TY  - JOUR
A1  - Trauth, Martin H.
A1  - Asrat, Asfawossen
A1  - Düsing, Walter
A1  - Foerster, Verena
A1  - Krämer, K. Hauke
A1  - Marwan, Norbert
A1  - Maslin, Mark A.
A1  - Schäbitz, Frank
T1  - Classifying past climate change in the Chew Bahir basin, southern Ethiopia, using recurrence quantification analysis
JF  - Climate dynamics : observational, theoretical and computational research on the climate system
N2  - 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 different components, such as the waterbody, the sediment beneath lake, and the organisms living within and around the lake. Recurrence is a common feature of such dynamical systems, with recurring patterns in the state of the system reflecting typical influences. Identifying and defining these influences contributes significantly to our understanding of the dynamics of the system. Different recurring changes in precipitation, evaporation, and wind speed in the Chew Bahir basin could result in similar (but not identical) conditions in the lake (e.g., depth and area of the lake, alkalinity and salinity of the lake water, species assemblages in the water body, and diagenesis in the sediments). Recurrence plots (RPs) are graphic displays of such recurring states within a system. Measures of complexity were subsequently introduced to complement the visual inspection of recurrence plots, and provide quantitative descriptions for use in recurrence quantification analysis (RQA). We present and discuss herein results from an RQA on the environmental record from six short (< 17 m) sediment cores collected during the CBDP, spanning the last 45 kyrs. The different types of variability and transitions in these records were classified to improve our understanding of the response of the biosphere to climate change, and especially the response of humans in the area.
KW  - Paleoclimate dynamics
KW  - Eastern Africa
KW  - Pleistocene
KW  - Holocene
KW  - Time-series analysis
KW  - Recurrence plot
Y1  - 2019
U6  - https://doi.org/10.1007/s00382-019-04641-3
SN  - 0930-7575
SN  - 1432-0894
VL  - 53
IS  - 5-6
SP  - 2557
EP  - 2572
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Trauth, Martin H.
A1  - Foerster, Verena
A1  - Junginger, Annett
A1  - Asrat, Asfawossen
A1  - Lamb, Henry F.
A1  - Schäbitz, Frank
T1  - Abrupt or gradual?
BT  - Change point analysis of the late Pleistocene-Holocene climate record from Chew Bahir, southern Ethiopia
JF  - Quaternary research : an interdisciplinary journal
N2  - 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 similar to 15,700 to 15,460 yr) during the onset of the African Humid Period (AHP), and over 990 yr (from similar to 4875 to 3885 yr) during its protracted termination. The AHP was interrupted by a distinct dry period coinciding with the high-latitude Younger Dryas stadial, which had an abrupt onset (less than similar to 100 yr) at similar to 13,260 yr and lasted until similar to 11,730 yr. Wet-dry-wet transitions prior to the AHP may reflect the high-latitude Dansgaard-Oeschger cycles, as indicated by cross-correlation of the potassium record with the NorthGRIP ice core record between similar to 45-20 ka. These findings may contribute to the debates regarding the amplitude, and duration and mechanisms of past climate transitions, and their possible influence on the development of early modern human cultures.
KW  - Late Pleistocene
KW  - Holocene
KW  - Change point analysis
KW  - Principal component analysis
KW  - Paleoclimatology
KW  - Southern Ethiopian Rift
KW  - African Humid Period
KW  - Younger Dryas
KW  - Dansgaard-Oeschger cycles
Y1  - 2018
U6  - https://doi.org/10.1017/qua.2018.30
SN  - 0033-5894
SN  - 1096-0287
VL  - 90
IS  - 2
SP  - 321
EP  - 330
PB  - Cambridge Univ. Press
CY  - New York
ER  - 
TY  - JOUR
A1  - Foerster, Verena
A1  - Vogelsang, Ralf
A1  - Junginger, Annett
A1  - Asrat, Asfawossen
A1  - Lamb, Henry F.
A1  - Schäbitz, Frank
A1  - Trauth, Martin H.
T1  - Environmental change and human occupation of southern Ethiopia and northern Kenya during the last 20,000 years
JF  - Quaternary science reviews : the international multidisciplinary research and review journal
N2  - 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 the available archaeological record of human presence in the region. The correlation of this record with orbitally-driven insolation variations suggests a complex nonlinear response of the environment to climate forcing, reflected in several long-term and short-term transitions between wet and dry conditions, resulting in abrupt changes between favorable and unfavorable living conditions for humans. Correlating the archaeological record in the surrounding region of the Chew Bahir basin, presumably including montane and lake-marginal refugia for human populations, with our climate record suggests a complex interplay between humans and their environment during the last 20 ka. The result may contribute to our understanding of how a dynamic environment may have impacted the adaptation and dispersal of early humans in eastern Africa. (C) 2015 Elsevier Ltd. All rights reserved.
KW  - Archeology
KW  - Paleoclimate
KW  - African humid period
KW  - Push factor
KW  - Adaption
KW  - Migration
KW  - Hunter-gatherers
KW  - Foragers
KW  - Pastoralism
KW  - Chew Bahir
Y1  - 2015
U6  - https://doi.org/10.1016/j.quascirev.2015.10.026
SN  - 0277-3791
VL  - 129
SP  - 333
EP  - 340
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Förster, Verena
A1  - Junginger, Annett
A1  - Langkamp, Oliver
A1  - Gebru, Tsige
A1  - Asrat, Asfawossen
A1  - Umer, Mohammed
A1  - Lamb, Henry F.
A1  - Wennrich, Volker
A1  - Rethemeyer, Janet
A1  - Nowaczyk, Norbert
A1  - Trauth, Martin H.
A1  - Schäbitz, Frank
T1  - Climatic change recorded in the sediments of the Chew Bahir basin, southern Ethiopia, during the last 45,000 years
JF  - Quaternary international : the journal of the International Union for Quaternary Research
N2  - 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 history of the past 45 ka, with emphasis on the African Humid Period (AHP, similar to 15-5 ka calBP). Geochemical, physical and biological indicators show that Chew Bahir responded to climatic fluctuations on millennial to centennial timescales, and to the precessional cycle, since the Last Glacial Maximum. Potassium content of the sediment appears to be a reliable proxy for aridity, showing that Chew Bahir reacted to the insolation-controlled humidity increase of the AHP with a remarkably abrupt onset and a gradual termination, framing a sharply defined arid phase (similar to 12.8-11.6 ka calBP) corresponding to the Younger Dryas chronozone. The Chew Bahir record correlates well with low- and high-latitude paleoclimate records, demonstrating that the site responded to regional and global climate changes.
Y1  - 2012
U6  - https://doi.org/10.1016/j.quaint.2012.06.028
SN  - 1040-6182
VL  - 274
IS  - 19
SP  - 25
EP  - 37
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - GEN
A1  - Foerster, Verena
A1  - Vogelsang, Ralf
A1  - Junginger, Annett
A1  - Asrat, Asfawossen
A1  - Lamb, Henry F.
A1  - Schäbitz, Frank
A1  - Trauth, Martin H.
T1  - Reply to the comment on "Environmental change and human occupation of southern Ethiopia and northern Kenya during the last 20,000 years. Quaternary Science Reviews 129: 333-340"
T2  - Quaternary science reviews : the international multidisciplinary research and review journal
Y1  - 2016
U6  - https://doi.org/10.1016/j.quascirev.2016.04.003
SN  - 0277-3791
VL  - 141
SP  - 130
EP  - 133
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Cohen, Andrew
A1  - Campisano, C.
A1  - Arrowsmith, J. Ramón
A1  - Asrat, Asfawossen
A1  - Behrensmeyer, A. K.
A1  - Deino, A.
A1  - Feibel, C.
A1  - Hill, A.
A1  - Johnson, R.
A1  - Kingston, J.
A1  - Lamb, Henry F.
A1  - Lowenstein, T.
A1  - Noren, A.
A1  - Olago, D.
A1  - Owen, R. B.
A1  - Potts, R.
A1  - Reed, Kate
A1  - Renaut, R.
A1  - Schäbitz, Frank
A1  - Tiercelin, J. -J.
A1  - Trauth, Martin H.
A1  - Wynn, J.
A1  - Ivory, S.
A1  - Brady, K.
A1  - Rodysill, J.
A1  - Githiri, J.
A1  - Russell, J.
A1  - Förster, Verena
A1  - Dommain, René
A1  - Rucina, S.
A1  - Deocampo, D.
A1  - Russell, J.
A1  - Billingsley, A.
A1  - Beck, C.
A1  - Dorenbeck, G.
A1  - Dullo, L.
A1  - Feary, D.
A1  - Garello, D.
A1  - Gromig, R.
A1  - Johnson, T.
A1  - Junginger, A.
A1  - Karanja, M.
A1  - Kimburi, E.
A1  - Mbuthia, A.
A1  - McCartney, T.
A1  - McNulty, E.
A1  - Muiruri, V.
A1  - Nambiro, E.
A1  - Negash, E. W.
A1  - Njagi, D.
A1  - Wilson, J. N.
A1  - Rabideaux, N.
A1  - Raub, T.
A1  - Sier, M. J.
A1  - Smith, P.
A1  - Urban, J.
A1  - Warren, M.
A1  - Yadeta, M.
A1  - Yost, C.
A1  - Zinaye, B.
T1  - The Hominin Sites and Paleolakes Drilling Project: inferring the environmental context of human evolution from eastern African rift lake deposits
JF  - Scientific Drilling
N2  - 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 where fossil hominins (ancestors or close relatives of modern humans) are found, or from the study of deep sea drill cores. However, outcrop sediments are often highly weathered and thus are unsuitable for some types of paleoclimatic records, and deep sea core records come from long distances away from the actual fossil and stone tool remains. The Hominin Sites and Paleolakes Drilling Project (HSPDP) was developed to address these issues. The project has focused its efforts on the eastern African Rift Valley, where much of the evidence for early hominins has been recovered. We have collected about 2 km of sediment drill core from six basins in Kenya and Ethiopia, in lake deposits immediately adjacent to important fossil hominin and archaeological sites. Collectively these cores cover in time many of the key transitions and critical intervals in human evolutionary history over the last 4 Ma, such as the earliest stone tools, the origin of our own genus Homo, and the earliest anatomically modern Homo sapiens. Here we document the initial field, physical property, and core description results of the 2012-2014 HSPDP coring campaign.
Y1  - 2016
U6  - https://doi.org/10.5194/sd-21-1-2016
SN  - 1816-8957
SN  - 1816-3459
VL  - 21
SP  - 1
EP  - 16
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - GEN
A1  - Cohen, Abby
A1  - Campisano, Christopher
A1  - Arrowsmith, J. Ramon
A1  - Asrat, Asfawossen
A1  - Behrensmeyer, A. K.
A1  - Deino, A.
A1  - Feibel, C.
A1  - Hill, A.
A1  - Johnson, R.
A1  - Kingston, J.
A1  - Lamb, Henry F.
A1  - Lowenstein, T.
A1  - Noren, A.
A1  - Olago, D.
A1  - Owen, Richard Bernhart
A1  - Potts, R.
A1  - Reed, Kate
A1  - Renaut, R.
A1  - Schäbitz, F.
A1  - Tiercelin, J.-J.
A1  - Trauth, Martin  H.
A1  - Wynn, J.
A1  - Ivory, S.
A1  - Brady, K.
A1  - O’Grady, R.
A1  - Rodysill, J.
A1  - Githiri, J.
A1  - Russell, Joellen
A1  - Foerster, Verena
A1  - Dommain, René
A1  - Rucina, J. S.
A1  - Deocampo, D.
A1  - Russell, J.
A1  - Billingsley, A.
A1  - Beck, C.
A1  - Dorenbeck, G.
A1  - Dullo, L.
A1  - Feary, D.
A1  - Garello, D.
A1  - Gromig, R.
A1  - Johnson, T.
A1  - Junginger, Annett
A1  - Karanja, M.
A1  - Kimburi, E.
A1  - Mbuthia, A.
A1  - McCartney, Tannis
A1  - McNulty, E.
A1  - Muiruri, V.
A1  - Nambiro, E.
A1  - Negash, E. W.
A1  - Njagi, D.
A1  - Wilson, J. N.
A1  - Rabideaux, N.
A1  - Raub, Timothy
A1  - Sier, Mark Jan
A1  - Smith, P.
A1  - Urban, J.
A1  - Warren, M.
A1  - Yadeta, M.
A1  - Yost, Chad
A1  - Zinaye, B.
T1  - The Hominin Sites and Paleolakes Drilling Project
BT  - inferring the environmental context of human evolution from eastern African rift lake deposits
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - 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 where fossil hominins (ancestors or close relatives of modern humans) are found, or from the study of deep sea drill cores. However, outcrop sediments are often highly weathered and thus are unsuitable for some types of paleoclimatic records, and deep sea core records come from long distances away from the actual fossil and stone tool remains. The Hominin Sites and Paleolakes Drilling Project (HSPDP) was developed to address these issues. The project has focused its efforts on the eastern African Rift Valley, where much of the evidence for early hominins has been recovered. We have collected about 2 km of sediment drill core from six basins in Kenya and Ethiopia, in lake deposits immediately adjacent to important fossil hominin and archaeological sites. Collectively these cores cover in time many of the key transitions and critical intervals in human evolutionary history over the last 4 Ma, such as the earliest stone tools, the origin of our own genus Homo, and the earliest anatomically modern Homo sapiens. Here we document the initial field, physical property, and core description results of the 2012-2014 HSPDP coring campaign.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 611 
KW  - Turkana-Basin
KW  - Adar formation
KW  - climate-change
KW  - olorgesailie formation
KW  - Southern Ethiopia
KW  - global climate
KW  - Kenya Rift
KW  - Pleistocene
KW  - variability
KW  - patterns
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-412498
IS  - 611
ER  - 
TY  - JOUR
A1  - Foerster, Verena
A1  - Asrat, Asfawossen
A1  - Ramsey, Christopher Bronk
A1  - Brown, Erik T.
A1  - Chapot, Melissa S.
A1  - Deino, Alan
A1  - Düsing, Walter
A1  - Grove, Matthew
A1  - Hahn, Annette
A1  - Junginger, Annett
A1  - Kaboth-Bahr, Stefanie
A1  - Lane, Christine S.
A1  - Opitz, Stephan
A1  - Noren, Anders
A1  - Roberts, Helen M.
A1  - Stockhecke, Mona
A1  - Tiedemann, Ralph
A1  - Vidal, Celine M.
A1  - Vogelsang, Ralf
A1  - Cohen, Andrew S.
A1  - Lamb, Henry F.
A1  - Schaebitz, Frank
A1  - Trauth, Martin H.
T1  - Pleistocene climate variability in eastern Africa influenced hominin evolution
JF  - Nature geoscience
N2  - Despite more than half a century of hominin fossil discoveries in eastern Africa, the regional environmental context of hominin evolution and dispersal is not well established due to the lack of continuous palaeoenvironmental records from one of the proven habitats of early human populations, particularly for the Pleistocene epoch. Here we present a 620,000-year environmental record from Chew Bahir, southern Ethiopia, which is proximal to key fossil sites. Our record documents the potential influence of different episodes of climatic variability on hominin biological and cultural transformation. The appearance of high anatomical diversity in hominin groups coincides with long-lasting and relatively stable humid conditions from similar to 620,000 to 275,000 years bp (episodes 1-6), interrupted by several abrupt and extreme hydroclimate perturbations. A pattern of pronounced climatic cyclicity transformed habitats during episodes 7-9 (similar to 275,000-60,000 years bp), a crucial phase encompassing the gradual transition from Acheulean to Middle Stone Age technologies, the emergence of Homo sapiens in eastern Africa and key human social and cultural innovations. Those accumulative innovations plus the alignment of humid pulses between northeastern Africa and the eastern Mediterranean during high-frequency climate oscillations of episodes 10-12 (similar to 60,000-10,000 years bp) could have facilitated the global dispersal of H. sapiens.
KW  - Evolutionary ecology
KW  - Limnology
KW  - Palaeoclimate
Y1  - 2022
U6  - https://doi.org/10.1038/s41561-022-01032-y
SN  - 1752-0894
SN  - 1752-0908
VL  - 15
IS  - 10
SP  - 805
EP  - 811
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - JOUR
A1  - Foerster, Verena
A1  - Deocampo, Daniel M.
A1  - Asrat, Asfawossen
A1  - Günter, Christina
A1  - Junginger, Annett
A1  - Krämer, Kai Hauke
A1  - Stroncik, Nicole A.
A1  - Trauth, Martin H.
T1  - Towards an understanding of climate proxy formation in the Chew Bahir basin, southern Ethiopian Rift
JF  - Palaeogeography, palaeoclimatology, palaeoecology : an international journal for the geo-sciences
N2  - 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 micro-X-ray fluorescence and X-ray diffraction results suggest that the most likely process linking climate with potassium concentrations is the authigenic illitization of smectites during episodes of higher alkalinity and salinity in the closed -basin lake, due to a drier climate. Whole-rock and clay size fraction analyses suggest that illitization of the Chew Bahir clay minerals with increasing evaporation is enhanced by octahedral Al-to-Mg substitution in the clay minerals, with the resulting layer charge increase facilitating potassium-fixation. Linking mineralogy with geochemistry shows the links between hydroclimatic control, process and formation of the Chew Bahir K patterns, in the context of well-known and widely documented eastern African climate fluctuations over the last 45,000 years. These results indicate characteristic mineral alteration patterns associated with orbitally controlled wet-dry cycles such as the African Humid Period (similar to 15-5 ka) or high-latitude controlled climate events such as the Younger Dryas (similar to 12.8-11.6 ka) chronozone. Determining the impact of authigenic mineral alteration on the Chew Bahir records enables the interpretation of the previously established pXRF-derived aridity proxy K and provides a better paleohydrological understanding of complex climate proxy formation.
KW  - Paleoclimatology
KW  - Authigenic mineral transformation
KW  - Potassium
KW  - Illitization
KW  - Zeolites
Y1  - 2018
U6  - https://doi.org/10.1016/j.palaeo.2018.04.009
SN  - 0031-0182
SN  - 1872-616X
VL  - 501
SP  - 111
EP  - 123
PB  - Elsevier
CY  - Amsterdam
ER  -