Chew Bahir (Ethiopia) – A Paleoclimatic Archive: Initial Core Description and First Results


The Chew Bahir basin is located in southern Ethiopia. It is a tectonic graben, which is part of the East African Rift System (EARS). Its position close to the Omo Valley, which is considered to be the source region of the anatomically modern human (AMH), makes it an interesting target for interdisciplinary research.

The Chew Bahir project is embedded in the CRC 806 in project A3. The A3 project focuses on terrestrial sediment

Raphael Gromig, Project A3

archives (lacustrine sediments) in southern Ethiopia in order to reconstruct the Late Pleistocene and Holocene climate in the source region of the AMH. The Chew Bahir paleolake is a promising archive, which can contribute to understand the climate during the last 200 ka, which is the CRC 806-relevant time slice. In November 2014 an ICDP funded deep drilling campaign was conducted at the Chew Bahir basin. Two parallel holes were drilled, with a maximum depth in hole 2A of 278.58 meters below surface (mbs) and 266.38 mbs for 2B. As a first approximation the upper 80 m cover the last 200 ka. The water level of the lake underlies enormous fluctuations throughout the year, which are coupled to the rainy seasons. At least once during recorded history the lake completely dried up. The rain seasons and moisture availability are bound to the Intertropical Convergence Zone (ITCZ) and the Congo Air Boundary (CAB). Today the Chew Bahir basin is a saline mudflat. Besides these small-scale fluctuations, the lake reacts very sensitive to orbital forcing, mainly controlled by the precessional cycle (20 ka cycle).

Event Information:

Date, Time: 23/11/2015, 14:00 h – 14:45 h

Location: Room S22, Seminargebäude (Building 106), Universitätsstraße 37 , Cologne

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