Geochronological and petrological constraints from the evolution in the Saxon Granulite Massif,Germany, on the Variscan continental collision orogeny     

Jochen Rtzler  Martin J. Timmerman 《Journal of Metamorphic Geology》2021,39(1):3-38

Controversy over the plate tectonic affinity and evolution of the Saxon granulites in a two‐ or multi‐plate setting during inter‐ or intracontinental collision makes the Saxon Granulite Massif a key area for the understanding of the Palaeozoic Variscan orogeny. The massif is a large dome structure in which tectonic slivers of metapelite and metaophiolite units occur along a shear zone separating a diapir‐like body of high‐P granulite below from low‐P metasedimentary rocks above. Each of the upper structural units records a different metamorphic evolution until its assembly with the exhuming granulite body. New age and petrologic data suggest that the metaophiolites developed from early Cambrian protoliths during high‐P amphibolite facies metamorphism in the mid‐ to late‐Devonian and thermal overprinting by the exhuming hot granulite body in the early Carboniferous. A correlation of new Ar–Ar biotite ages with published P–T–t data for the granulites implies that exhumation and cooling of the granulite body occurred at average rates of ~8 mm/year and ~80°C/Ma, with a drop in exhumation rate from ~20 to ~2.5 mm/year and a slight rise in cooling rate between early and late stages of exhumation. A time lag of c. 2 Ma between cooling through the closure temperatures for argon diffusion in hornblende and biotite indicates a cooling rate of 90°C/Ma when all units had assembled into the massif. A two‐plate model of the Variscan orogeny in which the above evolution is related to a short‐lived intra‐Gondwana subduction zone conflicts with the oceanic affinity of the metaophiolites and the timescale of c. 50 Ma for the metamorphism. Alternative models focusing on the internal Variscan belt assume distinctly different material paths through the lower or upper crust for strikingly similar granulite massifs. An earlier proposed model of bilateral subduction below the internal Variscan belt may solve this problem.  相似文献   

Quantitative multi-risk analysis for natural hazards: a framework for multi-risk modelling   总被引：2，自引：1，他引：1  

Jochen Schmidt  Iain Matcham  Stefan Reese  Andrew King  Rob Bell  Roddy Henderson  Graeme Smart  Jim Cousins  Warwick Smith  Dave Heron 《Natural Hazards》2011,58(3):1169-1192

This paper introduces a generic framework for multi-risk modelling developed in the project ‘Regional RiskScape’ by the Research Organizations GNS Science and the National Institute of Water and Atmospheric Research Ltd. (NIWA) in New Zealand. Our goal was to develop a generic technology for modelling risks from different natural hazards and for various elements at risk. The technical framework is not dependent on the specific nature of the individual hazard nor the vulnerability and the type of the individual assets. Based on this generic framework, a software prototype has been developed, which is capable of ‘plugging in’ various natural hazards and assets without reconfiguring or adapting the generic software framework. To achieve that, we developed a set of standards for treating the fundamental components of a risk model: hazards, assets (elements at risk) and vulnerability models (or fragility functions). Thus, the developed prototype system is able to accommodate any hazard, asset or fragility model, which is provided to the system according to that standard. The software prototype was tested by modelling earthquake, volcanic ashfall, flood, wind, and tsunami risks for several urban centres and small communities in New Zealand.  相似文献   

“Indicators of vulnerability and adaptive capacity”: Towards a clarification of the science–policy interface     

Jochen Hinkel   《Global Environmental Change》2011,21(1):198-208

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Classifying knowledge on climate change impacts, adaptation, and vulnerability in Europe for informing adaptation research and decision-making: A conceptual meta-analysis   总被引：3，自引：0，他引：3  

Mareen E. Hofmann  Jochen HinkelMarkus Wrobel 《Global Environmental Change》2011,21(3):1106-1116

Knowledge on climate change impacts, adaptation, and vulnerability is fragmented, because it is found in disparate case studies which use inconsistent terminology and focus on distinct aspects relevant to adaptation. While large-scale syntheses such as the Assessment Reports of the Intergovernmental Panel on Climate Change provide a high level overview and are useful for international decision-making, there is a need for systematic and flexible access to this research-based knowledge in order to aid future adaptation research and decision-making. Against this background, we present a ‘conceptual’ meta-analysis, a novel approach to meta-analyse studies on climate change impacts, adaptation, and vulnerability in Europe. The meta-analysis results in a classification scheme for relating the diverse studies. This scheme consists of (i) a classification of studies according to the type of adaptation-relevant results they produce and (ii) a hierarchical classification of the regional and thematic context of studies. The implementation of this scheme, for example in the form of a database, overcomes some of the identified gaps of current adaptation knowledge representation. We furthermore present a quantitative analysis of the classified studies that exemplifies how the developed classification scheme can be applied to get a systematic and quantitative overview of the knowledge they contain. Thus, the conceptual meta-analysis and the classification scheme represent a first step towards a systematisation of knowledge on climate change impacts, adaptation, and vulnerability and may be seen as a useful complement to qualitative literature reviews.  相似文献   

Evaluation of Combined Direct-Push Methods Used for Aquifer Model Generation   总被引：4，自引：0，他引：4  

by Ralf Köber  Götz Hornbruch  Carsten Leven  Lars Tischer  Jochen Großmann  Peter Dietrich  Holger Weiß  Andreas Dahmke 《Ground water》2009,47(4):536-546

Most established methods to characterize aquifer structure and hydraulic conductivities of hydrostratigraphical units are not capable of delivering sufficient information in the spatial resolution that is desired for sophisticated numerical contaminant transport modeling and adapted remediation design. With hydraulic investigation methods based on the direct-push (DP) technology such as DP slug tests, DP injection logging, and the hydraulic profiling tool, it is possible to rapidly delineate hydrogeological structures and estimate their hydraulic conductivity in shallow unconsolidated aquifers without the need for wells. A combined application of these tools was used for the investigation of a contaminated German refinery site and for the setup of hydraulic aquifer models. The quality of DP investigation and the models was evaluated by comparisons of tracer transport simulations using these models and measured breakthroughs of two natural gradient tracer tests. Model scenarios considering the information of all tools together showed good reproduction of the measured breakthroughs, indicating the suitability of the approach and a minor impact of potential technical limitations. Using the DP slug tests alone yielded significantly higher deviations for the determined hydraulic conductivities compared to considering two or three of the tools. Realistic aquifer models developed on basis of such combined DP investigation approaches can help optimize remediation concepts or identify flow regimes for aquifers with a complex structure.  相似文献   

Estimating reliability and resolution of probability forecasts through decomposition of the empirical score     

Jochen Br?cker 《Climate Dynamics》2012,39(3-4):655-667

Proper scoring rules provide a useful means to evaluate probabilistic forecasts. Independent from scoring rules, it has been argued that reliability and resolution are desirable forecast attributes. The mathematical expectation value of the score allows for a decomposition into reliability and resolution related terms, demonstrating a relationship between scoring rules and reliability/resolution. A similar decomposition holds for the empirical (i.e. sample average) score over an archive of forecast–observation pairs. This empirical decomposition though provides a too optimistic estimate of the potential score (i.e. the optimum score which could be obtained through recalibration), showing that a forecast assessment based solely on the empirical resolution and reliability terms will be misleading. The differences between the theoretical and empirical decomposition are investigated, and specific recommendations are given how to obtain better estimators of reliability and resolution in the case of the Brier and Ignorance scoring rule.  相似文献   

The coating hypothesis for ammonia ice particles in Jupiter: Laboratory experiments and optical modeling     

Konstantinos S. Kalogerakis  Jochen Marschall  Patricia A. Engel  Rhiannon T. Meharchand  Michael H. Wong 《Icarus》2008,196(1):202-215

We report laboratory experiments and modeling calculations investigating the effect of a hydrocarbon coating on ammonia ice spectral signatures. Observational evidence and thermochemical models indicate an abundance of ammonia ice clouds in Jupiter's atmosphere. However, spectrally identifiable ammonia ice clouds are found covering less than 1% of Jupiter's atmosphere, notably in areas of strong vertical transport, indicating a short lifetime for the signature of ammonia absorption on condensed ammonia particles [Baines, K.H., Carlson, R.W., Kamp, L.W., 2002. Icarus 159, 74-94]. Current literature has suggested coating of ammonia ice particles by a hydrocarbon haze as a possible explanation for this paradox. The work presented here supports the inference of a coating effect that can alter or suppress ammonia absorption features. In the experiments, thin films of ammonia ices are deposited in a cryogenic apparatus, coated with hydrocarbons, and characterized by reflection-absorption infrared spectroscopy. We have observed the effects on the ammonia ice absorption features near 3 and 9 μm with coverage by thin layers of hydrocarbons. Modeling calculations of these multilayer thin films assist in the interpretation of the experimental results and reveal the important role of optical interference in altering the aforementioned ammonia spectral features. Mie and T-matrix scattering calculations demonstrate analogous effects for ammonia ice particles and investigate the relative effects of ammonia ice particle size, shape, and coating layer thickness on the ice particle spectral signatures.  相似文献   

Determination of deployment specific chemical uptake rates for SPMD and PDMS using a passive flow monitor   总被引：1，自引：0，他引：1  

O'Brien D  Komarova T  Mueller JF 《Marine pollution bulletin》2012,64(5):1005-1011

Passive sampling techniques facilitate the time-integrated measurement of pollutant concentrations through the use of a selective receiving phase. Accurate quantification using passive sampling devices rely on the implementation of methods that will negate the effects of environmental factors (flow, temperature, etc.) or that will allow the calculation of the chemical specific rates of uptake (R(s)) into the passive sampler employed. We have applied an in situ calibration technique based on the dissolution of gypsum to measure the average water velocity to which a sampler has been exposed. We demonstrate that the loss of gypsum from the passive flow monitor (PFM) can be applied to predict changes in R(s) dependent on flow when using the absorbent SPMD (semipermeable membrane device) and PDMS (polydimethyl siloxan) passive samplers. The application of the PFM will enhance the accuracy of measurements made when calculating and reporting environmental pollutant concentrations using a passive sampling device.  相似文献   

Dynamics of the circulation in the Sea of Marmara: numerical modeling experiments and observations from the Turkish straits system experiment   总被引：4，自引：3，他引：1  

Jacopo?ChiggiatoEmail author  Ewa?Jarosz  Jeffrey?W.?Book  James?Dykes  Lucio?Torrisi  Pierre-Marie?Poulain  Riccardo?Gerin  Jochen?Horstmann  ?ükrü?Be?iktepe 《Ocean Dynamics》2012,62(1):139-159

During September 2008 and February 2009, the NR/V Alliance extensively sampled the waters of the Sea of Marmara within the framework of the Turkish Straits System (TSS) experiment coordinated by the NATO Undersea Research Centre. The observational effort provided an opportunity to set up realistic numerical experiments for modeling the observed variability of the Marmara Sea upper layer circulation at mesoscale resolution over the entire basin during the trial period, complementing relevant features and forcing factors revealed by numerical model results with information acquired from in situ and remote sensing datasets. Numerical model solutions from realistic runs using the Regional Ocean Modeling System (ROMS) produce a general circulation in the Sea of Marmara that is consistent with previous knowledge of the circulation drawn from past hydrographic measurements, with a westward meandering current associated with a recurrent large anticyclone. Additional idealized numerical experiments illuminate the role various dynamics play in determining the Sea of Marmara circulation and pycnocline structure. Both the wind curl and the strait flows are found to strongly influence the strength and location of the main mesoscale features. Large displacements of the pycnocline depth were observed during the sea trials. These displacements can be interpreted as storm-driven upwelling/downwelling dynamics associated with northeasterly winds; however, lateral advection associated with flow from the Straits also played a role in some displacements.  相似文献   

Active Galactic Nuclei     

Martin Haas  Peter Biermann  Rolf Chini  Jochen Heidt  Wolfram Kollatschny  Helmut Meusinger  Ralf Siebenmorgen 《Astronomische Nachrichten》2007,328(7):665-680

F11 Jets, supernovae, gammabursts – more light for theory? F35 A Direct Comparison of the QSO Samples from VPMS and SDSS F36 Gravitational Microlensing Simulations and Ensemble Broad‐Band Variability of the QSOs from VPMS F42 Luminosity function of low redshift quasars F43 Star Formation around Active Galactic Nuclei – Results from near infrared observations F58 High‐Redshift Quasars as Probes of Early Star Formation F66 On the dust emission of Seyfert nuclei F72 Propagation of Very Light MHD Jets F78 Giant Outflows in MassiveHigh‐z Radio Galaxies: Direct Evidence for AGNFeedback in the Early Universe F89 Lowfrequency mapping of ‘normal’ FR II radio galaxies: Resolving the puzzle of X‐shaped radio sources F90 Nature of X‐shaped radio sources: A statistical approach F100 Cosmological growth of Supermassive Black Holes: constraints on kinetic and radiative energy feedback F107 Molecular Tori in AGN F136 Electron‐Ion Recombination Rate Coefficients of Iron M‐Shell Ions for X‐Ray Astronomy F139 Hydrodynamic models of obscuring tori F145 The unique BL Lac Object S5 0716+714 F158 On the Cluster Environment of the BL Lac Object OJ 287 F179 The circumnuclear dust in nearby AGN resolved by mid‐infrared interferometry F184 NIR‐imaging of SDSS BL Lac objects F190 Blazar Observations in the TeV energy range with the MAGIC Telescope F198 Gas Inflow Rates in Nearby AGN Galaxies F202 Two zone SSC model for blazar jets F215 Long‐termVHE γ ‐ray monitoring of bright blazars with a dedicated telescope F218 Long termmonitoring of bright TeV Blazars with the MAGIC telescope F220 Fifteen Blazars in Very‐High Energy Gamma Rays: A Comparative Study F229 Numerical calculation of blazar spectra. Application to 1 ES 1218+30.4 F230 Blazar spectral energy distributions corrected for gamma ray attenuation F240 Observation of PG 1553+113 with the MAGIC Telescope F243 VHE Gamma‐Ray Flare of PKS2155‐304 detected by the MAGIC telescope F245 Observations of 3C279 with the MAGIC Telescope F258 Diffraction limited near infrared imaging spectroscopy of the NLR of NGC4151  相似文献