The International Decade of East African Lakes (IDEAL) drilling initiative for the African Great Lakes

Abstract

The Great Lakes of East Africa are one of the most exciting targets for obtaining long core records on Earth. Since their early exploration by 19 century naturalists their unique geological and biological attributes have been objects of curiosity for scientists from a wide range of disciplines. Since early in the 20 century it has also been evident that an extremely long and detailed history of regional paleoclimate and paleoenvironments could be gleaned from the study of their sediments. Beginning in the 1980s seismic reflection profiling of Lakes Malawi and Tanganyika revealed extremely thick packages (up to several km) of rift-related sediments lying on the bottoms of these lakes (Rosendahl et al., 1986), indicating histories extending back to the Miocene. The International Decade of the East African Lakes (IDEAL) was formed to promote investigation of these limnological and paleolimnological aspects of the African lakes. IDEAL is a multidisciplinary science initiative and is a component of the PAGES Core Project within IGBP. One of the central themes of IDEAL since its inception has been to advance our understanding of the history of the African Great Lakes through coordinated programs of paleolimnological and paleoclimate research (Johnson & Odada, 1996). Much of this work to date has involved the collection and interpretation of relatively short core records and seismic data on the various Great Lakes, to better define the most promising target areas for a program of scientific drilling. Our long-term goal is to obtain climate and paleoenvironmental records that cover the past several million years at stratigraphic resolutions comparable to ice cores, but in a part of the world that has been critical for ecosystem (and notably human) evolution. Obtaining such records is now within our grasp. The recent decision of the International Continental Drilling Program (ICDP) and the US National Science Foundation (NSF) to fund the purchase and testing of the GLAD 800 drilling system means that a community resource for deep lake drilling will be available within the next few years. Given this recent development and a background of considerable prior research in the Great Lakes region, the IDEAL Steering Committee sponsored a planning workshop for a drilling campaign on what are arguably the two most exciting targets of ‘deep-time’ paleolimnological research on Earth, Lakes Malawi and Tanganyika.