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  • ddc:550  (211)
  • Analytical Chemistry and Spectroscopy
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  • German  (151)
  • English  (82)
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  • German  (151)
  • English  (82)
  • French  (3)
  • 1
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    ARGE GMIT, Bonn
    Publication Date: 2024-06-19
    Description: Die Ausgabe der Geowissenschaftlichen Mitteilungen vom Juni 2024 enthält die Themenblöcke: GEOfokus: Die Ur-Ems – ein Fluss legt sich zurück -Vom Ende der Eiszeit zurück in die Zukunft-, GEOaktiv (Wirtschaft, Beruf, Forschung und Lehre), GEOlobby (Gesellschaften, Verbände, Institutionen), GEOreport (Geowissenschaftliche Öffentlichkeitsarbeit, Tagungsberichte, Ausstellungen, Exkursionen, Publikationen), GEOszene (Würdigungen, Nachrufe).
    Description: DFG, SUB Göttingen
    Description: journal
    Keywords: ddc:550 ; GMIT
    Language: German
    Type: doc-type:book , publishedVersion
    Format: 136
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  • 2
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    ARGE GMIT, Bonn
    Publication Date: 2023-10-16
    Description: Die Ausgabe der Geowissenschaftlichen Mitteilungen vom September 2023 enthält die Themenblöcke: GEOfokus: Unterbindung förderinduzierter Salzwasseraufstiege in Trinkwasserbrunnen, GEOaktiv (Wirtschaft, Beruf, Forschung und Lehre), GEOlobby (Gesellschaften, Verbände, Institutionen), GEOreport (Geowissenschaftliche Öffentlichkeitsarbeit, Tagungsberichte, Ausstellungen, Exkursionen, Publikationen), GEOszene (Würdigungen, Nachrufe).
    Description: journal
    Keywords: ddc:550 ; GMIT
    Language: German
    Type: doc-type:book , publishedVersion
    Format: 112
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  • 3
    Publication Date: 2023-11-23
    Description: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉Spectral induced polarization (SIP) laboratory measurements on water‐saturated rocks show a strong correlation between the electrical polarization strength and the inner surface area of rocks. We investigate the influence of inner surface roughness on the SIP response by simulating the frequency‐dependent complex conductivity of micro‐scale rock models. Starting with smooth grain models, we introduce surface roughness using two different approaches: increasing the surface roughness in a fractal‐like manner, and creating random surface structures, resulting in more natural‐looking surfaces. We find that surface roughness has two distinct effects on the SIP response: (a) a shift in the position and magnitude of the primary relaxation frequency to lower frequencies and lower magnitudes, respectively, and (b) the formation of secondary polarizations above the polarization frequency of the primary polarization. We also compare the relaxation time and normalized chargeability obtained by Debye decomposition and the imaginary conductivity at 1 Hz of our models with mechanistic models and empirical relations. We point out the congruences and offer explanations for the discrepancies between our models and the empirical observations. We conclude that the results of our study are applicable to real rocks and that the SIP method has the potential to detect inner surface roughness. However, the SIP method it not able to discriminate between signals from rough particles and a distribution of smooth particles.〈/p〉
    Description: Plain Language Summary: The spectral induced polarization method measures the electrical conductivity of the subsurface at depths of investigation ranging from a few dm to several 100 m. The potential of the method to detect mineral resources, contamination, microbial activity, etc. makes it a promising tool for today's environmental challenges. However, due to the complexity of the underlying physical and chemical processes the interpretation of SIP measurements often remains qualitative. Mathematical and mechanistic models used to describe the processes are usually simplified with respect to geometry, chemistry, and physical properties. In this study, we use computer simulations to investigate the surfaces of spherical particles (grains). After simulating the SIP response of models with smooth and rough surfaces, we analyze the influence of surface roughness on the SIP response. We find that surface roughness causes distinct changes in the SIP response compared to the smooth grain. However, we also find that this introduces an ambiguity in the interpretation of SIP data.〈/p〉
    Description: Key Points: 〈list list-type="bullet"〉 〈list-item〉 〈p xml:lang="en"〉Inner surface roughness of rocks has substantial impact on spectral induced polarization response〈/p〉〈/list-item〉 〈list-item〉 〈p xml:lang="en"〉Surface roughness shifts the primary polarization peak to lower frequencies〈/p〉〈/list-item〉 〈list-item〉 〈p xml:lang="en"〉Surface roughness causes additional polarizations above the primary peak frequency〈/p〉〈/list-item〉 〈/list〉 〈/p〉
    Description: https://doi.org/10.5281/ZENODO.7049722
    Keywords: ddc:550 ; SIP ; surface ; roughness
    Language: English
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  • 4
    Publication Date: 2023-12-07
    Description: Publishing data with a DOI (Digital Object Identifier) is becoming increasingly popular, and many researchers are being asked by journals to publish the data underlying the research results described in the article. Where does the data come from and how do I cite it correctly? […] This publication is a translation of the FID GEO article in 〈a href="http://doi.org/10.23689/fidgeo-5688"〉GMIT 90.〈/a〉
    Description: research
    Keywords: ddc:550 ; GMIT ; Geowissenschaftliche Mitteilungen
    Language: English
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  • 5
    Publication Date: 2023-12-07
    Description: The ORCID is an open alphanumeric identifier used to uniquely identify researchers.In an increasingly connected scientific landscape, the growing number of published research outputs (data, text, software) and new open publishing models pose major challenges for scientific publication management. The repositories available to FID GEO, GEO-LEOe-docs (SUB Goettingen) and GFZ Data Services (GFZ), have long been working with PIDs such as the Digital Object Identifier (DOI ) and the Open Researcher and Contributor iD (ORCID iD ), and recommend the use of the ORCID. This publication is a translation of the FID GEO article in 〈a href="http://doi.org/10.23689/fidgeo-5832"〉GMIT 87.〈/a〉
    Description: DFG, SUB Göttingen, GFZ Potsdam
    Description: research
    Keywords: ddc:550 ; GMIT
    Language: English
    Type: doc-type:article , publishedVersion
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  • 6
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    ARGE GMIT, Bonn
    Publication Date: 2024-01-04
    Description: Die Ausgabe der Geowissenschaftlichen Mitteilungen vom September 2023 enthält die Themenblöcke: GEOfokus: Dimensionierung und Betrieb von Erdwärmesonden, GEOaktiv (Wirtschaft, Beruf, Forschung und Lehre), GEOlobby (Gesellschaften, Verbände, Institutionen), GEOreport (Geowissenschaftliche Öffentlichkeitsarbeit, Tagungsberichte, Ausstellungen, Exkursionen, Publikationen), GEOszene (Würdigungen, Nachrufe).
    Description: journal
    Keywords: ddc:550 ; GMIT
    Language: German
    Type: doc-type:book , publishedVersion
    Format: 120
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  • 7
    Publication Date: 2023-02-28
    Description: Im Albvorsprung südlich Regensburg liegen zwischen Störungen der mesozoischen Schichttafel schmale Becken. Während deren Bildung setzte sich ein klastischer Sedimentkomplex in den expandierenden Becken ab, der in das obere Untermiozän-untere Mittelmiozän gestellt wird und in konkav aufgebogener Lagerungsform vorliegt. Die Diskordanz an der Basis der überlagernden Sand- und Geröllschichten wird dem Mittelmiozän zugerechnet und zeigt den Abschluß der tektonischen Beckenbildung. Es wird angenommen, dass die Verbiegung des nach 150° tauchenden, älteren Hemauer Sattels ein Spannungsfeld verursachte und damit senkrecht zu dessen Achse orientierte Dehnungsbrüche und ein konjugiertes Scherkluftsystem erzeugte. Dadurch kam es vermutlich zu den extensionalen Beckenbildungen, deren Längsachsen an den Maxima der Kluftrichtungen und Bruchflächen orientiert waren. Dieses System wurde von der in Mitteleuropa heute ~140° streichenden horizontalen Schubspannung (Prinz & Strauss 2018) überlagert. Darüber hinaus können beide von Peterek et al. (1997) über Paläostress-Analysen für den Zeitraum des (beginnenden) Neogens dargestellten Extensionsregimes zur Erklärung der tektonischen Beckenbildungen im hier untersuchten Gebiet beitragen. Die Ergebnisse stellen Grundlagen für Baugrunduntersuchungen im Bereich Regensburg-Süd und Bad Abbach dar.
    Description: research
    Keywords: ddc:550 ; Miozäne Dehnungsbecken ; Tertiär ; Regensburg-Süd ; Bad Abbach
    Language: German
    Type: doc-type:article
    Format: 19
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  • 8
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    ARGE GMIT, Bonn
    Publication Date: 2023-07-04
    Description: Die Ausgabe der Geowissenschaftlichen Mitteilungen vom Juni 2022 enthält die Themenblöcke: GEOfokus:Mariengraben - Am Puls der tiefen Erde, GEOaktiv (Wirtschaft, Beruf, Forschung und Lehre), GEOlobby (Gesellschaften, Verbände, Institutionen), GEOreport (Geowissenschaftliche Öffentlichkeitsarbeit, Tagungsberichte, Ausstellungen, Exkursionen, Publikationen), GEOszene (Würdigungen, Nachrufe).
    Description: DFG, SUB Göttingen
    Description: journal
    Keywords: ddc:550 ; GMIT
    Language: German
    Type: doc-type:book , publishedVersion
    Format: 124
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  • 9
    Publication Date: 2023-07-21
    Description: Oceanic circulation and mass‐field variability play important roles in exciting Earth's wobbles and length‐of‐day changes (ΔΛ), on time scales from days to several years. Modern descriptions of these effects employ oceanic angular momentum (OAM) series from numerical forward models or ocean state estimates, but nothing is known about how ocean reanalyses with sequential data assimilation (DA) would fare in that context. Here, we compute daily OAM series from three 1/4° global ocean reanalyses that are based on the same hydrodynamic core and input data (e.g., altimetry, Argo) but different DA schemes. Comparisons are carried out (a) among the reanalyses, (b) with an established ocean state estimate, and (c) with Earth rotation data, all focusing on the period 2006–2015. The reanalyses generally provide credible OAM estimates across a range of frequencies, although differences in amplitude spectra indicate a sensitivity to the adopted DA scheme. For periods less than 120 days, the reanalysis‐based OAM series explain ∼40%–50% and ∼30%–40% of the atmosphere‐corrected equatorial and axial geodetic excitation, similar to what is achieved with the state estimate. We find mixed performance of the reanalyses in seasonal excitation budgets, with some questionable mean ocean mass changes affecting the annual cycle in ΔΛ. Modeled excitations at interannual frequencies are more uncertain compared to OAM series from the state estimate and show hints of DA artifacts in one case. If users are to choose any of the tested reanalyses for rotation research, our study points to the Ocean Reanalysis System 5 as the most sensible choice.
    Description: Key Points: We evaluate three ocean reanalyses for their skill in explaining Earth rotation variations on different time scales from 2006 to 2015. For periods 〈120 days, reanalyses explain 40%–50% of atmosphere‐reduced polar motion excitation variance, similar to an ocean state estimate. Reanalyses show mixed skill in seasonal excitation budgets and, in one case, hints of data assimilation artifacts at interannual periods.
    Description: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Description: https://resources.marine.copernicus.eu/product-detail/GLOBAL_REANALYSIS_PHY_001_031/INFORMATION
    Description: https://isdc.gfz-potsdam.de/ggfc-oceans/oam/
    Description: https://www.ncei.noaa.gov/access/metadata/landing-page/bin/iso?id=gov.noaa.ngdc.mgg.dem:316
    Description: https://podaac-tools.jpl.nasa.gov/drive/files/GeodeticsGravity/tellus/L3/mascon/RL06/JPL/v02/CRI/netcdf
    Description: https://keof.jpl.nasa.gov/combinations/
    Keywords: ddc:550 ; Earth rotation ; ocean angular momentum ; ocean reanalysis ; data assimilation
    Language: English
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  • 10
    Publication Date: 2023-07-21
    Description: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉Benthic oxygen dynamics and the exchange of oxygen and other solutes across the sediment‐water interface play a key role for the oxygen budget of many limnic and shallow marine systems. The sediment‐water fluxes are largely determined by two factors: sediment biogeochemistry and the thickness of the diffusive boundary layer that is determined by near‐bottom turbulence. Here, we present a fully coupled benthic‐pelagic modeling system that takes these processes and their interaction into account, focusing especially on the modulation of the sediment‐water fluxes by the effects of near‐bottom turbulence and stratification. We discuss the special numerical methods required to guarantee positivity and mass conservation across the sediment‐water interface in the presence of rapid element transformation, and apply this modeling system to a number of idealized scenarios. Our process‐oriented simulations show that near‐bottom turbulence provides a crucial control on the sediment‐water fluxes, the oxygen penetration depth, and the re‐oxidation of reduced compounds diffusing upward from the deeper benthic layers especially on time scales of a few days, characterizing oceanic tides, internal seiching motions in lakes, and mesoscale atmospheric variability. Our results also show that the response of benthic‐pelagic fluxes to rapid changes in the forcing conditions (e.g., storm events) can only be understood with a fully coupled modeling approach.〈/p〉
    Description: Plain Language Summary: Oxygen is one of the most relevant ecosystem parameters in marine systems and in lakes. In shallow systems, the overall oxygen budget is often controlled by the sedimentary oxygen demand, and it is therefore crucial to account for the exchange of oxygen and other solutes between the sediment and the water column. In this, context, a thin (millimeter‐scale) “diffusive sublayer,” located immediately above the sediment surface, is known to play an especially important role as it may form a bottleneck for the solute exchange. As the thickness of this sublayer is controlled by hydrodynamic processes, sediment‐water fluxes are affected by complex feedbacks between physical and biogeochemical processes. Here, we describe a fully coupled numerical modeling system that takes these feedback mechanisms into account, including advanced numerical methods guaranteeing that the total mass of all solutes is conserved (even if these are transformed) and that their concentrations do not become negative. Using a series of idealized examples, it is shown that near‐bottom hydrodynamic processes have an important impact on the sediment‐water fluxes, the depth to which oxygen penetrates into the upper sediment layers, and the re‐oxidation of reduced chemical compounds in the sediments. These feedbacks are particularly important for processes with time scales of a few days, like ocean tides, internal oscillations in lakes, and short‐term atmospheric disturbances (e.g., storm events).〈/p〉
    Description: Key Points: First fully coupled benthic‐pelagic modeling system accounting for the effects of near‐bottom turbulence on sediment‐water solute fluxes. Hydrodynamic effects control benthic biogeochemistry and fluxes especially on time scales of a few days, and during extreme events. New numerical methods that guarantee mass conservation and positivity across the sediment‐water interface.
    Description: Leibniz Association
    Description: German Research Foundation
    Description: Swiss National Science Foundation
    Description: UK Natural Environment Research Council
    Description: Department for Environment Food and Rural Affairs
    Description: https://gotm.net/
    Description: https://github.com/fabm-model
    Description: https://doi.org/10.5281/zenodo.7950383
    Description: https://doi.org/10.5281/zenodo.7950866
    Keywords: ddc:550 ; sediment-water fluxes ; benthic biogeochemistry ; numerical modeling
    Language: English
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  • 11
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    ARGE GMIT, Bonn
    In:  ARGE GMIT
    Publication Date: 2023-03-27
    Description: Die Ausgabe der Geowissenschaftlichen Mitteilungen vom September 2022 enthält die Themenblöcke: GEOfokus: Zwischen Scylla und Charybdis - Die Rolle von Recycling und Primärrohstoffen am Beispiel von Kupfer und Lithium, GEOaktiv (Wirtschaft, Beruf, Forschung und Lehre), GEOlobby (Gesellschaften, Verbände, Institutionen), GEOreport (Geowissenschaftliche Öffentlichkeitsarbeit, Tagungsberichte, Ausstellungen, Exkursionen, Publikationen), GEOszene (Würdigungen, Nachrufe).
    Description: journal
    Keywords: ddc:550 ; GMIT
    Language: German
    Type: doc-type:book , publishedVersion
    Format: 124
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  • 12
    Publication Date: 2023-06-12
    Description: Soils and landscapes are bridges of space and time, as they simultaneously and authentically show essential aspects that were previously separated by time and space (such as cultural and activity-related aspects from past and present) to the trained observer - albeit only in excerpts. Therefore, this article presents a series of impact indicators for soil changes, starting with extreme (anthropogenic) interventions and ending with equally extreme ("natural") events. An essential difference to specifically planning-relevant or human ecological concepts, which, for example, specify land use/load categories, is that the following impact indicators perceive soils as a phenomenon in themselves and do not define them through attributed functions. Particular attention is focused on their changeability and vital development potential, as well as on their property as a sphere of penetration of living and material things, with emphasis on the noetic effect. The intervention or event spaces on the earth's surface can be differentiated quantitatively through the type, strength, and duration of the phenomena. The intensity of all processes can be described by amplitude (the strength of the interventions/events) and frequency (the repetition rate of the interventions/events) and can be specifically identified and quantified by, for example, material inputs or outputs per unit of time. For the first time, there would be a system for measuring the ecological quality of anthropogenic land use, which could serve as an "alert system for the external technological culture," and could help us become aware of our "inner" culture.
    Description: research
    Keywords: ddc:550 ; Boden ; Landschaft ; Bodendegeneration ; Deutschland ; Anthropogene Bodenveränderung
    Language: German
    Type: doc-type:article
    Format: 9
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  • 13
    Publication Date: 2023-07-18
    Description: Methane seeps are typified by the formation of authigenic carbonates, many of which exhibit corrosion surfaces and secondary porosity believed to be caused by microbial carbonate dissolution. Aerobic methane oxidation and sulfur oxidation are two processes capable of inducing carbonate corrosion at methane seeps. Although the potential of aerobic methanotrophy to dissolve carbonate was confirmed in laboratory experiments, this process has not been studied in the environment to date. Here, we report on a carbonate corrosion experiment carried out in the REGAB Pockmark, Gabon‐Congo‐Angola passive margin, in which marble cubes were deployed for 2.5 years at two sites (CAB‐B and CAB‐C) with apparent active methane seepage and one site (CAB‐D) without methane seepage. Marble cubes exposed to active seepage (experiment CAB‐C) were found to be affected by a new type of microbioerosion. Based on 16〈italic toggle="no"〉S r〈/italic〉RNA gene analysis, the biofilms adhering to the bioeroded marble mostly consisted of aerobic methanotrophic bacteria, predominantly belonging to the uncultured Hyd24‐01 clade. The presence of abundant 〈sup〉13〈/sup〉C‐depleted lipid biomarkers including fatty acids (〈italic toggle="no"〉n〈/italic〉‐C〈sub〉16:1ω8c〈/sub〉, 〈italic toggle="no"〉n〈/italic〉‐C〈sub〉18:1ω8c〈/sub〉, 〈italic toggle="no"〉n〈/italic〉‐C〈sub〉16:1ω5t〈/sub〉), various 4‐mono‐ and 4,4‐dimethyl sterols, and diplopterol agrees with the dominance of aerobic methanotrophs in the CAB‐C biofilms. Among the lipids of aerobic methanotrophs, the uncommon 4α‐methylcholest‐8(14)‐en‐3β,25‐diol is interpreted to be a specific biomarker for the Hyd24‐01 clade. The combination of textural, genetic, and organic geochemical evidence suggests that aerobic methanotrophs are the main drivers of carbonate dissolution observed in the CAB‐C experiment at the REGAB pockmark.〈/p〉
    Description: Deutscher Akademischer Austauschdienst http://dx.doi.org/10.13039/501100001655
    Keywords: ddc:550 ; carbonate ; corrosion ; lipid biomarker ; methane seep ; methanotrophic bacteria ; microbioerosion
    Language: English
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  • 14
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    ARGE GMIT, Bonn
    Publication Date: 2024-04-05
    Description: Die Ausgabe der Geowissenschaftlichen Mitteilungen vom März 2024 enthält die Themenblöcke: GEOfokus: Geoparks in Deutschland – Modellregionen nachhaltiger Entwicklung, GEOaktiv (Wirtschaft, Beruf, Forschung und Lehre), GEOlobby (Gesellschaften, Verbände, Institutionen), GEOreport (Geowissenschaftliche Öffentlichkeitsarbeit, Tagungsberichte, Ausstellungen, Exkursionen, Publikationen), GEOszene (Würdigungen, Nachrufe).
    Description: journal
    Keywords: ddc:550 ; GMIT
    Language: German
    Type: doc-type:book , publishedVersion
    Format: 112
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  • 15
    Publication Date: 2024-04-09
    Description: thesis
    Keywords: ddc:550 ; GEOMIN ; Deutsche Geologische Gesellschaft – Geologische Vereinigung ; Deutsche Mineralogische Gesellschaft
    Language: English
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  • 16
    Publication Date: 2024-05-08
    Description: [...] ROR stands for Research Organization Registry and is an open registry for research organizations. The registry is developed and operated as a joint initiative of the California Digital Library, Crossref and DataCite. ROR already references more than 103,000 organizations, ranging from universities and extramural research institutions to government agencies, research funders and government departments. [...] This publication is a translation of the FID GEO article in 〈a href="http://doi.org/10.23689/fidgeo-5750"〉GMIT 91.〈/a〉
    Description: research
    Keywords: ddc:550 ; GMIT ; Geowissenschaftliche Mitteilungen
    Language: English
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  • 17
    Publication Date: 2023-09-13
    Description: The distance to failure of the upper crustal rock in the prevalent stress field is of importance to better understand fault reactivation by natural and induced processes as well as to plan and manage georeservoirs. In particular, the contemporary stress state is one of the key ingredients for this assessment. To provide a continuous description of the 3D absolute stress state geomechanical‐numerical models are used. However, stress magnitude data for model calibration are sparse and incomplete and thus, the resulting model uncertainties are large. In order to reduce the uncertainties, we incorporate additional constraints on stress magnitudes to check the plausibility of different data‐based stress states. We use formation integrity tests, borehole breakouts, drilling induced fractures, and observations of seismicity and distinct seismological quiescence. This information is weighted according to its confidence and the agreement with the different modeled stress states is assessed. The information is introduced to a Bayesian approach to estimate weights of the modeled stress states and thereby identify their plausibility. A case study in southern Germany shows the ability of the approach to identify from a wide range of stress states a small number of plausible ones and reject implausible stress states. This significantly reduces the number of stress states and thus lowers the model uncertainties.
    Description: Plain Language Summary: The upper crust of the Earth (upper few kilometers) is subject to a kind of pressure, referred to as stress. When the stress becomes larger than the strength of the rock, the rock breaks. Sometimes this can be measured or even felt as a seismic event. It happens naturally but may also happen due to human activity. To prevent such induced seismic event, it is important to know the stress state. But there is only few information on the magnitude of the stress so we need computer models to predict the stress state. These models are often not very precise since there is only few information on the stress magnitudes and in addition they are often contradicting. We use all stress magnitude information individually to model various stress states. Then we look at other information that is related to the stress state but does not provide stress magnitude information on its own. We compare this information with the modeled stress states to find out whether a stress state agrees with the additional information or not. This allows us to identify a few realistic stress state models out of a wide range of possible ones. This reduces the uncertainties of the stress predictions.
    Description: Key Points: Bayesian approach to uncertainty quantification and reduction of 3D geomechanical‐numerical models of the undisturbed stress state. Additional constraints on the stress state by formation integrity tests, borehole breakouts, and drilling induced tensile fractures. Constraints on the differential stress by observation of seismicity or distinct seismological quiescence.
    Description: Bundesministerium für Bildung, Wissenschaft und Forschung http://dx.doi.org/10.13039/501100013699
    Description: Helmholtz Association http://dx.doi.org/10.13039/501100009318
    Description: Helmholtz Centre Potsdam ‐ Deutsches GeoForschungsZentrum GFZ
    Description: RI Fabrice Cotton
    Description: Federal Company for radioactive waste disposal
    Description: https://github.com/MorZieg/FAST_Calibration
    Keywords: ddc:550 ; geomechanics ; uncertainties ; stress state ; modeling ; Bayes
    Language: English
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  • 18
    Publication Date: 2023-01-14
    Description: Spaceborne impact ionization mass spectrometers, such as the Cosmic Dust Analyzer on board the past Cassini spacecraft or the SUrface Dust Analyzer being built for NASA's upcoming Europa Clipper mission, are of crucial importance for the exploration of icy moons in the Solar System, such as Saturn's moon Enceladus or Jupiter's moon Europa. For the interpretation of data produced by these instruments, analogue experiments on Earth are essential. To date, thousands of laboratory mass spectra have been recorded with an analogue experiment for impact ionization mass spectrometers. Simulation of mass spectra of ice grains in space is achieved by a Laser Induced Liquid Beam Ion Desorption (LILBID) approach. The desorbed cations or anions are analyzed in a time‐of‐flight mass spectrometer. The amount of unstructured raw data is increasingly challenging to sort, process, interpret and compare with data from space. Thus far this has been achieved manually for individual mass spectra because no database containing the recorded reference spectra was available. Here we describe the development of a comprehensive, extendable database containing cation and anion mass spectra from the laboratory LILBID facility. The database is based on a Relational Database Management System with a web server interface and enables filtering of the laboratory data using a wide range of parameters. The mass spectra can be compared not only with data from past and future space missions but also mass spectral data generated by other, terrestrial, techniques. The validated and approved subset of the database is available for general public (https://lilbid-db.planet.fu-berlin.de).
    Description: Plain Language Summary: Thousands of laboratory mass spectra, each with an individual set of experimental parameters, have been recorded so far using a facility situated at Freie Universität Berlin, Germany. The mass spectra help analyze and interpret data returned from spacecraft in the vicinity of icy moons in the Solar System. The unstructured laboratory data is increasingly challenging to sort and compare to the data from space. We developed an extendable database containing the laboratory data. The database is available for general public and allows filtering the stored data for a wide range of experimental parameters and, in turn, significantly improves analysis of data not only from past space missions but also future missions in particular.
    Description: Key Points: We describe the development of a comprehensive spectral database containing laboratory analogue data for spaceborne mass spectrometers. The database is based on a Relational Database Management System with a web interface and accessible for community use. Filtering the laboratory data using a wide range of experimental parameters allows a straightforward analysis of returned flight data.
    Description: EC, Horizon 2020 Framework Programme (H2020) http://dx.doi.org/10.13039/100010661
    Description: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Description: https://doi.org/10.5281/zenodo.6863855
    Description: https://sbnarchive.psi.edu/pds3/cassini/cda/COCDA_0007.tar.gz
    Keywords: ddc:550 ; mass spectral database ; analogue experiments ; ice grains ; ocean worlds ; SUDA ; ENIA ; LILBID ; TOF‐MS
    Language: English
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  • 19
    Publication Date: 2023-03-15
    Description: poster
    Keywords: ddc:550 ; InSAR
    Language: English
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  • 20
    Publication Date: 2023-08-29
    Description: conference
    Keywords: ddc:550 ; GEOMIN ; Deutsche Geologische Gesellschaft – Geologische Vereinigung ; Deutsche Mineralogische Gesellschaft ; Clathrate hydrate
    Language: English
    Type: doc-type:book , publishedVersion
    Format: 440
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  • 21
    Publication Date: 2022-12-08
    Description: Während der Corona-Pandemie schrieb der Schüler Pascal Schmitt mit Unterstützung des Vereins Wiechert'sche Erdbebenwarte Göttingen e.V.  im "Homeschooling" eine Facharbeit über die Auswertung seismischer Daten. Darin werden einige Daten eines Nah- und eines Fernbebens analysiert, die in Göttingen an der modernen Station GTTG (STS-2-Seismometer) und der historischen Station GTT (Wiechert-Seismographen) registriert wurden - nah und fern, neu und alt werden miteinander verglichen.
    Description: DFG, SUB Göttingen
    Description: research
    Keywords: ddc:551.22 ; ddc:550 ; GTT ; GTTG ; STS-2-Seismometer ; Wiechert-Seismographen ; Nahbeben ; Vergleiche
    Language: German
    Type: doc-type:article
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  • 22
    Publication Date: 2022-12-08
    Description: Aus Anlass des 100. Jahrestages der Gründung der Deutschen Geophysikalischen Gesellschaft im Jahre 1922 in Leipzig erschien 2019 im Verlag Edition am Gutenbergplatz Leipzig das Taschenbuch „Wiechert, Mintrop & Co. – Die 24 Gründungsväter der Deutschen Geophysikalischen Gesellschaft“ von Franz Jacobs und Michael Börngen (s. gleichlautenden Archivbeitrag in DGG-Mitteilungen, 1/2019: 36–37 sowie das anbei dargestellte Titelblatt des Buches). Die damalige Präsidentin und heutige Vize-Präsidentin der DGG, Heidrun Kopp, hat mit einem Geleitwort beigetragen. Das Buch kann über den Buchhandel unter ISBN 978-3-95922-107-8 bestellt werden. Der folgende Artikel erinnert an die Meteorologin Luise Lammert, Schriftführerin der Versammlung, auf der der Gründungsbeschluss gefasst wurde.
    Description: DFG, SUB Göttingen
    Description: research
    Keywords: ddc:550 ; Luise Charlotte Lammert
    Language: German
    Type: doc-type:article
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  • 23
    Publication Date: 2022-12-09
    Description: Leben und Werk des deutschen Geophysikers und Meteorologen Friedrich Bidlingmaier. In den Jahren 1901-03 nahm er als Physiker an der deutschen Südpolexpedition unter E. von Drygalski teil, dessen Ergebnisse zur Erforschung des Erdmagnetismus beitrugen. Er erfand den Doppelkompass zur Messung der horizontalen geomagnetischen Intensität. Cape Bidlingmaier an der Nordküste von Heard Island im südlichen Indischen Ozean trägt seinen Namen.
    Description: research
    Keywords: ddc:550 ; Geomagnetismus ; Observatorium
    Language: German
    Type: doc-type:article
    Format: 5
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  • 24
    Publication Date: 2023-01-17
    Description: It is generally agreed that the resolution of a regular quadrilateral mesh is the side length of quadrilateral cells. There is less agreement on the resolution of triangular meshes, exacerbated by the fact that the numbers of edges or cells on triangular meshes are approximately three or two times larger than that of vertices. However, the geometrical resolution of triangular meshes, that is, maximum wavenumbers or smallest wavelengths that can be represented on such meshes, is a well defined quantity, known from solid state physics. These wavenumbers are related to a smallest common mesh cell (primitive unit cell), and the set of mesh translations that map it into itself. They do not depend on whether discrete degrees of freedom are placed on vertices, cells or edges. For equilateral triangles the smallest wavelength equals twice the triangle height. Resolutions of quadrilateral and triangular meshes approximately agree if they have the same numbers of vertices.
    Description: Plain Language Summary: Some models used in climate studies are formulated on triangular computational meshes. We discuss how to determine the smallest scales that are resolved on such meshes. They are referred to as a mesh resolution. The notion of mesh resolution is commonly used to relate climate model results simulated on different meshes.
    Description: Key Points: Geometrical resolution of an equilateral triangular mesh is defined by the height of its triangles. Quadrilateral and triangular meshes with the same number of vertices have approximately the same resolution.
    Description: Collaborative Research Centre
    Description: German Research Foundation
    Keywords: ddc:550 ; triangular meshes ; resolved wavenumbers
    Language: English
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  • 25
    facet.materialart.
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    ARGE GMIT, Bonn
    Publication Date: 2023-01-09
    Description: Die Ausgabe der Geowissenschaftlichen Mitteilungen vom September 2022 enthält die Themenblöcke: GEOfokus: Klimagerechte Geowissenschaften Glaubwürdigkeit und Vorbild, GEOaktiv (Wirtschaft, Beruf, Forschung und Lehre), GEOlobby (Gesellschaften, Verbände, Institutionen), GEOreport (Geowissenschaftliche Öffentlichkeitsarbeit, Tagungsberichte, Ausstellungen, Exkursionen, Publikationen), GEOszene (Würdigungen, Nachrufe).
    Description: DFG, SUB Göttingen
    Description: journal
    Keywords: ddc:550 ; GMIT
    Language: German
    Type: doc-type:book , publishedVersion
    Format: 132
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  • 26
    Publication Date: 2022-06-26
    Description: Efficient compositional models are required to simulate underground gas storage in porous formations where, for example, gas quality (such as purity) and loss of gas due to dissolution are of interest. We first extend the concept of vertical equilibrium (VE) to compositional flow, and derive a compositional VE model by vertical integration. Second, we present a hybrid model that couples the efficient compositional VE model to a compositional full‐dimensional model. Subdomains, where the compositional VE model is valid, are identified during simulation based on a VE criterion that compares the vertical profiles of relative permeability at equilibrium to the ones simulated by the full‐dimensional model. We demonstrate the applicability of the hybrid model by simulating hydrogen storage in a radially symmetric, heterogeneous porous aquifer. The hybrid model shows excellent adaptivity over space and time for different permeability values in the heterogeneous region, and compares well to the full‐dimensional model while being computationally efficient, resulting in a runtime of roughly one‐third of the full‐dimensional model. Based on the results, we assume that for larger simulation scales, the efficiency of this new model will increase even more.
    Description: Key Points: A compositional vertical equilibrium model is coupled to its full‐dimensional counterpart. A criterion is developed to adaptively identify and assign regions where the vertical equilibrium model is applicable during simulation. A test case of hydrogen storage in a heterogeneous porous aquifer demonstrates efficiency and accuracy of the hybrid model.
    Description: Deutsche Forschungsgemeinschaft (DFG) http://dx.doi.org/10.13039/501100001659
    Description: https://git.iws.uni-stuttgart.de/dumux-pub/Becker2021b.git
    Keywords: ddc:551.49 ; ddc:550
    Language: English
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  • 27
    Publication Date: 2022-06-22
    Description: Basal melting of marine‐terminating glaciers, through its impact on the forces that control the flow of the glaciers, is one of the major factors determining sea level rise in a world of global warming. Detailed quantitative understanding of dynamic and thermodynamic processes in melt‐water plumes underneath the ice‐ocean interface is essential for calculating the subglacial melt rate. The aim of this study is therefore to develop a numerical model of high spatial and process resolution to consistently reproduce the transports of heat and salt from the ambient water across the plume into the glacial ice. Based on boundary layer relations for momentum and tracers, stationary analytical solutions for the vertical structure of subglacial non‐rotational plumes are derived, including entrainment at the plume base. These solutions are used to develop and test convergent numerical formulations for the momentum and tracer fluxes across the ice‐ocean interface. After implementation of these formulations into a water‐column model coupled to a second‐moment turbulence closure model, simulations of a transient rotational subglacial plume are performed. The simulated entrainment rate of ambient water entering the plume at its base is compared to existing entrainment parameterizations based on bulk properties of the plume. A sensitivity study with variations of interfacial slope, interfacial roughness and ambient water temperature reveals substantial performance differences between these bulk formulations. An existing entrainment parameterization based on the Froude number and the Ekman number proves to have the highest predictive skill. Recalibration to subglacial plumes using a variable drag coefficient further improves its performance.
    Description: Plain Language Summary: In a world of global warming, the melting of glaciers terminating as floating ice tongues into the oceans of Arctic and Antarctic regions allows those glaciers to flow faster and hence to make a considerable contribution to global mean sea‐level rise. Underneath the ice‐ocean interface, turbulent currents of the order of 10 m thickness (so‐called plumes) develop that transport the melt water from the grounding line where the glacier enters the ocean toward the calving front that marks the seaward end of the glacier. At its base, ambient relatively warm and salty ocean water is mixed into the plumes and is vertically transported toward the ice‐ocean interface, where the melting is increased due to the additional heat supply. Understanding these processes is essential for their incorporation into computer models for the prediction of such melt processes. In this study, an accurate simulation model for the water column is constructed that is able to consistently reproduce these processes. The algorithms developed here are proven to provide reliable results also for models with only a few grid points across the plume and can therefore be implemented into climate models with surface‐following coordinates to more accurately simulate future scenarios of sea level rise.
    Description: Key Points: A vertically resolving model with second‐moment turbulence closure has been constructed for subglacial plumes. Convergent numerical formulations for the ocean‐to‐ice fluxes of momentum, freshwater and heat have been derived from an analytical model. Model results are consistent with bulk parameterizations for the entrainment of ambient water.
    Description: Bundesministerium für Bildung und Forschung (BMBF) http://dx.doi.org/10.13039/501100002347
    Description: https://doi.org/10.5281/zenodo.6203838
    Keywords: ddc:550
    Language: English
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  • 28
    facet.materialart.
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    ARGE GMIT, Bonn
    Publication Date: 2022-09-14
    Description: Die Ausgabe der Geowissenschaftlichen Mitteilungen vom September 2022 enthält die Themenblöcke: GEOfokus: Rohstoffe für die deutsche Energiewende, GEOaktiv (Wirtschaft, Beruf, Forschung und Lehre), GEOlobby (Gesellschaften, Verbände, Institutionen), GEOreport (Geowissenschaftliche Öffentlichkeitsarbeit, Tagungsberichte, Ausstellungen, Exkursionen, Publikationen), GEOszene (Würdigungen, Nachrufe).
    Description: DFG, SUB Göttingen
    Description: journal
    Keywords: ddc:550
    Language: German
    Type: doc-type:book , publishedVersion
    Format: 100
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  • 29
    Publication Date: 2022-10-17
    Description: Hydrogen is a promising alternative to carbon based energy carriers and may be stored in large quantities in subsurface storage deposits. This work assesses the impact of static (density and phase equilibria) and dynamic (viscosity and diffusion coefficients) properties on the pressure field during the injection and extraction of hydrogen in the porous subsurface. In a first step, we derive transport properties for water, hydrogen and their mixture using the Perturbed‐Chain Statistical Associating Fluid Theory equation of state in combination with an entropy scaling approach and compare model predictions to alternative models from the literature. Our model compares excellently to experimental transport coefficients and models from literature with a higher number of adjustable parameters, such as GERG2008, and shows a clear improvement over empirical correlations for transport coefficients of hydrogen. In a second step, we determine the effect of further model reduction by comparing our against a much simpler model applying empirical transport coefficients from the literature. For this purpose, hydrogen is periodically injected into and extracted out of a dome‐shaped porous aquifer under a caprock. Our results show that density and viscosity of hydrogen have the highest impact on the pressure field, and that a thermodynamic model like the new model presented here is essential for modeling the storage aquifer, while keeping the number of coefficients at a minimum. In diffusion‐dominated settings such as the diffusion of hydrogen through the caprock, our developed diffusion coefficients show a much improved dependence on temperature and pressure, leading to a more accurate approximation of the diffusive fluxes.
    Description: Key Points: We model the phase behavior of pure hydrogen and the binary hydrogen‐water mixture using the Perturbed‐Chain Statistical Associating Fluid Theory equation of state. New entropy scaling relations for the transport properties of hydrogen and water and diffusion coefficients of their mixture are derived. The impact of the newly derived fluid properties is analyzed for a scenario of hydrogen storage in a porous aquifer.
    Description: Deutsche Forschungsgemeinschaft (DFG) http://dx.doi.org/10.13039/501100001659
    Description: https://git.iws.uni-stuttgart.de/dumux-pub/sauerborn2020a
    Keywords: ddc:550
    Language: English
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  • 30
    Publication Date: 2022-08-05
    Description: Vlasov solvers that operate on a phase‐space grid are highly accurate but also numerically demanding. Coarse velocity space resolutions, which are largely unproblematic in particle‐in‐cell (PIC) simulations, can lead to numerical heating or oscillations in continuum Vlasov methods. To address this issue, we present a new dual Vlasov solver which is based on an established positivity preserving advection scheme for the update of the distribution function and an energy conserving partial differential equation solver for the kinetic update of mean velocity and temperature. The solvers work together via moment fitting during which the maximum entropy part of the distribution function is replaced by the solution from the partial differential equation solver. This numerical scheme makes continuum Vlasov methods competitive with PIC methods concerning computational cost and enables us to model large scale reconnection in Earth's magnetosphere with a fully kinetic continuum method. The simulation results agree well with measurements by the MMS spacecraft.
    Description: Key Points: A moment fitting continuum Vlasov solver is presented that preserves positivity of the distribution function and conserves total energy. The method behaves well at low velocity space resolutions, making it competitive with PIC methods concerning computational cost. There is good agreement of the simulations with measurements of magnetic reconnection by the MMS spacecraft.
    Description: Helmholtz Association (亥姆霍兹联合会致力) http://dx.doi.org/10.13039/501100009318
    Description: https://vlasov.tp1.ruhr-uni-bochum.de/data/paper-JGR-2021
    Keywords: ddc:550 ; ddc:538.7
    Language: English
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  • 31
    Publication Date: 2022-10-05
    Description: In recent years, Spatial Markov Models have gained popularity in simulating solute transport in heterogeneous formations. They describe the transition times of particles between equidistant observation planes by statistical distributions, assuming correlation of the transit times of individual particles between subsequent steps. By this, the approach naturally captures preasymptotic solute dispersion. In this study, we analyze Spatial Markov Models assuming bivariate log‐normal distributions of the particle slowness (i.e., the inverse velocity) in subsequent transitions. The model is fully parameterized by the mean Eulerian velocity, the variance of the log‐slowness, and the correlation coefficient of log‐slowness in subsequent steps. We derive closed‐form expressions for distance‐dependent ensemble dispersion, which is defined in terms of the second‐central moments of the solute breakthrough curves. We relate the coefficients to the properties of the underlying log‐hydraulic conductivity field assuming second‐order stationarity. The results are consistent with linear stochastic theory in the limit of small log‐conductivity variances, while the approach naturally extends to high‐variance cases. We demonstrate the validity of the approach by comparison to three‐dimensional particle‐tracking simulations of advective transport in heterogeneous media with isotropic, exponential correlation structure for log‐conductivity variances up to five. This study contributes to relating solute dispersion to metrics of the porous‐medium structure in cases of strong heterogeneity.
    Description: Key Points: We derive closed‐form expressions of ensemble dispersion in the spatial‐Markov framework of solute transport. The expressions are consistent with linear theory in the limit of small log‐conductivity variances, but extend to high‐variance cases. Comparison to particle‐tracking simulations of advective transport in 3‐D heterogeneous domains show excellent agreement.
    Description: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Description: https://doi.org/10.5281/zenodo.6554308
    Description: https://www.hsl.rl.ac.uk/catalogue/hsl_mi20.html
    Keywords: ddc:550
    Language: English
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  • 32
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    ARGE GMIT, Bonn
    Publication Date: 2022-06-27
    Description: Die Ausgabe der Geowissenschaftlichen Mitteilungen vom März 2022 enthält die Themenblöcke: GEOfokus: (Archäometrie in Deutschland), GEOaktiv (Wirtschaft, Beruf, Forschung und Lehre), GEOlobby (Gesellschaften, Verbände, Institutionen), GEOreport (Geowissenschaftliche Öffentlichkeitsarbeit, Tagungsberichte, Ausstellungen, Exkursionen, Publikationen), GEOszene (Würdigungen, Nachrufe).
    Description: DFG, SUB Göttingen
    Description: journal
    Keywords: ddc:550
    Language: German
    Type: doc-type:book , publishedVersion
    Format: 104
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  • 33
    facet.materialart.
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    ARGE GMIT, Bonn
    Publication Date: 2022-06-27
    Description: Die Ausgabe der Geowissenschaftlichen Mitteilungen vom März 2022 enthält die Themenblöcke: GEOfokus: Die marine Seismik der Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), GEOaktiv (Wirtschaft, Beruf, Forschung und Lehre), GEOlobby (Gesellschaften, Verbände, Institutionen), GEOreport (Geowissenschaftliche Öffentlichkeitsarbeit, Tagungsberichte, Ausstellungen, Exkursionen, Publikationen), GEOszene (Würdigungen, Nachrufe).
    Description: DFG, SUB Göttingen
    Description: journal
    Keywords: ddc:550
    Language: German
    Type: doc-type:book , publishedVersion
    Format: 116
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  • 34
    Publication Date: 2022-06-16
    Description: Atmospheric delay corrections for satellite altimetry measurements are essential for deriving highly accurate sea surface heights and reliable global mean sea level (GMSL) trend estimates. A commonly used method to correct for ionospheric path delays are the usage of GNSS‐based Global Ionospheric Maps (GIM). The different orbit heights of GNSS and altimeter satellites require an adaption of GIM corrections to account for free electrons in the Earth plasmasphere. This study shows that the widely used scaling approach based on the International Reference Ionosphere (IRI) is not able to accurately scale the GIM models. The impact of neglecting the plasmaspheric part of the atmosphere strongly correlates with the solar activity of about 11 years. This manifests itself as trend errors in global GMSL. For the Jason period (2002–2021) a trend error of 0.17 mm/year can be shown, which is even larger for smaller periods (e.g., 1.0 mm/year for Jason‐1 lifetime). The application of an additional constant scaling factor of 0.886 can reduce the trend differences to below 0.05 mm/year.
    Description: Plain Language Summary: Global mean sea level (GMSL) rise is an important indicator for climate change. To precisely measure this quantity that is only in the order of about 3 mm/year, satellite altimeters are used. Their observations have to be corrected for influences in the Earth atmosphere. This study shows deficiencies in one commonly used correction data set. These corrections, based on observations from the Global Navigation Satellite Systems (GNSS) are not accounting for the higher part of the atmosphere, the plasmasphere. Neglecting this influence derives systematic errors with a 11 years cycle that impacts the estimation of GMSL by up to 1 mm/year, depending on the period under investigation. It is recommended to apply an additional scaling of the available corrections in order to reduce the trend error to below 0.05 mm/year.
    Description: Key Points: Global Ionospheric Map corrections in altimetry Sensor Geophysical Data Records are not fully scaled to account for plasmaspheric electron content. Neglecting the plasmaspheric effect leads to trends of up to 1 mm/year in Global mean sea level estimates. The additional application of a scale factor improves the consistency in trend with respect to dual‐frequency satellite altimetry data.
    Description: https://podaac.jpl.nasa.gov/
    Description: https://www.aviso.altimetry.fr/
    Description: https://openadb.dgfi.tum.de/en/products/vertical-total-electron-content/
    Keywords: ddc:538.767 ; ddc:550
    Language: English
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  • 35
    Publication Date: 2022-07-26
    Description: Im Steinbruch der Firma Balz (Pappenheim) wurde ein Intervall von 18 m Mächtigkeit im Bereich der Unteren Mergelplatte und der Oberen Mergelplatte (Grenzbereich Malm Delta 1-3) der Treuchtlingen Formation untersucht. Die Schichtfolge (16 Bänke; Schichten) kann über mehrere 10-er Kilometer in der Südlichen Frankenalb korreliert werden. Die Bänke sind durch deutliche »Hauptfugen« voneinander getrennt und zeigen oft auch schwach ausgebildete Bank-interne »Nebenfugen«. Die mikrofazielle Analyse wurde anhand von 22 Proben mittels petrographischer Dünnschliffe und röntgenographischer-Analysen zur Ermittlung der tonmineralogischen Zusammensetzung der Nichtkarbonate durchgeführt. Die Bänke bauen sich aus Horizonten verschiedener Partikelkalke (Mikrofazies-Typen) mit charakteristischen Karbonatgehalten auf. Matrix-reiche Wackestones (92-96% Karbonatgehalt), Partikel-reiche Packstones und mikrobielle Bindstones (94-98%) wechseln sich in vertikaler Folge ab. Eingeschaltete Mergel sind entsprechend ihres Anteils an Nichtkarbonaten unterschiedlich ausgebildet. Die Partikelkalke zeigen wechselnde Matrix-Gehalte und Mächtigkeiten von Zentimetern bis Dezimetern innerhalb der Bänke. Sie spiegeln einen stetigen Wechsel der Wasserenergie von gering bis mäßig im Ablagerungsraum wider. Dünne Schalen planktonischer Bivalven (Filamente) wurden zu Zeiten erhöhter Wasserenergie aus entfernten, südlichen Meeresbereichen eingeschwemmt. Mikrobielle Lagen deuten auf eine Fixierung von vorher abgelagerten Sedimenten. Mikrobielle Aktivität führte zu dünnen, mikrobiellen Sedimentlagen, zu rundlichen Onkoiden mit mikritischen Kernen und zur Bildung von länglichen Filament-Onkoiden mit dünnen, langen Filamenten als Kern. Kleine domförmige mikrobielle »Stromatolithe«, Zusammenwachen von Tubiphyten und Serpuliden in kleinen Clustern stellen kleine riffogene Strukturen dar, die lokal am Meeresbodens wachsen konnten, der nur ein geringes Relief von Zentimeter bis Dezimeter Höhe aufgewiesen hat. Röntgenographisch, tonmineralogische Untersuchen zeigen vier Zonen unterschiedlicher Zusammensetzung der Tonmineral-Vergesellschaftung. Eine basale Mica-Chlorit-Zone wird von einer Kaolinit-Mica-Montmorillonit-Zone überlagert, die an der Unteren Mergelplatte endet. Der Bereich zwischen der Unteren und der Oberen Mergelplatte (Bank 19 bis Bank 25) weist in der liegenden Hälfte eine Mica-Mixed-Layer-Montmorillonit-Zone mit Spuren von Chlorit und eine Mica-Montmorillonit-Zone im oberen Teil auf. Zusammenhänge zwischen dem Vorkommen von Onkoiden und Filament-Onkoiden sowie den Tonmineral-Assoziationen deuten auf spezifische klimatologische Bedingungen hin. Die Entwicklung eines tropisch humiden zu einem tropischen, semi-ariden Klima mit entsprechendem Verwitterungspotential kristalliner Gesteine des nahen Böhmischen Massivs und Bildungsbedingungen der Tonmineral-Assoziationen im Untersuchungsbereich ist wahrscheinlich
    Description: research
    Keywords: ddc:550
    Language: German
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  • 36
    Publication Date: 2022-07-26
    Description: Die verschiedenen architektonischen Baustile in einer Stadt geben der Nachwelt jeweils Zeugnis von der kulturellen und politischen Entwicklung. Dabei spielen die Baumaterialien vom historischen Naturstein bis hin zu den heute modernen technologischen Materialien (Kunststein, Glasbausteine, Beton, Metall etc.) eine wesentliche Rolle. Viele Jahrhunderte lang stand nur eine sehr begrenzte Palette an Naturwerksteinen zur Verfügung und es wurden zunächst sogenannte „Weichgesteine“ (Sandsteine, Kalkstein) genutzt, die leicht abzubauen und zu verarbeiten waren und die aus nahe gelegenen Abbaugebieten (»Steinbruch vor der Haustür«) stammten, oder auf Flüssen antransportiert werden konnten. Deshalb sind ältere Ortschaften und Städte durch eine lokalspezifische Gesteinsmonotonie gekennzeichnet, was sich in Erlangen in der Verwendung des in der Stadt und in der nahen Umgebung anstehenden Burgsandsteins widerspiegelt. Mitte des 19. Jahrhunderts traten für den technischen Aufschwung in der Steinindustrie entscheidende Veränderungen ein. Aufgrund der verbesserten maschinellen Bearbeitung kamen auch hier nun vermehrt Hartgesteine (Granit,Gabbro, Basalt) zur Verwendung. Durch neue Transportmöglichkeiten (Kanäle, Straße, Schiene) wurde auch die Einfuhr »exotischer Fremdgesteine« aus weitentfernten Abbaugebieten möglich. Seit der zweiten Hälfte des 19. Jahrhunderts kamen Kunststeine hinzu, mit denen natürliche Gesteine häufig perfekt imitiert werden können. Besondere politische Ereignisse, wie z. B. der deutsch französische Krieg (1870-1871) und damit zusammenhängend die Lieferungen von Fremdgesteinen nach Deutschland als Reparationsleistungen (Savonnières Kalkstein, Napoléon Kalkstein) dokumentieren noch heute markante Einschnitte in der Palette der verwendeten Naturwerksteine. In einem relativ engen Zeitfenster von der Hochzeit der Industrialisierung und auch der Deutschen Steinindustrie bis zu Beginn des ersten Weltkrieges (1900-1914) können diese vielschichtigen Einflüsse anhand von vier, in diesem Zeittraum errichteten Bauwerken in Erlangen exemplarisch aufgezeigt werden. Dabei geben auch die jeweiligen Zeitspannen von der Planung bis zur Fertigstellung und Einweihung der Gebäude Hinweise auf die politische und bautechnische Situation. Das Christian-Ernst-Gymnasium wurde aus der Prinz-Ludwig-Schule vom ersten Spatenstich im November 1901 bis zur Einweihung im November 1902 in nur einem Jahr fertig gestellt. Das Marie-Therese-Gymnasium, welches als neues Schulhaus in der Schillerstraße aus der »Städtischen höheren Töchterschule« hervorgegangen ist, wurde 1909 eingeweiht und erst 1965 offiziell als städtisches Marie-Therese-Gymnasium benannt. Die Universitätsbibliothek wurde 1910 geplant und nach der Grundsteinlegung 1911 bereits nach 2 Jahren Bauzeit im November 1913 eröffnet. Dabei hat der Termin des 170. Geburtstages der Friedrich-Alexander-Universität am 4. November 1913 sicher für entsprechenden Zeitdruck gesorgt und die Bauarbeiten beschleunigt. Der Bau des Instituts für Angewandten Chemie, der wahrscheinlich auch zur Unterstützung der Forschung an kriegswichtigen Materialen schnell errichtet werden musste, wurde nach kurzer Planung 1914 begonnen. Doch führten dann kriegsbedingte Schwierigkeiten, wozu wahrscheinlich auch der Mangel an Arbeitskräften aufgrund der Mobilmachung gehörte, zu großen Verzögerungen, weshalb der Rohbau erst 1916 fertiggestellt wurde und das Institut erst zum Wintersemester 1920 nach dem ersten Weltkrieg (1914-1918) bezogen werden konnte. Die Gestaltung der Front des Christian-Ernst-Gymnasiums, der Eingangsbereiche mit Portalen und Knaben- und Mädchenkopf aus schönem Roten Mainsandstein sowie einer darüber befindlichen Sandsteinbalustrade mit kunstvoll behauenen Vasen zeugen von einem ausgewogenen, repräsentativen Baustil. Die bronzene Büste des Prinzregenten auf einem Sockel aus ausgesuchtem hellem Untersberger Marmor (Kalkstein) sowie die ganze Gestaltung des Eingangsbereichs dokumentieren die positive Einstellung der Erlanger Bürger zu diesem Bauwerk. Die Gestaltung des Innenbereichs mit Wasserbecken aus poliertem Treuchtlinger Kalkstein sowie den beiden großzügig gestalteten Treppenhäusern mit Stufen aus Nammering Granit und schönen Holzbalustern bezeugen ebenso die gelungene architektonische Gesamtplanung wie auch die leider nicht mehr vollständig erhaltenen, geschwungenen Oberlichter über den Eichentüren zu den einzelnen Räumen. Auch die Gestaltung der Fußböden in den Gängen mit geschmackvollem Schwarz-Weiß-Muster der Bodenfliesen, die damals eine moderne technische Entwicklung (Trockenpressen) darstellten, lässt die Wertschätzung des Schulbaus bei den Bürgern und Architekten erkennen. Der Schulbau spiegelt auch heute noch die Freude am schönen Gestalten wider, die man damals hatte und in kurzer Zeit umsetzte und wirkt auch im Inneren heute noch fast fröhlich durch die von den beiden Treppenhäusern ausgehenden, lichtdurchflossenen Flure. Der heute als Marie-Therese-Gymnasium bekannt Bau in der Schillerstraße wurde etwa sieben Jahre später ebenfalls in sehr kurzer Bauzeit von der Planung 1908 bis zum Bezug 1909 des Neubau errichtet, der zunächst zur Unterbringung der »Städtischen höheren weiblichen Bildungsanstalt« diente. Der aufwändige neubarocke Stil ist trotz nachfolgender Veränderungen gut erhalten geblieben und zeigt auch noch das Chörlein an der Ostfassade vor dem 1956 erfolgten Erweiterungsbau. Muschelkalk und Coburger Bausandstein wurden für die Fassade ebenso wie am Christian-Ernst-Gymnasium verwendet und dokumentieren den Stil eines Schulbaus zu dieser Zeit. Doch wurden die Schmuckelemente des Eingangsportals mit großen Figuren und des großen Bayernwappens am Marie-Therese- Gymnasium aus grobporigem Muschelkalk geschlagen und kein feinkörniger Sandstein zur Modellierung verwendet. Eine Eingangshalle und ein trotz der Rundbögen geradliniges, kantig erscheinendes zentrales Treppenhaus weisen mehr auf einen pragmatischen Baustil im Inneren hin. Dieser Eindruck wird sowohl durch die intensive Verwendung von grobem Betonkunststein in Pfeilern und Balustern als auch durch einfarbige dunkelgrüne Wandfliesen und die teilweise verwendeten roten Bodenfliesen unterstützt. Die großen Keramikausgussbecken und besonders der Fußboden aus Linoleum, das sich in der zweiten Hälfte des 19. Jahrhunderts als moderner elastischer Bodenbelag durchgesetzt hat, zeigen im Innenbereich eine andere als im Christian-Ernst-Gymnasium, aber ebenfalls eine dem Stand der Technik zeitgemäße, moderne Gestaltung. Die ehemals verglasten, bunten Oberlichter, die dem Bau ein lichtdurchflossenes fröhliches Bild gaben, sind leider nicht mehr erhalten, weshalb der Eindruck im Inneren eher etwas klamm und gedämpft ist. Der geplante Besuch der Königsfamilie Ende Juli 1914 kam aufgrund des sich abzeichnenden Weltkrieges nicht zu Stande. Zu Ehren der Königin aber gab man dem Bau den Namen »Marie-Therese-Schule«, der 1965 von der Stadt in »Marie-Therese-Gymnasium« umgewandelt wurde. Der Neubau der Universitätsbibliothek, der 1910 geplant wurde, spiegelt in seinen beiden Teilen, dem Magazin- und dem Verwaltungstrakt eine komplexe Planungs- und Baugeschichte wider. Die Besuche der Planer von damals modernen Universitätsbibliotheken in anderen Universitätsstädten haben zu einem innovativen, dem neuesten Stand der Technik entsprechenden Magazintrakt mit selbst tragender Stahlkonstruktion geführt. Für den Außenbereich war die architektonische Eingliederung in die benachbarten Universitätsbauten im Markgrafenstil wie dem Kollegienhaus die Vorgabe. Dies wurde durch den Abriss der Reifbrauerei und die dadurch zur Verfügung stehenden Burgsandsteinquader begünstigt. Auch dass deren Menge nicht ausreichte, stellte kein Hindernis dar, konnten in dieser Zeit der Blüte von Steinbruchunternehmen doch problemlos zwei neue Brüche am Burgberg eröffnet werden. Die Gestaltung des Innenbereichs zeichnet sich durch architektonische, künstlerische Elemente aus, die sowohl durch Holzvertäfelung und Einbauten im Direktorenbereich und Sitzungssaal als auch durch die Auswahl der Naturwerksteine im Treppenhaus und in den Fluren einen repräsentativen Gesamteindruck vermitteln. Doch scheint hier gegen Ende der durch das 170-jährige Universitätsjubiläum (4. November 1913) vorgegebenen Bauzeit Zeitdruck entstanden zu sein, so dass manche Natursteinarbeiten nicht mehr mit der vorgesehenen Sorgfalt ausgeführt wurden. Dieser Umstand spiegelt sich besonders in den beidseitigen kastenartigen Konstruktionen aus nur 2 cm starken, schlecht verfugten Platten des Kalksteins Napoléon wider, die beidseitig des Treppenaufgangs angefertigt und mit zierlichen, zu klein erscheinenden Handläufen versehen wurden. Es kann angenommen werden, dass die Kalksteinplatten aus Reparationsleistungen des Deutsch-Französischen Krieges zu den Marmorwerken Funk in Nürnberg gelangt sind und hier verbaut wurden. In anderen repräsentativen Gebäuden dieser Zeit sind oft massive Geländer aus poliertem, edlem Naturstein zu finden. Auch die Platten aus Napoléon-Kalkstein in den Fluren erscheinen etwas rasch angebracht worden zu sein. Die grobkörnigen, bräunlichen Betonkunststeine aus denen die kurzen Mäuerchen mit Durchbruch und Holzbalustern und die Pfeiler hergestellt wurden, wirken leicht störend im gesamten repräsentativen Erscheinungsbild des Treppenhauses. Die schönen Rundbögen mit Kartuschen an den Eingängen zu den Fluren und vor allem die großen lichtgebenden Fenster aus Antikglas mit ziselierter Ornamentik verleihen dem Treppenhaus dagegen seinen großzügigen Eindruck. Das Gebäude der Universitätsbibliothek spiegelt den Wunsch nach einem hochmodernen (Magazintrakt) und gleichzeitig repräsentativen Gebäude (Verwaltungstrakt) wider. Die vollständige Umsetzung dieses Plans scheint unter dem Zeitdruck gelitten zu haben. Man griff daher wohl auch auf gerade verfügbares Material zurück, das wahrscheinlich günstig zu haben war und verwendete größere massive Kalksteine (Napoléon und Treuchtlinger Kalke) nur bei den beiden Wasserbecken in den Fluren. Auch die großen Säulen aus Muschelkalk zeigen, dass sie rasch und ohne weitere Qualitätsauswahl aus unterschiedlichen Muschelkalkschichten entnommen wurden, weshalb sie sowohl im als auch gegen das Lager übereinandergesetzt wurden, was bei derartigen Säulen steintechnisch nicht üblich ist. Der 1914 begonnene Bau des Instituts für Angewandte Chemie spiegelt seine besondere Bestimmung zur Förderung der Forschung im Zusammenhang mit dem ersten Weltkrieg eindrucksvoll wider. Der bis auf »heroische Figuren« über dem Eingangsbereich schnörkellose Bau zeigt die Vorherrschaft von Betonkunststein in der Fassade und in den großen Pfeilern im Treppenhaus. Die Elemente des vom Denkmalschutz besonders hervorgehobenen Holzzauns spannen sich zwischen mit grobem Beton überdeckte Backstein-Pfeilern, die heute besonders starke Schäden durch Abplatzen und Abschalen aufweisen. Der schmucklose Eingangsbereich leitet über zu einem ebenso schmucklosen Inneren mit überwiegend unterschiedlichen, einfarbigen Bodenfliesen und verschiedenen Kunststeinen. Nur die Eingangshalle ist mit dem für Bodenplatten besonders beliebten Solnhofener Kalkstein versehen. Ebenso sind nur der Gedenkstein an Prof. Max Busch, der damalige Rektor der Universität, und die Gedenktafel zur Würdigung der großzügigen Spender zur Errichtung des Baus in Treuchtlinger Kalkstein gefertigt wurden. Die Übergänge zwischen den verschiedenen Typen der Bodenfliesen sind abrupt und grenzen verschiedene Bereiche im Gebäude ab. Dazwischen wurde auch hier das damals hochmoderne Linoleum in großem Maße in unterschiedlichen Farben verwendet. Die großen Fenster aus Antikglas sind von besonderem Interesse. Hier wurde der Zweck des Baus in den verschiedenen Ornamenten in der Mitte der sechs Fenstereinheiten dokumentiert. Von der Erforschung der chemischen Elemente bis hin zu Düngemitteln und schließlich zum Sprengstoff wird der Einfluss der kriegswichtigen, praktischen Forschung deutlich. Die künstlerische Interpretation der hier schwerfälligen Rocaille-Ornamentik lässt keinen interpretatorischen Spielraum und ist wohl dem Wunsch des Auftraggebers angepasst, auf den sich der Künstler eingelassen hat. Glücklicherweise haben kriegsbedingte Schwierigkeiten dazu geführt, dass der Bau erst 1920 also etwa 2 Jahre nach dem Ende des ersten Weltkrieges bezogen werden konnte, und dadurch die kriegswichtigen Forschungsthemen anderen Schwerpunkten weichen mussten. Die Grundstücksgrenze zum heutigen Kitzmann-Areal stellt eine wertvolle, historisch verbürgte Grundstücksgrenze mit einem Teil der historischen Erlanger Stadtmauer dar, der auch bei heute eventuell anstehenden Baumaßnahmen nicht verändert werden darf. Das Direktionszimmer, das sich zentral in der zweiten Etage befindet, fällt aus dem Rahmen des nüchternen Zweckbaus. Hier wurde, wie im Direktionszimmer der Universitätsbibliothek, ein repräsentativer Raum mit einer Verkleidung und Wandschränken aus Eichenholz geschaffen. Dieser Raum wurde in den letzten Jahren als Bibliothek genutzt. Wie in der Universitätsbibliothek sollte das Ensemble des historischen Raumes unter Denkmalschutz gestellt werden
    Description: DFG, SUB Göttingen
    Description: research
    Keywords: ddc:550
    Language: German
    Type: doc-type:article , publishedVersion
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  • 37
    Publication Date: 2022-12-15
    Description: Seit nunmehr 50 Jahren erscheinen die Mainzer Geowissenschaftlichen Mitteilungen (MGM) des Landesamtes für Geologie und Bergbau, vormals Geologisches Landesamt. Grund genug, Rückschau zu halten und dieses kleine Jubiläum mit einem eigenen Beitrag in den MGM zu würdigen. In den vergangenen 50 Jahren hat nicht nur das Layout Veränderungen erfahren, auch weitere Themen sind entsprechend neuen Aufgaben des Geologischen Dienstes hinzugekommen und haben das Spektrum des Inhaltes erweitert.
    Description: Abstract: With the current issue the journal "Mainzer Geowissenschaftliche Mitteilungen" (MGM) celebrates its 50th birthday - a good reason for a retrospective view on the history of the journal. During the past 50 years not only the layout has changed several times but also new topics were introduced eventually according to changing and expanding tasks of the Federal Geological Survey.
    Description: editorial
    Keywords: ddc:550 ; Verlagswesen
    Language: German
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  • 38
    Publication Date: 2022-12-15
    Description: The subduction of serpentinized slabs is the dominant process to transport “water” into Earth's mantle, and plays a pivotal role for subduction dynamics. Antigorite, the most abundant serpentine mineral in subduction settings, may imprint a seismic signature on serpentinized slabs, making them seismically distinguishable from the dry, non‐serpentinized ones. However, the complete single‐crystal elasticity of antigorite has not been experimentally constrained at high pressures, hindering the use of seismological approaches to detect serpentinization in subducting slabs. Here, we report the full elastic stiffness tensor of antigorite by single‐crystal Brillouin spectroscopy and X‐ray diffraction up to 7.71(5) GPa. We use our results to model seismic properties of antigorite‐bearing rocks and show that their seismological detectability depends on the geometrical relation between seismic wave paths and foliation of serpentinized rocks. In particular, we demonstrate that seismic shear anisotropy shows low sensitivity to serpentinization for a range of relevant geometries.
    Description: Plain Language Summary: The subduction of serpentinized slabs plays a key role in the deep recycling of water into the Earth's interior. Antigorite is the main serpentine mineral in subducting slabs, and the most important carrier of water. Antigorite‐bearing rocks are predicted to have a distinct seismic signature, potentially allowing them to be detected with seismological approaches. However, our current knowledge on seismic properties of antigorite‐bearing rocks is limited, mostly hampered by a lack of experimental constraints on single‐crystal elasticity of antigorite at relevant pressures. In this study, state‐of‐the‐art techniques were employed to produce the first experimental description of the complete high‐pressure elasticity of antigorite single crystals. Our experimental data set was implemented in the modeling of seismic properties of antigorite‐bearing rocks at pressures relevant for subduction. Our results were used to discuss the relation between seismic wave path and shear wave anisotropy in serpentinized slabs, and challenge the use of shear wave splitting as a proxy for serpentinization in slabs.
    Description: Key Points: Single‐crystal elasticity of antigorite at high pressures is determined by Brillouin spectroscopy and X‐ray diffraction experiments. Seismic signature of serpentinized slabs is constrained in a relevant composition‐pressure space. Serpentinization in slabs may be undetectable through shear wave anisotropy.
    Description: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Description: EC Horizon 2020 Framework Programme http://dx.doi.org/10.13039/100010661
    Description: https://doi.org/10.6084/m9.figshare.20348748
    Description: https://doi.org/10.6084/m9.figshare.20348781
    Keywords: ddc:550 ; serpentine ; elasticity ; Brillouin spectroscopy ; antigorite ; seismic anisotropy ; shear wave splitting
    Language: English
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  • 39
    Publication Date: 2022-12-01
    Description: Geological maps are complex to produce through intensive and expensive field studies. Comparisons of geophysical data with geological conditions are difficult and often only qualitatively possible. The following work therefore examines an automated procedure to better reconcile this information. For this purpose, the terracing method, and a cluster analysis of potential field (gravity and magnetic field) and petrophysical data from the Karasjok and Ligurian Sea regions are used to interpret this geophysical measurements in a geological way. Two different tectonic regions were selected: (1) The Karasjok region is located in Northern Norway, where the Karasjok Greenstone Belt (KGB) dominates geological settings, consisting of abundant ultramafic intrusions, komatiites, gabbroic intrusions, amphibolites and migmatites. (2) The Ligurian-Provençal basin, part of the Western Mediterranean Sea, which is located between the French-Italian coastline and the island of Corsica. Geologically the area is characterised by the spreading zone in the Western Mediterranean. The high-resolution Airborne Gravity Gradient Survey and aeromagnetic datasets of the Karasjok region cover an area of 20 km x 30 km with a data resolution of 50 m. The dataset of the Ligurian basin cover a much larger area with the resolution of 5 km. Data constraints come from former LOBSTER and LISA campaigns and a study in the research group at CAU Kiel, new compilation of the AlpArray Gravity Research Group (AAGRG), besides data of the ICGEM Potsdam (disturbance) and the GOCE mission. By aid of the terracing algorithm, the boundaries of the anomalies are to be sharpened and regions with constant field amplitude were generated. For this purpose, a shape index-based algorithm was applied, which uses the shape index calculated at each field point to grade the function. Through an iterative process and the variation of parameters, the terracing result is refined. The resulting data sets are then further processed using a cluster analysis method. Here, the k-mean algorithm for domain classification is used to divide the geophysical measurement data into groups (cluster) of similar properties. The number of clusters k is specified and the data points are assigned to the respective clusters through an iterative process. Using the data of the datasets mentioned above the results of this applications are successfully compared with the corresponding geological maps of the two areas.
    Description: Deutsche Forschungsgemeinschaft (DFG), SPP "MB-4D"
    Description: https://doi.org/10.5880/fidgeo.2020.045 (Zahorec et al., 2021) via GFZ Data Services
    Description: poster
    Keywords: ddc:550 ; Clustering ; terracing ; gravity field ; Liguro-Provencial Basin
    Language: English
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  • 40
    Publication Date: 2022-12-01
    Description: Der Hessische Erdbebenkatalog ist eine Zusammenstellung historischer und aktueller Informationen zu Erdbeben in Hessen und direkter Umgebung von Hessen. Er wird vom Hessischen Erdbebendienst geführt und regelmäßig aktualisiert. Eine 50 km-Umhüllende wurde um Hessen herum gelegt, um auch Erdbeben und die dazugehörenden Bereiche zu betrachten, die Auswirkungen auf Hessen haben können. Eine Vollständigkeit wird jedoch nur für das Gebiet des Landes Hessen angestrebt. Für den seismischen Katalog Hessen (SKHe2022) wurden verschiedene, verfügbare Erdbebenkataloge und Ausarbeitungen zu Grunde gelegt. Des Weiteren beinhaltet der Katalog Ereignisse aus mehreren wissenschaftlichen Publikationen. Das Stichdatum für den Katalog ist der 31.12.2021. Der Erdbebenkatalog Hessen wird auch in Zukunft fortgeschrieben und ist damit als Zwischenstand zu sehen. In Zukunft wird er halbjährig aktualisiert und der Öffentlichkeit über den Geologie-Viewer des Hessischen Landesamtes für Naturschutz, Umwelt und Geologie unter geologie.hessen.de zur Verfügung gestellt. Im seismischen Katalog Hessen werden fünf Zeiträume beschrieben. Dabei handelt es sich für den Zeitraum 800 bis 1700 um Daten, die aus Chroniken ermittelt wurden. Für den Zeitraum 1701 bis 1950 beruhen viele der älteren Ereignisse auf makroseismischen Daten. Durch den aufkommenden Zeitungsdruck wurden wesentlich mehr Daten erhoben als in dem Zeitraum davor. Seit Anfang des 20. Jahrhunderts wurden dann auch Erdbeben instrumentell aufgezeichnet. Das analog-instrumentelle Zeitalter wird für den Zeitraum 1951 bis 1975 angegeben. Das digital-instrumentelle Zeitalter gilt ab 1976. Es wurde eine Priorisierung der einzelnen Erdbebenereignisse, wenn mehrere Ereignisse von unterschiedlichen Quellen aufgezeichnet wurden, durchgeführt. In der aktuellen Version sind sämtliche bekannte induzierte Ereignisse identifiziert worden. In der veröffentlichten Version sind diese induzierten Ereignisse nicht mehr enthalten, so dass der Erdbebenkatalog des Landes Hessen als rein tektonischer, auf natürlichen Erdbeben basierender, Erdbebenkatalog angesehen werden kann. Die stärksten historischen Erdbeben traten in den Jahren 858, 1733 und 1858 in Mainz, 1619 im südlichen Taunus, 1767 in Rothenburg/Fulda, sowie als Erdbebenschwarm in Groß-Gerau (1869-1871), 1871 in Lorsch und im Odenwald auf. Das stärkste Erdbeben in den letzten Jahren fand im Jahr 2014 bei Ober-Ramstadt im Odenwald mit einer Magnitude von 4,2 statt.
    Description: poster
    Keywords: ddc:550 ; Erdbeben ; Seismischer Katalog ; Hessen ; Oberrheingraben
    Language: German
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  • 41
    Publication Date: 2022-12-01
    Description: Aeromagnetic surveys help us to learn about geology. To achieve good coverage, surveys need to be merged. However, conventional methods introduce long-wavelength bias and cannot handle the individual survey quality. We develop a new approach to process large aeromagnetic surveys with an equivalent layer approach and combine them with satellite data. To facilitate the usage of large data sets, we divide the study area into blocks and treat each block individually. We adjust the block size according to the resolution of the equivalent source model. Within each block we solve for equivalent sources using an iterative linear inversion with Tikhonov regularization. We apply a multi-resolution strategy by iteratively decreasing the dipole spacing, dipole depth and block size. In each step, the resolution is applied to the residual of the previous steps. This ensures both a good representation of the large and small-scale structures as well as reasonable computational costs. Advantages of the blockwise inversion are the handling with large data sets due to splitting up the study area and neglecting influences of sources above a certain distance. This reduces computational costs and still fits the data well in comparison with an unblocked inversion. Some structures cannot be resolved well with just one dipole layer, so the multi-resolution strategy enables to have a better fit by separating regional and local sources. For the final compilation, we replace the long wavelengths part of the aeromagnetic data with satellite data to spherical harmonic degree 110. We demonstrate our new approach with a newly compiled large data base for Greenland.
    Description: poster
    Keywords: ddc:550 ; aeromagnetic ; inversion ; greenland ; multi-layer
    Language: English
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  • 42
    Publication Date: 2022-12-01
    Description: In Folge des Klimawandels kommt es in Mitteleuropa vermehrt zu Dürreperioden und Austrocknung von Böden. Indem tief- und flachwurzelnde Nutzpflanzen sinnvoll kombiniert werden, kann die Verfügbarkeit von Wasser teils auch ohne künstliche Bewässerungsmaßnahmen verbessert werden. Die Tiefwurzler erschließen tiefer gelegenes Wasser und können es so umverteilen (‚hydraulische Umverteilung‘), dass auch benachbarte Flachwurzler mit Wasser versorgt werden. Mit dem Ziel eine solche Umverteilung von Wasser durch Pflanzen mithilfe geoelektrischer Methoden zu untersuchen, wurde in dieser Studie ein Versuchsaufbau entwickelt und getestet. Auf 23 Feldern wurden verschiedene Kombinationen der Pflanzen beobachtet. Dafür wurden sowohl Oberflächenmessungen mittels Gleichstromgeoelektrik, als auch Bohrlochmessungen mittels Spektraler Induzierter Polarisation (SIP) durchgeführt. Die Ergebnisse wurden mit konventionellen Bodenfeuchtemessgeräten (time domain reflectometry, TDR) verglichen, welche die Bodenfeuchte nur punktuell erfassen können. Für die Bohrlochmessungen wurde ein experimenteller Aufbau zur Beobachtung der räumlichen Verteilung des Wassers im Untergrund umgesetzt. Um eine hohe Auflösung im Bereich der flachen Wurzeln zu erreichen, wurde ein bohrlochartiges System genutzt. Dieses besteht aus metallischen Ringelektroden, die an einem Holzstab befestigt sind, der senkrecht in den Boden eingebracht wird. Die Elektroden haben dabei nahe der Oberfläche die kleinsten Abstände (5cm), da in diesem Bereich die Wurzeln der Tief- und Flachwurzler gemeinsam vorkommen. Hier soll die Auflösung möglichst hoch sein, damit die Wasserumverteilung gut beobachtet werden kann. Mit zunehmender Tiefe nehmen die Elektrodenabstände zu. Hier ist eine geringere Auflösung ausreichend, da nur die Tiefwurzler Wasser aufnehmen. Da die Stäbe bereits vor dem Sähen der Pflanzen in den Boden gebracht wurden, war ein Monitoring über mehrere Monate möglich: Zur Aussaat der Pflanzen Ende März, während des Wachstums und im September während eines finalen Bewässerungsexperimentes. Die bisherigen Auswertungen der Ergebnisse zeigen, dass sich die zeitliche Entwicklung der Bodenfeuchte anhand der geoelektrischen Daten gut nachvollziehen lässt und im Gegensatz zu den TDR-Daten auch die räumliche Verteilung hoch aufgelöst (〈5cm) erfasst werden kann. Die Oberflächenmessungen zeigen, dass die Schichtung des Bodens über die Plots variiert, was sich auf die Vergleichbarkeit der Ergebnisse auswirken kann.
    Description: poster
    Keywords: ddc:550 ; Geophysik ; Geoelektrik ; Monitoring ; Induzierte Polarisation
    Language: German
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  • 43
    Publication Date: 2022-12-01
    Description: Recent years have shown an increased interest in Polar research and in particular in understanding tectonics and seismic hazard in the Arctic. To understand the seismic activity in the European Arctic, the seismic bulletins should be as complete as possible. We present a new seismic event bulletin for the European Arctic (70° – 90° N, -15° – 75° E), for the 24-year long period 1990 – 2013. The poster will show in detail the merging of the different sources taken in account for the compilation, the homogenization of the data and the relocation of the seismic events. With respect to the ISC bulletin for this region, the new bulletin contains 5,932 new seismic events and 54,630 new seismic onset readings from stations mostly located at regional distances. The gains are distributed over the entire study region, with the most significant contributions across the Svalbard Archipelago, along the Knipovich and northern Mohns Ridges, as well as northern Fennoscandia.
    Description: Norwegian Research Council Grant 233973/H30
    Description: Russian Foundation for Basic Research Grant 14-05-93080
    Description: Russian Foundation for Basic Research Grant 18-05-70018
    Description: https://doi.org/10.31905/TYLLQY8T
    Description: poster
    Keywords: ddc:550 ; European Arctic ; Seismic Bulletin
    Language: English
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  • 44
    Publication Date: 2022-12-01
    Description: During the last few years, the use of Ground-Penetrating-Radar (GPR) multi-channel antenna arrays in the Archaeological Prospection increased dramatically. The main advantage of this type of survey is a much faster data acquisition combined with a dense profile spacing. However, most of the common multi-channel arrays consist of antennae with a spacing of not smaller than 8 cm. The aim of our test survey was to evaluate how an even denser spacing of 4 cm that is provided by the IDS Stream-C GPR device at a centre frequency of 600 MHz can improve the detection of small archaeological features. As a test site, we chose the Great Bath in Kempten-Cambodunum. This first capital of the Roman province Rhaetia never has been overbuilt in the following centuries and even today it is used as a grassland declared as an Archaeological Park. Already in 1911, the Great Bath was excavated and beside the walls of different building phases, also small features like a multitude of hypocaust pillars were unearthed. Hence, this building structure depicts an ideal test site and a 40x40m grid covering the main part of the construction was chosen for the application of the antenna array. As a comparison, the same grid was contemporaneously surveyed with a single antenna IDS Duo device (600 and 200 MHz) and a 50 cm profile spacing. Regarding the walls of the Roman bath, the two surveys show comparable results: both datasets represent the stone constructions of 50 – 90 cm width quite well. Furthermore, the depth slices of both devices provide a differentiation of the single building phases. Nevertheless, the resolution for the multi-channel antenna array is of course much higher due to the denser profile spacing. Huger differences occur for the hypocaust pillars of 25 cm lateral length. These features can be mapped in detail with the 4 cm profile spacing of the IDS Stream-C system. Whereas the IDS Duo can only resolve some of the hypocausts, a multitude of them gets visible between 70 and 110 cm depth in the Stream-C data. As a conclusion, it can be stated that standard archaeological remains like stone walls, for sure, can be surveyed with single antenna GPR devices in a common profile spacing of 50 cm. However, in case of the existence of faint archaeological features the application of ultra-dense antenna arrays like the IDS Stream-C is advisable to get a comprehensive overview of a site without the necessity to excavate them.
    Description: poster
    Keywords: ddc:550 ; Ground-Penetrating Radar ; GPR ; Multichannel Antenna Array ; Roman Bath ; Hypocaust Pillars
    Language: English
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  • 45
    Publication Date: 2022-12-01
    Description: Mit dem zerstörungsfreien Verfahren der nuklear magnetischen Resonanz (NMR) mit Fokus auf 1H-Protonen lässt sich der Feuchtegehalt in porösen Materialien bestimmen und bei einem vollgesättigten Medium eine Porengrößenverteilung ableiten. Für die Ermittlung der Porengrößenverteilung muss die gemessene T2-Relaxationszeitenverteilung mit dem Parameter Oberflächenrelaxivität (OR) umgerechnet werden. Ist dieser Parameter für das zu untersuchende Medium unbekannt, kann dieser mithilfe von Vergleichsverfahren abgeschätzt werden. Dabei kommen z. B. Gassorption, Quecksilberporosimetrie (MIP), Dünnschliff-Mikroskopie oder µ-Computer-Tomographie (µ-CT) zum Einsatz. Da die verschiedenen Verfahren allerdings unterschiedliche Auflösungsgrenzen aufweisen und auf verschiedenen physikalischen Prinzipien beruhen, können die ermittelten ORs für ein Medium stark variieren. Um ein besseres Verständnis für die OR und die Einflüsse der Vergleichsverfahren zu bekommen, wurden 19 verschiedene Sandsteintypen untersucht. Die OR wurde zum einen basierend auf der spezifischen inneren Oberfläche aus der dynamischen Dampfsorption (DVS) und der Gassorption abgeleitet. Zum anderen wurden die Relaxationszeitenverteilungen durch manuelles Anpassen der OR derart in Porengrößenverteilungen umgerechnet, sodass es eine Übereinstimmung mit den Porengrößenverteilungen aus MIP und/oder µ-CT gibt. Die Umrechnung von Relaxationszeitverteilungen in eine Porengrößenverteilung berücksichtigt dabei sowohl fast- als auch slow-diffusion. Insgesamt ergab sich für die Sandsteine ein breites Spektrum an ORs, bei dem die über die innere spezifische Oberfläche ermittelten ORs andere Größenordnungen aufwiesen (〈 10 µm/s), als bei dem Vergleich mit MIP oder µ-CT (bis 600 µm/s). Die mit MIP und µ-CT ermittelten Werten lagen dabei um einen Faktor von 1 bis 30 auseinander. Dieser umfangreiche Datensatz, der vier verschiedene Vergleichsverfahren einbezieht, soll neue Erkenntnisse in der Charakterisierung von porösen Materialien (z. B. bezüglich der Oberflächenrauigkeit) und in der Ursache für die starke Variation der OR ermöglichen. Durch das Berücksichtigen von fast- als auch slow-diffusion, können dabei sogar Daten in eine Porengrößenverteilung umgerechnet werden, bei denen das fast-diffusion-Kriterium nach Brownstein und Tarr nicht erfüllt ist. Außerdem ergibt sich aus der Berücksichtigung des slow-diffusion-Regimes ein neues Verständnis für die obere Auflösungsgrenze von NMR.
    Description: poster
    Keywords: ddc:550 ; Nuklear magnetische Resonanz ; Oberflächenrelaxivität ; Sandsteine
    Language: German
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  • 46
    Publication Date: 2022-12-01
    Description: Das Poster präsentiert die Ergebnisse des kombinierten Einsatzes von NMR und LIBS zur Verfolgung von Feuchtigkeit und Schadionen in Baustoffen. Es wurden dazu mit zwei Sandsteine und zwei zementäre Baustoffe kapillare Saugversuche durchgeführt. Die Materialien wurden 5 mm tief in Natriumchloridlösungen einer Konzentration von 1 mol/l und 4 mol/l getaucht. Mit NMR wurde der Feuchteanstieg, mit LIBS der Chloridionenanstieg ermittelt. Ergebnisse sind unter anderem, dass die Feuchte den Ionen immer vorauseilt. Außerdem ist die Anstiegsgeschwindigkeit direkt abhängig vom Porensystem und von der Lösungskonzentration.
    Description: poster
    Keywords: ddc:550 ; NMR ; LIBS ; Transportprozesse ; Ionentransport ; Feuchtetransport
    Language: German
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  • 47
    Publication Date: 2022-12-01
    Description: The Floodrisk project takes a muti- and interdisciplinary look on the effects of the rise in mine water level in abandoned coal mine regions in Germany. Such effects are heterogeneous ground uplift, stress changes due to the pore pressure changes and the reactivation potential of faults. One of the most directly measurable effects is the induced seismicity. It is known from previous studies that the flooding of old mines can lead to a renewed increase in induced microseismicity in these regions. We focused on the observation of the eastern Ruhr area and investigate in detail the relationship between mine water rise and induced seismicity in the Haus Aden dewatering area. For this purpose, we operate a network of up to 30 short period seismic stations in the region of the former "Bergwerk Ost" colliery, which had the highest seismicity rate in the Ruhr area during active mining. Continuous monitoring of seismicity and mine water levels is available for this region from the active mining phase, through the post-mining phase to flooding. Since the beginning of the flooding, more than 20000 onsets were picked and over 1700 induced events were localised in a magnitude range from -0.7 up to 2.6 MLv. For some larger events, focal mechanisms could be determined. The spatial distribution of hypocentres is divided into two areas, with few events in the central study area and over 95% of earthquakes in its eastern part. Many of these events are spatially clustered and some show quite high waveform similarity. This allows relative localisation to increase the accuracy of the location. Comparing the old galleries,which today serve as the main underground waterways, with the localisations from the relative localisation, strong correlations can be seen. The measured temporal trend of the mine water level, after pumps were shut down in mid-2019, shows a strong correlation with the temporal evolution of the observed micro seismicity. In the first months after the pumps are switched off, the water levels at the observation points rise only slowly and isolated microseismic events occur again. In November 2019, the rise in water levels doubled and at the same time, the strongest induced event in the measurement period was recorded with a magnitude of 2.6 MLv. In the years 2020, 2021 66 and 58 events 〉= MLv 1 were observed, respectively. In contrast to this number only 2- 9 events 〉= MLv 1 per year were observed in the post-minig phase before flooding.
    Description: Bundesministerium für Bildung und Forschung
    Description: poster
    Keywords: ddc:550 ; induced seismicity ; post mining ; mine water rise ; Ruhr Area
    Language: English
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  • 48
    Publication Date: 2022-12-01
    Description: In the last few years, several Unmanned Aerial Vehicle (UAV) based magnetometer systems have been tested for archaeological prospection. Due to their higher sensitivity, scalar magnetometers have been preferred as test sensors. However, total field magnetometer are vulnerable to disturbances, especially those generated by the UAV itself. Therefore, most UAV scalar magnetometer systems use the method of increasing the distance between magnetic sensors and the UAV to reduce interference. But freely suspended sensors tend to swing on ropes under the UAV and can produce data that are strongly influenced by heading errors. For our test, we therefore chose the UAV-fixed, compact setup of the SENSYS MagDrone R4, which is equipped with five three-axis FGM3D/75 fluxgate sensors at 50 cm spacing and is covering a swath width of 2.5 m. The 200Hz sampling rate of the R4 allows easy filtering of interference generated by the UAV and external disturbances like power lines or infrastructure. Magnetograms with a spatial resolution of up to 0.20 m per pixel were produced from the data. At Ganacker, we chose the former infrastructure core of the World War II German Air Force airfield as a test site. A wide range of archaeological structures and features with high magnetic contrast were expected on this area. The test site is currently an open agricultural area with a quite flat terrain. Hence, the R4 could be operated at a fixed flight height of just one metre above the surface of the terrain that is controlled actively by a radar sensor. An area of around 110 hectares were prospected within only four days. The MagDrone R4 system thus offers an outstanding survey area progress that cannot even reached by common vehicle-moved multi-sensor arrays. Here, we present the first results of this test survey by comparing the magnetograms, historical and current geodata. Most of the expected archaeological features and several unknown ones were detected by the R4 system. Our results show that the R4 system is well suited for mapping large archaeological structures with high magnetisations. In the future, we want to compare the R4 data with data from a ground-based fluxgate magnetometer. We also want to test whether the system is suitable for detecting archaeological features that have lower magnetic susceptibility and remanence contrasts with the surrounding soil.
    Description: poster
    Keywords: ddc:550 ; UAV magnetometer survey ; 3-axis fluxgate magnetometers ; archaeological prospection ; low-level flight ; Second World War airfield ; conflict landscapes
    Language: English
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  • 49
    Publication Date: 2022-12-01
    Description: Das Ziel des COSC-2 (Collisonal Orogeny in the Scandinavian Caledonides) Projektes ist es, die Entstehungsprozesse der Skanden zu untersuchen. Hierfür sind Kenntnisse über die Deformationen / Faltungsprozesse von großer Wichtigkeit, die sich aus der Richtung der remanenten Magnetisierung ableiten lassen. Die teufenabhängigen Magnetisierungsvektoren lassen sich aus dreikomponetigen Bohrlochmagnetikdaten berechnen. Als Datengrundlage dienen Messungen, die mit einem Dipmeter in der COSC2-Bohrung in Järpen (Schweden) durchgeführt wurden. Es wurden 5 Messungen mit 1cm Messpunktabstand in verschiedenen Teufenbereichen zwischen 100m und 2250m Teufe aufgezeichnet. Anhand der in der Sonde verbauten Accelerometer und dem bekannten Verlauf der Bohrung konnten die Magnetfelddaten in das geographische Referenzsystem reorientiert werden. Die erreichte Genauigkeit beträgt 1,5° in der Deklination und 0,16° in der Inklination. Um die Magnetisierung der durchbohrten Gesteinseinheiten zu bestimmen wird an die reorientierten Magnetfelddaten ein Schichtmodell nach Bosum et al (1988) angepasst. Dieses Modell nähert die Schichten durch zentral durchbohrte Zylinder. Das Modell von Bosum geht von einem Zylinder aus, der senkrecht zu den Deckflächen zentral durchbohrt wird. In der COSC-2 Bohrung ist aber zum einen das Bohrloch geneigt, zum anderen weisen auch die durchbohrten Schichten eine Neigung auf. Aus diesem Grund erweitern wir das Bosum-Modell nach Ehmann (2016) für beliebige Schichtinklinationen. Die Schichtmächtigkeiten werden durch die Lithologie der Bohrung bestimmt, die aus den Bohrkernen abgeleitet wurde. Eine erste Analyse zeigt, dass in den oberen 1200m der Bohrung nur schwach magnetisierte Gesteine vorherrschen. Darunter folgen stärker magnetisierte-Schichten, die im Mittel eine Magnetisierung von 1A/m aufweisen. Im Bereich von 1590m bis 1850m befindet sich eine stark magnetisierte Sektion, die sich in vier Bereiche aufteilen lässt. Die Magnetisierung in dieser Sektion beträgt bis zu 5 A/m. In der stark magnetisierten Sektion können zwei Bereiche identifiziert werden, in denen die Inklination der Magnetisierungen von 40° auf bis zu 80° ansteigt. Die beiden Bereiche mit hoher Inklination weichen in ihrer Deklination von der mittleren Deklination der Sektion um +90° und -90° ab. Diese Variationen deuten auf Deformationen der Gesteinsschichten hin. Unterhalb dieser Sektion schließt sich eine Sektion mit Magnetisierungen von etwa 1 A/m und Inklinationen von etwa 15° an.
    Description: DFG, Fördernummer VI 836/5-1
    Description: poster
    Keywords: ddc:550
    Language: German
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  • 50
    Publication Date: 2022-11-29
    Description: Anlässlich des Arbeitstreffens der GeoUm im Rahmen des Bibliothekskongresses 2022 wurde eine kurze Bilanz für den FID GEO bis heute und ein Ausblick auf geplante Entwicklungen für die aktuell beantragte 3. Förderphase vorgetragen
    Description: DFG, SUB Göttingen, GFZ Potsdam
    Description: poster
    Keywords: ddc:550 ; Fachinformationsdienst Geowissenschaften
    Language: German
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  • 51
    Publication Date: 2022-11-29
    Description: Die DFG-geförderten Fachinformationsdienste FID GEO, FID Karten und FID Montan unterstützen ihre jeweils eigene Fachcommunity und agieren zudem als gemeinsames Cluster für das System Erde. Im Zentrum stehen elektronisches Publizieren, Erwerbung und Digitalisierung von Spezialliteratur und Karten sowie die Unterstützung bei der Beschaffung von Geodaten und der Publikation von Forschungsdaten. Spezielle Rechercheinstrumente und in den Suchraum eingebundene fachspezifische Literaturnachweisdatenbanken bieten qualifizierten Zugang zu Informationen. Die hier vorgestellten Fachinformationsdienste kooperieren eng miteinander und ergänzen sich in ihren Angeboten für eine verbesserte Forschungsumgebung in der Erdsystemforschung im Sinne offener Wissenschaft. Das gemeinsame Ziel ist, aus dem FID-Cluster ein echtes Netzwerk zu knüpfen, welches interdisziplinär agiert und gleichermaßen fachspezifisch die Bedarfe der Wissenschaft bedient. Die drei Fachinformationsdienste werden einige ihrer Services kurz vorstellen, Beispiele einer kooperativen Zusammenarbeit und gemeinsame Herausforderungen präsentieren.
    Description: DFG, SUB Göttingen,TU Bergakademie Freiberg, TU Berlin, GFZ Potsdam
    Description: presentation
    Keywords: ddc:550 ; ddc:020 ; ddc:900 ; FID ; Karthographie ; Geowissenschaften ; Montan
    Language: German
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  • 52
    Publication Date: 2022-11-29
    Description: In diesem Poster sollen die Möglichkeiten des offenen Publizierens in den Geowissenschaften, von der Probe über die Daten bis zum fertigen Manuskript und wie der FID GEO diesen Prozess begleitet, gezeigt werden. Hierbei liegt der Fokus auf den Services und Informationssystemen, die dauerhaft verfügbare und verlässlich zitierbare elektronische Publikationen von Schriften und Daten gewährleisten. Es soll das Potenzial und die Nutzbarkeit der beiden Repositorien vorgestellt werden. Der Service der Publikation von Schriften wird im Fachinformationsdienst-eigenem Fachrepositorium GEO-LEOe-docs bereitgestellt. Das fachspezifische Forschungsdaten Repositorium GFZ Data Services steht für die Veröffentlichung von Forschungsdaten und wissenschaftlicher Software aus den Erd- und Umweltwissenschaften zur Verfügung.
    Description: DFG, SUB Göttingen, GFZ Potsdam
    Description: poster
    Keywords: ddc:550 ; Geowissenschaften ; Fachinformationsdienst ; FID GEO
    Language: German
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  • 53
    Publication Date: 2022-11-29
    Description: Knowledge sharing in academia has been considered indispensable and is becoming a priority in most European funding schemes. Although we are already quite familiar with the different possibilities to publish our results in open-access journals, open science means way more than that. Open science aims at opening up research processes and granting access to research outputs to researchers, professionals and amateur scientists. There are different ways to ensure the storage and reusability of our data, making it available to other scientists. Furthermore, most of the scientific disciplines migrate their analyses to open-source environments (e.g., R, Phyton). However, tons of code produced remain stored in our personal computers either because we do not know the appropriate tools to share them with our colleagues or because we believe that it is not well structured. In this short course, you would learn how to establish links between publications, data, software and methods. Hence, we will discuss with our experts: i) the options to share our data and code with other peers, ii) obtain some tips to better organize our scripts, and iii) uncover potential barriers to sharing research and discuss possible solutions.
    Description: DFG, SUB Göttingen, GFZ Potsdam
    Description: presentation
    Keywords: ddc:550 ; Repository ; Data Management ; Open Science
    Language: English
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  • 54
    Publication Date: 2022-11-29
    Description: The rise of Open Science practices is impacting the entire scientific publishing culture. The transition to Open Access for text publications goes hand in hand with the growing demand to make scientific data and software available to the general public. The FAIR data principles play a key role in this, designed to make research and the underlying data easily findable, accessible, interoperable, and reusable for humans and machines. Geosciences data are as diverse as their content. They range from large real-time data streams of international observing networks to small data sets produced by individual researchers at their laboratories. Consequently, there need to be different strategies for data management and publication in which research data repositories can be important partners for the researchers. The Specialised Information Service for Geoscience (FID GEO) is a DFG-funded project that is promoting a holistic approach of Open Science that includes scholarly literature, data, samples, and scientific software equally and pushes for their interlinkage. FID GEO has become an important player for connecting researchers, data repositories, information infrastructures, German geoscientific societies, and publishers. FID GEO actively provides data and text publishing services through its affiliated repositories GFZ Data Services and GEO-LEOe-docs, as well as on-demand digitization of printed geoscience literature and maps. In addition, FID GEO aims to inform the German-based geoscience community about all aspects of Open Science and FAIR data by bringing the discussions to the individual disciplines through various communication channels.
    Description: DFG, SUB Göttingen, GFZ Potsdam
    Description: http://doi.org/10.5194/egusphere-egu22-13354
    Description: presentation
    Keywords: ddc:550 ; Open Science ; Geoscience
    Language: English
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  • 55
    Publication Date: 2022-11-29
    Description: The rise of Open Science practices is impacting the entire scientific publishing culture. The transition to Open Access for text publications goes hand in hand with the growing demand to make scientific data and software available to the general public. The FAIR data principles play a key role in this, designed to make research and the underlying data easily findable, accessible, interoperable, and reusable for humans and machines. Geosciences data are as diverse as their content. They range from large real-time data streams of international observing networks to small data sets produced by individual researchers at their laboratories. Consequently, there need to be different strategies for data management and publication in which research data repositories can be important partners for the researchers. The Specialised Information Service for Geoscience (FID GEO) is a DFG-funded project that is promoting a holistic approach of Open Science that includes scholarly literature, data, samples, and scientific software equally and pushes for their interlinkage. FID GEO has become an important player for connecting researchers, data repositories, information infrastructures, German geoscientific societies, and publishers. FID GEO actively provides data and text publishing services through its affiliated repositories GFZ Data Services and GEO-LEOe-docs, as well as on-demand digitization of printed geoscience literature and maps. In addition, FID GEO aims to inform the German-based geoscience community about all aspects of Open Science and FAIR data by bringing the discussions to the individual disciplines through various communication channels.
    Description: DFG, SUB Göttingen, GFZ Potsdam
    Description: presentation
    Keywords: ddc:550 ; Open Science ; Geoscience
    Language: English
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  • 56
    Publication Date: 2022-11-29
    Description: FZ Data Services is a domain repository for geosciences data comprising the Earth, Space and Environmental Sciences. It assigns digital object identifier (DOI) to data and scientific software since 2004. Hosted at the GFZ German Research Centre for Geosciences (GFZ), the repository has a focus on the curation of long-tail data by domain scientists on one hand, but also provides DOI minting services for several global monitoring networks/observatories in geodesy and geophysics and collaborative projects. Furthermore, as Allocating Agent for the International Generic Sample Number (IGSN), the globally unique persistent identifier for physical samples, GFZ is providing IGSN minting services for physical samples. GFZ Data Services increases the interoperability of long-tail data through (1) the provision of comprehensive domain-specific data description via standardised and machine-readable metadata with controlled domain vocabularies. Metadata is (2) complemeted with comprehensive and standardised technical data descriptions or reports; and (3) by embedding the research data in wider context by providing cross-references through Persistent Identifiers (DOI, IGSN, ORCID, Fundref) to related research products (text, data, software) and people or institutions involved. In addition to the task as a research data publisher, GFZ Data Services is the central node for research data management at the GFZ with information on metadata, data formats, the data publication workflow, FAQ, links to different versions of our metadata editor and downloadable data description templates. Specific data publication guidance is complemented by more general information on data management, like a data management roadmap for PhD students.
    Description: GFZ Potsdam
    Description: presentation
    Keywords: ddc:550 ; Data Management ; Repository
    Language: English
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  • 57
    Publication Date: 2022-11-29
    Description: Die Fachinformationsdienste FID GEO, FID KARTEN und FID MONTAN veranstalteten eine gemeinsame Online-Session für die geowissenschaftlichen Fachreferate. Dabei wurden die einzelnen Fachinformationsdienste und ihre Services präsentiert und es wurde Gelegenheit geben, über zusätzliche Anforderungen an die Dienste aus Sicht der Fachreferate zu sprechen.
    Description: DFG, SUB Göttingen
    Description: presentation
    Keywords: ddc:550 ; Open Access ; Text Publikation
    Language: German
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  • 58
    Publication Date: 2022-11-29
    Description: The shift towards Open Science practices is increasingly demanded by science policy. The transition to Open Access for text publications goes hand in hand with a growing demand to make data, scientific software and samples, freely and FAIRly available to the general public. A persistent problem here is the clear and permanent accessibility and re-usability of scientific publications. This development affects both the scientific publication culture as well as the information infrastructures and poses major challenges to the German- based geosciences community. The specialized information service for geosciences (FID GEO) is a service funded by the German Research Foundation (DFG) and supports the cultural change towards Open Access publications. Hereby, FID GEO pursues a holistic approach to Open Science, including scientific literature, data, samples, and scientific software, and aims to promote their interconnection. FID GEO actively provides data and text publishing services through the affiliated repositories GFZ Data Services and GEO-LEOe-docs, as well as an on-demand digitization service of printed geoscientific literature and maps. The focus here is on the services and information systems that ensure permanently available and reliably citable publications of writings and data. Specifically, the service for text publications is provided in the FID GEOs own subject repository GEO-LEOe- docs. The affiliated research data repository GFZ Data Services is available for the publication of research data and scientific software from the earth and environmental sciences. In addition, FID GEO aims to comprehensively inform the German-based geoscientific community about Open Science and FAIR data by bringing the discussions to the individual disciplines through various communication channels. To strengthen the open information culture in the geosciences, FID GEO collaborates with strategic (inter)national initiatives such as NFDI4Earth, COPDESS and OneGeochemistry.
    Description: DFG, SUB Göttingen, GFZ Potsdam
    Description: poster
    Keywords: ddc:550 ; Open Access
    Language: English
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  • 59
    Publication Date: 2022-11-29
    Description: The Berlin Declaration from 2003 was the starting point for Open Access to scholarly publications. Today, however, we speak about Open Science that reaches far beyond Open Access and represents collaborative, transparent and accessible research that includes all kinds of research results: scholarly literature, research data, software, samples, instruments, etc. In addition, efforts such as the FAIR Principles and the Enabling FAIR Data Commitment Statement, combined with increasing demands for machine accessibility to data, have raised user expectations towards the capabilities of research data repositories and datacentres. These repositories are often key partners supporting researchers in fulfilling the new requirements. This presentation will draw the line from major statements and requirements of Open Science, delineate the role of research data repositories as well as major research infrastructures, like the fNFDI4Earth or EPOS (European Plate Observing System) are additional players in making research data accessible in harmonised form.
    Description: DFG, SUB Göttingen, GFZ Potsdam
    Description: presentation
    Keywords: ddc:550 ; Data ; Open Science
    Language: English
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  • 60
    Publication Date: 2022-11-29
    Description: Als DFG-geförderter Service der Niedersächsischen Staats- und Universitätsbibliothek Göttingen (SUB) und des Deutschen GeoForschungsZentrums GFZ unterstützt der Fachinformationsdienst Geowissenschaften (FID GEO) den Wandel in der Forschungs- und Publikationskultur hin zu Open Science. Die freie Zugänglichkeit, aber auch Praktiken wie die korrekte Dokumentation und Verknüpfung verschiedener Forschungsbestandteile und Veröffentlichungsformate (Probenregistrierung, Datenpublikation, Texte, Karten, Software), stehen hier im Fokus. Der FID GEO bietet mit dem von der SUB Göttingen betriebenen Fachrepositorium GEO-LEOe-docs eine sachgerechte Open-Access-Publikation geowissenschaftlicher Werke an. Liegen diese nur gedruckt vor, übernimmt der FID GEO auch die unentgeltliche und professionelle Digitalisierung im Vorfeld der Online-Veröffentlichung. Seit 2021 ist die Telma auf der Startseite von GEO-LEOe-docs als fortlaufende Netzpublikation prominent hervorgehoben. Bereits seit 2018 erscheint sie parallel zum Druck als frei zugängliche Online-Publikation auf GEO-LEOe-docs. Ein großer Teil älterer TELMA-Artikel konnte digitalisiert und ebenfalls online gestellt werden. Die neueren Entwicklungen im FID GEO, darunter die Einbindung von ORCID und fortlaufenden Netzpublikationen im Repositorium, werden vorgestellt. Auch hat sich das jährliche DownloadVolumen von GEO-LEOe-docs in den letzten vier Jahren (2021 gegenüber 2017) verzehnfacht. Dass die Wissenschaft insgesamt besser vorankommt, wenn vorhergehende Forschungsergebnisse den Forschenden umfassender zugänglich sind, versteht sich. Doch auch für Autor*innen ist die frei zugängliche Publikation ihrer Ergebnisse im Open Access von Vorteil, da sie zu einer erhöhten Verbreitung der Veröffentlichungen führt, die folglich auch häufiger zitiert werden. Ebenso profitieren die Journale davon, da sich ihre Reichweite und damit die Beliebtheit der Zeitschrift erhöht. www.fidgeo.de https://e-docs.geo-leo.de/
    Description: DFG, SUB Göttingen
    Description: presentation
    Keywords: ddc:550 ; Open Access
    Language: German
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  • 61
    Publication Date: 2022-11-29
    Description: How open is our research? A discussion on the state of Open Science in the field of mineralogy and petrology. Vortrag bei der Arbeitsgruppe Mineralogie+Petrologie der Uni Potsdam, 29.04.2022 A brief look at current trends toward an open science with a focused look at the state of the art in mineralogy and petrology. Followed by a discussion on how research in mineralogy and petrology can become more open.
    Description: DFG, GFZ Potsdam
    Description: presentation
    Keywords: ddc:550 ; Open Access
    Language: English
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  • 62
    Publication Date: 2023-01-26
    Description: We present the first‐generation full‐waveform tomographic model (SinoScope 1.0) for the crust‐mantle structure beneath China and adjacent regions. The three‐component seismograms from 410 earthquakes recorded at 2,427 stations are employed in iterative gradient‐based inversions for three successively broadened period bands of 70–120 s, 50–120 s, and 30–120 s. Synthetic seismograms were computed using GPU‐accelerated spectral‐element simulations of seismic wave propagation in 3‐D anelastic models, and Fréchet derivatives were calculated based on an adjoint‐state method facilitated by a checkpointing algorithm. The inversion involved 352 iterations, which required 18,600 wavefield simulations. SinoScope 1.0 is described in terms of isotropic P‐wave (VP), horizontally and vertically polarized S‐wave velocities (VSH and VSV), and mass density (ρ), which are independently constrained with the same data set coupled with a stochastic L‐BFGS quasi‐Newton optimization scheme. It systematically reduced differences between observed and synthetic full‐length seismograms. We performed a detailed resolution analysis by repairing input random parametric perturbations, indicating that resolution lengths can approach the half propagated wavelength within the well‐covered areas. SinoScope 1.0 reveals strong lateral heterogeneities in the lithosphere, and features correlate well with geological observations, such as sedimentary basins, Holocene volcanoes, Tibetan Plateau, Philippine Sea Plate, and various tectonic units. The asthenosphere lies below the lithosphere beneath East and Southeast Asia, bounded by subduction trenches and cratonic blocks. Furthermore, we observe an enhanced image of well‐known slabs along strongly curved subduction zones, which do not exist in the initial model.
    Description: Plain Language Summary: Subduction (a geological process where the oceanic lithosphere descends into the Earth's mantle at convergent boundaries) has been the dominant plate‐tectonic process in the broad Asian region since the Mesozoic (252–66 million years ago). The nature of cold subducting slabs and hot mantle flows can record and affect the tectonic evolution of the overriding lithospheric plates. In this study, we conduct the full waveform inversion on a large data set to image the crust‐mantle structure of this region. The computationally demanding simulations were performed on two of the world's fastest supercomputing facilities. Our new model delivers seismic illumination of the region at unprecedented resolution and exhibits sharper and more detailed shear wave velocity structure in the lithosphere with greatly improved correlations with surface tectonic units compared to previous tomographic models. The narrow low‐velocity layer (generally referred to as asthenosphere) below the lithosphere is present beneath East and Southeast Asia, bounded by subduction trenches and cratonic blocks. The continuous and intense subduction processes are responsible for high‐velocity anomalous bodies in the mantle and the formation of the asthenosphere mentioned above.
    Description: Key Points: We construct a new full‐waveform tomographic model of the broad Asian region for 30–120 s period via adjoint and spectral‐element methods. The resolution analysis shows reasonably good resolution in the frequency band of interest and limited trade‐offs between model parameters. Our model shed new light on the subsurface behavior of cold subducting slabs & hot mantle flows and their relation to the overriding plates.
    Description: China Scholarship Council http://dx.doi.org/10.13039/501100004543
    Description: Swiss National Supercomputing Center
    Description: European Unions Horizon 2020
    Description: The Collaborative Seismic Earth Model
    Description: National Natural Science Foundation of China
    Description: Korea Meteorological Administration Research and Development Program
    Description: Korean Government
    Description: Ministry of Education
    Description: https://doi.org/10.5281/zenodo.6597380
    Keywords: ddc:550 ; Asia ; mantle ; lithosphere ; seismic tomography ; computional seismology
    Language: English
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  • 63
    Publication Date: 2023-01-27
    Description: Abrupt fluid emissions from shallow marine sediments pose a threat to seafloor installations like wind farms and offshore cables. Quantifying such fluid emissions and linking pockmarks, the seafloor manifestations of fluid escape, to flow in the sub‐seafloor remains notoriously difficult due to an incomplete understanding of the underlying physical processes. Here, using a compositional multi‐phase flow model, we test plausible gas sources for pockmarks in the south‐eastern North Sea, which recent observations suggest have formed in response to major storms. We find that the mobilization of pre‐existing gas pockets is unlikely because free gas, due to its high compressibility, damps the propagation of storm‐induced pressure changes deeper into the subsurface. Rather, our results point to spontaneous appearance of a free gas phase via storm‐induced gas exsolution from pore fluids. This mechanism is primarily driven by the pressure‐sensitivity of gas solubility, and the appearance of free gas is largely confined to sediments in the vicinity of the seafloor. We show that in highly permeable sediments containing gas‐rich pore fluids, wave‐induced pressure changes result in the appearance of a persistent gas phase. This suggests that seafloor fluid escape structures are not always proxies for overpressured shallow gas and that periodic seafloor pressure changes can induce persistent free gas phase to spontaneously appear.
    Description: Plain Language Summary: Thousands of pockmarks, circular depressions in the seafloor, were reported in North Sea, presumably formed in response to wave motions during major storms. It has been hypothesized that these pockmarks formed as pre‐existing shallow free‐gas pockets were mobilized by pressure changes of the waves. However, mechanisms that could have mobilized free‐gas are not yet constrained. Moreover, large scale free‐gas accumulations have not been reported in this region, and therefore, commonly invoked mechanisms like tensile failure and breaching of capillary seals are hard to justify as they rely on the presence of pre‐existing gas pockets. Here, through modeling studies, we tackle the question of the source of the observed free‐gas. Our study consists of two parts: First, assuming that some hitherto unknown shallow free‐gas pocket is indeed present, we test whether storm‐induced pressure changes could breach capillary seals. We find that free‐gas damps pressure changes due to its high compressibility, making the mobilization of pre‐existing gas unlikely. In the second part, we propose an alternative mechanism where free‐gas spontaneously appears due to exsolution from pore‐fluids. We test the feasibility of this mechanism and show how periodic pressure changes can lead to a persistent gas phase, that could explain the elusive gas source linked to these pockmarks.
    Description: Key Points: Storm‐induced pressure changes can lead to spontaneous appearance of free gas phase near the seafloor. This process is driven by pressure‐sensitive phase instabilities. This mechanism could help explain elusive gas sources in recently observed pockmarks in the North Sea.
    Description: Aker BP (AkerBP) http://dx.doi.org/10.13039/100016998
    Description: Deutsche Forschungsgemeinschaft, DFG
    Keywords: ddc:550 ; pockmarks ; storm related pockmarks ; spontaneous free gas ; gas source ; modeling
    Language: English
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  • 64
    Publication Date: 2023-11-24
    Description: This GGR Bibliographic Review is a survey of approximately 5200 geoanalytical publications for the year 2021. Selected articles, numbering over 340, containing measurement results for relevant geological and environmental reference materials are listed with individual summaries of target analytes, relevant reference materials and producers. A brief summary of a selection of these publications is included that highlights notable developments in geoanalytical studies, newly developed or characterised RMs, and new datasets of established reference materials that have been re‐analysed using improved or state‐of‐the‐art measurement techniques.
    Description: Key Points: Literature review of 5200 geoanalytical publications for the year 2021. 344 selected articles with summaries of target analytes, relevant reference materials and producers. Selected publications include data obtained by new analytical developments and improved analytical protocols for established RMs, and identifies recently developed RMs for specific scientific topics.
    Description: http://georem.mpch-mainz.gwdg.de/
    Keywords: ddc:550 ; review ; analytical geochemistry ; geochemical reference materials ; reference material data ; GeoReM database ; environmental reference materials
    Language: English
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  • 65
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    Deutsche Geophysikalische Gesellschaft, Hamburg
    In:  Herausgeberexemplar
    Publication Date: 2021-08-07
    Description: Die Jubiläumsschrift zum 75jährigen Bestehen der Deutschen Geophysikalischen Gesellschaft (DGG) enthält zahlreiche Beiträge von Mitgliedern zu vier Schwerpunkten: 1) Eine Aktualisierung der Geschichte der DGG vor allem zu den an Ereignissen reichen letzten 25 Jahren sowie Ergänzungen zu vorausgegangenen Darstellungen. 2) Die Darstellung der Geschichte geophysikalischer Institute und Institutionen in Deutschland inklusive eines Rückblicks auf das erfolgreiche Wirken ihrer verdienstvollen Persönlichkeiten. 3) Die Beschreibung einer Auswahl in der deutschen Geophysik angegangener Großprojekte der letzten 25 Jahre. 4) In Anlehnung an die Festschrift zum 50jährigen Gründungsjubiläum ist schließlich noch ein Kapitel zu geophysikalischen 'Detailthemen' ausgeführt. In ihm sind auch Beiträge enthalten, die Traditionslinien bzw. Arbeiten betreffen, die in der früheren DDR aufgenommen worden waren und z.T. keine direkte Fortsetzung an einer Nachfolgeinstitution gefunden haben.
    Description: commemorativepublication
    Keywords: 550 ; Geschichte der Geophysik ; Festschriften {Geophysik} ; Deutsche Geophysikalische Gesellschaft ; Deutschland ; Geophysik ; Geschichte ; FID-GEO-DE-7
    Language: German
    Type: anthology_digi
    Format: 226 S.
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  • 66
    facet.materialart.
    Unknown
    DGG, [Münster]
    In:  Herausgeberexemplar
    Publication Date: 2021-05-06
    Description: Wird heute genug für die wissenschaftliche und technologische Steuerung des sich immer rasanter vollziehenden globalen und regionalen Wandels der Bio- und Geosphäre getan? Hat die internationale Gemeinschaft die Kraft zu einem sinnvollen, übergreifenden "Umwelt-Management"? Geophysik kann auf Grund ihrer interdisziplinären Stellung innerhalb der Naturwissenschaften und mit ihren vielfältigen Beziehungen zur Technik zum effizienten Einsatz der Kräfte und Mittel beitragen - in einer Zeit weltweiter sozialer, politischer und eben auch ökologischer Konflikte. Geophysik kann notwendige Prioritäten wissenschaftlich begründen und verfechten und somit helfen, weittragende und konsensfähige Entscheidungen vorzubereiten, um gesellschaftliche Akzeptanz und Unterstützung für die Politik zu erreichen. Die Deutsche Geophysikalische Gesellschaft - getragen von ihrer Verantwortung um den Beitrag der Geophysik für die gemeinsame Zukunft - wendet sich im 75. Jahr ihres Bestehens mit dieser Denkschrift an die Öffentlichkeit. Teil I enthält einen Überblick zur Spezifik, zur Stellung, zu den Zielen und zur Bedeutung der Geophysik. Im Teil II stellen führende Geophysiker ausgewählte Beispiele moderner geophysikalischer Forschung vor. Teil III ist statistisch angelegt und gibt einen kurzen Überblick zu den in Deutschland angesiedelten Institutionen geophysikalischer Lehre und Forschung. Die Denkschrift "Mit Geophysik in die Zukunft" will Politiker, Industrielle, Wissenschaftler, Vertreter der Medien und interessierte Bürger erreichen, um im Interesse des Gemeinwohls zu angemessener Wissenschaftsförderung und kluger Zukunftsgestaltung beizutragen.
    Description: commemorativepublication
    Description: DFG, SUB Göttingen
    Keywords: 550 ; Wissenschaftsorganisation und -pflege {Geophysik} ; Geophysik ; Wissenschaft ; Forschung ; Deutschland ; FID-GEO-DE-7
    Language: German
    Type: anthology_digi
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  • 67
    Publication Date: 2022-04-04
    Description: Observations in polar regions show that sea ice deformations are often narrow linear features. These long bands of deformations are referred to as Linear Kinematic Features (LKFs). Viscous‐plastic sea ice models have the capability to simulate LKFs and more generally sea ice deformations. Moreover, viscous‐plastic models simulate a larger number and more refined LKFs as the spatial resolution is increased. Besides grid spacing, other aspects of a numerical implementation, such as the placement of velocities and the associated degrees of freedom, may impact the formation of simulated LKFs. To explore these effects this study compares numerical solutions of sea ice models with different velocity staggering in a benchmark problem. Discretizations based on A‐,B‐, and C‐grid systems on quadrilateral meshes have similar resolution properties as an approximation with an A‐grid staggering on triangular grids (with the same total number of vertices). CD‐grid approximations with a given grid spacing have properties, specifically the number and length of simulated LKFs, that are qualitatively similar to approximations on conventional Arakawa A‐grid, B‐grid, and C‐grid approaches with half the grid spacing or less, making the CD‐discretization more efficient with respect to grid resolution. One reason for this behavior is the fact that the CD‐grid approach has a higher number of degrees of freedom to discretize the velocity field. The higher effective resolution of the CD‐discretization makes it an attractive alternative to conventional discretizations.
    Description: Plain Language Summary: Sea ice in the Arctic and Antarctic Oceans plays an important role in the exchange of heat and freshwater between the atmosphere and the ocean and hence in the climate in general. Satellite observations of polar regions show that the ice drift sometimes produces long features that are either cracks (leads) and zones of thicker sea ice (pressure ridges). This phenomenon is called deformation. It is mathematically described by the non‐uniform way in which the ice moves. For numerical models of sea ice motion it is difficult to represent this deformation accurately. Details of the numerics may affect the way these models simulate leads and ridges, their number and length. Specifically, we find by comparing different numerical models, that the way the model variables are ordered on a computational grid to solve the mathematical equations of sea ice motion has an effect of how many deformation features can be represented on a grid with a given spacing between grid points. A new discretization (ordering of model variables) turns out to resolve more details of the approximated field than traditional methods.
    Description: Key Points: The placement of the sea ice velocity has a mayor influence on the number of simulated linear kinematic features (LKFs). The CD‐grid resolves twice as many LKFs compared to A, B, C‐grids. A, B, C‐grids on quadrilateral meshes resolve a similar number of LKFs as A‐grids on triangular meshes (with the same total number of nodes).
    Keywords: ddc:550 ; ddc:551.343
    Language: English
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  • 68
    Publication Date: 2022-04-01
    Description: Porosity is one of the key properties of fluvial sediments. It is defined as the ratio of pore volume to total volume. In river science, porosity is often assumed to be spatially constant, which might be a gross simplification of reality. Ignoring the spatial variations in porosity can cause errors in morphological, ecological, hydrological, hydrogeological and sedimentological applications. Although detailed information about spatial porosity variations can be obtained from porosity measurements at field sites, such information has never been collected where these variations might be important. In this study, field porosity measurements were carried out to quantify the magnitude of the spatial porosity variation for four different sedimentological environments of a braided river: a confluence, a tributary delta, a braid bar and a secondary channel. A nuclear density gauge was used for the measurement of porosity. The nuclear density gauge proved to be a time‐saving and labour‐saving technique that produces accurate porosity values with a root mean square error of 0.03. The four sedimentological environments showed significant differences in porosity, with mean porosity being lower for confluence and bar than for delta and secondary channel. Semi‐variogram analysis showed the absence of any spatial correlation in porosity for distances beyond 4 m. This shows that distance cannot be used as a parameter for porosity extrapolation in a fluvial system unless the extrapolation distance is less than 4 m. At least eight measurements of porosity are required to obtain a reliable estimate of mean porosity in a sedimentary environment, i.e. with uncertainty 〈0.03. Although grain size characteristics were found to have a significant impact on porosity, the relationships between these parameters and porosity were not very strong in this study. The unique porosity dataset, presented in this article, provides a valuable source of information for researchers and river managers.
    Description: Deutsche Forschungsgemeinschaft
    Keywords: ddc:550
    Language: English
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  • 69
    Publication Date: 2022-03-31
    Description: Mixed sand‐ and gravel‐bed rivers record erosion, transport, and fining signals in their bedload size distributions. Thus, grain‐size data are imperative for studying these processes. However, collecting hundreds to thousands of pebble measurements in steep and dynamic high‐mountain river settings remains challenging. Using the recently published digital grain‐sizing algorithm PebbleCounts, we were able to survey seven large (≥ 1,000 m2) channel cross‐sections and measure thousands to tens‐of‐thousands of grains per survey along a 100‐km stretch of the trunk stream of the Toro Basin in Northwest Argentina. The study region traverses a steep topographic and environmental gradient on the eastern margin of the Central Andean Plateau. Careful counting and validation allows us to identify measurement errors and constrain percentile uncertainties using large sample sizes. In the coarse ≥2.5 cm fraction of bedload, only the uppermost size percentiles (≥95th) vary significantly downstream, whereas the 50th and 84th percentiles show less variability. We note a relation between increases in these upper percentiles and along‐channel junctions with large, steep tributaries. This signal is strongly influenced by lithology and geologic structures, and mixed with local hillslope input. In steep catchments like the Toro Basin, we suggest nonlinear relationships between geomorphic metrics and grain size, whereby the steepest parts of the landscape exert primary control on the upper grain‐size percentiles. Thus, average or median metrics that do not apply weights or thresholds to steeper topography may be less predictive of grain‐size distributions in such settings.
    Description: Plain Language Summary: Rock fragments on hillsides are transported to rivers, eventually becoming pebbles, sand, and mud as they are carried downstream by flowing water. The initial size of the pebbles, the way the size changes downstream, and the overprinting of the sizes with new pebbles from other hills and tributaries all form a complex process that can be difficult to disentangle. Yet studying the size of the pebbles at a given stream location or in a sedimentary deposit can provide insights into the conditions of their transport in terms of local upstream patterns of erosion, tectonics, and climate. We show that just looking at the size of the large pebbles on a riverbed can be used to infer the sources of material, but, since there are fewer large pebbles, they require more measurements to quantify. This necessitates new methods for pebble measurement using modern image‐processing tools.
    Description: Key Points: Complex grain‐size distributions in dynamic mountain rivers can be computed via thousands of measurements from PebbleCounts. Many measurements allow robust estimation of higher percentiles and we observe the most significant changes in the ≥95th percentile. Downstream grain‐size variation is nonlinearly related to variations in topographic steepness and lithology.
    Description: Deutsches Zentrum für Luft‐ und Raumfahrt (DLR) http://dx.doi.org/10.13039/501100002946
    Description: Deutsche Forschungsgemeinschaft (DFG) http://dx.doi.org/10.13039/501100001659
    Description: Bundesministerium für Bildung und Forschung (BMBF) http://dx.doi.org/10.13039/501100002347
    Description: Brandenburger Staatsministerium für Wissenschaft, Forschung und Kultur (MWFK) http://dx.doi.org/10.13039/501100004581
    Description: https://zenodo.org/record/5089789
    Keywords: ddc:551.3 ; ddc:550
    Language: English
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  • 70
    Publication Date: 2022-03-29
    Description: A reanalysis is a physically consistent set of optimally merged simulated model states and historical observational data, using data assimilation. High computational costs for modeled processes and assimilation algorithms has led to Earth system specific reanalysis products for the atmosphere, the ocean and the land separately. Recent developments include the advanced uncertainty quantification and the generation of biogeochemical reanalysis for land and ocean. Here, we review atmospheric and oceanic reanalyzes, and more in detail biogeochemical ocean and terrestrial reanalyzes. In particular, we identify land surface, hydrologic and carbon cycle reanalyzes which are nowadays produced in targeted projects for very specific purposes. Although a future joint reanalysis of land surface, hydrologic, and carbon processes represents an analysis of important ecosystem variables, biotic ecosystem variables are assimilated only to a very limited extent. Continuous data sets of ecosystem variables are needed to explore biotic‐abiotic interactions and the response of ecosystems to global change. Based on the review of existing achievements, we identify five major steps required to develop terrestrial ecosystem reanalysis to deliver continuous data streams on ecosystem dynamics.
    Description: Plain Language Summary: A reanalysis is a unique set of continuous variables produced by optimally merging a numerical model and observed data. The data are merged with the model using available uncertainty estimates to generate the best possible estimate of the target variables. The framework for generating a reanalysis consists of the model, the data, and the model‐data‐fusion algorithm. The very specific requirements of reanalysis frameworks have led to the development of Earth‐compartment specific reanalysis for the atmosphere, the ocean and land. Here, we review atmospheric and oceanic reanalyzes, and in more detail biogeochemical ocean and terrestrial reanalyzes. In particular, we identify land surface, hydrologic, and carbon cycle reanalyzes which are nowadays produced in targeted projects for very specific purposes. Based on a review of existing achievements, we identify five major steps required to develop reanalysis for terrestrial ecosystem to shed more light on biotic and abiotic interactions. In the future, terrestrial ecosystem reanalysis will deliver continuous data streams on the state and the development of terrestrial ecosystems.
    Description: Key Points: Reanalyzes provide decades‐long model‐data‐driven harmonized and continuous data sets for new scientific discoveries. Novel global scale reanalyzes quantify the biogeochemical ocean cycle, terrestrial carbon cycle, land surface, and hydrologic processes. New observation technology and modeling capabilities allow in the near future production of advanced terrestrial ecosystem reanalysis.
    Description: European Union's Horizon 2020 research and innovation programme
    Description: Deutsche Forschungsgemeinschaft
    Description: U.S. Department of Energy
    Description: Emory University's Halle Institute for Global Research and the Halle Foundation Collaborative Research
    Description: NSF
    Description: NASA
    Description: Natural Environment Research Council
    Description: European Union'’s Horizon 2020 research and innovation programme
    Description: NSERC Discovery program, the Ocean Frontier Institute, and MEOPAR
    Description: Research Foundation Flanders (FWO)
    Description: Helmholtz Association
    Description: NASA Terrestrial Ecosystems
    Keywords: ddc:550
    Language: English
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  • 71
    Publication Date: 2023-09-12
    Description: Determination of earth pressures is one of the fundamental tasks in geotechnical engineering. Although many different methods have been utilized to present passive earth pressure coefficients, the influence of non-associated plasticity on the passive earth pressure problem has not been discussed intensively. In this study, finite-element limit analysis and displacement finite-element analysis are applied for frictional materials. Results are compared with selected data from literature in terms of passive earth pressure coefficients, shape of failure mechanism and robustness of the numerical simulation. The results of this study show that passive earth pressure coefficients determined with an associated flow rule are comparable to the Sokolovski solution. However, comparison with a non-associated flow rule reveals that passive earth pressure coefficients are significantly over predicted when following an associated flow rule. Moreover, this study reveals that computational costs for determination of passive earth pressure are considerably larger following a non-associated flow rule. Additionally, the study shows that numerical instabilities arise and failure surfaces become non-unique. It is shown that this problem may be overcome by applying the approach suggested by Davis (Soil Mech 341–354, 1968).
    Description: Ruhr-Universität Bochum (1007)
    Keywords: ddc:550 ; Finite-element limit analysis ; Finite-element analysis ; Non-associated plasticity ; Passive earth pressure
    Language: English
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  • 72
    Publication Date: 2023-09-13
    Description: The pure cross-anisotropy is understood as a special scaling of strain (or stress). The scaled tensor is used as an argument in the elastic stiffness (or compliance). Such anisotropy can be overlaid on the top of any elastic stiffness, in particular on one obtained from an elastic potential with its own stress-induced anisotropy. This superposition does not violate the Second Law. The method can be also applied to other functions like plastic potentials or yield surfaces, wherever some cross-anisotropy is desired. The pure cross-anisotropy is described by the sedimentation vector and at most two constants. Scaling with more than two purely anisotropic constants is shown impossible. The formulation was compared with experiments and alternative approaches. Static and dynamic calibration of the pure anisotropy is also discussed. Graphic representation of stiffness with the popular response envelopes requires some enhancement for anisotropy. Several examples are presented. All derivations and examples were accomplished using the algebra program Mathematica.
    Description: Karlsruher Institut für Technologie (KIT) (4220)
    Keywords: ddc:550 ; Cross-anisotropy ; Hyperelasticity ; Inherent anisotropy ; Response envelopes ; Scaling of strain ; Transverse isotropy
    Language: English
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  • 73
    Publication Date: 2023-03-15
    Description: The near-surface geology of northern Germany is characterized by glacial deposits, deformed by rising Permian and Upper Triassic salt structures. Ground motions potentially associated with salt tectonic processes are very slow and are superimposed by signals of e.g. hydrological and anthropogenic sources. To measure them requires the detection of motion rates in the range of a few millimeters per year with sufficient spatial coverage. For large areas little is known about the rates and the characteristics of ground motions, even though they directly affect anthropogenic infrastructure and could have an impact on the future use of the underground for storage purposes or the exploitation of geothermal energy. To measure ground motion, we use radar interferometric time series data provided by the German Aerospace Center and the Federal Institute for Geosciences and Natural Resources' Ground motion service. These data are based on Synthetic Aperture Radar images acquired by ESA's ERS and Sentinel satellites. Time-series analyses are possible for temporally stable backscattering objects (persistent scatterers) on the ground. Generally, this results in spatially dense observations over built-up areas and sparse observations over rural areas. We use a set of geostatistical methods to analyze these time series data. We detect signals of large-scale surface-deforming processes such as the subsidence of the marshes. We see small-scale signals like the swelling of Permian anhydrite at the Segeberger "Kalkberg". And we can observe subsidence processes over the historic town of Lübeck. Our work extends the area of application of the PS-InSAR technique from areas with high motion rates to regions with particular low motion rates. We discuss methods that can be used to link ERS data to the Sentinel-1 data, in particular, to separate long-term motion processes from short-term effects. We are working on techniques that shall help to decompose different signal sources. Finally, we aim to prepare a set of tools, that can be used by the community.
    Description: poster
    Keywords: ddc:550 ; InSAR ; Persistent scatterer ; Ground motion
    Language: English
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  • 74
    Publication Date: 2023-08-25
    Description: The objective of the current study is to utilize an innovative method called “change probabilities” for describing fracture roughness. In order to detect and visualize anisotropy of rock joint surfaces, the roughness of one-dimensional profiles taken in different directions is quantified. The central quantifiers, change probabilities, are based on counting monotonic changes in discretizations of a profile. These probabilities, which usually vary with the scale, can be reinterpreted as scale-dependent Hurst exponents. For a large class of Gaussian stochastic processes, change probabilities are shown to be directly related to the classical Hurst exponent, which generalizes a relationship known for fractional Brownian motion. While related to this classical roughness measure, the proposed method is more generally applicable, therefore increasing the flexibility of modeling and investigating surface profiles. In particular, it allows a quick and efficient visualization and detection of roughness anisotropy and scale dependence of roughness.
    Description: Karlsruher Institut für Technologie http://dx.doi.org/10.13039/100009133
    Description: Bundesministerium für Bildung und Forschung http://dx.doi.org/10.13039/501100002347
    Keywords: ddc:550 ; Fracture roughness ; Anisotropy ; Change probability ; Fractional Brownian motion ; Hurst exponent ; Scale dependence ; 60G18 ; 60G15
    Language: English
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  • 75
    Publication Date: 2023-07-29
    Description: After the publication of the type-profiles for the estimation of the joint roughness coefficient (JRC) a discussion evolved about how to adequately use these traces. Based on the chart numerous researchers assembled mathematical correlations with various parameters seeking objectivity in the determination of JRC. Within these works differences concerning the database and the mathematical implementations exist. Consequently, each correlation, although predominantly the same parameters are used, leads to different JRC values. In theory, for any arbitrary profile, irrespective of the particular calculation approach, the same JRC should result. This is a requisite because of the referencing of all correlations to the 10 type-profiles. However, it is shown in this study that in most cases equal or even satisfactorily similar results are not obtained. The discrepancies are vast when non-standard profiles are evaluated, in this case, more than 40,000 traces from six different rock surfaces that cover a broad range of roughness categories. The simple intuitive parameter Z2 served as an agent for the statistical methods because of its broad use and consequently good comparability. On the part of the fractal approaches, three definitions were used. However, JRC inferred from fractal correlations are very much dependent on the particular calculation routine. In fact, the theory of fractals is overly complex for the sparse and low-resolution type-profiles. In summary, fractal approaches do not produce safer or more reliable estimates of roughness compared to simple statistical means and using Z2 perfectly suffices to determine the class of JRC.
    Description: Projekt DEAL
    Keywords: ddc:550 ; Compass walking ; FFT ; Spectral analysis ; RMS correlation ; Z 2 ; Shear strength
    Language: English
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  • 76
    Publication Date: 2023-07-29
    Description: In this study, we carried out reactivation potential analysis of discontinuities revealed from four exploration boreholes penetrating heavily faulted and folded Upper Carboniferous rock strata of the Ruhr region. We performed this study based on the notion that slip is controlled by the ratio of shear to effective normal stresses acting on a pre-existing plane of weakness in the prevailing stress field configuration. The results of this analysis were supported by indicators of localized fluid flow, both on micro- and macro-scales, which confirm relationship between secondary permeability and in situ stress state in the Ruhr region. Findings from this study, in conjunction with results of destructive laboratory testing, indicate that the steep NW–SE- and NNE–SSW-striking planar discontinuities are likely to be either close to the critical state or critically stressed in the in situ stress configuration in the Ruhr region. These planar structures, as evidenced by indicators of localized permeability, are the main fluid pathways in the studied region. The NE–SW-striking discontinuities, on the other hand, are most likely to be closed and hydraulically inactive in the prevailing stress state. Based on results gained from this study, implications for utilization of deep geothermal energy in the region were discussed.
    Description: Bundesministerium für Bildung und Forschung http://dx.doi.org/10.13039/501100002347
    Description: Fraunhofer-Einrichtung für Energieinfrastruktur und Geothermie IEG (1050)
    Keywords: ddc:550 ; Reservoir geomechanics ; Geothermal geomechanics ; Crustal stresses ; Geothermal energy ; Deep geothermal systems ; Ruhr region
    Language: English
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  • 77
    Publication Date: 2023-07-29
    Description: The coexistence of a wide variety of subsurface uses in urban areas requires increasingly demanding geological prediction capacities for characterizing the geological heterogeneities at a small-scale. In particular, detrital systems are characterized by the presence of highly varying sediment mixtures which control the non-constant spatial distribution of properties, therefore presenting a crucial aspect for understanding the small-scale spatial variability of physical properties. The proposed methodology uses the lithological descriptions from drilled boreholes and implements sequential indicator simulation to simulate the cumulative frequencies of each lithological class in the whole sediment mixture. The resulting distributions are expressed by a set of voxel models, referred to as Di models. This solution is able to predict the relative amounts of each grain fraction on a cell-by-cell basis and therefore also derive a virtual grain size distribution. Its implementation allows the modeler to flexibly choose both the grain fractions to be modeled and the precision in the relative quantification. The concept of information entropy is adapted as a measure of the disorder state of the clasts mixture, resulting in the concept of “Model Lithological Uniformity,” proposed as a measure of the degree of detrital homogeneity. Moreover, the “Most Uniform Lithological Model” is presented as a distribution of the most prevailing lithologies. This method was tested in the city of Munich (Germany) using a dataset of over 20,000 boreholes, providing a significant step forward in capturing the spatial heterogeneity of detrital systems and addressing model scenarios for applications requiring variable relative amounts of grain fractions.
    Description: Bayerisches Staatsministerium für Umwelt und Verbraucherschutz http://dx.doi.org/10.13039/501100010219
    Description: Technische Universität München (1025)
    Keywords: ddc:550 ; Geological 3-D modeling ; Geostatistics ; Sequential indicator simulation ; Lithological heterogeneity ; Underground management
    Language: English
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  • 78
    Publication Date: 2022-12-08
    Description: Einer der bekanntesten Forscher in Ungarn war der 1919 verstorbene Lóránd Eötvös. Dieser Artikel wurde zum Gedenken erstellt. Viele wissenschaftliche Theorien und Erfindungen sind mit seinem Namen verbunden. Beispiele sind der Eötvös-Effekt, das Torsionspendel oder die Vermutung der „fünften Kraft“.
    Description: DFG, SUB Göttingen
    Description: research
    Keywords: ddc:550 ; Kontinentalwanderung ; Wegener ; polare Abstoßungskraft ; Milanković
    Language: German
    Type: doc-type:article , publishedVersion
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  • 79
    Publication Date: 2022-09-26
    Description: Die Instrumente an Bord des am 9. Februar 2020 gestarteten Solar Orbiters beobachten die Sonne und messen die Teilchen und elektromagnetischen Felder im Sonnenwind. Dieser Artikel gibt eine Übersicht über die Mission und fasst eine Auswahl der ersten Ergebnisse zusammen. Solar Orbiter wird in den kommenden Jahren durch seine detaillierten Beobachtungen der Sonne und Messungen des Sonnenwindes das Feld der Weltraumgeophysik maßgeblich mitbestimmen.
    Description: DFG, SUB Göttingen
    Description: research
    Keywords: ddc:550
    Language: German
    Type: doc-type:article
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  • 80
    Publication Date: 2022-07-12
    Description: Die Erdbeben in Thüringen und angrenzenden Gebieten aus den Jahren von 841 bis 2020 werden zusammengestellt. Damit wird für dieses Gebiet ein schneller Überblick über die Seismizität ermöglicht. In dieser, nunmehr letzten Ausgabe, wurden die bekannten historischen seismischen Ereignisse mit Rücksicht auf eine neue Quelle auf einen neuen Stand gebracht. Die Verteilung der Erdbeben, so zeigt sich, folgt ausgewählten geologischen Störungen. Sie rechtfertigt die Aufteilung des Untersuchungsgebietes in vier seismische Regionen.
    Description: report
    Keywords: ddc:550 ; ddc:551.22
    Language: German
    Type: doc-type:book
    Format: 38
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  • 81
    Publication Date: 2022-09-20
    Description: Die 1902 von Emil Wiechert errichtete Göttinger Erdbebenstation GTT ist heute noch voll funktionsfähig und wird seit 2005 vom Verein Wiechert'sche Erdbebenwarte Göttingen betreut und von vielen Besuchern bestaunt. Die Registrierung einer 3 km entfernten Bombensprengung zeigt eindrucksvoll die große Übereinstimmung der Seismogramme des 17t-Pendels von GTT und dem benachbarten STS-2-Breitbandseismometer der Station GTTG.
    Description: DFG, SUB Göttingen
    Description: research
    Keywords: ddc:550
    Language: German
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  • 82
    Publication Date: 2022-09-20
    Description: Aus Anlass des 100. Jahrestages der Gründung der Deutschen Geophysikalischen Gesellschaft im Jahre 1922 in Leipzig erschien im Verlag Edition am Gutenbergplatz Leipzig das Taschenbuch „Wiechert, Mintrop & Co. – Die 24 Gründungsväter der Deutschen Geophysikalischen Gesellschaft“ von Franz Jacobs und Michael Börngen (siehe gleichlautenden Archivbeitrag in DGG-Mitteilungen 1/2019: 36–37). Die DGG-Präsidentin Heidrun Kopp hat darin das Geleitwort geschrieben. Das Buch kann über den Buchhandel unter ISBN 978-3-95922-107-8 bestellt werden. Der folgende Artikel über den Aachener Meteorologen Peter Polis ist ein leicht erweitertes Kapitel aus diesem Buch.
    Description: DFG, SUB Göttingen
    Description: research
    Keywords: ddc:550
    Language: German
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  • 83
    Publication Date: 2022-12-01
    Description: Die Methode der Spektrale Induzierte Polarisation (SIP) misst die Frequenzabhängigkeit des spezifischen elektrischen Widerstandes von Gesteinen nach Betrag und Phase. In der Frequenzabhängigkeit des Widerstandes spiegelt sich unter anderem die Geometrie des Porenraumes und den darin befindlichen Fluiden wieder. Üblicherweise wird das Widerstandsspektrum mit monofrequenten Signalen sequentiell vermessen. Diese Vorgehensweise erweist sich bei großskaligen Messanordnungen mit hohen Störspannungen als vorteilhaft da die Energie des Messgerätes auf einen schmalen Frequenzbereich konzentriert und eine Unterscheidung von Nutz- und Störfrequenzen erleichtert wird. Bei Labormessungen spielen Störspannungen häufig nur eine untergeordnete Rolle. Wichtiger ist hier ein möglichst hoher Messfortschritt. Am schnellsten ist die sequentielle SIP Messung, wenn jeweils nur Einzelperioden verwendet werden. Bei einer Frequenz pro Oktave, dauert die Gesamtmessung idealerweise doppelt so lange wie die längste Periode andauert. Überlagert man jedoch sämtliche Einzelfrequenzen (multifrequente Anregung) dann benötigt man nur die halbe Zeit. Der höhere Messfortschritt geht jedoch einher mit einer verringerten Messgenauigkeit. Ursache hierfür ist, dass die Einzelamplituden soweit verringert werden müssen, dass die Summenamplitude nicht die maximale Ausgangsspannung des Messgerätes überschreitet. Im Poster wird ein neu entwickeltes 88-kanaliges SIP-Labor-Messgerät (SIP-LAB-FAST) vorgestellt, das eine Anregung mit 1 - 24 Frequenzen gleichzeitig erlaubt. Bei z.B. einer Frequenz pro Octave lässt sich so ein Frequenzbereich von über 7 Dekaden mit einer Einzelmessung vermessen. Eine multifrequente Anregung erfordert auch eine leistungsfähige Hardware zur Echtzeit-Verarbeitung der Zeitreihen von Strom und Spannung. Hierzu wurde für jede Frequenz eine Diskrete Fourier Transformation (DFT) implementiert. Mittels einer multivariaten Kohärenzanalyse werden dann aus den Fourier Koeffizienten das komplexwertige Impedanz-Spektrum, sowie den zugehörigen Vertrauensintervallen berechnet. Durch die freie Wahl des Anregungssignales erhält der SIP Anwender eine erweiterte Möglichkeit den Messablauf optimal an die Fragestellung anzupassen. Ein Vergleich der mono- und multifrequenten Messergebnisse von verschiedenen Materialproben belegt die Leistungsfähigkeit der neuartigen Messtechnik.
    Description: poster
    Keywords: ddc:550 ; Geophysik ; Induzierte Polarisation
    Language: German
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  • 84
    Publication Date: 2022-12-01
    Description: Over the last years, installations of wind turbines (WTs) increased worldwide. Owing to negative effects on humans, WTs are often installed in areas with low population density. Because of low anthropogenic noise, these areas are also well suited for sites of seismological stations. As a consequence, WTs are often installed in the same areas as seismological stations. By comparing the noise in recorded data before and after installation of WTs, seismologists noticed a substantial worsening of station quality leading to conflicts between the operators of WTs and earthquake services. In this study, we compare different techniques to reduce or eliminate the disturbing signal from WTs at seismological stations. For this purpose, we selected a seismological station that shows a significant correlation between the power spectral density and the hourly windspeed measurements. Usually, spectral filtering is used to suppress noise in seismic data processing. However, this approach is not effective when noise and signal have overlapping frequency bands which is the case for WT noise. As a first method, we applied the continuous wavelet transform (CWT) on our data to obtain a time-scale representation. From this representation, we estimated a noise threshold function (Langston & Mousavi, 2019) either from noise before the theoretical P-arrival (pre-noise) or using a noise signal from the past with similar ground velocity conditions at the surrounding WTs. Therefore, we installed low cost seismometers at the surrounding WTs to find similar signals at each WT. From these similar signals, we obtain a noise model at the seismological station, which is used to estimate the threshold function. As a second method, we used a denoising autoencoder (DAE) that learns mapping functions to distinguish between noise and signal (Zhu et al., 2019). In our tests, the threshold function performs well when the event is visible in the raw or spectral filtered data, but it fails when WT noise dominates and the event is hidden. In these cases, the DAE removes the WT noise from the data. However, the DAE must be trained with typical noise samples and high signal-to-noise ratio events to distinguish between signal and interfering noise. Using the threshold function and pre-noise can be applied immediately on real-time data and has a low computational cost. Using a noise model from our prerecorded database at the seismological station does not improve the result and it is more time consuming to find similar ground velocity conditions at the surrounding WTs.
    Description: poster
    Keywords: ddc:550
    Language: English
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  • 85
    Publication Date: 2022-12-01
    Description: As part of the German continental seismic reflection program (Deutsches Kontinentales Reflexionsseismisches Programm, DEKORP), three large seismic traverses (with the sub-profiles: DEKORP'84-2S and '86-2N; DEKORP'88-9N; DEKORP'90-3A and '90-3B) were measured in the state of Hesse in Germany. The main research topic of DEKORP were deep seismic studies to investigate the lithospheric structure beneath Germany. Thus, for acquisition, strong sources were used to image in these depths, resulting in an excellent S/N ratio, but the main focus was not on the uppermost kilometres. From today's perspective, however, this depth range is of great interest for a wide range of possible technical applications (including medium-deep and deep geothermal projects). The DEKORP profiles cover approx. 450 km in the state of Hesse and mostly cross areas where only insufficient geological data exist (i.e. only few deep boreholes). In order to close or reduce these knowledge gaps, these DEKORP lines were reprocessed in 2019/20. The focus of the reprocessing was on improving the resolution / mapping of geological structures down to a depth of 6 km (approx. 3 s TWT) to describe the prolongation of faults and geological structures in more detail than in previous studies. Nevertheless, deeper structures were also reinterpreted and compared to previous interpretations. The results were directly incorporated into the new geological 3D model of the state of Hesse, developed by the Technical University of Darmstadt (Hessen3D 2.0, BMWi-FKZ: 0325944). In order to achieve these goals and in view of the fact that today's processing methods have improved considerably compared to the 1990‘s, a state-of-the-art reprocessing was applied for all DEKORP profiles traversing the state of Hesse. In comparison to the original processing, additional processing steps like CRS instead of CDP stacking, turning-ray tomography and prestack depth migration were carried out. We present exemplary results of the reprocessing as well as initial geological reinterpretations for the profile DEKORP'88-9N.
    Description: poster
    Keywords: ddc:550 ; DEKORP ; Reprocessing of 2D seismic profiles ; Hesse ; Upper Rhine Graben ; DEKORP'88-9N
    Language: English
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  • 86
    Publication Date: 2022-12-01
    Description: The work presented here is part of ongoing studies in the AlpArray initiative and the priority program "MB-4D" regarding the modelling of the lithosphere in the Ligurian Sea (northwestern Mediterranean Sea). It will be based on constraining data from LOBSTER and LISA campaigns of past GEOMAR projects and a study in our research group at CAU Kiel. Our motivation is the combination and interdisciplinary interpretation of independent information from geology, tectonics, geophysics, and petrology. The existing gravity fields, especially the new compilation of the AlpArray Gravity Research Group (AAGRG) is considered as database (high resolution Free Air- and Bouguer anomalies) and the isostatic residual field, besides data of the ICGEM Potsdam (disturbance) and the ESA GOCE gradients for gravity and data for the magnetic field anomaly. The gravity and magnetic fields are analyzed using Euler deconvolution with regularization (R. Pašteka, Comenius University Bratislava) and application of curvature analysis we use both, the fields themselves and their gradients. Besides the calculation of the so-called "3rd derivative" of the gravity potential, we also investigate a possible use of the invariants of the gravity field based on gradient data and compare and correlate the results with structural and tectonic maps in the area of the Ligurian Sea and the adjacent French and Italian mainland. The findings from these comparisons will later be used to initiate the compilation of 3D density and susceptibility models for the studied region.
    Description: poster
    Keywords: ddc:550 ; Gravity gradients, ; curvature gravity field ; Gravity invariants ; Ligurean Sea
    Language: English
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  • 87
    Publication Date: 2022-12-01
    Description: FloodRisk is an interdisciplinary project focusing on the effects of mine water level rise in bandoned coal mine regions in Germany. Such effects are heterogeneous ground uplift, stress changes due to the change in pore pressure and the reactivation of potential faults. One of the most directly measurable effects is certainly the induced micro seismicity. It is known from previous studies that the flooding of old mines can lead to a renewed increase level in induced micro seismicity in these regions. In this study the relationship between mine water rise, fluid-induced stress changes and induced seismicity in the Haus Aden dewatering area in the eastern Ruhr area (Germany) will be investigated in more detail. For this purpose, we operate a network of currently 21 short period seismic stations in the region of the former "Bergwerk Ost" colliery, which had the highest seismicity rate in the Ruhr area during active underground coal mining. This network is still to be expanded to cover the entire water drainage area, about 30 Raspberry Shake sensors are waiting for the possibility of installation. Nevertheless, the existing network registered almost 1000 induced micro seismic events in a magnitude range from -0.7 up to 2.6 MLv. Many of these events are spatially clustered and some show quite high waveform similarity. This allows relative localisation and can increase the accuracy of the location. The depth location of the earthquakes, within the limits of localisation accuracy, agrees very well with the distribution of seismicity at the time of active mining. The spatial distribution so far seems to be limited by a large inactive transverse fault in the west. It needs to be clarified what influence this fault has on the propagation of mine water in the underground. The measured temporal trend of the mine water level, after pumps were shut down in mid-2019, shows a strong correlation with the temporal evolution of the observed micro seismicity. In the first months after the pumps are switched off, the water levels at the observation points rise only slowly and isolated microseismic events occur again. In November 2019, the rise in water levels doubled and at the same time, the strongest induced event in the measurement period was recorded with a magnitude of 2.6 MLv . In the following months, the seismicity rate ranged from 8 to 34 events above 0.5 MLv per month, some of which were felt.
    Description: Bundesministerium für Bildung und Forschung
    Description: poster
    Keywords: ddc:550 ; induced microseismicity ; FloodRisk ; waveform similarity ; raising mine water level
    Language: English
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  • 88
    Publication Date: 2022-12-01
    Description: We introduce an approach for 3D joint interpretation of potential fields and its derivatives under the condition of constraining data and information. The interactive 3D gravity and magnetic application IGMAS (Interactive Gravity and Magnetic Application System) has been around for more than 30 years, initially developed on a mainframe and then transferred to the first DOS PCs, before it was adapted to Linux in the ’90s and finally implemented as a cross-platform Java application with GUI. Since 2019 IGMAS+ is maintained and developed in the Helmholtz Centre Potsdam – GFZ German Research Centre by the staff of Section 4.5 – Basin Modelling and ID2 – eScience Centre. The core of IGMAS+ applies an analytical solution of the volume integral for the gravity and magnetic effect of a homogeneous body. It is based on the reduction of the three-folded integral to an integral over the bounding polyhedrons that are formed by triangles. Later the algorithm has been extended to cover all elements of the gravity tensor as well and the optimized storage enables fast leastsquares inversion of densities and changes to the model geometry and this flexibility makes geometry changes easy. Because of the triangular model structure of model interfaces, IGMAS can handle complex structures (multi- Z surfaces) like the overhangs of salt domes and variable densities due to voxelization. To account for the curvature of the Earth, we use spherical geometries. Therefore IGMAS+ is capable to handle models from big-scale to regional and small-scale models (meters) used in Applied Geophysics.
    Description: poster
    Keywords: ddc:550 ; Potential field modelling ; Complex modelling ; Visualization ; Software development
    Language: English
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  • 89
    Publication Date: 2022-12-01
    Description: A new crustal model of the Volga-Uralian subcraton was built. The compilation of the model was subdivided in two steps: (1) inverse gravity modeling followed by (2) thorough forward gravity modeling. For inverse gravity modeling GOCE gravity gradients were used. The effect of the Earth sphericity was taken into account by using tesseroids. Density contrasts between crust and mantle were varied laterally according to the tectonic units present in the region. The model is constrained by the available seismic data including receiver function studies, and deep reflection and refraction profiles. The Moho discontinuity obtained during the gravity inversion was consequently modified, and complemented by the sedimentary cover, upper crust, lower crust, and lithospheric mantle layers in the process of forward gravity modeling. Obtained model showed crustal thickness variation from 34 to more than 55 km in some areas. The thinnest crust with the thickness below 40 km appeared on the Pericaspian basin with the thickest sedimentary column. A relatively thin crust was found along the central Russia rift system, while the thickest crust is located underneath Ural Mountains as well as in the center of the Volga-Uralian subcraton. In both areas the crustal thickness exceeds 50 km. At the same time, the gravity misfit of ca. 95 mGal between the measured Bouguer gravity anomaly and forward calculated gravity field was revealed in the central area of the Volga-Uralian subcraton. This misfit was interpreted and modeled as high-density lower crust which can possibly represent an underplated material. In the end, the new crustal model of Volga-Uralian subcraton respects the gravity and seismic constraints, and reflects the main geological features of the region. This model will be used for further geothermal analysis of the area.
    Description: poster
    Keywords: ddc:550 ; Crustal model ; Gravity ; Inversion ; Volgo-Uralia ; Tesseroids ; Moho
    Language: English
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  • 90
    Publication Date: 2022-12-01
    Description: poster
    Keywords: ddc:550
    Language: English
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  • 91
    Publication Date: 2022-12-01
    Description: Passive seismische Messungen des Umgebungsrauschens sind effektive und nicht-invasive Methoden, um die Struktur des lokalen Untergrunds und mögliche Verstärkungen seismischer Bodenbewegungen zu ermitteln. Liegt beispielsweise Lockersediment auf Festgestein auf, so kann dies bei seismischen Ereignissen eine verstärkende Wirkung auf die seismische Beanspruchung darüberliegender Gebäude haben. Um einen ersten Überblick über den Standort zu bekommen, wird mithilfe von Einzelstationsmessungen die Fundamentalfrequenz, mit welcher der Untergrund schwingt, ermittelt (H/V-Kurven). Liegt diese in einem ähnlichen Bereich wie die Resonanzfrequenzen von Gebäuden (ca. 1 - 10 Hz) wirkt dies verstärkend, sodass auch seismische Ereignisse mit geringer Magnitude eine erhöhte Einwirkung in Bezug auf Fühlbarkeit und Schäden zur Folge haben. Des Weiteren werden zur Erstellung eines Geschwindigkeit-Tiefen-Profils mehrere Stationen zu einem Array kombiniert. Aus den gemessenen Daten werden mittels einer hochauflösenden Frequenz-Wellenzahl-Analyse (hrFK) und einer räumlichen Autokorrelation (SPAC) Dispersionskurven ermittelt, welche die Phasengeschwindigkeiten von Oberflächenwellen in Abhängigkeit der Frequenz angeben. Die resultierenden Dispersionskurven werden am Ende invertiert, um das Geschwindigkeits-Tiefen-Profil für den lokalen Untergrund zu erhalten. Insgesamt wurden auf den Flussterrassen der Weser drei Array-Messungen an unterschiedlichen Standorten, sowie mehrere H/V-Messungen durchgeführt. Ziel ist es, eine bestmögliche Strategie sowohl für die Vorgehensweise bei den Messungen, als auch für die Auswertung der Daten zu entwickeln und eine bessere Eingrenzung der Tiefenprofile der S-Wellengeschwindigkeiten zu erreichen. So wurde bei der Auswertung der Daten unter anderem eine Trennung in Love- und Rayleigh-Wellen vorgenommen, um die Geschwindigkeitsprofile besser bestimmen zu können. In Zukunft sind zudem Tests mit Variationen der Array-Geometrien geplant, um zukünftige Messungen hinsichtlich Logistik, Messdauer und Personaleinsatz zu optimieren.
    Description: poster
    Keywords: ddc:550
    Language: German
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  • 92
    Publication Date: 2022-12-01
    Description: This presentation summarizes input data, procedures and results of probabilistic seismic hazard assessment (PSHA) in Bangladesh in the framework of the project ‘Geo information for Urban Planning and Adaptation to Climate Change’. It is a cooperation of the Geological Survey of Bangladesh (GSB) and the Federal Institute for Geosciences and Natural Resources (BGR) of Germany. The main aim of the project is to provide city planners with “Ground Suitability Maps”, which display different geo-factors. Seismic hazard is one of the geo-factors that contributes to these maps. For the derivation of “Ground Suitability Maps”, the influence of the local underground conditions will be taken into account additionally. A major part of Bangladesh is located in earthquake prone regions due to active tectonics. The Indian plate moves north-eastward towards the Eurasian plate at a velocity of about 6 cm/year. This motion leads to thrusting to the north (Himalaya) and to subduction to the east together with strike-slip mechanism. The thrusting and subduction processes have caused large historical earthquakes even inside Bangladesh (e.g. 1885 Bengal Earthquake M7 and 1918 Srimangal Earthquake M7.6). Therefore, it is crucial to assess seismic hazard in urban planning in Bangladesh. The input databases were compiled from the literature, reviewed and evaluated in this study. These are earthquake catalogs, the distribution of active faults and ground motion prediction equations. The most consistent and reliable databases were selected to be used in PSHA. The data of the earthquake catalog were declustered to eliminate the duplicated events, aftershocks and foreshocks. The spatial distribution of areal seismic sources was characterized using the distributions of earthquakes in the catalog and active faults. The completeness analysis of the earthquake catalog was performed and the Gutenberg-Richter magnitude recurrence distribution was derived for each seismic source. The results of PSHA are presented in the form of peak ground acceleration (PGA) maps with 10% exceedance probability in 50 years. As usual in regional PSHA, the results were compiled assuming bedrock as underground condition (so-called engineering bedrock with shear velocity of Vs30≥760 m/s). The northern and eastern parts of Bangladesh show the highest seismic hazard with PGA around 0.4 g with 10% exceedance probability in 50 years. This observation was expected because of the active tectonics in these parts.
    Description: poster
    Keywords: ddc:550
    Language: English
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  • 93
    Publication Date: 2022-12-01
    Description: Im Standortauswahlgesetz wird in § 22 zum Ausschlusskriterium „Seismische Aktivität“ ausgeführt, dass ein Gebiet nicht als Endlagerstandort geeignet ist, wenn die örtliche seismische Gefährdung größer als in Erdbebenzone 1 nach DIN EN 1998-1/NA:2011-01 ist. Diese Norm wird in Kürze durch eine Aktualisierung ersetzt, die dem Stand von Wissenschaft und Technik entspricht. Der Entwurf hierzu, E DIN EN 1998-1/NA:2018-10, enthält keine Zuordnungen in Erdbebenzonen mehr, sondern weist die seismische Gefährdung räumlich kontinuierlich aus. Die Bundesanstalt für Geowissenschaften und Rohstoffe (BGR) hat im Auftrag der Bundesgesellschaft für Endlagerung einen Vorschlag zur Anwendung dieses Ausschlusskriteriums unter Verwendung von E DIN EN1998-1/NA:2018-10 erarbeitet. Die BGR schlägt vor, als Grenzwert zur Anwendung des Ausschlusskriteriums den Wert der spektralen Antwortbeschleunigung im Plateaubereich von 1,8 ms-2 in E DIN EN 1998-1/NA:2018-10 zu verwenden. Dieser Wert entspricht der makroseismischen Intensität 7, für den die seismische Gefährdung größer als in Erdbebenzone 1 nach DIN EN 1998-1/NA:2011-01 ist. Für Gebiete, in denen dieser Wert überschritten wird, gilt das Ausschlusskriterium als erfüllt. Grundsätzlich ist das Ausschlusskriterium „Seismische Aktivität“ im Standortauswahlgesetz jedoch wenig geeignet, um die Erdbebengefährdung eines Standortes für ein Endlager für hochradioaktive Abfälle zu ermitteln. Der Bewertungszeitraum für die Sicherheit des Endlagers beträgt eine Million Jahre und unterscheidet sich erheblich vom Betrachtungszeitraum von 50 Jahren der Norm DIN EN 1998-1/NA. Die Intensität bzw. die Beschleunigung gilt für die Erdoberfläche; die Endlagerung hochradioaktiver Abfälle soll jedoch in tiefen geologischen Formationen erfolgen. Neben der Gefährdung aufgrund von seismischen Bodenbewegungen als Bewertungsmaßstab des Ausschlusskriteriums hat eine andere Art der Gefährdung durch Erdbeben für Endlager in tiefen geologischen Formationen eine größere Bedeutung, nämlich bruchartige Verschiebungen im Endlagerbereich. Das Ausschlusskriterium „Seismische Aktivität“ bezieht sich im Unterschied zu allen anderen Ausschlusskriterien im Standortauswahlgesetz § 22 nicht auf ein wissenschaftlich formuliertes Merkmal, sondern auf eine Norm, deren Bemessungsgrößen aufgrund eines Kompromisses zwischen Sicherheitsbetrachtungen und wirtschaftlichen Überlegungen wie erhöhten Baukosten festgelegt wurden.
    Description: poster
    Keywords: ddc:550 ; Seismische Gefährdung ; Endlagerung ; Standortauswahlgesetz ; Baunorm ; Eurocode 8
    Language: German
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  • 94
    Publication Date: 2022-12-01
    Description: As part of the EPOS-Norway infrastructure project, NORSAR received funding from the Research Council of Norway for a new regional seismic array on Bjørnøya (Bear Island) in the European Arctic. After along planning phase, a six-element broadband array was installed by NORSAR staff in August 2019 and has been providing data to NORSAR in near real-time since then. Due to several logistical and administrative constraints the 6-element array has an aperture of only 300 m. All sites are equipped with Kinemetrics MBB-2 sensors and Earth Data EDR-209 digitizers that are installed in near-surface vaults. Data are automatically copied to the Norwegian node of the European Integrated Data Archive (EIDA) and are openly available. Due to environmental restrictions less than the planned 9 array sites could be installed on Bjørnøya and the non-used instruments are now available to extend the broadband station Hornsund (HSPB), Southern Spitsbergen, to another small aperture broadband array, also with 6 sites. The array installation had to be postponed because of the ongoing pandemic and is now planned for the Arctic summer 2021.
    Description: poster
    Keywords: ddc:550
    Language: English
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  • 95
    Publication Date: 2022-12-01
    Description: Seismotectonic regions are a basic input in seismic hazard assessment. Several seismotectonic zonations for Germany have been proposed in the past. We have developed a new regionalization based on the definition in the German Nuclear Safety Standard: “A seismotectonic unit is a region for which uniformity is assumed regarding seismic activity, geological structure and development and, in particular, regarding neotectonic conditions”. Our new concept aims for transparent implementation of geological criteria, which we initially analyze separately from seismicity. We strive for a better documentation and justification of the geological elements used to delimit seismotectonic regions, based on an analysis of the geological evolution in six time slices from the Permian (300 Ma) to the Present. The time slices are separated by marked changes in the tectonic regime and associated with the development of new fault systems or reactivation of existing ones. The present-day fault network comprises faults from all time slices. For each time slice, a subset of active faults has been extracted based on geological evidence for fault activity at that time. Uncertainties of these age assignments are documented. The fault subsets delimit regions of different strain intensity. The superposition of strain intensity distributions across all time slices identifies regions affected by polyphase deformation and regions nearly undeformed over geological time, potentially indicating areas of increased or reduced present-day seismic hazard. Our new zonation consists of fewer regions than earlier ones. The geological zonation correlates well with recent seismicity in areas of Cenozoic rifting and reasonably well with less frequent earthquakes in a belt affected by Mesozoic extension and contraction. However, a few stronger earthquake cluster in regions of low geological strain. The most prominent earthquake clusters (Swabian Jura, Vogtland / NW Bohemia) also defy a simple correlation with known geological structures.
    Description: poster
    Keywords: ddc:550
    Language: English
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  • 96
    Publication Date: 2022-12-01
    Description: poster
    Keywords: ddc:550
    Language: English
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  • 97
    Publication Date: 2022-12-01
    Description: Übertiefte Täler in den Alpen ermöglichen uns glaziale Sedimentation und somit einen Teil der quartären Klimageschichte zu verstehen. Reflexionsseimsik kann dabei verwendet werden, um punktuelle Bohrlochdaten in die Fläche zu projizieren oder eine potentielle Bohrlokation vorzuerkunden. Im Rahmen des ICDP-Projekts ‚Drilling Overdeepened Alpine Valleys‘ (DOVE) sollen eine Reihe von Bohrungen in alpinen, glazial-übertieften Tälern abgeteuft werden. Eine der Bohrungen soll 2021 in einem übertieften Tal des Rheingletschers bei Basadingen, nahe der deutsch-schweizerischen Grenze abgeteuft werden. In Zusammenarbeit mit der ETH Zürich, wurden zwei Profile im Abstand von ca. 500 m annähernd senkrecht zum Talverlauf aufgenommen. Das erste Profil ist 1246 m lang und bestand aus einer festen Auslage von 624 Geophonen. Das zweite Profil ist 1120 m lang und wurde mit 200 3-Komponenten-Geophonen im roll-along-Verfahren aufgenommen. Für beide Profile wurde bei jedem zweiten Geophon (zwei Meter Geophonabstand) mit einem hydraulischen 4-t Vibrator ein linearer 12-s-Sweep von 20-240 Hz angeregt. Beide seismischen Profile bilden ein asymmetrisches, übertieftes Becken mit ca. 260 m Tiefe ab, wobei der tiefste Bereich nur einen kleinen Teil des breiteren Hauptbeckens einnimmt. Die Auffüllung ist durch mindestens drei Diskordanzen, deutlichen Onlaps und Erosionshorizonten zwischen den Sedimenteinheiten gekennzeichnet. Wir interpretieren die Talfüllung als das Produkt eines hochdynamischen, sedimentären Systems. Der untere Teil, innerhalb des tiefsten Bereichs des Beckens, ist mit chaotisch abgelagerten Sedimenten gefüllt. Der Teil oberhalb einer Diskordanz enthält steil einfallende Reflektoren, die wahrscheinlich 20-30 m mächtige, progradierende Mäanderbanken einer glazial-fluviatilen Umgebung darstellen. Unterhalb des tiefsten Bereichs des Beckens sehen wir Versätze in Reflektoren, die auf Verwerfungen in der Tertiären Molasse hinweisen und mit bekannten Verwerfungen an der Oberfläche korrelieren. Wir vermuten, dass die Verwerfungen das Gestein geschwächt und somit die verstärkte Erosion an dieser Stelle gefördert haben.
    Description: poster
    Keywords: ddc:550 ; Seismik ; Geophysik ; Alpen ; Quartär ; übertieft ; Schweiz ; Beckenfüllung ; Sedimentation ; glazial ; Erosion ; Processing ; DMO
    Language: German
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  • 98
    Publication Date: 2022-12-01
    Description: As a result of the joint project ‘Subsurface Potentials for Storage and Economic Use in the North German Basin’ (German acronym: TUNB) the Geological Surveys of Northern Germany and the Federal Institute for Geosciences and Natural Resources (BGR) finalized a coherent geological 3D-model of the deep subsurface of the North German Basin in early 2021. The model consists of 13 major base surfaces from Oligocene to Zechstein, fault surfaces and hull surfaces of salt diapirs. In the northwestern part it is based on the datasets of the Tectonic Atlas of NW-Germany (GTA) along with well and seismic data from the hydrocarbon industry. Additionally to modelling the onshore part of Schleswig-Holstein and Hamburg and insuring cross-border consistency to the neighboring federal states, the Geological Survey of Schleswig-Holstein (LLUR) reconstructed a 3D-large-scale velocity model based on previous work from Jaritz et al. (1991). Their velocity approach was developed within the GTA-project and is based on sonic-log and check-shot-velocities. It assumes a linear velocity increase, which is calculated from specific global gradients for different major lithostratigraphic layers and laterally varying starting-velocities. To validate the constructed 3D-velocity-model, its velocities were compared to velocities measured at boreholes by oil and gas companies. In general, a good agreement was found between modeled and measured data (deviation 〈 5%), in which the average velocities seemed to resemble the check-shot data more accurately than the interval velocities the sonic-log-measurements. In distinct locations, the velocity model was used to convert the newly constructed TUNB-horizons from the depth- to the time-domain in order to compare them to seismic sections. Whereas overall a good agreement between horizons and seismic reflectors was found, differences were identified especially in structural complex areas. Whether these can be attributed to earlier interpretations from the GTA, the modelling of the horizons or insufficiencies in the velocity-model has yet to be determined. A follow-up project to the TUNB-project is anticipated to start in early summer 2021. The goal of the project is to derive a consistent velocity model over large parts of the North German Basin. Main challenges will be integrating available borehole and seismic data into existing velocity-modelling approaches with a special focus on establishing cross border consistency to eastern federal states.
    Description: poster
    Keywords: ddc:550
    Language: English
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  • 99
    Publication Date: 2022-12-01
    Description: Die zerstörungsfreie Ermittlung der Materialfeuchte in Baustoffen ist für das Bauwesen von großer Bedeutung, denn ein erhöhter Feuchteeintrag kann zu Schimmelbildung, Alkali-Kieselsäure-Reaktionen, Korrosion etc. führen und somit ein hohes Schadenspotential mit sich bringen. Auch wenn zur qualitativen Lokalisierung möglicher Schad- und Risikostellen bereits zahlreiche zerstörungsfreie Verfahren in der Praxis Anwendung finden, besteht ein Mangel an quantitativen Verfahren, die auch bei niedrigen Feuchtegehalten sensitiv sind. Eine Methode zur zerstörungsfreien und quantitativen Bestimmung des Feuchtegehaltes und der effektiven Porosität ist die 1H-Kernspinresonzanzmethode (NMR). Da NMR sensitiv für die molekulare Beweglichkeit von Wasserstoffprotonen ist, lassen sich Informationen über die Bindungsform und -stärke sowie der Umgebung (Porengröße und Mineralzusammensetzung) der Wasserstoffprotonen gewinnen. Obwohl es bereits seit über 20 Jahren mobile NMR-Messeräte gibt, wird NMR heutzutage immer noch weitestgehend im Labor eingesetzt. Dies liegt daran, dass sie aufgrund der verwendeten Permanentmagnete schwer sind und nur äußerst geringe Eindringtiefen ermöglichen. In einer derzeit laufenden Forschungsarbeit wird deshalb ein speziell für Bohrkerne entworfener NMR-Tomograph eingesetzt. Mit seiner minimalen Echozeit von 50 µs lässt sich (abhängig von der Oberflächenrelaxivität) Wasser bis in nanometergroßen Poren erfassen. Um die Sensitivität von NMR bei Teilsättigung zu untersuchen, wurden verschiedene Sandsteinproben in Exsikkatoren mit relativen Luftfeuchten im Bereich von 33 % bis 96 % gelagert. Als Referenzen dienen zum einen das NMR-Signal bei Vollsättigung und zum anderen die Porengrößenverteilung aus Quecksilberporosimetriemessungen (MIP). Um die NMR-Sensitivität zu bewerten, wird die Korrelation der NMR-Amplitude mit den gravimetrisch ermittelten Feuchtegehalten sowie ein Vergleich der Porosität aus NMR und MIP betrachtet. Zu beachten ist in diesem Zusammenhang, dass sowohl die Reduzierung der Wasserfilmdicke als auch die Verkleinerung von Porengrößen zu einer ähnlichen Verkürzung der T2-Relaxationszeit führt. Als Ausblick wird ein Lösungsansatz vorgestellt, bei dem die NMR-Signale mit der Wasserfilmdickenberechnung basierend auf der relativen Luftfeuchte im Material korreliert werden.
    Description: poster
    Keywords: ddc:550
    Language: German
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  • 100
    Publication Date: 2022-12-01
    Description: About 25% of the Earth’s mid-ocean ridges spread at ultraslow rates of less than 20 mm/yr. However, most of these ultraslow spreading ridges are located in geographically remote areas, which hamper investigation. Consequently, how the crust forms and ages at such spreading centres, which traditional models predict to be magma-starved and cold, remains poorly understood. One of the most accessible ultra-slow spreading centres is the Mid Cayman Spreading Centre (MCSC), in the Caribbean Sea, with spreading rates of ~15-17 mm/yr. CAYSEIS project was proposed to survey the Cayman Trough area in order to obtain new data that constraints the nature of the crust, tectonic structures, lithologies outcropping and hydrothermal processes taking place in this area. Understanding the sub-seabed geophysical structure of the MCSC is key to understanding not only the lithologies and structures exposed at the seabed, but more fundamentally, how they are related at depth and what role hydrothermal fluid flow plays in the geodynamics of ultraslow spreading. CAYSEIS was a joint and multidisciplinary programme of German, British and US American top tier scientists designed for the obtaining of a new high-quality dataset, including 3D Wide-Angle Seismic (WAS), magnetic, gravimetric and seismological data. During the CAYMAN project, we took leverage of the CAYSEIS dataset to invert a 3D tomographic model of the Cayman Trough lithosphere using the Tomo3D code (Meléndez et al., 2015; 2019). This is one of the first times that the Tomo3D code is used for 3D inversion of real datasets. Thus, we are checking our results comparing them with tomographic inversions of 2D lines and testing the different parameters to obtain the more accurate and higher resolution model as possible. The results of this experiment will show not only the lithospheric structure along and across the MSCS, including the exhumed Ocean Core Complexes in the surrounding areas, but the 3D lithospheric configuration of the region which is important to understand the crustal formation processes and the evolution of ultra-slow spreading settings.
    Description: Poster
    Description: poster
    Keywords: ddc:550 ; 3D tomography ; crustal characterization ; ultra-slow spreading ; Cayman Trough
    Language: English
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