|
Organizers |
The Eastern Mediterranean speleothems record vs. the Atlantic and the Indian Ocean Monsoonal system
by
M. Bar-Matthews
Geological Survey of Israel
Coauthors: Bar-Matthews, M.Geological Survey of Israel, 30 Malchei Israel St. Jerusalem, Israel, 95501, Almogi-Labin, A. Geological Survey of Israel, 30 Malchei Israel St. Jerusalem, Israel, 95501, Ayalon, A. Geological Survey of Israel, 30 Malchei Israel St. Jerusalem, Israel, 95501
The middle east region is influenced by two different climatic systems, one originates in the Atlantic Ocean, passing over the Mediterranean Sea, and the second one originates in the Indian Ocean passing over the Red Sea and is associated with the monsoonal system.
We compared between the oxygen isotopic records of cave deposits (speleothems) from central Israel with those of planktonic foraminifera G. ruber from the Eastern Mediterranean, and the central Red Sea. The general isotopic pattern of all the three records is similar during the last 180 Ky.
The isotopic composition of the vapor source, the isotopic composition of the rain and the mean annual temperature determine Speleothems oxygen isotopic composition. Thus, their oxygen isotopic values are always lower than that of G. ruber. There is a nearly constant offset of about 5.5± 0.5‰ between Eastern Mediterranean isotopic record and the speleothems throughout glacial – interglacial periods, indicating the intimate link between the two systems. In contrast the offset between the speleothems record and the Red Sea range between 3 and 5.5‰, indicating that the two systems operate in different modes. The largest offsets between these systems occur during increased hydrological activity in the Eastern Mediterranean coinciding with the sapropel events (Stages 5.5 and 1.1).
Although the three records resemble each other, it is clearly seen that the land system in the Eastern Mediterranean region is mainly influenced by the Atlantic vapor source.
Date received: March 29, 2001
Copyright © 2001 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # cagc-57.