LAKE TANGANYIKA DRILLING: ADDRESSING WORLD-CLASS SCIENTIFIC QUESTIONS IN PALEOCLIMATOLOGY, TECTONICS, AND EVOLUTIONARY ECOLOGY IN AFRICA’S OLDEST LAKE

Lake Tanganyika (East Africa) is the one of the oldest, largest, and deepest lakes found anywhere on Earth. Drilling Tanganyika could transform our understanding of tropical climate systems, processes of biological diversification, and Earth surface (source-to-sink) processes in rift basins. Lake Tanganyika contains the only known sedimentary sequence in the tropics that continuously spans the last ~8-10 Ma at drillable depths, and the lake’s sediments are an established world-class archive of high-fidelity records of precipitation, temperature, lake level, vegetation, and atmospheric dynamics. Drill cores will allow us to test the response of African climate to fundamentally important reorganizations of the Earth System, such as the response of tropical climates to Miocene-present changes in global climate boundary conditions, mid-Pliocene termination of a permanent El Niño, and the onset and intensification of high latitude glacial cycles. The lake contains textbook examples of aquatic biodiversity and endemism, with deeply rooted patterns of diversification across multiple taxonomic groups. Drill cores will allow unique assessments of diversification and extinction using both fossils and preserved DNA. The lake is situated within the Miombo woodlands, one of the largest tropical dry forests on Earth and a biodiversity hotspot that is under intense pressure from climate and land use change. Drill cores will afford new insight into the long term effects of climate, fire, and disturbance on the ecology and biogeography of tropical dry forests. Lake Tanganyika is a spectacular natural laboratory to study the rates and processes of extensional deformation, volcanism and coupled surface processes, and patterns of weathering and erosion that may serve as a positive feedback on geodynamics. Drill cores will provide a critical constraint on the rates of these processes over long timescales.

In the last four years we have convened a series of workshops attended by nearly 100 scientists to gauge interest and coordinate research in drilling Lake Tanganyika. We have in hand thousands of kilometers of exquisite seismic reflection data to locate potential drilling targets, and plan an International Continental Drilling Program workshop to plan drilling operations.