TY  - JOUR
A1  - Wichura, Henry
A1  - Bousquet, Romain
A1  - Oberhänsli, Roland
A1  - Strecker, Manfred
A1  - Trauth, Martin H.
T1  - Evidence for middleUocene uplift of the East African Plateau
N2  - Cenozoic uplift of the East African Plateau has been associated with fundamental climatic and environmental changes in East Africa and adjacent regions. While this influence is widely accepted, the timing and the magnitude of plateau uplift have remained unclear. This uncertainty stems from the lack of datable, geomorphically meaningful reference horizons that could record surface uplift. Here, we document the existence of significant relief along the East African Plateau prior to rifting, as inferred from modeling the emplacement history of one of the longest terrestrial lava flows, the similar to 300-km-long Yatta phonolite flow in Kenya. This 13.5 Ma lava flow originated on the present-day eastern Kenya Rift flank, and utilized a riverbed that once routed runoff from the eastern rim of the plateau. Combining an empirical viscosity model with subsequent cooling and using the Yatta lava flow geometry and underlying paleotopography (slope angle), we found that the prerift slope was at least 0.2 degrees, suggesting that the lava flow originated at a minimum elevation of 1400 m. Hence, high paleotopography in the Kenya Rift region must have existed by at least 13.5 Ma. We infer from this that middle Miocene uplift occurred, which coincides with the two-step expansion of grasslands, as well as important radiation and speciation events in tropical Africa.
Y1  - 2010
UR  - http://geology.gsapubs.org/
U6  - https://doi.org/10.1130/G31022.1
SN  - 0091-7613
ER  - 
TY  - JOUR
A1  - Weinelt, Mara
A1  - Kuhnt, Wolfgang
A1  - Sarnthein-Lotichius, Johann Michael
A1  - Altenbach, Alexander V.
A1  - Costello, O.
A1  - Erlenkeuser, Helmut
A1  - Mathiessen, J.
A1  - Pflaumann, Uwe
A1  - Simstich, J.
A1  - Struck, J.
A1  - Thies, A.
A1  - Trauth, Martin H.
A1  - Vogelsang, E.
T1  - Paleoceanographic proxies in the northern North Atlantic
Y1  - 2001
SN  - 3-540-67231-1
ER  - 
TY  - JOUR
A1  - Walter, Marius J.
A1  - Trauth, Martin H.
T1  - A MATLAB based orientation analysis of Acheulean handaxe accumulations in Olorgesailie and Kariandusi, Kenya Rift
JF  - Journal of human evolution
N2  - The Pleistocene archeological record in East Africa has revealed unusual accumulations of Acheulean handaxes at prehistoric sites. In particular, there has been intensive debate concerning whether the artifact accumulation at the Middle Pleistocene Olorgesailie (Southern Kenya Rift) and Kariandusi (Central Kenya Rift) sites were a result of fluvial reworking or of in situ deposition by hominids. We used a two-step approach to test the hypothesis of fluvial reworking. Firstly, the behavior of handaxes in water currents was investigated in a current flume and the flow threshold required to reorientate the handaxes was determined. The results of these experiments suggested that, in relatively high energy and non-steady flow conditions, handaxes will reorientate themselves perpendicular to the current direction. Secondly, an automated image analysis routine was developed and applied to archeological plans from three Acheulean sites, two at Olorgesailie and one at Kariandusi, in order to determine the orientations of the handaxes. A Rayleigh test was then applied to the orientation data to test for a preferred orientation. The results revealed that the handaxes at the Upper Kariandusi Site and the Olorgesailie Main Site Mid Trench had a preferential orientation, suggesting reworking by a paleocurrent. The handaxes from the Olorgesailie Main Site H/6A, however, appeared to be randomly oriented and in situ deposition by the producers therefore remains a possibility.
KW  - Excavation plan
KW  - Artifact
KW  - Flume channel
KW  - Shape detection
KW  - Rayleigh test
Y1  - 2013
U6  - https://doi.org/10.1016/j.jhevol.2013.02.011
SN  - 0047-2484
VL  - 64
IS  - 6
SP  - 569
EP  - 581
PB  - Elsevier
CY  - London
ER  - 
TY  - JOUR
A1  - Tronicke, Jens
A1  - Trauth, Martin H.
T1  - Classroom-sized geophysical experiments
BT  - magnetic surveying using modern smartphone devices
JF  - European Journal of Physics
N2  - Modern mobile devices (i.e. smartphones and tablet computers) are widespread, everyday tools, which are equipped with a variety of sensors including three-axis magnetometers. Here, we investigate the feasibility and the potential of using such mobile devices to mimic geophysical experiments in the classroom in a table-top setup. We focus on magnetic surveying and present a basic setup of a table-top experiment for collecting three-component magnetic data across well-defined source bodies and structures. Our results demonstrate that the quality of the recorded data is sufficient to address a number of important basic concepts in the magnetic method. The shown examples cover the analysis of magnetic data recorded across different kinds of dipole sources, thus illustrating the complexity of magnetic anomalies. In addition, we analyze the horizontal resolution capabilities using a pair of dipole sources placed at different horizontal distances to each other. Furthermore, we demonstrate that magnetic data recorded with a mobile device can even be used to introduce filtering, transformation, and inversion approaches as they are typically used when processing magnetic data sets recorded for real-world field applications. Thus, we conclude that such table-top experiments represent an easy-to-implement experimental procedure (as student exercise or classroom demonstration) and can provide first hands-on experience in the basic principles of magnetic surveying including the fundamentals of data acquisition, analysis and processing, as well as data evaluation and interpretation.
KW  - geophysics
KW  - magnetic surveying
KW  - table-top experiment
Y1  - 2018
U6  - https://doi.org/10.1088/1361-6404/aaad5b
SN  - 0143-0807
SN  - 1361-6404
VL  - 39
IS  - 3
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Trauth, Martin H.
A1  - Strecker, Manfred
T1  - Formation of landslide-dammed lakes during a wet period between 40,000 - 25,000 yr B.P. in northwestern Argentina
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Trauth, Martin H.
A1  - Strecker, Manfred
T1  - Late Pleistocene Lake-Level Fluctuations in the Naivasha Basin, Kenia
Y1  - 1996
ER  - 
TY  - JOUR
A1  - Trauth, Martin H.
A1  - Sarnthein, Michael
A1  - Arnold, Maurice
T1  - Bioturbational mixing depth and carbon flux at the seafloor
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Trauth, Martin H.
A1  - Maslin, Mark A.
A1  - Deino, Alan
A1  - Strecker, Manfred
T1  - Late Cenozoic Moisture History of East Africa
N2  - Lake sediments in 10 Ethiopian, Kenyan, and Tanzanian rift basins suggest that there were three humid periods at 2.7 to 2.5 million years ago (Ma), 1.9 to 1.7 Ma, and 1.1 to 0.9 Ma, superimposed on the longer-term aridification of East Africa. These humid periods correlate with increased aridity in northwest and northeast Africa and with substantial global climate transitions. These episodes could have had important impacts on the speciation and dispersal of mammals and hominins, because a number of key events, such as the origin of the genus Homo and the evolution of the species Homo erectus, took place in this region during that time.
Y1  - 2005
UR  - http://dx.doi.org/10.1126/science.1112964
ER  - 
TY  - JOUR
A1  - Trauth, Martin H.
A1  - Maslin, Mark A.
A1  - Deino, Alan L.
A1  - Strecker, Manfred
A1  - Bergner, Andreas G. N.
A1  - Dühnforth, Miriam
T1  - High- and low-latitude forcing of Plio-Pleistocene African climate and human evolution
N2  - The late Cenozoic climate of East Africa is punctuated by episodes of short, alternating periods of extreme wetness and aridity, superimposed on a regime of subdued moisture availability exhibiting a long-term drying trend. These periods of extreme climate variability appear to correlate with maxima in the 400-thousand-year (kyr) component of the Earth's eccentricity cycle. Prior to 2.7 Ma the wet phases appear every 400 kyrs, whereas after 2.7 Ma, the wet phases appear every 800 kyrs, with periods of precessional-forced extreme climate variability at 2.7-2.5 Ma, 1.9-1.7 Ma, and 1.1-0.9 Ma before present. The last three major lake phases occur at the times of major global climatic transitions, such as the onset of Northern Hemisphere Glaciation (2.7-2.5 Ma), intensification of the Walker Circulation (1.9-1.7 Ma), and the Mid-Pleistocene Revolution (1.0-0.7 Ma). High-latitude forcing is required to compress the Intertropical Convergence Zone so that East Africa becomes locally sensitive to precessional forcing, resulting in rapid shifts from wet to dry conditions. These periods of extreme climate variability may have provided a catalyst for evolutionary change and driven key speciation and dispersal events amongst mammals and hominins in East Africa. (C) 2007 Elsevier Ltd. All rights reserved.
Y1  - 2008
U6  - https://doi.org/10.1016/j.jhevol.2006.12.009
ER  - 
TY  - JOUR
A1  - Trauth, Martin H.
A1  - Maslin, Mark A.
A1  - Deino, Alan L.
A1  - Junginger, Annett
A1  - Lesoloyia, Moses
A1  - Odada, Eric O.
A1  - Olago, Daniel O.
A1  - Olaka, Lydia A.
A1  - Strecker, Manfred
A1  - Tiedemann, Ralph
T1  - Human evolution in a variable environment : the amplifier lakes of Eastern Africa
N2  - The development of rise Cenozoic East African Rift System (EARS) profoundly re-shaped the landscape and significantly increased the amplitude of short-term environmental response to climate variation. In particular, the development of amplifier lakes in rift basins after three million years ago significantly contributed to this exceptional sensitivity of East Africa to climate change compared to elsewhere on the African continent. Amplifier lakes are characterized by tectonically-formed graben morphologies in combination with an extreme contrast between high precipitation in the elevated parts of the catchment and high evaporation in the lake area. Such amplifier lakes respond rapidly to moderate, precessional-forced climate shifts, and as they do so apply dramatic environmental pressure to the biosphere. Rift basins, when either extremely dry or lake-filled, form important barriers for migration, mixing and competition of different populations of animals and hominins. Amplifier lakes link long-term, high-amplitude tectonic processes and short-term environmental fluctuations. East Africa may have become the place where early humans evolved as a consequence of this strong link between different time scales. (C) 2010 Elsevier Ltd. All rights reserved.
Y1  - 2010
UR  - http://www.sciencedirect.com/science/journal/02773791
U6  - https://doi.org/10.1016/j.quascirev.2010.07.007
SN  - 0277-3791
ER  - 
TY  - JOUR
A1  - Trauth, Martin H.
A1  - Maslin, Mark A.
T1  - Comment on "Diatomaceous sediments and environmental change in the Pleistocene Olorgesailie Formation, southern Kenya Rift" by R.B. Owen, R. Potts, A.K. Behrensmeyer and P. Ditchfield [Palaeogeography, Palaeoclimatology, Palaeoecology 269 (2008) 17-37]
N2  - Owen et al. [Owen. R.B.. Potts, R., Behrensmeyer, A.K., Ditchfield, P. 2008. Diatomaceous sediments and environmental change in the Pleistocene Olorgesailie Formation, southern Kenya Rift Valley. Palaeogeography, Palaeochmatology, Palaeoccology, 269. 17-37], Diatomaceous sediments and environmental change in the Pleistocene Olorgesailie Formation. southern Kenya Rift. Palaeogeography Palaeoclimatology Palaeciecology, 269, 17-37) argued that diatom assemblage variations in the Olorgesailie Formation indicate considerable environmental instability with both wetter and drier periods, contradicting the proposed period of lake stability and wet climatic conditions between ca 11 and 0.9 million years ago as proposed by Trauth et al [Trauth, M.H. Maslin, MA.. Demo. A.. Strecker, M R.. 2005. Late Cenozoic moisture history of East Africa. Science 309. 2051-2053., Trauth, M H. Mashn. M.A., Deino, A., Bergner. A G.N.. Diihnforth, M. Strecker. M.R, 2007 High- and low-latitude forcing of Plio-Pleistocene East African climate and hL.man evolution. journal of Human Evolution 53, 475-486] Contrary to the interpretation of our work by O Nen et al. [Owen. R.B, Potts, R. Behrensmeyer, A.K. Ditchfield. P. 2008], we never said that the proposed periods of large lakes were characterized by stable conditions.
Y1  - 2009
UR  - http://www.sciencedirect.com/science/journal/00310182
U6  - https://doi.org/10.1016/j.palaeo.2009.02.030
SN  - 0031-0182
ER  - 
TY  - JOUR
A1  - Trauth, Martin H.
A1  - Marwan, Norbert
T1  - Introduction-time series analysis for Earth, climate and life interactions
JF  - Quaternary science reviews : the international multidisciplinary research and review journal
Y1  - 2022
U6  - https://doi.org/10.1016/j.quascirev.2022.107475
SN  - 0277-3791
SN  - 1873-457X
VL  - 284
PB  - Elsevier
CY  - Amsterdam [u.a.]
ER  - 
TY  - JOUR
A1  - Trauth, Martin H.
A1  - Larrasoaña, Juan C.
A1  - Mudelsee, Manfred
T1  - Trends, rhythms and events in plio-pleistocene African climate
N2  - We analyzed published records of terrigenous dust flux from marine sediments off subtropical West Africa, the eastern Mediterranean Sea, and the Arabian Sea, and lake records from East Africa using statistical methods to detect trends, rhythms and events in Plio-Pleistocene African climate. The critical reassessment of the environmental significance of dust flux and lake records removes the apparent inconsistencies between marine vs. terrestrial records of African climate variability. Based on these results, major steps in mammalian and hominin evolution occurred during episodes of a wetter, but highly variable climate largely controlled by orbitally induced insolation changes in the low latitudes.
Y1  - 2009
UR  - http://www.sciencedirect.com/science/journal/02773791
U6  - https://doi.org/10.1016/j.quascirev.2008.11.003
SN  - 0277-3791
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  - Trauth, Martin H.
A1  - Deino, Alan
A1  - Strecker, Manfred
T1  - Response of the East African climate to orbital forcing during the Last Interglacial (130-117 kyr BP) and the early Last Glacial (117-60 kyr BP)
Y1  - 2001
SN  - 0091-7613
ER  - 
TY  - JOUR
A1  - Trauth, Martin H.
A1  - Deino, Alan
A1  - Bergner, Andreas G. N.
A1  - Strecker, Manfred
T1  - East African climate change and orbital forcing during the last 175 kyr BP
N2  - Variations in the temporal and spatial distribution of solar radiation caused by orbital changes provide a partial explanation for the observed long-term fluctuations in African lake levels. The understanding of such relationships is essential for designing climate-prediction models for the tropics. Our assessment of the nature and timing of East African climate change is based on lake-level fluctuations of Lake Naivasha in the Central Kenya Rift (0°55'S 36°20'E), inferred from sediment characteristics, diatoms, authigenic mineral assemblages and 17 single-crystal 40Ar/39Ar age determinations. Assuming that these fluctuations reflect climate changes, the Lake Naivasha record demonstrates that periods of increased humidity in East Africa mainly followed maximum equatorial solar radiation in March or September. Interestingly, the most dramatic change in the Naivasha Basin occurred as early as 146 kyr BP and the highest lake level was recorded at about 139 to 133 kyr BP. This is consistent with other well-dated low-latitude climate records, but does not correspond to peaks in Northern Hemisphere summer insolation as the trigger for the ice- age cycles. The Naivasha record therefore provides evidence for low-latitude forcing of the ice-age climate cycles.
Y1  - 2003
ER  - 
TY  - JOUR
A1  - Trauth, Martin H.
A1  - Bookhagen, Bodo
A1  - Mueller, Andreas
A1  - Strecker, Manfred
T1  - Erosion and climate change in the Santa Maria Basin, NW Argentina during the last 40,000 yrs
N2  - Present erosion and sediment flux in the semi-arid intramontane Santa Maria Basin, NW Argentina are compared with conditions during a period of wetter and more variable climate at about 30,000 14C yrs ago. The results suggest that the influence of climate change on the overall erosional sediment budget is significant, mainly because of a change in the erosion regime coupled with an increase in mass movements. The most effective mechanism to increase landslide activity in this environment is a highly variable climate on inter-annual timescales. In contrast, Quaternary changes in erosional budgets due to variations in moisture regimes is small in the Santa Maria Basin. Since the magnitude of a potential increase in background erosion as well as enhanced landsliding is smaller than typical levels of uncertainty of erosional budgets for such large basins, it is not likely that climate-driven erosional unloading can influence tectonic style and rates in this semi-arid environment on time scales of several 103 to 104 years.
Y1  - 2003
ER  - 
TY  - JOUR
A1  - Trauth, Martin H.
A1  - Bookhagen, Bodo
A1  - Marwan, Norbert
A1  - Strecker, Manfred
T1  - Multiple landslide clusters record quaternary climate changes in the northwestern Argentine andes
N2  - The chronology of multiple landslide deposits and related lake sediments in the semi-arid eastern Argentine Cordillera suggests that major mass movements cluster in two time periods during the Quaternary, i.e. between 40 and 25 and after 5 14C kyr BP. These clusters may correspond to the Minchin (maximum at around 28-27 14C kyr BP) and Titicaca wet periods (after 3.9 14C kyr BP). The more humid conditions apparently caused enhanced landsliding in this environment. In contrast, no landslide-related damming and associated lake sediments occurred during the Coipasa (11.5- 10 14C yr BP) and Tauca wet periods (14.5-11 14C yr BP). The two clusters at 40-25 and after 5 14C kyr BP may correspond to periods where the El Niño-Southern Oscillation (ENSO) and Tropical Atlantic Sea Surface Temperature Variability (TAV) were active. This, however, was not the case during the Coipasa and Tauca wet periods. Lake-balance modelling of a landslide-dammed lake suggests a 10-15% increase in precipitation and a 3-4 ° C decrease in temperature at ~30 14C kyr BP as compared to the present. In addition, time-series analysis reveals a strong ENSO and TAV during that time. The landslide clusters in northwestern Argentina are therefore best explained by periods of more humid and more variable climates.
Y1  - 2003
UR  - http://dx.doi.org/10.1016/S0031-0182(03)00273-6
ER  - 
TY  - JOUR
A1  - Trauth, Martin H.
A1  - Bergner, Andreas G. N.
A1  - Foerster, Verena
A1  - Junginger, Annett
A1  - Maslin, Mark A.
A1  - Schäbitz, Frank
T1  - Episodes of environmental stability versus instability in Late Cenozoic lake records of Eastern Africa
JF  - Journal of human evolution
N2  - 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 Ethiopian Rift; between 11 ka and 4 ka), (2) the MIS 5-4 transition in the Naivasha basin (Central Kenya Rift; between 160 ka and 50 ka), and (3) the Early Mid Pleistocene Transition (EMPT) in the Olorgesailie basin (Southern Kenya Rift; between 1.25 Ma and 0.4 Ma). A probabilistic age modeling technique is used to determine the timing of these transitions, taking into account possible abrupt changes in the sedimentation rate including episodes of no deposition (hiatuses). Interestingly, the stable-unstable conditions identified in the three records are always associated with an orbitally-induced decrease of insolation: the descending portion of the 800 kyr cycle during the EMPT, declining eccentricity after the 115 ka maximum at the MIS 5-4 transition, and after similar to 10 ka. This observation contributes to an evidence-based discussion of the possible mechanisms causing the switching between environmental stability and instability in Eastern Africa at three different orbital time scales (10,000 to 1,000,000 years) during the Cenozoic. This in turn may lead to great insights into the environmental changes occurring at the same time as hominin speciation, brain expansion, dispersal out of Africa, and cultural innovations and may provide key evidence to build new hypotheses regarding the causes of early human evolution. (C) 2015 Elsevier Ltd. All rights reserved.
KW  - Paleoclimate
KW  - East Africa
KW  - Human evolution
KW  - Lakes
KW  - Sediments
Y1  - 2015
U6  - https://doi.org/10.1016/j.jhevol.2015.03.011
SN  - 0047-2484
VL  - 87
SP  - 21
EP  - 31
PB  - Elsevier
CY  - London
ER  - 
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  - Alonso, Ricardo N.
A1  - Haselton, Kirk R.
A1  - Hermanns, Reginald L.
A1  - Strecker, Manfred
T1  - Climate change and mass movements in the NW Argentine Andes
Y1  - 2000
ER  - 
TY  - BOOK
A1  - Trauth, Martin H.
T1  - Python Recipes for Earth Sciences
T3  - Springer Textbooks in Earth Sciences, Geography and Environment
N2  - Python is used in a wide range of geoscientific applications, such as in processing images for remote sensing, in generating and processing digital elevation models, and in analyzing time series. This book introduces methods of data analysis in the geosciences using Python that include basic statistics for univariate, bivariate, and multivariate data sets, time series analysis, and signal processing; the analysis of spatial and directional data; and image analysis. The text includes numerous examples that demonstrate how Python can be used on data sets from the earth sciences. The supplementary electronic material (available online through Springer Link) contains the example data as well as recipes that include all the Python commands featured in the book.
KW  - computational geosciences
KW  - geoinformatics
KW  - geostatistics
KW  - mathematical geology
KW  - geomodeling
KW  - digital elevation models
KW  - climate time series analysis
Y1  - 2022
SN  - 978-3-031-07719-7
SN  - 978-3-031-07718-0
SN  - 978-3-031-07720-3
SN  - 978-3-031-07721-0
U6  - https://doi.org/10.1007/978-3-031-07719-7
SN  - 2510-1307
SN  - 2510-1315
PB  - Springer
CY  - Cham
ER  - 
TY  - JOUR
A1  - Trauth, Martin H.
T1  - Spectral analysis in quaternary sciences
JF  - Quaternary science reviews : the international multidisciplinary research and review journal
N2  - Spectral analysis is a technique of time-series analysis that decomposes signals into linear combinations of harmonic components. Rooted in the 19th century, spectral analysis gained popularity in palaeoclimatology since the early 1980s. This was partly due to the availability of long time series of past climates, but also the development of new, partly adapted methods and the increasing spread of affordable personal computers. This paper reviews the most important methods of spectral analysis for palaeoclimate time series and discusses the prerequisites for their application as well as advantages and disadvantages. The paper also offers an overview of suitable software, as well as computer code for using the methods on synthetic examples.
KW  - Spectral analysis
KW  - Paleoclimate
KW  - Orbital forcing
KW  - MATLAB
Y1  - 2021
U6  - https://doi.org/10.1016/j.quascirev.2021.107157
SN  - 0277-3791
SN  - 1873-457X
VL  - 270
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - BOOK
A1  - Trauth, Martin H.
T1  - MATLAB recipes for earth sciences
Y1  - 2007
SN  - 978-3-540-72748-4
PB  - Springer
CY  - Berlin, New York
ER  - 
TY  - BOOK
A1  - Trauth, Martin H.
T1  - Matlab in geosciences : recipes for data analysis
T3  - MATLAB® Recipes for Earth Sciences
N2  - MATLAB is used in a wide range of applications in geosciences, such as image processing in remote sensing, generation and processing of digital elevation models and the analysis of time series. This book introduces basic methods of data analysis in geosciences using MATLAB. The text includes a brief description of each method and numerous examples demonstrating how MATLAB can be used on data sets from earth sciences. All MATLAB recipes can be easily modified in order to analyse the reader's own data sets. The book comes with a CD containing exemplary data sets and a digital version of the MATLAB recipes. (Springer)
Y1  - 2006
SN  - 3-540-27983-0
U6  - https://doi.org/10.1007/3-540-27984-9
PB  - Springer-Verlag Berlin Heidelberg
CY  - Berlin, Heidelberg
ER  - 
TY  - BOOK
A1  - Trauth, Martin H.
T1  - MATLAB recipes for earth sciences : with CD-ROM
N2  - MATLAB is used in a wide range of applications in geosciences, such as image processing in remote sensing, generation and processing of digital elevation models and the analysis of time series. This book introduces basic methods of data analysis in geosciences using MATLAB. The text includes a brief description of each method and numerous examples on how MATLAB can be used on data sets from earth sciences. All MATLAB recipes can easily be modified in order to analyse the reader's own data sets. The book comes with a CD containing example data sets and a digital version of the MATLAB recipes.
Y1  - 2006
SN  - 3-540-27983-0
PB  - Springer
CY  - Heidelberg
ER  - 
TY  - JOUR
A1  - Trauth, Martin H.
T1  - TURBO2 - a MATLAB simulation to study the effects of bioturbation on paleoceanographic time series
JF  - Computers & geosciences : an international journal devoted to the publication of papers on all aspects of geocomputation and to the distribution of computer programs and test data sets ; an official journal of the International Association for Mathematical Geology
N2  - Bioturbation (or benthic mixing) causes significant distortions in marine stable isotope signals and other palaeoceanographic records. Although the influence of bioturbation on these records is well known it has rarely been dealt systematically. The MATLAB program called TURBO2 can be used to simulate the effect of bioturbation on individual sediment particles. It can therefore be used to model the distortion of all physical, chemical, and biological signals in deep-sea sediments, such as Mg/Ca ratios and UK37-based sea-surface temperature (SST) variations. In particular, it can be used to study the distortions in paleoceanographic records that are based on individual sediment particles, such as SST records based on foraminifera assemblages. Furthermore. TURBO2 provides a tool to study the effect of benthic mixing of isotope signals such as C-14, delta O-18, and delta C-13, measured in a stratigraphic carrier such as foraminifera shells.
KW  - Bioturbation
KW  - Modeling
KW  - MATLAB
KW  - Deep-sea records
KW  - Foraminifera
KW  - Stable oxygen isotopes
Y1  - 2013
U6  - https://doi.org/10.1016/j.cageo.2013.05.003
SN  - 0098-3004
SN  - 1873-7803
VL  - 61
IS  - 12
SP  - 1
EP  - 10
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Trauth, Martin H.
T1  - Noise removal from duplicate paleoceanographic times-series : the use of adaptive filtering techniques
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Trauth, Martin H.
T1  - TURBO : a dynamic-probabilistic simulation to studdy the effects of bioturbation on paleoceanographic time series
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Trauth, Martin H.
T1  - A new probabilistic technique to build an age model for complex stratigraphic sequences
JF  - Quaternary geochronology : the international research and review journal on advances in quaternary dating techniques
N2  - The age models of fluvio-lacustrine sedimentary sequences are often subject of discussions in paleoclimate research. The techniques employed to build an age model are very diverse, ranging from visual or intuitive estimation of the age-depth relationship over linear or spline interpolations between age control points to sophisticated Bayesian techniques also taking into account the most likely deposition times of the type of sediment within the sequence. All these methods, however, fail in detecting abrupt variations in sedimentation rates, including the possibility of episodes of no deposition (hiatus), which is the strength of the method presented in this work. The new technique simply compares the deposition time of equally thick sediment slices from the differences of subsequent radiometric age dates and the unit deposition times of the various sediment types. The percentage overlap of the distributions of these two sources of information, together with the evidence from the sedimentary record, helps to build an age model of complex sequences including abrupt variations in the rate of deposition including one or many hiatuses. (C) 2014 Elsevier B.V. All rights reserved.
KW  - Age-depth modelling
KW  - Stratigraphy
KW  - Sedimentation rate
KW  - Hiatus
KW  - MATLAB
Y1  - 2014
U6  - https://doi.org/10.1016/j.quageo.2014.03.001
SN  - 1871-1014
SN  - 1878-0350
VL  - 22
SP  - 65
EP  - 71
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - THES
A1  - Trauth, Martin H.
T1  - Orbital forcing and environmental changes in East Africa and South Amerika
Y1  - 2002
ER  - 
TY  - JOUR
A1  - Stoof-Leichsenring, Kathleen Rosemarie
A1  - Junginger, Annett
A1  - Olaka, Lydia A.
A1  - Tiedemann, Ralph
A1  - Trauth, Martin H.
T1  - Environmental variability in Lake Naivasha, Kenya, over the last two centuries
JF  - Journal of paleolimnolog
N2  - Lake Naivasha, Kenya, is one of a number of freshwater lakes in the East African Rift System. Since the beginning of the twentieth century, it has experienced greater anthropogenic influence as a result of increasingly intensive farming of coffee, tea, flowers, and other horticultural crops within its catchment. The water-level history of Lake Naivasha over the past 200 years was derived from a combination of instrumental records and sediment data. In this study, we analysed diatoms in a lake sediment core to infer past lacustrine conductivity and total phosphorus concentrations. We also measured total nitrogen and carbon concentrations in the sediments. Core chronology was established by (210)Pb dating and covered a similar to 186-year history of natural (climatic) and human-induced environmental changes. Three stratigraphic zones in the core were identified using diatom assemblages. There was a change from littoral/epiphytic diatoms such as Gomphonema gracile and Cymbella muelleri, which occurred during a prolonged dry period from ca. 1820 to 1896 AD, through a transition period, to the present planktonic Aulacoseira sp. that favors nutrient-rich waters. This marked change in the diatom assemblage was caused by climate change, and later a strong anthropogenic overprint on the lake system. Increases in sediment accumulation rates since 1928, from 0.01 to 0.08 g cm(-2) year(-1) correlate with an increase in diatom-inferred total phosphorus concentrations since the beginning of the twentieth century. The increase in phosphorus accumulation suggests increasing eutrophication of freshwater Lake Naivasha. This study identified two major periods in the lake's history: (1) the period from 1820 to 1950 AD, during which the lake was affected mainly by natural climate variations, and (2) the period since 1950, during which the effects of anthropogenic activity overprinted those of natural climate variation.
KW  - Lake sediments
KW  - Diatoms
KW  - Conductivity
KW  - Lake Naivasha
KW  - Human impact
KW  - Eutrophication
Y1  - 2011
U6  - https://doi.org/10.1007/s10933-011-9502-4
SN  - 0921-2728
VL  - 45
IS  - 3
SP  - 353
EP  - 367
PB  - Springer
CY  - Dordrecht
ER  - 
TY  - JOUR
A1  - Stoof-Leichsenring, Kathleen Rosemarie
A1  - Epp, Laura Saskia
A1  - Trauth, Martin H.
A1  - Tiedemann, Ralph
T1  - Hidden diversity in diatoms of Kenyan Lake Naivasha a genetic approach detects temporal variation
JF  - Molecular ecology
N2  - This study provides insights into the morphological and genetic diversity in diatoms occurring in core sediments from tropical lakes in Kenya. We developed a genetic survey technique specific for diatoms utilizing a short region (7667 bp) of the ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit (rbcL) gene as genetic barcode. Our analyses (i) validated the use of rbcL as a barcoding marker for diatoms, applied to sediment samples, (ii) showed a significant correlation between the results obtained by morphological and molecular data and (iii) indicated temporal variation in diatom assemblages on the inter- and intra-specific level. Diatom assemblages from a short core from Lake Naivasha show a drastic shift over the last 200 years, as littoral species (e.g. Navicula) are replaced by more planktonic ones (e.g. Aulacoseira). Within that same period, we detected periodic changes in the respective frequencies of distinct haplotype groups of Navicula, which coincide with wet and dry periods of Lake Naivasha between 1820 and 1938 AD. Our genetic analyses on historical lake sediments revealed inter- and intra-specific variation in diatoms, which is partially hidden behind single morphotypes. The occurrence of particular genetic lineages is probably correlated with environmental factors.
KW  - diatoms
KW  - DNA barcoding
KW  - historical DNA
KW  - intra-specific variation
KW  - rbcL
KW  - tropical lake sediments
Y1  - 2012
U6  - https://doi.org/10.1111/j.1365-294X.2011.05412.x
SN  - 0962-1083
VL  - 21
IS  - 8
SP  - 1918
EP  - 1930
PB  - Wiley-Blackwell
CY  - Malden
ER  - 
TY  - JOUR
A1  - Maslin, Mark
A1  - Trauth, Martin H.
A1  - Christensen, B.
T1  - A changing climate for human evolution
Y1  - 2005
SN  - 0016-8556
ER  - 
TY  - JOUR
A1  - Maslin, Mark A.
A1  - Trauth, Martin H.
T1  - Plio-pleistocene East African pulsed climate variability and its influence on early human evolution
Y1  - 2009
SN  - 978-1-4020-9979-3
ER  - 
TY  - JOUR
A1  - Maslin, Mark A.
A1  - Shultz, Susanne
A1  - Trauth, Martin H.
T1  - A synthesis of the theories and concepts of early human evolution
JF  - Philosophical transactions of the Royal Society of London : B, Biological sciences
N2  - Current evidence suggests that many of the major events in hominin evolution occurred in East Africa. Hence, over the past two decades, there has been intensive work undertaken to understand African palaeoclimate and tectonics in order to put together a coherent picture of how the environment of Africa has varied over the past 10 Myr. A new consensus is emerging that suggests the unusual geology and climate of East Africa created a complex, environmentally very variable setting. This new understanding of East African climate has led to the pulsed climate variability hypothesis that suggests the long-term drying trend in East Africa was punctuated by episodes of short alternating periods of extreme humidity and aridity which may have driven hominin speciation, encephalization and dispersals out of Africa. This hypothesis is unique as it provides a conceptual framework within which other evolutionary theories can be examined: first, at macro-scale comparing phylogenetic gradualism and punctuated equilibrium; second, at a more focused level of human evolution comparing allopatric speciation, aridity hypothesis, turnover pulse hypothesis, variability selection hypothesis, Red Queen hypothesis and sympatric speciation based on sexual selection. It is proposed that each one of these mechanisms may have been acting on hominins during these short periods of climate variability, which then produce a range of different traits that led to the emergence of new species. In the case of Homo erectus (sensu lato), it is not just brain size that changes but life history (shortened inter-birth intervals, delayed development), body size and dimorphism, shoulder morphology to allow thrown projectiles, adaptation to long-distance running, ecological flexibility and social behaviour. The future of evolutionary research should be to create evidence-based meta-narratives, which encompass multiple mechanisms that select for different traits leading ultimately to speciation.
KW  - human evolution
KW  - East Africa
KW  - palaeoclimatology
KW  - hominin
KW  - pulsed climate variability framework
Y1  - 2015
U6  - https://doi.org/10.1098/rstb.2014.0064
SN  - 0962-8436
SN  - 1471-2970
VL  - 370
IS  - 1663
PB  - Royal Society
CY  - London
ER  - 
TY  - JOUR
A1  - Maslin, Mark A.
A1  - Pancost, Richard D.
A1  - Wilson, Katy E.
A1  - Lewis, Jonathan
A1  - Trauth, Martin H.
T1  - Three and half million year history of moisture availability of South West Africa evidence from ODP site 1085 biomarker records
JF  - Palaeogeography, palaeoclimatology, palaeoecology : an international journal for the geo-sciences
N2  - Ocean Drilling Program Site 1085 provides a continuous marine sediment record off southern South West Africa for at least the last three and half million years. The n-alkane partial derivative(13) C record from this site records changes in past vegetation and provides an indication of the moisture availability of SW Africa during this time period. Very little variation, and no apparent trend, is observed in the n-alkane delta C-13 record, suggesting stable long-term conditions despite significant changes in East African tectonics and global climate. Slightly higher n-alkane delta C-13 values occur between 3.5 and 2.7 Ma suggesting slightly drier conditions than today. Between 2.5 and 2.7 Ma there is a shift to more negative n-alkane delta C-13 values suggesting slightly wetter conditions during a similar to 0.2 Ma episode that coincides with the intensification of Northern Hemisphere Glaciation (iNHG). From 2.5 to 0.4 Ma the n-alkane delta C-13 values are very consistent, varying by less than +/- 0.5 parts per thousand and suggesting little or no long-term change in the moisture availability of South West Africa over the last 2.5 million years. This is in contrast to the long-term drying trend observed further north offshore from the Namib Desert and in East Africa. A comparison of the climate history of these regions suggests that Southern Africa may have been an area of long-term stability over the last 3.5 Myrs.
KW  - Plio-Pleistocene
KW  - Aridity
KW  - SW Africa
KW  - Biomarkers
KW  - Palaeoclimate
KW  - Human evolution
Y1  - 2012
U6  - https://doi.org/10.1016/j.palaeo.2011.12.009
SN  - 0031-0182
VL  - 317
SP  - 41
EP  - 47
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Maslin, Mark A.
A1  - Brierley, Chris M.
A1  - Milner, Alice M.
A1  - Shultz, Susanne
A1  - Trauth, Martin H.
A1  - Wilson, Katy E.
T1  - East African climate pulses and early human evolution
JF  - Quaternary science reviews : the international multidisciplinary research and review journal
N2  - Current evidence suggests that all of the major events in hominin evolution have occurred in East Africa. Over the last two decades, there has been intensive work undertaken to understand African palaeoclimate and tectonics in order to put together a coherent picture of how the environment of East Africa has varied in the past. The landscape of East Africa has altered dramatically over the last 10 million years. It has changed from a relatively flat, homogenous region covered with mixed tropical forest, to a varied and heterogeneous environment, with mountains over 4 km high and vegetation ranging from desert to cloud forest. The progressive rifting of East Africa has also generated numerous lake basins, which are highly sensitive to changes in the local precipitation-evaporation regime. There is now evidence that the presence of precession-driven, ephemeral deep-water lakes in East Africa were concurrent with major events in hominin evolution. It seems the unusual geology and climate of East Africa created periods of highly variable local climate, which, it has been suggested could have driven hominin speciation, encephalisation and dispersal out of Africa. One example is the significant hominin speciation and brain expansion event at -1.8 Ma that seems to have been coeval with the occurrence of highly variable, extensive, deep-water lakes. This complex, climatically very variable setting inspired first the variability selection hypothesis, which was then the basis for the pulsed climate variability hypothesis. The newer of the two suggests that the long-term drying trend in East Africa was punctuated by episodes of short, alternating periods of extreme humidity and aridity. Both hypotheses, together with other key theories of climate-evolution linkages, are discussed in this paper. Though useful the actual evolution mechanisms, which led to early hominins are still unclear and continue to be debated. However, it is clear that an understanding of East African lakes and their palaeoclimate history is required to understand the context within which humans evolved and eventually left East Africa. (C) 2014 The Authors. Published by Elsevier Ltd.
KW  - Human evolution
KW  - East Africa
KW  - Palaeoclimatology
KW  - Palaeoliminology
KW  - Tectonics
KW  - Hominin
KW  - Orbital forcing
KW  - Cenozoic climate transitions
KW  - Pulsed climate variability hypothesis
Y1  - 2014
U6  - https://doi.org/10.1016/j.quascirev.2014.06.012
SN  - 0277-3791
VL  - 101
SP  - 1
EP  - 17
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Marwan, Norbert
A1  - Trauth, Martin H.
A1  - Vuille, Mathias
A1  - Kurths, Jürgen
T1  - Comparing modern and Pleistocene ENSO-like influences in NW Argentina using nonlinear time series analysis methods
N2  - Higher variability in rainfall and river discharge could be of major importance in landslide generation in the north-western Argentine Andes. Annual layered (varved) deposits of a landslide dammed lake in the Santa Maria Basin (26°S, 66°W) with an age of 30,000 14C years provide an archive of precipitation variability during this time. The comparison of these data with present-day rainfall observations tests the hypothesis that increased rainfall variability played a major role in landslide generation. A potential cause of such variability is the El Niño/ Southern Oscillation (ENSO). The causal link between ENSO and local rainfall is quantified by using a new method of nonlinear data analysis, the quantitative analysis of cross recurrence plots (CRP). This method seeks similarities in the dynamics of two different processes, such as an ocean-atmosphere oscillation and local rainfall. Our analysis reveals significant similarities in the statistics of both modern and palaeo-precipitation data. The similarities in the data suggest that an ENSO-like influence on local rainfall was present at around 30,000 14C years ago. Increased rainfall, which was inferred from a lake balance modeling in a previous study, together with ENSO-like cyclicities could help to explain the clustering of landslides at around 30,000 14C years ago.
Y1  - 2003
UR  - http://arxiv.org/abs/nlin.CD/0303056
ER  - 
TY  - JOUR
A1  - Marwan, Norbert
A1  - Trauth, Martin H.
A1  - Schwarz, Udo
A1  - Kurths, Jürgen
A1  - Strecker, Manfred
T1  - Climate dynamics of varved pleistocene lake sediments in nw Argentina
Y1  - 1999
SN  - 1029-7006
ER  - 
TY  - JOUR
A1  - Krüger, Johanna
A1  - Foerster, Verena Elisabeth
A1  - Trauth, Martin H.
A1  - Hofreiter, Michael
A1  - Tiedemann, Ralph
T1  - Exploring the Past Biosphere of Chew Bahir/Southern Ethiopia: Cross-Species Hybridization Capture of Ancient Sedimentary DNA from a Deep Drill Core
JF  - Frontiers in Earth Science
N2  - 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 conditions around critical episodes of hominin evolution. Identification of biological taxa based on their sedimentary ancient DNA (sedaDNA) traces can contribute to understand past ecological and climatological conditions of the living environment of our ancestors. However, sedaDNA recovery from tropical environments is challenging because high temperatures, UV irradiation, and desiccation result in highly degraded DNA. Consequently, most of the DNA fragments in tropical sediments are too short for PCR amplification. We analyzed sedaDNA in the upper 70 m of the composite sediment core of the HSPDP drill site at Chew Bahir for eukaryotic remnants. We first tested shotgun high throughput sequencing which leads to metagenomes dominated by bacterial DNA of the deep biosphere, while only a small fraction was derived from eukaryotic, and thus probably ancient, DNA. Subsequently, we performed cross-species hybridization capture of sedaDNA to enrich ancient DNA (aDNA) from eukaryotic remnants for paleoenvironmental analysis, using established barcoding genes (cox1 and rbcL for animals and plants, respectively) from 199 species that may have had relatives in the past biosphere at Chew Bahir. Metagenomes yielded after hybridization capture are richer in reads with similarity to cox1 and rbcL in comparison to metagenomes without prior hybridization capture. Taxonomic assignments of the reads from these hybridization capture metagenomes also yielded larger fractions of the eukaryotic domain. For reads assigned to cox1, inferred wet periods were associated with high inferred relative abundances of putative limnic organisms (gastropods, green algae), while inferred dry periods showed increased relative abundances for insects. These findings indicate that cross-species hybridization capture can be an effective approach to enhance the information content of sedaDNA in order to explore biosphere changes associated with past environmental conditions, enabling such analyses even under tropical conditions.
KW  - Chew Bahir
KW  - hybridization capture
KW  - ICDP
KW  - paleoclimate
KW  - past biosphere
KW  - sedaDNA
KW  - sediment core
Y1  - 2021
U6  - https://doi.org/10.3389/feart.2021.683010
SN  - 2296-6463
SP  - 1
EP  - 20
PB  - Frontiers in Earth Science
CY  - Lausanne, Schweiz
ER  - 
TY  - GEN
A1  - Krüger, Johanna
A1  - Foerster, Verena Elisabeth
A1  - Trauth, Martin H.
A1  - Hofreiter, Michael
A1  - Tiedemann, Ralph
T1  - Exploring the Past Biosphere of Chew Bahir/Southern Ethiopia: Cross-Species Hybridization Capture of Ancient Sedimentary DNA from a Deep Drill Core
T2  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - 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 conditions around critical episodes of hominin evolution. Identification of biological taxa based on their sedimentary ancient DNA (sedaDNA) traces can contribute to understand past ecological and climatological conditions of the living environment of our ancestors. However, sedaDNA recovery from tropical environments is challenging because high temperatures, UV irradiation, and desiccation result in highly degraded DNA. Consequently, most of the DNA fragments in tropical sediments are too short for PCR amplification. We analyzed sedaDNA in the upper 70 m of the composite sediment core of the HSPDP drill site at Chew Bahir for eukaryotic remnants. We first tested shotgun high throughput sequencing which leads to metagenomes dominated by bacterial DNA of the deep biosphere, while only a small fraction was derived from eukaryotic, and thus probably ancient, DNA. Subsequently, we performed cross-species hybridization capture of sedaDNA to enrich ancient DNA (aDNA) from eukaryotic remnants for paleoenvironmental analysis, using established barcoding genes (cox1 and rbcL for animals and plants, respectively) from 199 species that may have had relatives in the past biosphere at Chew Bahir. Metagenomes yielded after hybridization capture are richer in reads with similarity to cox1 and rbcL in comparison to metagenomes without prior hybridization capture. Taxonomic assignments of the reads from these hybridization capture metagenomes also yielded larger fractions of the eukaryotic domain. For reads assigned to cox1, inferred wet periods were associated with high inferred relative abundances of putative limnic organisms (gastropods, green algae), while inferred dry periods showed increased relative abundances for insects. These findings indicate that cross-species hybridization capture can be an effective approach to enhance the information content of sedaDNA in order to explore biosphere changes associated with past environmental conditions, enabling such analyses even under tropical conditions.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1244 
KW  - Chew Bahir
KW  - hybridization capture
KW  - ICDP
KW  - paleoclimate
KW  - past biosphere
KW  - sedaDNA
KW  - sediment core
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-550071
SN  - 1866-8372
SP  - 1
EP  - 20
PB  - Universitätsverlag Potsdam
CY  - Potsdam
ER  - 
TY  - JOUR
A1  - Junginger, Annett
A1  - Trauth, Martin H.
T1  - Hydrological constraints of paleo-Lake Suguta in the Northern Kenya Rift during the African Humid Period (15-5 ka BP)
JF  - Global and planetary change
N2  - During the African Humid Period (AHP, 15-5 ka BP) an almost 300 m deep paleo-lake covering 2200 km(2) developed in the Suguta Valley, in the Northern Kenya Rift Data from lacustrine sediments and paleo-shorelines indicate that a large paleo-lake already existed by 13.9 ka BP, and record rapid water level fluctuations of up to 100 m within periods of 100 years or less, and a final lowstand at the end of the AHP (5 ka BP). We used a hydro-balance model to assess the abruptness of these water level fluctuations and identify their causes. We observed that fluctuations within the AHP were caused by abrupt changes in precipitation of 26-40%. Despite the absence of continuous lacustrine data documenting the onset of the AHP in the Suguta Valley, we conclude from the hydro-balance model that only an abrupt onset to the AHP, prior to 14.8 ka BP, could have led to high water levels recorded. The modeling results suggest that the sudden increase in rainfall was the direct consequence of an eastward migration of the Congo Air Boundary (CAB), caused by an enhanced atmospheric pressure gradient between East Africa and southern Asia during a northern hemisphere (NH) summer insolation maximum. In contrast the end of the AHP must have been gradual despite an abrupt change in the source of precipitation when a decreasing pressure gradient between Asia and Africa prevented the CAB from reaching the study area. This abruptness was probably buffered by a contemporaneous change in precession producing an insolation maximum at the equator during September-October. This change would have meant that the only rain source was the Intertropical Convergence Zone (IT CZ), which would have carried a greater amount of moisture during the short rainy season thus slowing the fall in water level over a period of about 1000 years in association with the reduction in insolation. The results of this study provide an indication of the amount of time available for humans in north-eastern Africa to adapt in response to a changing climate, from hunting and gathering to farming and herding.
KW  - East African Rift System
KW  - Suguta Valley
KW  - African Humid Period
KW  - Congo Air Boundary
Y1  - 2013
U6  - https://doi.org/10.1016/j.gloplacha.2013.09.005
SN  - 0921-8181
SN  - 1872-6364
VL  - 111
IS  - 12
SP  - 174
EP  - 188
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Junginger, Annett
A1  - Roller, Sybille
A1  - Olaka, Lydia A.
A1  - Trauth, Martin H.
T1  - The effects of solar irradiation changes on the migration of the Congo Air Boundary and water levels of paleo-Lake Suguta, Northern Kenya Rift, during the African Humid Period (15-5 ka BP)
JF  - Palaeogeography, palaeoclimatology, palaeoecology : an international journal for the geo-sciences
N2  - The water-level record from the 300 m deep paleo-lake Suguta (Northern Kenya Rift) during the African Humid Period (AHP, 15-5 ka BP) helps to explain decadal to centennial intensity variations in the West African Monsoon (WAM) and the Indian Summer Monsoon (ISM). This water-level record was derived from three different sources: (1) grain size variations in radiocarbon dated and reservoir corrected lacustrine sediments, (2) the altitudes and ages of paleo-shorelines within the basin, and (3) the results of hydro-balance modeling, providing important insights into the character of water level variations (abrupt or gradual) in the amplifier paleo-Lake Suguta. The results of these comprehensive analyses suggest that the AHP highstand in the Suguta Valley was the direct consequence of a northeastwards shift in the Congo Air Boundary (CAB), which was in turn caused by an enhanced atmospheric pressure gradient between East Africa and India during a northern hemisphere insolation maximum. Rapidly decreasing water levels of up to 90 m over less than a hundred years are best explained by changes in solar irradiation either reducing the East African-Indian atmospheric pressure gradient and preventing the CAB from reaching the study area, or reducing the overall humidity in the atmosphere, or a combination of both these effects. In contrast, although not well documented in our record we hypothesize a gradual end of the AHP despite an abrupt change in the source of precipitation when a decreasing pressure gradient between Asia and Africa prevented the CAB from reaching the Suguta Valley. The abruptness was probably buffered by a contemporaneous change in precession producing an insolation maximum at the equator during October. Whether or not this is the case, the water-level record from the Suguta Valley demonstrates the importance of both orbitally-controlled insolation variations and short-term changes in solar irradiation as factors affecting the significant water level variations in East African rift lakes.
KW  - East African Rift System
KW  - Suguta Valley
KW  - African Humid Period
KW  - Congo Air Boundary
Y1  - 2014
U6  - https://doi.org/10.1016/j.palaeo.2013.12.007
SN  - 0031-0182
SN  - 1872-616X
VL  - 396
SP  - 1
EP  - 16
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Hermanns, Reginald L.
A1  - Trauth, Martin H.
A1  - McWilliams, Michael O.
A1  - Strecker, Manfred
T1  - Tephrochronologic Constraints on temporal Distribution of large Landslides in NW-Argentina
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Garcin, Yannick
A1  - Junginger, Annett
A1  - Melnick, Daniel
A1  - Olago, Daniel O.
A1  - Strecker, Manfred
A1  - Trauth, Martin H.
T1  - Late Pleistocene-Holocene rise and collapse of the Lake Suguta, northern Kenya Rift
Y1  - 2009
UR  - http://www.sciencedirect.com/science/journal/02773791
U6  - https://doi.org/10.1016/j.quascirev.2008.12.006
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  - 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  - 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  - 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  -