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. 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 - Altenbach, Alexander V. A1 - Pflaum, U. A1 - Scheibel, Thomas R. A1 - Thies, A. A1 - Timm, M. A1 - Trauth, Martin H. T1 - Scaling percentages of benthic forminifera with flux rates of organic carbon Y1 - 1999 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 - 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 - 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 - 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 - 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 - Bookhagen, Bodo A1 - Haselton, Kirk R. A1 - Trauth, Martin H. T1 - Hydrological modelling of a Pleistocene landslide-dammed lake in the Santa Maria Basin, NW Argentina Y1 - 2001 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 - THES A1 - Trauth, Martin H. T1 - Orbital forcing and environmental changes in East Africa and South Amerika Y1 - 2002 ER - TY - JOUR A1 - Bergner, Andreas G. N. A1 - Trauth, Martin H. A1 - Bookhagen, Bodo T1 - Magnitude of precipitation : evaporation changes in the Naivasha Basin (Kenya) during the last 150 kyrs N2 - We modeled the two most extreme highstands of Lake Naivasha during the last 175 k.y. to estimate potential precipitation/ evaporation changes in this basin. In a first step, the bathymetry of the paleolakes at f135 and 9 k.y. BP was reconstructed from sediment cores and surface outcrops. Second, we modeled the paleohydrologic budget during the highstands using a simplified coupled energy mass-balance model. Our results show that the hydrologic and hence the climate conditions at f135 and 9 k.y. BP were similar, but significantly different from today. The main difference is a f15% higher value in precipitation compared to the present. An adaptation and migration of vegetation in the cause of climate changes would result in a f30% increase in precipitation. The most likely cause for such a wetter climate at f135 and 9 k.y. BP is a more intense intertropical convergence and increased precipitation in East Africa. Y1 - 2003 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 - 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 - 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 - Bergner, Andreas G. N. A1 - Trauth, Martin H. T1 - Comparison of the hydrologic and hydrochemical evolution of Lake Naivasha (Kenya) during three highstands between 175 and 60 kyr BP N2 - Three diatomite beds exposed in the Ol Njorowa Gorge south of Lake Naivasha, Central Kenya Rift, document three major lake-level highstands between 175 and 60 kyr BP. Diatom transfer-function estimates of hydrological and hydrochemical parameters suggest that a deep and large freshwater lake existed during the highstands at 135 and 80 kyr BP. In contrast, a shallower but more expanded freshwater lake existed at 110 kyr BP. The best analog for the most extreme highstand at 135 kyr BP is the highstand during the Early Holocene humid period from 10 to 6 kyr BP. The environmental conditions as reconstructed from diatom assemblages suggest long-lasting episodes of increased humidity during the high lake periods. This contrasts to the modern situation with a relatively shallow Lake Naivasha characterized by rapid water level fluctuations within a few decades. The most likely cause for the variable hydrological conditions since 175 kyr BP is orbitally driven insolation changes on the equator and increased lateral moisture transport from the ocean. Y1 - 2004 UR - http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6V6R-4DJBSX8-1- N&_cdi=5821&_user=1584062&_orig=search&_coverDate=12%2F02%2F2004&_sk=997849998&view=c&wchp=dGLbVzz- zSkzS&md5=b3fffa6b95a86827cd25fd74be3 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 - 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 - 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 - Alonso, Ricardo N. A1 - Bookhagen, Bodo A1 - Carrapa, Barbara A1 - Coutand, Isabelle A1 - Haschke, Michael A1 - Hilley, George E. A1 - Schoenbohm, Lindsay M. A1 - Sobel, Edward A1 - Strecker, Manfred A1 - Trauth, Martin H. A1 - Villanueva, Arturo T1 - Tectonics, climate and landscape evolution of the Southern Central Andes : the Argentine Puna Plateau and adjacent regions between 22 and 30°S Y1 - 2006 SN - 978-3-540- 24329-8 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 - JOUR A1 - Dühnforth, Miriam A1 - Bergner, Andreas G. N. A1 - Trauth, Martin H. T1 - Early Holocene water budget of the Nakuru-Elmenteita basin, Central Kenya Rift Y1 - 2008 UR - http://www.springerlink.com/content/100294 U6 - https://doi.org/10.1007/s10933-006-9003-z SN - 0921-2728 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. 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 - 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 - Bergner, Andreas G. N. A1 - Strecker, Manfred A1 - Trauth, Martin H. A1 - Deino, Alan L. A1 - Gasse, Francoise A1 - Blisniuk, Peter Michael A1 - Duehnforth, Miriam T1 - Tectonic and climatic control on evolution of rift lakes in the Central Kenya Rift, East Africa N2 - The long-term histories of the neighboring Nakuru-Elmenteita and Naivasha lake basins in the Central Kenya Rift illustrate the relative importance of tectonic versus climatic effects on rift-lake evolution and the formation of disparate sedimentary environments. Although modem climate conditions in the Central Kenya Rift are very similar for these basins, hydrology and hydrochemistry of present-day lakes Nakuru, Elmenteita and Naivasha contrast dramatically due to tectonically controlled differences in basin geometries, catchment size, and fluvial processes. In this study, we use eighteen C-14 and Ar-40/Ar-39 dated fluvio-lacustrine sedimentary sections to unravel the spatiotemporal evolution of the lake basins in response to tectonic and climatic influences. We reconstruct paleoclimatic and ecological trends recorded in these basins based on fossil diatom assemblages and geologic field mapping. Our study shows a tendency towards increasing alkalinity and shrinkage of water bodies in both lake basins during the last million years. Ongoing volcano-tectonic segmentation of the lake basins, as well as reorganization of upstream drainage networks have led to contrasting hydrologic regimes with adjacent alkaline and freshwater conditions. During extreme wet periods in the past, such as during the early Holocene climate optimum, lake levels were high and all basins evolved toward freshwater systems. During drier periods some of these lakes revert back to alkaline conditions, while others maintain freshwater characteristics. Our results have important implications for the use and interpretation of lake sediment as climate archives in tectonically active regions and emphasize the need to deconvolve lacustrine records with respect to tectonics versus climatic forcing mechanisms. Y1 - 2009 UR - http://www.sciencedirect.com/science/journal/02773791 U6 - https://doi.org/10.1016/j.quascirev.2009.07.008 SN - 0277-3791 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 - 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 - Epp, Laura Saskia A1 - Stoof, Kathleen R. A1 - Trauth, Martin H. A1 - Tiedemann, Ralph T1 - Historical genetics on a sediment core from a Kenyan lake : intraspecific genotype turnover in a tropical rotifer is related to past environmental changes N2 - Using molecular genetic methods and an ancient DNA approach, we studied population and species succession of rotifers of the genus Brachionus in the Kenyan alkaline-saline crater lake Sonachi since the beginning of the 19th century as well as distribution of Brachionus haplotypes in recent and historic sediments of other lakes of the East African Rift System. The sediment core record of Lake Sonachi displays haplotypes of a distinct evolutionary lineage in all increments. Populations were dominated by a single mitochondrial haplotype for a period of 150 years, and two putatively intraspecific turnovers in dominance occurred. Both changes are concordant with major environmental perturbations documented by a profound visible change in sediment composition of the core. The first change was very abrupt and occurred after the deposition of volcanic ash at the beginning of the 19th century. The second change coincides with a major lake level lowstand during the 1940s. It was preceded by a period of successively declining lake level, in which two other haplotypes appeared in the lake. One of these putatively belongs to another species documented in historical and recent Kenyan lake sediments. The analysis of plankton population dynamics through historical time can reveal patterns of population persistence and turnover in relation to environmental changes. Y1 - 2010 UR - http://www.springerlink.com/content/100294 U6 - https://doi.org/10.1007/s10933-009-9379-7 SN - 0921-2728 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 - 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 - 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 - Epp, Laura Saskia A1 - Stoof-Leichsenring, Kathleen Rosemarie A1 - Trauth, Martin H. A1 - Tiedemann, Ralph T1 - Molecular profiling of diatom assemblages in tropical lake sediments using taxon-specific PCR and Denaturing High-Performance Liquid Chromatography (PCR-DHPLC) JF - Molecular ecology resources N2 - Here we present a protocol to genetically detect diatoms in sediments of the Kenyan tropical Lake Naivasha, based on taxon-specific PCR amplification of short fragments (approximately 100 bp) of the small subunit ribosomal (SSU) gene and subsequent separation of species-specific PCR products by PCR-based denaturing high-performance liquid chromatography (DHPLC). An evaluation of amplicons differing in primer specificity to diatoms and length of the fragments amplified demonstrated that the number of different diatom sequence types detected after cloning of the PCR products critically depended on the specificity of the primers to diatoms and the length of the amplified fragments whereby shorter fragments yielded more species of diatoms. The DHPLC was able to discriminate between very short amplicons based on the sequence difference, even if the fragments were of identical length and if the amplicons differed only in a small number of nucleotides. Generally, the method identified the dominant sequence types from mixed amplifications. A comparison with microscopic analysis of the sediment samples revealed that the sequence types identified in the molecular assessment corresponded well with the most dominant species. In summary, the PCR-based DHPLC protocol offers a fast, reliable and cost-efficient possibility to study DNA from sediments and other environmental samples with unknown organismic content, even for very short DNA fragments. KW - diatoms KW - environmental DNA KW - lake sediments KW - PCR-DHPLC Y1 - 2011 U6 - https://doi.org/10.1111/j.1755-0998.2011.03022.x SN - 1755-098X VL - 11 IS - 5 SP - 842 EP - 853 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Donges, Jonathan Friedemann A1 - Donner, Reik Volker A1 - Rehfeld, Kira A1 - Marwan, Norbert A1 - Trauth, Martin H. A1 - Kurths, Jürgen T1 - Identification of dynamical transitions in marine palaeoclimate records by recurrence network analysis JF - Nonlinear processes in geophysics N2 - The analysis of palaeoclimate time series is usually affected by severe methodological problems, resulting primarily from non-equidistant sampling and uncertain age models. As an alternative to existing methods of time series analysis, in this paper we argue that the statistical properties of recurrence networks - a recently developed approach - are promising candidates for characterising the system's nonlinear dynamics and quantifying structural changes in its reconstructed phase space as time evolves. In a first order approximation, the results of recurrence network analysis are invariant to changes in the age model and are not directly affected by non-equidistant sampling of the data. Specifically, we investigate the behaviour of recurrence network measures for both paradigmatic model systems with non-stationary parameters and four marine records of long-term palaeoclimate variations. We show that the obtained results are qualitatively robust under changes of the relevant parameters of our method, including detrending, size of the running window used for analysis, and embedding delay. We demonstrate that recurrence network analysis is able to detect relevant regime shifts in synthetic data as well as in problematic geoscientific time series. This suggests its application as a general exploratory tool of time series analysis complementing existing methods. Y1 - 2011 U6 - https://doi.org/10.5194/npg-18-545-2011 SN - 1023-5809 VL - 18 IS - 5 SP - 545 EP - 562 PB - Copernicus CY - Göttingen ER - TY - JOUR A1 - Donges, Jonathan Friedemann A1 - Donner, Reik Volker A1 - Trauth, Martin H. A1 - Marwan, Norbert A1 - Schellnhuber, Hans Joachim A1 - Kurths, Jürgen T1 - Nonlinear detection of paleoclimate-variability transitions possibly related to human evolution JF - Proceedings of the National Academy of Sciences of the United States of America N2 - Potential paleoclimatic driving mechanisms acting on human evolution present an open problem of cross-disciplinary scientific interest. The analysis of paleoclimate archives encoding the environmental variability in East Africa during the past 5 Ma has triggered an ongoing debate about possible candidate processes and evolutionary mechanisms. In this work, we apply a nonlinear statistical technique, recurrence network analysis, to three distinct marine records of terrigenous dust flux. Our method enables us to identify three epochs with transitions between qualitatively different types of environmental variability in North and East Africa during the (i) Middle Pliocene (3.35-3.15 Ma B. P.), (ii) Early Pleistocene (2.25-1.6 Ma B. P.), and (iii) Middle Pleistocene (1.1-0.7 Ma B. P.). A deeper examination of these transition periods reveals potential climatic drivers, including (i) large-scale changes in ocean currents due to a spatial shift of the Indonesian throughflow in combination with an intensification of Northern Hemisphere glaciation, (ii) a global reorganization of the atmospheric Walker circulation induced in the tropical Pacific and Indian Ocean, and (iii) shifts in the dominating temporal variability pattern of glacial activity during the Middle Pleistocene, respectively. A reexamination of the available fossil record demonstrates statistically significant coincidences between the detected transition periods and major steps in hominin evolution. This result suggests that the observed shifts between more regular and more erratic environmental variability may have acted as a trigger for rapid change in the development of humankind in Africa. KW - African climate KW - Plio-Pleistocene KW - climate-driven evolution KW - dynamical transitions KW - nonlinear time series analysis Y1 - 2011 U6 - https://doi.org/10.1073/pnas.1117052108 SN - 0027-8424 VL - 108 IS - 51 SP - 20422 EP - 20427 PB - National Acad. of Sciences CY - Washington ER - TY - JOUR A1 - Borchardt, Sven A1 - Trauth, Martin H. T1 - Remotely-sensed evapotranspiration estimates for an improved hydrological modeling of the early holocene mega-lake Suguta, northern Kenya Rift JF - Palaeogeography, palaeoclimatology, palaeoecology : an international journal for the geo-sciences N2 - The actual evapotranspiration is an important, but difficult to determine, element in the water balance of lakes and their catchment areas. Reliable data on evapotranspiration are not available for most lake basins for which paleoclimate reconstructions and modeling have been performed, particularly those in remote parts of Africa. We have used thermal infrared multispectral data for 14 ASTER scenes from the TERRA satellite to estimate the actual evapotranspiration in the 12,800 km(2) catchment of the Suguta Valley, northern Kenya Rift Evidence from sediments and paleo-shorelines indicates that, during the African Humid Period (AHP, 14.8 to 5.5 kyrs BP), this valley contained a large lake, 280 m deep and covering similar to 2200 km(2), which has now virtually disappeared. Evapotranspiration estimates for the Suguta Basin were generated using the Surface Energy Balance Algorithm for Land (SEBAL). Climate data required for the model were extracted from a high-resolution gridded dataset obtained from the Climatic Research Unit (East Anglia, UK). Results suggest significant spatial variations in evapotranspiration within the catchment area (ranging from 450 mm/yr in the basin to the north to 2000 mm/yr in more elevated areas) and precipitation that was similar to 20% higher during the AHP than in recent times. These results are in agreement with other estimates of paleo-precipitation in East Africa. The extreme response of the lake system (similar to 280 m greater water depth than today, and a lake surface area of 2200 km(2)) to only moderately higher precipitation illustrates the possible sensitivity of this area to future climate change. KW - Actual evapotranspiration KW - Remote sensing KW - Water balance model KW - East African Rift KW - Kenya KW - SEBAL Y1 - 2021 U6 - https://doi.org/10.1016/j.palaeo.2012.07.009 SN - 0031-0182 VL - 361 IS - 22 SP - 14 EP - 20 PB - Elsevier CY - Amsterdam 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 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 - 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 - 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 - 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 - 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 - Dulanya, Zuze A1 - Reed, Jane M. A1 - Trauth, Martin H. T1 - Mapping changing shorelines in the Malombe and Chiuta lakes of Malawi-environmental effects of recent climatic variations JF - Catena : an interdisciplinary journal of soil science, hydrology, geomorphology focusing on geoecology and landscape evolution N2 - This study examines patterns of climate variability by mapping shoreline changes between 1973 and 2008 for two shallow lakes in Malawi, East Africa. Multi-temporal LANDSAT data covering eight different years within the period of investigation were utilised for lake-area mapping, using image classification techniques. The approach was verified using simple comparisons with local rainfall data and satellite altimetry data. Results indicated that the lake areas varied between the different years investigated and that, although the lakes were affected by the same climate-forcing mechanisms, the individual basin characteristics had a critical effect on their responses. The most likely drivers for the climate-related shoreline variations are the El Nino/Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD), causing synchronous changes to the water levels in both lakes, albeit showing differences in climate signal amplification. KW - Lake Malombe KW - Lake Chiuta KW - Lake-area KW - ENSO/IOD Y1 - 2013 U6 - https://doi.org/10.1016/j.catena.2012.10.016 SN - 0341-8162 VL - 104 IS - 10 SP - 111 EP - 119 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 - Dulanya, Zuze A1 - Croudace, Ian A1 - Reed, Jane M. A1 - Trauth, Martin H. T1 - Palaeolimnological reconstruction of recent environmental change in Lake Malombe (S. Malawi) using multiple proxies JF - Water SA N2 - Shallow inland water bodies in Malawi continue to be threatened by various environmental challenges despite their importance to the fisheries industry. Due to the complex interaction between natural and anthropogenic disturbances, disentangling the effect of the two may be a complicated process. The littoral zone of most water bodies is important in environmental reconstructions including pollution and lake level monitoring. This study used a littoral zone, transect-based approach employing multi-proxy palaeolimnological techniques to reconstruct recent environmental change (ca. 100 yrs.) in Lake Malombe in the Malawi Rift, East Africa. The results of the study could inform fisheries management in Lake Malombe, which experienced a catastrophic decline in fish stocks. Results support documentary evidence for the complete desiccation of the lake less than 100 years ago. Subsequently, there is evidence for accelerated eutrophication in the recent past. In light of these results, it is concluded that transect sampling approaches rather than relying on single core measurements, and the need for careful consideration of the types of proxy, are significant considerations in palaeoenvironmental reconstructions. KW - littoral zone KW - palaeolimnology KW - diatoms KW - Lake Malombe Y1 - 2014 U6 - https://doi.org/10.4314/wsa.v40i4.17 SN - 0378-4738 SN - 1816-7950 VL - 40 IS - 4 SP - 717 EP - 727 PB - Water Research Commission CY - Pretoria 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 -