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Extremely arid conditions in tropical Africa occurred in several discrete episodes between 135 and 90 ka, as demonstrated by lake core and seismic records from multiple basins [Scholz CA, Johnson TC, Cohen AS, King JW, Peck J, Overpeck JT, Talbot MR, Brown ET, Kalindekafe L, Amoako PYO, et al. (2007) Proc Natl Acad Sci USA 104:16416-16421]. This resulted in(More)
The environmental backdrop to the evolution and spread of early Homo sapiens in East Africa is known mainly from isolated outcrops and distant marine sediment cores. Here we present results from new scientific drill cores from Lake Malawi, the first long and continuous, high-fidelity records of tropical climate change from the continent itself. Our record(More)
[1] The tropics play a major role in global climate dynamics, and are vulnerable to future climate change. We present a record of East African climate since 55 ka, preserved in Lake Malawi sediments, that indicates rapid shifts between discrete climate modes related to abrupt warming (DO) events observed in Greenland. Although the timing of the Malawi(More)
Introduction and Geological Setting. The Bosum-twi impact crater is centered at 06°32'N and 01°25'W, and is almost completely filled by a lake. Bosumtwi is one of only four known impact craters associated with a tektite strewn field [1]. It is a well-preserved complex impact structure that displays a pronounced rim. The crater is excavated in 2.1-2.2 Ga(More)
Although persistent drought in West Africa is well documented from the instrumental record and has been primarily attributed to changing Atlantic sea surface temperatures, little is known about the length, severity, and origin of drought before the 20th century. We combined geomorphic, isotopic, and geochemical evidence from the sediments of Lake Bosumtwi,(More)
a r t i c l e i n f o The recovery of detailed and continuous paleoclimate records from the interior of the African continent has long been of interest for understanding climate dynamics of the tropics, and also for constraining the environmental backdrop to the evolution and spread of early Homo sapiens. In 2005 an international team of scientists(More)
Presite Surveys and Model Predictions: In preparation for the scientific drilling of the Lake Bo-sumtwi crater, a wide range of geophysical and petro-physical studies were conducted over the past 10 years. In 1997 a high-resolution airborne geophysical survey revealed a halo-shaped magnetic anomaly [1]. Physical properties of suevites collected north of the(More)
Seismic data reveal that water level in Lake Malawi, East Africa, was 250 to 500 meters lower before about 25,000 years ago. Water levels in Lake Tanganyika at that time were more than 600 meters below the current lake level. A drier climate appears to have caused these low stands, but tectonic tilting may also have been a contributing factor in Lake(More)