Description
The Chew Bahir basin has proven to be an outstanding site for paleoclimate studies of the past ~620 kyr within the Hominin Sites and Paleolakes Drilling Project (HSPDP). We are proposing to return to this unique location with a new project to core ~900 m beyond the ~300 m base of the first Chew Bahir deep cores collected in 2014 to reach a total depth of 1,200 m to presumably reach the base of the Quaternary. The aim of pilot study proposed here is to prepare for new deeper drilling and to gain the necessary knowledge about the spatio-temporal sedimentation processes and conditions at a new drilling site. The principal research questions addressed by our new pilot project are: (1) What is a suitable strategy for drilling lakes? (2) Are the findings from the Chew Bahir climate archive transferable to a different drilling location? and (3) How does a rift basin become a climate archive? During the first two years of the project, we will work on the following tasks: (1) Hyperspectral satellite remote sensing, (2) Landscape modeling, (3) Nearsurface geophysical exploration, (4) Extracting short sediment cores, (5) Initial analysis of the cores, and (6) Data analysis and documentation. During the project, we will test the following hypotheses: (1) Drilling aimed at obtaining high-quality climate archives in rift lakes should be carried out at the edge of the basin, not in the center, (2) Paleoclimate should never be determined from a single core, (3) A solid understanding of proxy-forming processes is a necessary prerequisite for reconstructing paleoclimate from lake sediments, (4) Climate signals in sediment require careful numerical and statistical pre-treatment, (5) The climate in northeast Africa was rarely stable, but frequently tipped, with and without warning, in both directions: from dry to wet and back again, and (6) Different global and regional frameworks lead to different forms of transitions. Even though the main objective of the project is to prepare for a deeper drilling in Chew Bahir, the pilot study will also enable interesting and attractive research questions to be answered that have arisen in the decade since the previous series of shallow and deep corings.