Experimental impact cratering: A summary of the major results of the MEMIN research unit          下载免费PDF全文

Thomas Kenkmann  Alex Deutsch  Klaus Thoma  Matthias Ebert  Michael H. Poelchau  Elmar Buhl  Eva-Regine Carl  Andreas N. Danilewsky  Georg Dresen  Anja Dufresne  Nathanaël Durr  Lars Ehm  Christian Grosse  Max Gulde  Nicole Güldemeister  Christopher Hamann  Lutz Hecht  Stefan Hiermaier  Tobias Hoerth  Astrid Kowitz  Falko Langenhorst  Bernd Lexow  Hanns-Peter Liermann  Robert Luther  Ulrich Mansfeld  Dorothee Moser  Manuel Raith  Wolf Uwe Reimold  Martin Sauer  Frank Schäfer  Ralf Thomas Schmitt  Frank Sommer  Jakob Wilk  Rebecca Winkler  Kai Wünnemann 《Meteoritics & planetary science》2018,53(8):1543-1568

This paper reviews major findings of the Multidisciplinary Experimental and Modeling Impact Crater Research Network (MEMIN). MEMIN is a consortium, funded from 2009 till 2017 by the German Research Foundation, and is aimed at investigating impact cratering processes by experimental and modeling approaches. The vision of this network has been to comprehensively quantify impact processes by conducting a strictly controlled experimental campaign at the laboratory scale, together with a multidisciplinary analytical approach. Central to MEMIN has been the use of powerful two-stage light-gas accelerators capable of producing impact craters in the decimeter size range in solid rocks that allowed detailed spatial analyses of petrophysical, structural, and geochemical changes in target rocks and ejecta. In addition, explosive setups, membrane-driven diamond anvil cells, as well as laser irradiation and split Hopkinson pressure bar technologies have been used to study the response of minerals and rocks to shock and dynamic loading as well as high-temperature conditions. We used Seeberger sandstone, Taunus quartzite, Carrara marble, and Weibern tuff as major target rock types. In concert with the experiments we conducted mesoscale numerical simulations of shock wave propagation in heterogeneous rocks resolving the complex response of grains and pores to compressive, shear, and tensile loading and macroscale modeling of crater formation and fracturing. Major results comprise (1) projectile–target interaction, (2) various aspects of shock metamorphism with special focus on low shock pressures and effects of target porosity and water saturation, (3) crater morphologies and cratering efficiencies in various nonporous and porous lithologies, (4) in situ target damage, (5) ejecta dynamics, and (6) geophysical survey of experimental craters.  相似文献   

A new type of article for Terra Nova          下载免费PDF全文

Max Coleman  Jean Braun  Georges Calas  Carlo Doglioni  Klaus Mezger  Jason Phipps Morgan 《地学学报》2015,27(6):399-399

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Fractional crystallization of Si-undersaturated alkaline magmas leading to unmixing of carbonatites on Brava Island (Cape Verde) and a general model of carbonatite genesis in alkaline magma suites     

Daniel Weidendorfer  Max W. Schmidt  Hannes B. Mattsson 《Contributions to Mineralogy and Petrology》2016,171(5):43

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Free allocation in the 3rd EU ETS period: assessing two manufacturing sectors     

Christian Stenqvist  Max Åhman 《Climate Policy》2016,16(2):125-144

This article provides an analysis of the EU Emissions Trading Scheme (ETS) and the harmonized benchmark-based allocation procedures by comparing two energy-intensive sectors with activities in three Member States. These sectors include the cement industry (CEI) and the pulp and paper industry (PPI) in the UK, Sweden, and France. Our results show that the new procedures are better suited for the more homogeneous CEI, in which the outcome of stricter allocation of emissions allowances is consistent between Member States. For the more heterogeneous PPI – in terms of its product portfolios, technical infrastructures, and fuel mixes – the allocation procedures lead to diverse outcomes. It is the lack of product benchmark curves, and the alternative use of benchmark values that are biased towards a fossil fuel-mix and are based on specific energy use rather than emission intensity, which leads to allocations to the PPI that do not represent the average performance of the top 10% of GHG-efficient installations. Another matter is that grandfathering is still present via the historically based production volumes. How to deal with structural change and provisions regarding capacity reductions and partial cessation is an issue that is highly relevant for the PPI but less so for the CEI.

Policy relevance

After an unprecedented amount of consultation with industrial associations and other stakeholders, a harmonized benchmark-based allocation methodology was introduced in the third trading period of the EU ETS. Establishing a reliable and robust benchmark methodology for free allocation that shields against high direct carbon costs, is perceived as fair and politically acceptable, and still incentivizes firms to take action, is a significant challenge. This article contributes to a deeper understanding of the challenges in effectively applying harmonized rules in industrial sectors that are heterogeneous. This is essential for the debate on structural reformation of the EU ETS, and for sharing experiences with other emerging emissions trading systems in the world that also consider benchmark methodologies.  相似文献   

Biased estimation: a simple framework for inversion and uncertainty analysis with prior information   总被引：1，自引：0，他引：1  

Max A. Meju 《Geophysical Journal International》1994,119(2):521-528

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The control of the production process of phytoplankton by the physical structure of the aquatic environment with special reference to its optical properties   总被引：2，自引：0，他引：2  

Barbara B. Prézelin  Max M. Tilzer  Oscar Schofield  Clivia Haese 《Aquatic Sciences - Research Across Boundaries》1991,53(2-3):136-186

This tutorial was designed for nonbiologists requiring an introduction to the nature and general timescales of phytoplankton responses to physical forcing in aquatic environments. As such, an effort was made to highlight biological markers which might assist in identifying, measuring and/or validating physical processes controlling the variability in the distribution, abundance, composition and activity of phytoplankton communities. Given the recent advances in environmental optics and remote sensing capabilities, a special emphasis was placed on the nature and utility of phytoplankton optical properties in current bio-optical modelling efforts to predict temporal and spatial variability in phytoplankton productivity and growth.  相似文献   

The Southern part of the Armorican orogeny: A result of crustal shortening related to reactivation of a pre-Hercynian mafic belt during Carboniferous time     

J.P. Lefort  Cl. Audren  M.D. Max 《Tectonophysics》1982,89(4):359-377

This synthesis of detailed geological and geophysical information relates deep crustal structure to deformation and the emplacement of granites in the South Armorican Massif and the adjacent continental shelf. Near the continental margin a zone of geophysical anomalies is regarded as a nearly complete line of suture between a southern continent and America. A major mafic body in the trace of the supposed suture in interpreted as a relic of probable oceanic crust which has apparently acted as a deflector of regional strain.It is proposed that late in the Hercynian collision history, during late Carboniferous time, compressional strain acted across the mafic body and can be directly related to generation of younger regional structures in the metasediments and to localization of granite emplacement.  相似文献   

Crustal transit time monitoring using PKP     

Max Wyss  R. Kind 《Pure and Applied Geophysics》1983,121(2):269-285

The arrival time difference for the AB branch of PKP from deep Tonga earthquakes is constant over years with a standard deviation of ±0.05 seconds at seismographs located 10 to 50 km from each other. If published travel time curves are used to calculate the relative residuals of PKP the standard deviation from the constant mean is improved by approximately 0.01 seconds for AB branch data. For the BC branch, standard deviations of relative travel times of ±0.06 seconds are reduced to less than ±0.05 seconds by calculating relative residuals. We conclude that changes of crustal transit time forP-waves could be resolved, based on careful PKP arrival time measurement at two or more neighboring stations if the changes exceed 0.05 sec and last for more than one year. The conditions for achieving this result are that PKP from Tonga earthquakes is clearly recorded, and that time-keeping is accurate. The data on which these conclusions are based were obtained from the Graefenberg seismograph array, which is located in West Gemany and consists of 13 stations separated by distances of 10 km to 100 km. We propose that relative arrival times of PKP from Tonga could be used in the Mediterranean - Middle East area to search for precursory travel time changes before large earthquakes.  相似文献   

Carbon and hydrogen isotopic compositions of the NBS 22 and NBS 21 stable isotope reference materials: An inter-laboratory comparison     

Martin Schoell  Eckhard Faber  Max L. Coleman 《Organic Geochemistry》1983,5(1):3-6

Measurement of 17 laboratories on the stable isotope reference materials, NBS 22 lubricating oil and NBS 21 graphite, resulted in a revised calibration on the PDB scale. NBS 22 ¹³C/¹²C ratios of all laboratories did not demonstrate a gausssian distribution. Therefore, values which resulted from direct comparison with NBS 20 carbonate standards were selected the mean value of which is $\text{?29.81 ± 0.06?}$; this value is recommended as new value for NBS 22. The reported variations in δ¹³C for NBS 21 were consistent within the accuracies for single meaurements; the mean value is ?28.16 ± 0.01. The variations of D/H ratios of NBS 22 also were consistent with the accuracy quoted, with a mean value of ?119?.  相似文献   

Comment on 'The magnetotelluric phase tensor' by T. Grant Caldwell, Hugh M. Bibby and Colin Brown   总被引：1，自引：0，他引：1  

Max Moorkamp 《Geophysical Journal International》2007,171(2):565-566

We demonstrate a minor inconsistency in the appendix of 'The magnetotelluric phase tensor' by Caldwell et al. that can lead to incorrect results, and provide a simple solution for this problem.  相似文献