The East African Rift System (EARS) is a key location for studying Plio-Pleistocene paleoclimate and hominin inhabitance. The region experienced profound reorganization during this interval as a response to volcanism, tectonics and... more
The East African Rift System (EARS) is a key location for studying Plio-Pleistocene paleoclimate and hominin inhabitance. The region experienced profound reorganization during this interval as a response to volcanism, tectonics and climate change, and arguably detailed spatiotemporally coherent climate datasets could provide evidence of causal links between geologic change and hominin evolution. However, continued tectonism, erosion, burial and volcanism obscures much of this information. Despite its rich fossil record, the Turkana basin in the northern Kenya Rift is no exception. It has been hypothesized that Lake Turkana and paleo-Lake Suguta to its south formed one 530-650 km long mega-lake before 221 ka ago, and was a major barrier for E-W dispersal of hominids and other terrestrial fauna. Here we present new information on basin development based on paleolandscape modeling and 87Sr/86Sr analysis on microfossils of newly discovered paleo-lake sequences in the Suguta Valley, permitting reconstruction of volcano-tectonic processes 900-700 ka ago. Contrary to previous assumptions, results suggest that two to three lakes separated by tectono-volcanic barriers formed instead of one mega-lake. These results have implications for previously formulated hypotheses about mega-lakes preventing W-E migration and exchange and suggest that during the early Middle Pleistocene E-W migrations were possible.
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Tectonic activity impacts the environment and identifying the influence of active faulting on environmental factors, such as vegetation growth and soil formation patterns, is valuable in better understanding ecosystem functions. We... more
Tectonic activity impacts the environment and identifying the influence of active faulting on environmental factors, such as vegetation growth and soil formation patterns, is valuable in better understanding ecosystem functions. We applied remote sensing techniques to illustrate how tectonic activity and lithology of bedrock influence temporal and spatial patterns of vegetation and soil parameters in a climatically sensitive, fault-controlled river basin in the Kenya-Tanzania transboundary region.The Mara River Basin lies in a region of previously unrecognised tectonic activity, characterised by subrecent extensional faulting along the Utimbara and Isuria faults. Faulting leads to spatially variable erosion and soil formation rates as well as disruption and modification of drainage systems. All these factors might be expected to exert controls on ecosystem dynamics on a range of lengths and timescales. We investigate tectonic controls on ecological processes in the Mara River Basin using a combination of geospatial mapping and multispectral image analysis. To map fault structures and to reveal signs of recent tectonic activity along the Utimbara and Isuria faults, we use high-resolution digital elevation models derived from 12m TanDEM-X data. To investigate spatiotemporal vegetation patterns and soil formation, we use a 5-year Normalised Difference Vegetation Index (NDVI) time-series, Clay Mineral Ratio (CMR) and Moisture Stress Index (MSI) derived from Sentinel 2 data. Whilst lithology does exert some control on ecological properties, we also observe that the downthrown hanging wall of the faults, especially directly adjacent to the escarpment, is consistently associated with a higher degree of vegetation, wetland formation and clay distribution. Analysis of spectral indices shows that the overall spatial pattern of vegetation cover is seasonally low in the flat plains and perennially high in the vicinity of more complex, tectonically influenced structures. The NDVI highlights several locations with permanently healthy vegetation along the escarpment which extend downslope for several kilometres. Our study shows that in the Mara River Basin, active normal faulting is an important stabiliser of vegetation growth patterns. We interpret this effect to be caused by favourable hydrological and pedological conditions along the escarpments and tectonically induced structures such as subrecent surface ruptures and a series of small, fault-bounded alluvial fans exposing systematically high vegetation and clay values. This implies that tectonic activity has a direct beneficial influence on ecological processes in this climatically sensitive region. As future climate change in the area is expected to lead to accelerated habitat desiccation and deterioration of vegetation quality, suitable habitats for wildlife will progressively reduce and will likely be limited to tectonically active locations. Long-term insights into tectonic processes and the interplay between geology and soils can thus be useful for recent and future ecosystem management since the understanding of an area from a geological perspective can complement the understanding of other natural processes within it.
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Research Interests: Geology and Seismology
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The Lower Rhine Graben (Central Europe) is a prime example of a seismically active low-strain rift zone characterized by pronounced anthropogenic and climatic overprint of structures, and long recurrence intervals of large earthquakes.... more
The Lower Rhine Graben (Central Europe) is a prime example of a seismically active low-strain rift zone characterized by pronounced anthropogenic and climatic overprint of structures, and long recurrence intervals of large earthquakes. These factors render the identification of active faults and surface ruptures difficult. We investigated two fault scarps in the Lower Rhine Graben, to decipher their structural character, offset and potential seismogenic origin. Both scarps were modified by anthropogenic activity. The Hemmerich site liesc.20 km SW of Cologne, along the Erft Fault. The Untermaubach site lies SW of Düren, where the Schafberg Fault projects into the Rur River valley. At the Hemmerich site, geomorphic and geophysical data, as well as exploratory coring reveal evidence of repeated normal faulting. Geophysical analysis and palaeoseismological excavation at the Untermaubach site reveal a complex fault zone in Holocene gravels characterized by subtle gravel deformation. Differentiation of tectonic and fluvial features was only possible with trenching, because fault structures and grain sizes of the sediments were below the resolution of the geophysical data. Despite these issues, our investigation demonstrates that valuable insight into past earthquakes and seismogenic deformation in a low-strain environment can be revealed using a multidisciplinary approach.
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Continuous lake sediment archives integrate valuable information of geodynamic transformations, climatic fluctuations and anthropogenic environmental forcing through time. In many parts of the world, such as sub-Saharan Africa, lake... more
Continuous lake sediment archives integrate valuable information of geodynamic transformations, climatic fluctuations and anthropogenic environmental forcing through time. In many parts of the world, such as sub-Saharan Africa, lake ecosystems are important pillars of biodiversity and wildlife preservation and evolution, as well as political and economic stability, especially with regard to the rapid population growth and increasing food and water demand.Located in the central part of the rift valley region, lake Naivasha is the second largest freshwater lake in Kenya, covers a catchment area of ca. 3400 km2 and is considered a “wetland of international importance” (RAMSAR convention, 2011). Previous studies and real-time observations documented a rapid intensification of agricultural activities ranging from subsidy economy (upper catchment) to industrial-sized horticulture practices (lower catchment) from the second half of the 20th century towards the present. These were suggested to have significantly influenced the drainage systems of the catchment and hydrochemistry of the lake, with potentially negative effects on the entire ecosystem. In addition, potential anthropogenic metal influx from other modern, diffuse sources (such as fossil fuel combustion) due to the increasing anthropogenic density and activities in the immediate vicinity of the lake remain poorly constrained.We analysed major- and trace elements and Pb isotope compositions of lake sediments covering the past ca. 150 years, as well as the surrounding lithologies in order to reconstruct the pathway(s) and source(s) of elemental influx and accumulation into the lake. The characterization of the geological background in this tectonically and volcanologically active region was primarily set on the northern part of the catchment where, the two main lake-feeding rivers Malewa and Gilgil discharge into the lake. Element correlation indices point to i) a strong influence of the local geological background and, ii) a relatively stable catchment for this time-period as seen from sub-parallel REE+Y patterns along the monolith. Lead isotope compositions, on the other hand, show more radiogenic values in the sediment deposited before the 1900’s (206Pb/204Pb: 19.502 – 19.546) and a significant shift towards less radiogenic isotopic ratios from the second half of the 20th century (206Pb/204Pb: 19.228 – 19.304), which persists towards the top of the core. We combine our extended geochemical data with geospatial projections of the land use to build a time-integrated cause-and-effect assessment of metals into lake Naivasha and disentangle the cause for the change in the Pb isotope composition.
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ABSTRACT One of the most enigmatic problems in intraplate earthquake geology is the spatio-temporal recurrence pattern of large earthquakes. Intraplate regions such as the New Madrid seismic zone or the central European rift system are... more
ABSTRACT One of the most enigmatic problems in intraplate earthquake geology is the spatio-temporal recurrence pattern of large earthquakes. Intraplate regions such as the New Madrid seismic zone or the central European rift system are subject to considerable seismic hazards, because fault activity is highly disparate in space and time and our knowledge about the recurrence of large earthquakes is still rudimentary. The current debate in central Europe ranges from slip dominated by repeated large coseismic events to slip dominated by aseismic creep. Here, field evidence in support of the former is sparse, and hence, some authors concluded that many faults move by slow aseismic creep rather than by ground rupturing earthquakes. We report new results from a paleoseismic study carried out in the Lower Rhine Embayment across a subsidiary normal fault in the area of Germany's largest historical earthquake (1756 AD, ML 6.2±0.2) that clearly revealed field evidence of dynamic surface faulting. At the trench site, the fault is covered by <5 m-thick Holocene fluvial gravel and flood deposits overlaying Devonian shale. We mapped a surface offset of ~1 m and a ~10 m wide zone of localized deformation expressed by abundant fractures with aligned and broken clasts extending vertically throughout the entire gravel. Mapping of 237 fractured clasts and the long-axis orientation of ~10.000 clasts defines a deformation zone coinciding with the surface offset and two offset markers within the gravel layers. We interpret these features as the result of coseismic deformation at the near-surface end of the rupture. We rule out alternative processes which may lead to fracturing of pebbles such as freeze-thaw weathering or sediment loading effects, since both the gravel fabric and fracture planes coincide well with the fault orientation. We preclude slow deformation due to aseismic creep as governing process to cause rupturing of pebbles this close to the surface, as this would require an overburden stress of several hundreds of meters according to modelling results (e. g. Eidelmann, 1992, Geology). With a significantly smaller overburden, as in this study, a high differential acceleration force, such as a shock wave produced by an earthquake rupture or a seismic wave would be needed to overcome the pebble’s shear resistance. Preliminary radiocarbon data bracket the youngest event horizon to Latest Holocene age. In conclusion, we identified coseismic deformation at the trench site, because special conditions produced a number of features not usually observed in other fault exposures. The thin sedimentary cover (<5 m) above basement rocks and the high groundwater table, which may reduce the shear strength of the pebbles, may have played an important role in producing this deformation pattern. Our results imply that large surface rupturing earthquakes in low-strain intraplate regions may be more common than previously thought.
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This chapter examines the relationship between the changing geomorphology of physical land forms in tectonically and volcanically active regions, topography, soil nutrients, movements of large mammals, and patterns of human subsistence... more
This chapter examines the relationship between the changing geomorphology of physical land forms in tectonically and volcanically active regions, topography, soil nutrients, movements of large mammals, and patterns of human subsistence and dispersal in the early stages of human evolution. We place particular emphasis on the ways in which minor topographic barriers—for example, river gorges, fault scarps and basaltic lava flows—constrain the movements of large mammals during their seasonal migrations and offer opportunities for early humans to take advantage of predictable natural constrictions to ambush animals. We also emphasise the importance of soil edaphics—the mineral composition of soils as a source of trace elements essential for animal growth and health—as another key variable in determining the distribution and movements of animals and their human hunters. Soil edaphics are closely related to the nature of the underlying regolith or bedrock, and are consequently highly variable in their distribution, providing additional constraints on animal movements. We show how the combination of topographic and soil-edaphic mapping in conjunction with the observed locations of stone-tool or fossil assemblages can highlight patterns of early human behaviour, using examples from the East African and Jordanian Rifts and the Arabian margin of the Red Sea. Finally, we note that these methods have the potential to be applied more widely in other regions of the world and to problems of animal and human health at the present-day.
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The February 6th, 2023, Mw 7.8 Pazarcık earthquake in the Turkey-Syria border region raises the question of whether such a large earthquake could have been foreseen, as well as what is the maximum possible magnitude (Mmax) of earthquakes... more
The February 6th, 2023, Mw 7.8 Pazarcık earthquake in the Turkey-Syria border region raises the question of whether such a large earthquake could have been foreseen, as well as what is the maximum possible magnitude (Mmax) of earthquakes on the East Anatolian fault system and on continental transform faults in general. To answer such questions, knowledge of past earthquakes and of their causative faults is necessary. Here, we integrate data from historical seismology, paleoseismology, archeoseismology, and remote sensing to identify the likely source faults of fourteen Mw ≥ 7 earthquakes between AD 1000 and the present in the region. We find that the 2023 Pazarcık earthquake could have been foreseen in terms of location (the East Anatolian Fault) and timing (an earthquake along this fault was if anything overdue), but not magnitude. We hypothesize that the maximum earthquake magnitude for the East Anatolian Fault is in fact 8.2, i.e. a single end-to-end rupture of the entire fault, and that the 2023 Pazarcık earthquake did not reach Mmax by chance only. In fact, we suggest that such unusually large events are hard to model in terms of recurrence intervals, because they need a very specific set of circumstances to line up before they can happen. We also conclude that seismic hazard assessment along continental transforms cannot be done on individual fault systems, but must include neighboring systems as well, because they are not kinematically independent at any time scale.
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<p>The environmental and living conditions of a region are shaped by its relief, geology and climate, and control factors like hydrology and soil formation. While long-term climatic fluctuations and associated changes in... more
<p>The environmental and living conditions of a region are shaped by its relief, geology and climate, and control factors like hydrology and soil formation. While long-term climatic fluctuations and associated changes in environmental conditions are commonly viewed as the dominant natural factor in human evolution, the role of geological and pedological processes has so far received little attention. However, it makes a big difference to consider the effects of large-scale environmental changes in a homogeneous "static" landscape or to include the multitude of dynamic landscape factors that can lead to strong local effects with regard to the structure of the landscape and the availability of water and food.</p> <p>The NE Aegean is a key region of Pleistocene hominin presence at the crossroad between Africa, Asia and Europe situated in a geologically highly unstable region. Rodafnidia, an open-air Lower Paleolithic site on Lesbos, has revealed a unique Acheulean assemblage from excavated fluvio-lacustrine deposits dated between 476 and 164 ka BP. This site and its surrounding region represent a key location to study hominin subsistence and mobility and to investigate potential trans-Aegean migration corridors during Pleistocene sea-level lowstands. Geologically, Rodafnidia is situated on middle Pleistocene fluvial sediments consisting mainly of reworked early Miocene ignimbrites, and Pliocene marly limestones and marls, whereas the wider region is characterized by strong geochemical and pedochemical contrasts including nutritionally depleted soils on ophiolitic rocks, highly productive soils on marshy coastal deposits along the Kalloni Gulf, and a series of fault-controlled thermal sulfur springs at Lisvori and Polichnitos. We hypothesize that the attractiveness of Rodafnidia site for hominin presence was influenced by the local geology and tectonic activity controlling the long-term soil nutritional status of the region. We employ a combined geological-pedological study to unravel the paleoenvironmental conditions of the wider region. Our approach offers, in return, valuable insights into hominin-landscape interaction, relevant to landuse, resource exploitation and dispersal potential.</p> <p>Our systematic sampling and analysis of rocks, soil and water offers clues to the soil nutritional characteristics of the main lithological units exposed in the wider Rodafnidia area. Results reveal distinct differences in the nutritional status of soils developed on different geological substrates. While volcanic soils in the immediate Rodafnidia region and marshy soils along the coast comprise well-balanced nutritional levels, serpentinite soils dominating the ophiolitic highlands display highly problematic properties such as low Ca/Mg ratios and enhanced heavy metal concentrations. Soils on hot spring deposits are puzzling as they display both beneficial characteristics (high soil organic carbon, high calcium) and potentially harmful enhanced heavy metal levels.</p> <p>In a pedological context, Rodafinidia is located in a narrow zone of highly productive, nutrient rich soils in a wider region of geologically induced nutrient deficiencies. During sea-level lowstands, hominins along with other continental fauna could have crossed terrestrial passages between western Asia and the Eastern Aegean, and sites like Rodafnidia emerge as likely beneficial locations for hominin subsistence strategies. </p>
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Continuous lake sediment archives integrate valuable information of geodynamic transformations, climatic fluctuations and anthropogenic environmental forcing through time. In many parts of the world, such as sub-Saharan Africa, lake... more
Continuous lake sediment archives integrate valuable information of geodynamic transformations, climatic fluctuations and anthropogenic environmental forcing through time. In many parts of the world, such as sub-Saharan Africa, lake ecosystems are important pillars of biodiversity and wildlife preservation and evolution, as well as political and economic stability, especially with regard to the rapid population growth and increasing food and water demand.Located in the central part of the rift valley region, lake Naivasha is the second largest freshwater lake in Kenya, covers a catchment area of ca. 3400 km2 and is considered a “wetland of international importance” (RAMSAR convention, 2011). Previous studies and real-time observations documented a rapid intensification of agricultural activities ranging from subsidy economy (upper catchment) to industrial-sized horticulture practices (lower catchment) from the second half of the 20th century towards the present. These were suggested...
Research Interests:
The February 6th, 2023, Mw 7.8 Pazarcık earthquake in the Turkey-Syria border region raises the question of whether such a large earthquake could have been foreseen, as well as what is the maximum possible magnitude (Mmax) of earthquakes... more
The February 6th, 2023, Mw 7.8 Pazarcık earthquake in the Turkey-Syria border region raises the question of whether such a large earthquake could have been foreseen, as well as what is the maximum possible magnitude (Mmax) of earthquakes on the East Anatolian fault system and on continental transform faults in general. To answer such questions, knowledge of past earthquakes and of their causative faults is necessary. Here, we integrate data from historical seismology, paleoseismology, archeoseismology, and remote sensing to identify the likely source faults of fourteen Mw ≥ 7 earthquakes between AD 1000 and the present in the region. We find that the 2023 Pazarcık earthquake could have been foreseen in terms of location (the East Anatolian Fault) and timing (an earthquake along this fault was if anything overdue), but not magnitude. We hypothesize that the maximum earthquake magnitude for the East Anatolian Fault is in fact 8.2, i.e. a single end-to-end rupture of the entire fault, ...
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<p>The Victoria microplate is generally assumed to be internally rigid, i.e. non-deforming.  Here, we describe geomorphological evidence for active fragmentation of the microplate along the E-W to NE-SW striking... more
<p>The Victoria microplate is generally assumed to be internally rigid, i.e. non-deforming.  Here, we describe geomorphological evidence for active fragmentation of the microplate along the E-W to NE-SW striking Isuria-Utimbara fault system, Lake Victoria, in the Kenya-Tanzania transboundary region.</p> <p>The Isuria-Utimbara fault system has received little previous attention and is not recognised as seismically active. The fault system marks the northern boundary of the Mara River Basin and lies within the mapped extent of the Victoria microplate, an apparently relatively rigid block situated on the Tanzanian craton. The area is defined by low seismicity within the temporal limits of the instrumental record: seismicity is concentrated along the western arm (as well as, to a lesser extent, the southernmost part of the eastern arm) of the East African Rift (EAR). Here, we describe geomorphological evidence for geologically recent earthquake activity, which has produced scarps and alluvial fans in the hanging walls of the major escarpments. The scarps appear to be segmented, with typical segment lengths of approximately 15 km, and together sum to an along-strike length of approximately 100 km. The height of the scarps exceeds 8 m with a maximum height of 25 m (measured using TanDEM-X Digital Elevation Model (DEM) Global data which has a horizontal resolution of 12 m and an ~2 m height error). Considering the length of a typical segment, scaling relationships suggest the possibility for multiple >M<sub>w</sub> 6 earthquakes. If the segments slipped together, this would result in a maximum earthquake magnitude of >7. Although dating has not yet been carried out, a constraint on slip rate comes from displaced Neogene volcanics found above and below the main escarpment, which give a long-term vertical displacement rate of approximately 0.1mm/yr, comparable with stable continental intraplate settings. Our findings have implications for the seismic hazard of the region: although parts of the Mara River Basin are protected areas of great ecological importance, population density is increasing along the shores of Lake Victoria and a major gold mine lies directly to the south of the fault system. This fault appears to be fragmenting the Tanzanian craton, albeit at relatively slow rates, and cratonic settings are in general capable of producing large and damaging earthquakes due to the possibility for a large seismogenic thickness.</p>
Research Interests: Geology and Escarpment
<p>Tectonic activity impacts the environment and identifying the influence of active faulting on environmental factors, such as vegetation growth and soil formation patterns, is valuable in better understanding ecosystem... more
<p>Tectonic activity impacts the environment and identifying the influence of active faulting on environmental factors, such as vegetation growth and soil formation patterns, is valuable in better understanding ecosystem functions. We applied remote sensing techniques to illustrate how tectonic activity and lithology of bedrock influence temporal and spatial patterns of vegetation and soil parameters in a climatically sensitive, fault-controlled river basin in the Kenya-Tanzania transboundary region.</p> <p>The Mara River Basin lies in a region of previously unrecognised tectonic activity, characterised by subrecent extensional faulting along the Utimbara and Isuria faults. Faulting leads to spatially variable erosion and soil formation rates as well as disruption and modification of drainage systems. All these factors might be expected to exert controls on ecosystem dynamics on a range of lengths and timescales. We investigate tectonic controls on ecological processes in the Mara River Basin using a combination of geospatial mapping and multispectral image analysis. To map fault structures and to reveal signs of recent tectonic activity along the Utimbara and Isuria faults, we use high-resolution digital elevation models derived from 12m TanDEM-X data. To investigate spatiotemporal vegetation patterns and soil formation, we use a 5-year Normalised Difference Vegetation Index (NDVI) time-series, Clay Mineral Ratio (CMR) and Moisture Stress Index (MSI) derived from Sentinel 2 data. </p> <p>Whilst lithology does exert some control on ecological properties, we also observe that the downthrown hanging wall of the faults, especially directly adjacent to the escarpment, is consistently associated with a higher degree of vegetation, wetland formation and clay distribution. Analysis of spectral indices shows that the overall spatial pattern of vegetation cover is seasonally low in the flat plains and perennially high in the vicinity of more complex, tectonically influenced structures. The NDVI highlights several locations with permanently healthy vegetation along the escarpment which extend downslope for several kilometres. Our study shows that in the Mara River Basin, active normal faulting is an important stabiliser of vegetation growth patterns. We interpret this effect to be caused by favourable hydrological and pedological conditions along the escarpments and tectonically induced structures such as subrecent surface ruptures and a series of small, fault-bounded alluvial fans exposing systematically high vegetation and clay values. This implies that tectonic activity has a direct beneficial influence on ecological processes in this climatically sensitive region. As future climate change in the area is expected to lead to accelerated habitat desiccation and deterioration of vegetation quality, suitable habitats for wildlife will progressively reduce and will likely be limited to tectonically active locations. Long-term insights into tectonic processes and the interplay between geology and soils can thus be useful for recent and future ecosystem management since the understanding of an area from a geological perspective can complement the understanding of other natural processes within it.</p>
Research Interests:
<p>The East African Rift System (EARS) is a key location for studying Plio-Pleistocene paleoclimate and hominin inhabitance. The region experienced profound reorganization during this interval as a response to volcanism,... more
<p>The East African Rift System (EARS) is a key location for studying Plio-Pleistocene paleoclimate and hominin inhabitance. The region experienced profound reorganization during this interval as a response to volcanism, tectonics and climate change, and arguably detailed spatiotemporally coherent climate datasets could provide evidence of causal links between geologic change and hominin evolution.  However, continued tectonism, erosion, burial and volcanism obscures much of this information. Despite its rich fossil record, the Turkana basin in the northern Kenya Rift is no exception. It has been hypothesized that Lake Turkana and paleo-Lake Suguta to its south formed one 530-650 km long mega-lake before 221 ka ago, and was a major barrier for E-W dispersal of hominids and other terrestrial fauna. Here we present new information on basin development based on paleolandscape modeling and <sup>87</sup>Sr/<sup>86</sup>Sr analysis on microfossils of newly discovered paleo-lake sequences in the Suguta Valley, permitting reconstruction of volcano-tectonic processes 900-700 ka ago. Contrary to previous assumptions, results suggest that two to three lakes separated by tectono-volcanic barriers formed instead of one mega-lake. These results have implications for previously formulated hypotheses about mega-lakes preventing W-E migration and exchange and suggest that during the early Middle Pleistocene E-W migrations were possible.</p>
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Research Interests:
Research Interests:
Research Interests: Geography, Geology, Agricultural Sciences, Remote sensing and GIS applications in Landscape Research, Geomorphology and Active tectonics, and 11 moreEarth and Environmental Sciences, Hominin evolution, Acheulean, RIFT, Site Formation, Nakuru, African mammals, Hominins, Landscape and Land-use-history, Rift Valley Fever, and Complex Topography
Tectonically active regions are characterized by complex landscapes comprising soils with heterogeneous physicochemical properties. Spatial variability of nutrient sources enhances landscape biodiversity and creates heterogeneous habitats... more
Tectonically active regions are characterized by complex landscapes comprising soils with heterogeneous physicochemical properties. Spatial variability of nutrient sources enhances landscape biodiversity and creates heterogeneous habitats potentially attractive for animals and humans. In this study, we analyze the role of geological processes in the distributions of soil nutrients in the southern Kenya Rift, a key region in the interpretation of early human-landscape interactions. Our aim is to determine how spatial variations in rock chemistry, as well as topographic gradients and localized zones of rock fracturing from tectonic faulting determine the distributions of plant-available soil nutrients in soils. We hypothesize that present-day soil nutrient levels reflect the long-term chemical and geomorphological characteristics of the landscape and underlying parent material, and that regions with high nutrient availability occur along pathways correlating with locations of hominin ...
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Identification of active seismogenic faults in low-strain intraplate regions is a major challenge. The understanding of intraplate earthquakes is hampered by the spatiotemporal scattering of large earthquakes and by barely detectable... more
Identification of active seismogenic faults in low-strain intraplate regions is a major challenge. The understanding of intraplate earthquakes is hampered by the spatiotemporal scattering of large earthquakes and by barely detectable strain accumulation. In populated humid regions, both hillslope and anthropogenic processes are important challenges to the recognition of potentially active faults. The Lower Rhine Graben is the NW segment of the European Cenozoic Rift System. It is a prime example of a seismically active low-strain rift situated in a humid and densely populated region. The approximate location of potentially active fault segments in this region is well known, but knowledge of the recurrence of large earthquakes and of the dominant fault slip mode is still rudimentary. The current debate ranges from slip dominated by repeated large earthquakes to slip dominated by aseismic creep. The purpose of this thesis is to determine whether the Lower Rhine Graben is an exception ...
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We have studied the importance of geological and soil edaphic factors for the location and duration of inhabitance of hominin sites in the southern Kenya Rift, East Africa. Using examples from the Lake Magadi-Olorgesailie region, we... more
We have studied the importance of geological and soil edaphic factors for the location and duration of inhabitance of hominin sites in the southern Kenya Rift, East Africa. Using examples from the Lake Magadi-Olorgesailie region, we demonstrate that field mapping and analytical techniques derived from geology and soil science can provide important information for research in early hominin migration and land use.