Verena Foerster

University of Cologne | UOC · Institute of Geography Education

Southern Ethiopia has undergone tremendous climatic changes, from dry and relatively cold during the Last Glacial Maximum (LGM, 25–18 ka) to the African Humid Period (AHP, 15–5 ka), and back to present-day dry conditions. As a contribution to better understand the effects of climate change on vegetation and lakes, we here present a Predictive Veget...

Understanding eastern African paleoclimate is critical for contextualizing early human evolution, adaptation, and dispersal, yet Pleistocene climate of this region and its governing mechanisms remain poorly understood due to the lack of long, orbitally-resolved, terrestrial paleoclimate records. Here we present leaf wax hydrogen isotope records of...

Paleoanthropologists have long speculated about the role of environmental change in shaping human evolution in Africa. In recent years, drill cores of late Neogene lacustrine sedimentary rocks have yielded valuable high-resolution records of climatic and ecosystem change. Eastern African Rift sediments (primarily lake beds) provide an extraordinary...

There is ongoing debate concerning whether or not changes in the eastern African climate, both long-term and short-term, affected the evolution, dispersal, cultural development, and technological innovations of Homo sapiens – and if so, in what way. We present the wavelet spectral analysis results of a ∼620 kyr record of environmental change from t...

During the past 25 ka, southern Ethiopia has undergone tremendous climatic changes, from dry and relatively cold during the Last Glacial Maximum (LGM, 25–18 ka) to the African Humid Period (AHP, 15–5 ka), and back to present-day dry conditions. As a contribution to better understand the effects of climate change on vegetation and lakes, we here pre...

Eastern Africa has been a prime target for scientific drilling because it is rich in key paleoanthropological sites as well as in paleolakes, containing valuable paleoclimatic information on evolutionary time scales. The Hominin Sites and Paleolakes Drilling Project (HSPDP) explores these paleolakes with the aim of reconstructing environmental cond...

The hypothesis of a connection between the onset (or intensification) of Northern Hemisphere Glaciation, the stepwise increase in African aridity (and climate variability), and an important mammalian (including hominin) species turnover is a textbook example of the initiation of a scientific idea and its propagation in science. It is, however, also...

Despite eastern Africa being a key location in the emergence of Homo sapiens and their subsequent dispersal out of Africa, there is a paucity of long, well-dated climate records in the region to contextualize this history. To address this issue, we dated a ∼293 m long composite sediment core from Chew Bahir, south Ethiopia, using three independent...

Reconstructions of climatic and environmental conditions can contribute to current debates about the factors that influenced early human dispersal within and beyond Africa. Here we analyse a 200,000-year multi-proxy paleoclimate record from Chew Bahir, a tectonic lake basin in the southern Ethiopian rift. Our record reveals two modes of climate cha...

In this study, we synthesize terrestrial and marine proxy records, spanning the past 620 ky, to decipher pan-African climate variability and its drivers and potential linkages to hominin evolution. We find a tight correlation between moisture availability across Africa to El Niño Southern Ocean oscillation (ENSO) variability, a manifestation of the...

The Chew Bahir Drilling Project (CBDP) aims to test possible linkages between climate and hominin evolution in Africa through the analysis of sediment cores that have recorded environmental changes in the Chew Bahir basin (CHB). In this statistical project we used recurrence plots (RPs) together with a recurrence quantification analysis (RQA) to di...

Establishing robust environmental proxies at newly investigated terrestrial sedimentary archives is a challenge, because straightforward climate reconstructions can be hampered by the complex relationship between climate parameters and sediment composition, proxy preservation or (in)sufficient sample material. We present a minimally invasive hypers...

We present new mineralogical and geochemical data from modern sediments in the Chew Bahir basin and catchment, Ethiopia. Our goal is to better understand the role of modern sedimentary processes in chemical proxy formation in the Chew Bahir paleolake, a newly investigated paleoclimatic archive, to provide environmental context for human evolution a...

The use of cyclostratigraphy to reconstruct the timing of deposition of lacustrine deposits requires sophisticated tuning techniques that can accommodate continuous long-term changes in sedimentation rates. However, most tuning methods use stationary filters that are unable to take into account such long-term variations in accumulation rates. To ov...

The Ethiopian rift is known for its diverse landscape, ranging from arid and semi-arid savannahs to high and humid mountainous regions. Lacustrine sediments and paleo-shorelines indicate water availability fluctuated dramatically from deep fresh water lakes, to shallow highly alkaline lakes, to completely desiccated lakes. To investigate the role l...

The Neogene and Quaternary are characterized by enormous changes in global climate and environments, including global cooling and the establishment of northern high-latitude glaciers. These changes reshaped global ecosystems, including the emergence of tropical dry forests and savannahs that are found in Africa today, which in turn may have influen...

This paper reports on the application of advanced hyperspectral analysis to support the nondestructive study of samples from long sediment cores (up to 280 m coring depth) collected under the Hominin Sites and Paleolake Drilling Program (HSPDP) in the Chew Bahir region of southern Ethiopia. For this purpose, the bidirectional reflectance of 35 core...

The Chew Bahir Drilling Project (CBDP) aims to test possible linkages between climate and evolution in Africa through the analysis of sediment cores that have recorded environmental changes in the Chew Bahir basin. In this statistical project we consider the Chew Bahir palaeolake to be a dynamical system consisting of interactions between its diffe...

Eastern African hydroclimate in the early Holocene created a lush landscape in what is commonly referred to as the African Humid Period (AHP: ∼15 to 5 ka). The termination of the AHP was characterised by a climatic shift towards drier conditions. This resulted in the desiccation of many lakes and may have pressured hunter-gather societies to move t...

The sediments of the Chew Bahir playa lake in southern Ethiopia were cored down to 280 m depth in the context of HSPDP (Hominin Sites and Paleolakes Drilling Project) and CRC (Collaborative Research Center) 806 "Our way to Europe" projects. The main aim is to reconstruct the paleoenvironmental conditions during the development of anatomically moder...

The Kenyan and Ethiopian rifts in eastern Africa are known for their diverse landscape, ranging from arid and semi-arid savannahs to high and lush mountainous regions, where anatomically modern humans were present since ∼195 ka BP. Lacustrine sediments and paleo-shorelines indicate water availability fluctuated dramatically during this period from...

How do we convert variabilities and trends in hundreds of potential parameters that are typically analyzed in the framework of a scientific drilling project to actual climate proxies? Using the case study from the Chew Bahir core from the southern Ethiopian Rift, we will show that deciphering climate information from lake sediments is challenging,...

We used a change point analysis on a late Pleistocene–Holocene lake-sediment record from the Chew Bahir basin in the southern Ethiopian Rift to determine the amplitude and duration of past climate transitions. The most dramatic changes occurred over 240 yr (from ~15,700 to 15,460 yr) during the onset of the African Humid Period (AHP), and over 990...

Deciphering paleoclimate from lake sediments is a challenge due to the complex relationship between climate parameters and sediment composition. Here we show the links between potassium (K) concentrations in the sediments of the Chew Bahir basin in the Southern Ethiopian Rift and fluctuations in the catchment precipitation/evaporation balance. Our...

Our understanding of the impact of climate-driven environmental change on prehistoric human populations is hampered by the scarcity of continuous paleoenvironmental records in the vicinity of archaeological sites. Here we compare a continuous paleoclimatic record of the last 20 ka before present from the Chew Bahir basin, southwest Ethiopia, with t...

The role that climate and environmental history may have played in influencing human evolution has been the focus of considerable interest and controversy among paleoanthropologists for decades. Prior attempts to understand the environmental history side of this equation have centered around the study of outcrop sediments and fossils adjacent to wh...

We welcome the comment by Wright and Forman (2016) on our paper as a useful opportunity to stimulate the discussion around interdisciplinary comparative approaches using palaeoenviron- mental and archaeological data. The authors of the comment ques- tion our interpretation of the archaeological record, and the concept of a Holocene refugium in the...

In search of the environmental context of the evolution and dispersal of Homo sapiens and our close relatives within and beyond the African continent, the ICDP-funded Hominin Sites and Paleolakes Drilling Project (HSPDP) has recently cored five fluvio-lacustrine archives of climate change in East Africa. The sediment cores collected in Ethiopia and...

The role that climate and environmental history may have played in influencing human evolution has been the focus of considerable interest and controversy among paleoanthropologists for decades. Prior attempts to understand the environmental history side of this equation have centered around the study of outcrop sediments and fossils adjacent to wh...

Chew Bahir, a deep tectonically-bound basin in southern Ethiopia, today covered by ~2000 km2 of saline mudflats, is a newly explored and recently ICDP-cored climatic archive, containing a several kilometer thick infill of fine lacustrine deposits. The site lies in close proximity to the Lower Omo, site of the oldest known fossils of anatomically mo...

Episodes of environmental stability and instability may be equally important for African hominin speciation, dispersal, and cultural innovation. Three examples of a change from stable to unstable environmental conditions are presented on three different time scales: (1) the Mid Holocene (MH) wet-dry transition in the Chew Bahir basin (Southern Ethi...

Chew Bahir, as a newly explored and just recently ICDP-cored climatic archive, lies between the Main Ethiopian Rift and the Omo-Turkana basin, site of the oldest known fossils of anatomically modern humans. Today Chew Bahir is a saline mudflat in a deep tectonically-bound basin that contains a several kilometre thick sedimentary infill. This basin...

The Chew Bahir basin, as a newly explored sedimentary climatic archive, lies in a biogeographically highly sensitive transition zone between the Main Ethiopian Rift and the Omo-Turkana basin, the region where the fossils of the oldest known anatomically modern human were found. Thus, a continuous climatic history from this area could give valuable...

Klimaschwankungen und eine sich rasch verändernde Umwelt könnten erheblichen Einfluss auf die menschliche Evolution, Wanderungsbewegungen, und kulturelle als auch technische Entwicklungen gehabt haben. Um diesen möglichen Einfluss von kurzfristigen Klimaschwankungen und langfristigen Klimaänderungen auf verschiedenen Zeitskalen auf den frühen Mensc...

Sediment records from two lakes in the biodiversity hotspot of the Southern Ethiopian Rift were retrieved, Lake Chamo (c. 9 ka) and Chew Bahir (c. 45 ka). Sedimentological and palaeoecological proxies infer rapidly changing environmental conditions (wet-dry cycle) such as the African Humid Period. The fossil record in both archives is fairly rich i...

A rapidly changing environment is considered an important driver not just for human evolution but also for cultural and technological innovation and migration. To evaluate the impact that climatic shifts on different timescales might have had on the living conditions of prehistoric humans is one of the cornerstones in current research, but continuo...

Rapid changes in environmental conditions are considered to be an important driver for human evolution, cultural and technological innovation, and expansion out of Africa. However, the nature of these environmental changes, their amplitude and correlation with steps in human evolution is the subject of current debates. Here we present a high-resolu...

The structure and evolution of East Africa Rift Valley has made the region sensitive to climate change, with alternating wet and arid periods that may have influenced human evolution. Understanding environmental change and its impact on human societies for the last few millennia may provide insights that can be applied to longer records from the re...

Understanding the possible linkages between environmental history and human evolution requires a detailed record of climatic, tectonic and hydrographic history for the regions of interest. In eastern Africa, thick lacustrine deposits often occur in close proximity to some of the most important fossil hominin and artifact localities, providing an op...

East African paleoenvironments are highly variable, marked by extreme fluctuations in moisture availability, which has far-reaching implications for the origin, evolution and dispersal of Homo sapiens in and beyond the region. This paper presents results from a pilot core from the Chew Bahir basin in southern Ethiopia that records the climatic hist...

Chew Bahir, today a saline mudflat in a tectonically-bounded basin in southern Ethiopia, lies between the Main Ethiopian Rift and the Omo-Turkana basin, site of the oldest known anatomically modern human fossils. Sedimentary records from Chew Bahir can therefore provide fundamental data for reconstructing Late Quaternary environments in the source...

Quasi-continuous variations of the Earth's magnetic field recorded in lake sediments can provide detailed time series describing the evolution of the geomagnetic field. To make robust conclusions about underlying geodynamo processes an improvement in the global coverage of recording sites is required. Current lake data for the late Brunhes are bias...