Applied Geophysics at Lake Chew Bahir, Southern Ethiopia
In November/December 2014, four scientists from the Institute of Geophysics and Meteorology of the University of Cologne conducted a five weeks field survey at Lake Chew Bahir, Southern Ethiopia. The survey aimed to provide additional knowledge of the sedimentological structures of Chew Bahir. It was supported by our Ethiopian partners from the University of Addis Ababa.
We conducted 80 transient electromagnetic (TEM) measurements in the central-loop configuration utilizing 100 x 100 m² transmitter loops. TEM/3 induction coils from Zonge International served as receivers of the vertical and the east-west horizontal component of the magnetic field. The east-west horizontal component of the magnetic field was nearly perpendicular to the mountain ridge in the west of our research area. The vertical component is used to identify the thickness of the sediments or fluvial fans inside the sediments. The horizontal component is recorded for the investigation of possible 2D effects being caused by the surrounding mountains.
The results will be compared to existing borehole data and additionally be used to identify further suitable borehole locations for subsequent palaeoclimatological researches.
TEM transmitter station and operator crew at Lake Chew Bahir.
Photo: Marc Seidel