Das Projekt "Sub project: Hydrochemical and hydraulic properties of the continental upper crust at the KTB site" wird vom Umweltbundesamt gefördert und von Regierungspräsidium Freiburg, Abteilung 9 - Landesamt für Geologie, Rohstoffe und Bergbau durchgeführt. A constant rate pumping test of one year duration is planed to be carried out in the 4.0 km deep pilot hole of KTB. Watertable fluctuations in the pilot borehole and in the 9.1 km deep main borehole will be monitored as well. A wealth of data (pumping rate, watertable/ pressure, temperature, salinity/electrical conductivity, water samples,....) will become available, some even online. The first objective of the proposed project is to determine the flow system (type of aquifer model). From this deduced hydraulic model follow the hydraulic characteristics (such as: transmissivity, storage coefficient, fracture lengt/ width/aperture, permeability of fractures and matrix,....) describing the properties of the crystalline basement rocks in vicinity of the KTB pilot- and main hole. The length of the expect test radius is some 1000 m. The proposed project intends also to determine the degree of the hydraulic connection between the two holes (having a depth difference of 5.1 km). Additional information, such as water analyses, will be needed in interpreting the hydraulic data. A second major objective is the modelling of water-rock interaction (WRI) processes using the chemical data of KTB fluids. In particular the time series of chemical data will be used to model the kinetic and time dependent processes. We expect as well to see some breakthroughs of 'fresh, clean' crystalline basement water and another breakthrough resulting from fluid stored in the main hole and its surrounding.
Das Projekt "Sub project: Fluid injection test of the SE2-fault system at the KTB-VB (operation, co-ordination, seismic and hydraulic signals in KTB-HB)" wird vom Umweltbundesamt gefördert und von Helmholtz-Zentrum Potsdam Deutsches GeoForschungsZentrum durchgeführt. The Kontinentale Tiefbohrprogramm der Bundesrepublik Deutschland (KTB) was enormously successful. It has revealed a wealth of geoscientific data and new results of unrivalled quality and broadness. However, several of the main objectives have only been marginally investigated, and the scientific potential of the two KTB boreholes, the 4.0 km deep pilot hole (KTB-VB) and the 9.1 km deep main hole (KTB-HB) has by no means fully exploited. The general aim of this and accompanying projects is to study energy and fluid transport processes in continental fault systems at the KTB drill site. For that purpose it is proposed to carry out a fluid production test during a period of 12 months in the KTB-VB. During the test various geophysical, hydraulic and geochemical parameters will be monitored in real-time. Samples of uncontaminated deep seated crustal fluids and gases will be taken regularly for further detailed geochemical, geobiological and isotopic investigations. Data and samples will be provided to several research groups from different institutions for further detailed evaluation. Within this project, the operational work, and tasks of the science team will be co-ordinated, also geochemistry and isotopic composition of crustal gases will be investigated in detail.
Das Projekt "Phosphorus transport along soil pathways in forested catchments" wird vom Umweltbundesamt gefördert und von Technische Universität Dresden, Institut für Bodenkunde und Standortslehre durchgeführt. Phosphorus (P) is an essential nutrient for living organisms. Whereas agriculture avoids P-limitation of primary production through continuous application of P fertilizers, forest ecosystems have developed highly efficient strategies to adapt to low P supply. A main hypothesis of the SPP 1685 is that P depletion of soils drives forest ecosystems from P acquiring system (efficient mobilization of P from the mineral phase) to P recycling systems (highly efficient cycling of P). Regarding P fluxes in soils and from soil to streamwater, this leads to the assumption that recycling systems may have developed strategies to minimize P losses. Further, not only the quantity but also the chemistry (P forms) of transported or accumulated P will differ between the ecosystems. In our project, we will therefore experimentally test the relevance of the two contrasting hypothetical nutritional strategies for P transport processes through the soil and into streamwater. As transport processes will occur especially during heavy rainfall events, when preferential flow pathways (PFPs) are connected, we will focus on identifying those subsurface transport paths. The chemical P fractionation in PFPs will be analyzed to draw conclusions on P accumulation and transport mechanism in soils differing in their availability of mineral bound P (SPP core sites). The second approach is an intensive streamwater monitoring to detect P losses from soil to water. The understanding of P transport processes and P fluxes at small catchment scale is fundamental for estimating the P exports of forest soils into streams. With a hydrological model we will simulate soil water fluxes and estimate P export fluxes for the different ecosystems based on these simulations.
Das Projekt "Effect of habitat fragmentation on reptiles in South East Asia" wird vom Umweltbundesamt gefördert und von Zoologisches Forschungsmuseum Alexander König - Leibniz-Institut für Biodiversität der Tiere durchgeführt. Fragmentation of the natural environment has contributed to major biodiversity loss in South East Asia. Reptiles represent a significant biomass and occupy important functions in our ecosystem. However, these organisms are highly sensitive to relatively minor changes in temperature and habitat alteration. In this study we will investigate the effects of habitat fragmentation and potentially climate change on agamids at several sites in Southeast Asia. We will identify the species richness of agamids, their habitat use, and their diet. By using morphometrics, we aim to correlate morphology and habitat use and diet to explore the ecological niches these lizards occupy. We will also test for microhabitat preferences and optima to understand the ecological impacts on these species caused by forest fragmentation. We hope to use this approach to lay the foundations for macro-ecological modelling proving insights into future distributions and the impact of habitat connectivity.
Das Projekt "Sub project: Chronological framework for Lake Baikal and Lake Elgygytgyn drill cores and orbital forcing of continental climate in the Northern Hemisphere during the past 3.6 Ma" wird vom Umweltbundesamt gefördert und von Universität zu Köln, Institut für Geologie und Mineralogie durchgeführt. We propose to develop a new understanding of (a) orbital forcing and (b) evolution of the Northern Hemisphere continental climate during the Plio-Pleistocene using two world's longest continuous paleoclimate records obtained in ICDP-funded drilling projects: the recently obtained 3.6-Ma record from Lake Elgygytgyn, NE Siberia, and the uppermost 3.6-Ma portion of the record from Lake Baikal, SE Siberia. We will develop a common orbitally-tuned timescale for both records, establish accurate correlations of individual glacial-interglacial intervals in both records, and detail their relationship to marine oxygen isotope stages. We will then use the resultant new common timescale to address the orbital signatures in the continental proxy records of (i) the Pliocene '41-kyr world', (ii) the inception of the Northern Hemisphere glaciations at 2.7 Ma, and (iii) the transition to the '100-kyr world'. We will further address (iv) the 'mystery' of missing variance at precession frequencies in the marine delta 18O records of the 41-kyr world, and (v) test if the high-latitude orbitally-forced continental signal is consistent with the 'latitudinal heat gradient hypothesis' on the origin of the Pliocene ice-ages. A systematic Baikal-Elgygytgyn comparison over the past 3.6 Ma will also shed light on (vi) the mechanisms of amplification of climate changes in the Arctic as compared to those in the upper mid-latitudes of the Northern Hemisphere on orbital time scales.
Das Projekt "Exzellenzcluster 80 (EXC): Ozean der Zukunft" wird vom Umweltbundesamt gefördert und von Helmholtz-Zentrum für Ozeanforschung Kiel (GEOMAR), Forschungsbereich 2: Marine Biogeochemie, Forschungseinheit Biogeochemische Modellierung durchgeführt. By employing a new computational framework to efficiently simulate the transport of biogeochemical tracers in ocean circulation models, we propose to extend the applicability of the Kiel Climate Model (KCM) to time scales of several thousand years. This is orders of magnitude longer than the few-hundred year simulations currently possible, and it will enable us apply the state-of-the-art KCM, so far used to simulate the present and future ocean, also to paleo scenarios. To prepare the ground for future paleoceanographic applications, the work proposed here has two aims: 1. implement and test the computational method for the KCM, 2. use the new method to develop and identify a description of the sedimentation and remineralisation of particulate organic matter (POM) that, for our best estimate of the present ocean circulation, generates nutrient and oxygen distributions consistent with observations. By implication, this should be most appropriate for multimillennial simulations, including those required by paleo studies.
Das Projekt "Sub project: Molybdenum isotope signatures of mid-Cretaceous black shales: Implications on the spatial dimension of anoxic events?" wird vom Umweltbundesamt gefördert und von Leibniz Universität Hannover, Institut für Mineralogie durchgeführt. To evaluate the potential of Mo isotope compositions for the identification of global versus regional anoxia we propose to investigate the fractionation of Mo isotopes in sediments from regionally to globally distributed mid-Cretaceous black shales. The underlying idea is that during times of global or near-global anoxia, black shales can be expected to have served as the primary sink for Mo - as was the case during much of the Proterozoic. In contrast, under the predominantly oxic oceanic conditions prevailing in modern oceans, Fe-Mn-oxides appear to be the major sink for Mo. Adsorption to Mn-oxides, as it occurs under oxic conditions, leads to a significant fractionation of Mo isotopes, resulting in -isotopically heavy- modern seawater. However, the removal of Mo into black-shale sediments under anoxic conditions (e.g. Black Sea) does not seem to result in Mo isotopic fractionation. Hence, differences in the oceanic Mo mass balance should lead to a significant shift in Mo isotope systematics, depending on whether they result from the prevalence of either anoxic or oxic conditions. In fact, available Mo data from mid-Proterozoic and recent marine sediments support this view. Here we propose to test this hypothesis by analyzing the Mo isotope composition of mid-Cretaceous black shales that formed under different spatial and temporal boundary conditions. As a representative sample for an exceptional, presumably global and long-lived Oceanic Anoxic Event (OAE), black shales from OAE 2 (duration: -400 ka) will be analysed. To gain insights into the Mo isotope fractionation during a supraregional, short-lived (ca. 45 ka) black shale event, sediments from OAE 1b (restricted to the western Tethys and Central Atlantic) will be investigated. To evaluate the Mo isotope signal under regional anoxic conditions prevailing over long ( greater than 10 ma) time scales, black shale sediments under- and overlying OAE 2 at Demerara Rise (ODP Leg 207) will be studied. The outcome of the proposed study will be (1) the evaluation of a new, widely applicable geochemical proxy to identify signals of global versus regional anoxia; (2) the possibility to validate Mo isotope-based models on ocean redox evolution during the Proterozoic; and (3) a characterization of the geochemical environment during mid-Cretaceous black-shale formation using Mo and other redox-sensitive metals as well as sulfur isotopes.
Das Projekt "Sub project: Towards timescales of assimilation and magma mixing in the Large Igneous Province of Snake River Plain-Yellowstone, northwest United States" wird vom Umweltbundesamt gefördert und von Universität München, Department für Geo- und Umweltwissenschaften - Sektion Mineralogie, Petrologie & Geochemie durchgeführt. The breath of magma diversities in the Snake River Plain and Yellowstone (SRP-Y) volcanic fields presents a unique opportunity to study the interaction of a hot-spot-related thermal anomaly with the continental crust and the subsequent development of magma reservoirs. As a reservoir forms, primitive magma batches induce crustal melting and assimilation, and mixing. Mixing caused by a recharge of a more primitive magma is expected to be accompanied by heating of the reservoir which may obstruct fractionation and thus to precede it. The SRP-Y holds the tale of this chemical process and therefore provides the pieces of the puzzle portraying the evolution of magmas. A series of tests is proposed to systematically characterize the evolution and importance of mixing during the lifetime of reservoirs fed by a hotspot. This work aims to (1) identify end members in the SRP, and (2) to characterize their physical (e.g., density, viscosity) and chemical (e.g., interstitial melt's composition, volatile content) properties. In a second phase, this work will (3) assess the interaction between physical and chemical properties of the magmas involved in the SRP-Y systems; and (4) constrain changes in the timescale of assimilation and mingling in the SRP magma reservoirs.
Das Projekt "Sub project: Chemical hydrology of subduction zones: Processes, signals and fluid flow" wird vom Umweltbundesamt gefördert und von Universität Bremen, Zentrum für marine Umweltwissenschaften durchgeführt. Subduction zones play a central role in the geological activity of the earth. This activity may be expressed as devastating events such as earthquakes, tsunamis and explosive volcanism. Many processes that lead to such catastrophic behavior are driven by fluids. This study focuses on the chemical hydrology of the shallow portion ( less than 15 km) of subduction zones to shed light on processes that enable subducting sediments to behave seismogenically. Low-chlorinity and volatile content of near surface fluids in active convergent margins suggest that fluids migrate updip from deep sources. The exotic fluid composition, which has been documented for several active convergent margins, is thought to depend on temperature driven clay mineral dehydration. This assumption is hampered by observed low-chlorinity fluids away from fluid pathways that suggest additional fluid freshening mechanisms. Most importantly, a suite of water-rock processes has been hypothesized to occur at depth to enable stick-slip behavior but are only documented in fossil accretionary prisms but not in active ones. To tackle these problems the proposed study will analyze fluids extracted from laboratory hydrothermal compaction tests and natural fluids from two contrary active margins, the accretionary Nankai Trough (Japan) and the erosional Costa Rica margin. The hydrothermal device is a unique approach compared to other hydrothermal systems because it simulates in-situ burial conditions with increasing effective stress (P), decreasing porosity and increasing temperatures (T up to 150 degree C). Sediment end members of each margin will be tested under controlled PT conditions similar to the upper limit of the seismogenic zone to study clay dehydration and water-rock interaction using major and volatile element geochemistry and boron and lithium isotopes. Geochemical fingerprints from the hydrothermal tests will be used to better distinguish geochemical signals in natural fluids. Thus, a better insight into water-rock interaction and fluid flow in the subduction zones will be achieved.
Das Projekt "Sub project: Transport of veterinary medicines from soils to groundwater" wird vom Umweltbundesamt gefördert und von Forschungszentrum Jülich GmbH, Institut für Bio-und Geowissenschaften (IBG), IBG-3 Agrosphäre durchgeführt. Studies on the mobility and leaching of veterinary medicines with special emphasis on preferential flow using soil columns and lysimeters are continued. The lysimeters that were manured with pig slurry from pigs medicated with 14C labelled sulfadiazine (SDZ) and the lysimeters that were manured with pig slurry from pigs medicated with 14C labelled difloxacin (DIF) will be sampled destructively in order to obtain material balances on the fate of the veterinary medicines and their metabolites. Soil from the destructive sampling of the lysimeters is used in pot experiments to test the hypothesis that bonded SDZ (and DIF) including transformation products may become available through the action of the plant rhizosphere. Soil columns experiments are continued to study the effect of repeated application of slurry containing SDZ and the fate of 14C-labelled hydroxy-sulfadiazine. The knowledge from the soil column experiments is used to predict the transport of SDZ in soil with a numerical model. Therefore sorption experiments with soil from different horizons are mandatory as we experienced unexpected sorption behaviour. In addition we will prepare and conduct the central mesocosm and field experiment.
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