In autumn 2011, we successfully completed a west to east coring transect at lakes in different altitudes.
First, we cored Lake Babogaya, one of the Debre Zeyit volcan crater lakes at 1800 m a.s.l. south of Addis Ababa. Here, we retrieved a 16 m long sediment core from the deepest part (65 m water depth) of this nearly circular lake. Further, we gathered five short cores from different positions in order to understand the "recent" setting. The sediment cores in some parts show a fine lamination with alternating white and brownish layers. Once again, we worked successfully due to the immense help of our Ethiopian partners, Dr. Mohammed Umer (who died unexpectedly just 4 weeks later) and Dr. Asfawossen Asrat.
 The Addis-Cologne coring team on Lake Babogaya: Christian Tourney, Mohammed Umer, Frank Schäbitz, Asfawossen Asrat and Jonas Urban (from left to right). Photo: Oliver Langkamp (30-10-2011) |
Our next location was the Yardi lake (560 m a.s.l.) in the Afar region about 25 km west of the town of Gewana. This site is of great interest due to the famous skull from an "Anatomical Modern Human" (AMH) found at Herto, less than 2 km northeast of Yardi lake. However, that particular area is not easily accessible: first, one requires good relations to the Afar tribes living in this area and second, there is no direct path to reach the lake with heavy machinery. There is only one possibility: to use and follow the Awash river upstream! On the other hand, this is only advisable with a metal boat equipped with a strong engine, since the Awash is the home of numerous hippopotamus and crocodiles. This not being the case, we instead preferred to core in former lake sediments close to the recent shore. However, we plan to return later (better equipped) in order to core the lake Yardi sediments, which may contain information of the palaeoenvironment from the time when the AMH of Herto was living close by.
 The Awash river with hippopotamus, view to the Bouri peninsula with a Herto village in the background. Yardi lake is situated upstream, 2 km left of this site. Photo: Frank Schäbitz (14-11-2011) |
Another site we surveyed was Lake Haromaya (2010 m a.s.l.), situated on the eastern rift shoulder, west of the town of Harar. Due to the intensive use of the water by the population living in this region, the lake dried out some years ago. However, due to unexpected heavy rain a week before we arrived, the centre of the lake was covered with water about half a metre deep. For this reason we could only core close to the shore, where we gathered at least 5 m of lake sediments. However, with this lake we completed the easternmost part of our transect.
 Coring on the dried out part of Lake Haromaya in November 2011. Photo: Henry Lamb |
Finally, we visited the Dendi crater lakes, which have recently been connected by a first primitive dirt road. These double lakes are situated in a volcanic crater about 2800 m a.s.l., 90 km west of Addis Ababa. We inspected them for two days with our sonar and found that the easternmost lake is about 50 m deep, while the other reaches only 40 m water depth. Moreover, we checked the accessibility for our heavy drilling equipment and found a suitable place to launch the platform when we return in 2012.
 Dendi crater lakes at the endpoint of a new dirt road. Photo: Frank Schäbitz (19-11-2011) |
