ALBERT

Description: Fe(III) hydroxides stabilize organic carbon (OC) and P in soils. Observations of rising stream Fe concentrations are controversially posited to result from a flushing of iron‐rich deeper soil layers or a decrease of competing electron acceptors inhibiting Fe reduction (NO3− $\mathrm{N}{{\mathrm{O}}_{3}}^{-}$ and SO42− $\mathrm{S}{{\mathrm{O}}_{4}}^{2-}$). Here, we argue that catchment topography constrains the release of Fe, OC, and P to streams. We therefore incubated organic topsoil and mineral subsoil and modified the availability of NO3− $\mathrm{N}{{\mathrm{O}}_{3}}^{-}$. We found that Fe leaching was highest in topsoil. Fe, OC, and P released at quantities proportional to their ratios in the source soil. Supply of NO3− $\mathrm{N}{{\mathrm{O}}_{3}}^{-}$ reduced Fe leaching to 18% and increased pore water OC:Fe and P:Fe ratios. Subsoil, however, was an insignificant Fe source (〈0.5%). Here, the leached quantities of Fe, OC and P were highly disproportionate to the soil source with an excess of released OC and P. We tested if experimental findings scale up using data from 88 German catchments representing gradients in NO3− $\mathrm{N}{{\mathrm{O}}_{3}}^{-}$ concentration and topography. Average stream Fe concentrations increased with decreasing NO3− $\mathrm{N}{{\mathrm{O}}_{3}}^{-}$ and were high in catchments with shallow topography where high groundwater levels support reductive processes and topsoils are hydrologically connected to streams; but Fe concentrations were low in catchments with steep topography where flow occurs primarily through subsoils. OC:Fe and P:Fe ratios in the streams similarly varied by NO3− $\mathrm{N}{{\mathrm{O}}_{3}}^{-}$ and topography. This corroborates the findings from the laboratory experiment and suggests that catchment topography and competing electron acceptors constrain the formation of Fe‐reducing conditions and control the release of Fe, OC, and P to streams.

Description: Plain Language Summary: Iron is the second most abundant metal in the crust; its cycle is tightly connected to those of carbon, oxygen, and sulfur. The oxidized form (FeIII) is almost insoluble, but Fe can be mobilized by complexation or microbial Fe reduction. Both processes depend on availability of organic C. We found that Fe concentrations in streams were constrained by the topography of catchments and NO3− $\mathrm{N}{{\mathrm{O}}_{3}}^{-}$ abundance. Shallower catchments are characterized by higher groundwater tables connecting the organic topsoils efficiently to streams. NO3− $\mathrm{N}{{\mathrm{O}}_{3}}^{-}$ suppresses Fe reduction as a competing electron acceptor to Fe. We conclude that trends in soil wetness or atmospheric N deposition can change the stability of Fe and thus the release of PO43− $\mathrm{P}{{\mathrm{O}}_{4}}^{3-}$ and harmful metals to surface waters.

Description: Key Points: Organic topsoils leach substantial amounts of Fe when incubated in the absence of NO3, a competing electron acceptor that inhibits Fe reduction. Shallow catchments with fluvially coupled topsoils and low NO3 availability release 200 fold more Fe than steep ones with high NO3 abundance. Catchment topography and NO3 availability explain 62%–64% of the variability of Fe concentration and OC:Fe and P:Fe ratios across 88 streams.

Description: EFRE‐Europe

Description: https://doi.org/10.4211/hs.43601618877945c5a46b715aa98db729

Description: The radiogenic isotope heterogeneity of oceanic basalts is often assessed using 2D isotope ratio diagrams. But because the underlying data are at least six dimensional (87Sr/86Sr, 143Nd/144Nd, 176Hf/177Hf, and 208,207,206Pb/204Pb), it is important to examine isotopic affinities in multi‐dimensional data space. Here, we apply t‐distributed stochastic neighbor embedding (t‐SNE), a multi‐variate statistical data analysis technique, to a recent compilation of radiogenic isotope data of mid ocean ridge (MORB) and ocean island basalts (OIB). The t‐SNE results show that the apparent overlap of MORB‐OIB data trends in 2‐3D isotope ratios diagrams does not exist in multi‐dimensional isotope data space, revealing that there is no discrete “component” that is common to most MORB‐OIB mantle sources on a global scale. Rather, MORB‐OIB sample stochastically distributed small‐scale isotopic heterogeneities. Yet, oceanic basalts with the same isotopic affinity, as identified by t‐SNE, delineate several globally distributed regional domains. In the regional geodynamic context, the isotopic affinity of MORB and OIB is caused by capturing of actively upwelling mantle by adjacent ridges, and thus melting of mantle with similar origin in on, near, and off‐ridge settings. Moreover, within a given isotopic domain, subsidiary upwellings rising from a common deep mantle root often feed OIB volcanism over large surface areas. Overall, the t‐SNE results define a fundamentally new basis for relating isotopic variations in oceanic basalts to mantle geodynamics, and may launch a 21st century era of “chemical geodynamics.”

Description: Plain Language Summary: The isotopic heterogeneity of basalts erupted at mid ocean ridges (MORB) and ocean islands (OIB) reflects the chemical evolution of Earth's mantle. The visual inspection of various 2D isotope ratio diagrams has fueled a four decade‐long discussion whether basalt heterogeneity reflects melting of only a small number of mantle components, and in particular, whether the apparent overlap of local data trends in global 2D isotope ratio diagrams indicates that melting of a common mantle component contributes to most MORB‐OIB. Here, we use multi‐variate statistical data analysis to show that the apparent overlap of MORB‐OIB data trends in 2D isotope ratio diagrams does not exist in multi‐dimensional isotope data space. Our finding invalidates any inference made for mantle compositional evolution based on the previously proposed existence of a common mantle component, its potential nature or distribution within the mantle. Rather, global MORB‐OIB sample small‐scale isotopic heterogeneities that are distributed stochastically in the Earth's mantle. Yet, MORB‐OIB with the same isotopic affinity, as identified by our multi‐variate data analysis, delineate several globally distributed regional domains. Within the regional geodynamic context, this discovery forms a fundamentally new basis for relating isotopic variations in MORB‐OIB to mantle geodynamics.

Description: Key Points: Multi‐variate statistical data analysis (t‐distributed stochastic neighbor embedding) identifies global Sr‐Nd‐Hf‐Pb isotopic affinities of oceanic basalts. There is no “common mantle component;” rather, global mid ocean ridge‐ocean island basalts sample stochastically distributed small‐scale isotopic heterogeneities. Globally distributed regional domains of isotopically alike oceanic lavas define a new basis for relating isotopic variations to geodynamics.

Description: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659

Description: Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung http://dx.doi.org/10.13039/501100001711

Description: DAAD, German Academic Exchange Service

Description: https://doi.org/10.25625/0SVW6S

Description: https://doi.org/10.25625/BQENGN

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

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

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

Description: Radiocarbon (14C) is commonly used as a tracer of the carbon cycle to determine how fast carbon moves between different reservoirs such as plants, soils, rivers, or oceans. However such studies mostly emphasize the mean value (as Δ14C) of an unknown probability distribution. We introduce a novel algorithm to compute Δ14C distributions from knowledge of the age distribution of carbon in linear compartmental systems at steady‐state. Our results demonstrate that the shape of the distributions might differ according to the speed of cycling of ecosystem compartments and their connectivity within the system, and might contain multiple peaks and long tails. The distributions are also sensitive to the variations of Δ14C in the atmosphere over time, as influenced by the counteracting anthropogenic effects of fossil‐fuel emissions (14C‐free) and nuclear weapons testing (excess 14C). Lastly, we discuss insights that such distributions can offer for sampling and design of experiments aiming to capture the precise variance of Δ14C values present in the multi‐compartmental ecosystems.

Description: Plain Language Summary: Radiocarbon (14C) is a radioactive isotope of carbon prominent in environmental sciences for tracing the dynamics of ecosystems, especially as recent changes in atmospheric radiocarbon allow tracking excess 14C created by nuclear weapons testing in the atmosphere on timescales shorter than what can be determined using radioactive decay. For climate change mitigation, a crucial uncertainty is the time carbon captured through photosynthesis spends in ecosystems before being released. For this purpose, radiocarbon can be valuable as a biological tracer; however, it is necessary to accurately link the real age of carbon and its radiocarbon age, as they usually differ. Forests and soils are open systems, connecting components with intrinsically different cycling timescales, so that the mean age comes from an age distribution that is usually unknown. Here, we developed an algorithm to compute the 14C contents for models consisting of multiple interconnected carbon pools. Our approach offers more accurate estimations of the mean 14C content of the system and computations of the distribution of 14C within the system at different points in time. Results obtained from this method can provide additional insights on the dynamics of the carbon cycle in multiple compartments, and can help to better interpret observations.

Description: Key Points: Probability distributions of radiocarbon in ecosystem compartments can be derived from carbon age distributions. The shape of these distributions vary according to the speed of carbon cycling and the year of observation. Probability distributions of radiocarbon provide insights to study carbon dynamics and to interpret radiocarbon data.

Description: Bundesministerium für Bildung und Forschung (BMBF) http://dx.doi.org/10.13039/501100002347

Description: Max‐Planck‐Gesellschaft (MPG) http://dx.doi.org/10.13039/501100004189

Description: https://doi.org/10.5281/zenodo.6373329

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

Description: Four zircon Raman bands were previously calibrated to give consistent estimates of the accumulated self‐irradiation α‐dose in unannealed volcanic samples. Partial annealing of radiation damage produces inconsistent values because of differences in the relative annealing sensitivities. The damage estimates based on the external rotation band (DER) at ∼356 cm−1 and that based on the ν2(SiO4) band (D2) at ∼438 cm−1 are the most and least sensitive to damage annealing. The D2/DER‐ratio thus provides a numerical estimate of the extent of geologic annealing that a zircon sample has experienced. This ratio characterizes the thermal history of a zircon sample but also its state of radiation damage during the course of its geologic history, and thus the manner in which this state influences other thermochronologic methods. Meaningful interpretation of the zircon Raman age requires that the spectra are free of measurement artifacts. The major artifacts result from micrometer‐scale gradients of the damage densities within a zircon grain due to uranium and thorium zoning. The micrometer‐sized sampled volume may span different densities, producing overlapping spectra, causing apparent peak broadening, overestimated damage densities, and zircon Raman ages. The D3/D2‐ratio of the damage densities calculated from the ν3(SiO4) and ν2(SiO4) bands, most and least affected by overlap, is an efficient indicator of a meaningless signal. It reveals overlap in annealed and unannealed samples, because the used bands have similar responses to annealing. Multi‐band Raman maps can be converted to damage‐ratio maps for screening zircon mounts, and selecting spots for thermochronologic investigations.

Description: Plain Language Summary: Radioactive processes cause damage to the lattice of zircon crystals. This damage can be measured with a Raman instrument. Such measurements are important for methods determining the ages and thermal histories of zircon grains in rocks. Thus, the Raman measurements must be reliable and meaningful. This work proposes tools for detecting effects that hinder the interpretation of zircon Raman data. These effects are mixed signals and loss of damage due to exposure to elevated temperatures in the geologic environment. Zircon Raman spectra have different bands that respond differently to mixed signals and temperature. The ratio of the damage estimates from the least and most temperature‐sensitive bands thus indicates partial annealing. Raman spectra of zoned zircons often straddle areas with different lattice damage. Their overlapping signals cause artificial band broadening, and a damage overestimation. The ratio of the damage estimated from the least and the most affected bands identifies mixed signals and allows to reject unsuitable samples. The damage ratios can also be plotted in maps for damage screening and for selecting optimal spots for measurements.

Description: Key Points: Annealing and inhomogeneous damage are two main factors hindering radiation‐damage estimation for zircon Raman dating. Comparison of internal and external Raman bandwidths allows to detect partial annealing of radiation damage in zircon. Comparison of internal Raman bandwidths allows to detect artifactual broadening in zoned zircon.

Description: Studienstiftung des Deutschen Volkes (Studienstiftung) http://dx.doi.org/10.13039/501100004350

Description: http://dx.doi.org/10.25532/OPARA-155

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

Description: Methane production in peatlands is controlled by the availability of electron acceptors for microbial respiration, including peat dissolved organic matter (DOM) and particulate organic matter (POM). Despite the much larger mass of POM in peat, knowledge on the ranges of its electron transfer capacities—electron accepting capacity (EAC), and electron donating capacity (EDC)—is scarce in comparison to DOM and humic and fulvic acids. Moreover, it is unclear how peat POM chemistry and decomposition relate to its EAC and EDC. To address these knowledge gaps, we compiled peat samples with varying carbon contents from mid to high latitude peatlands and analyzed their EACPOM and EDCPOM, element ratios, decomposition indicators, and relative amounts of molecular structures as derived from mid infrared spectra. Peat EACPOM and EDCPOM are smaller (per gram carbon) than EAC and EDC of DOM and terrestrial and aquatic humic and fulvic acids and are highly variable within and between sites. Both are small in highly decomposed peat, unless it has larger amounts of quinones and phenols. Element ratio‐based models failed to predict EACPOM and EDCPOM, while mid infrared spectra‐based models can predict peat EACPOM to a large extent, but not EDCPOM. We suggest a conceptual model that describes how vegetation chemistry and decomposition control polymeric phenol and quinone contents as drivers of peat EDCPOM and EACPOM. The conceptual model implies that we need mechanistic models or spatially resolved measurements to understand the variability in peat EDCPOM and EACPOM and thus its role in controlling methane formation.

Description: Plain Language Summary: Peatlands accumulated large amounts of carbon via photosynthesis and slow decomposition of senesced plant material. Microorganisms within the peat form methane. For this reason, peatlands are important global sources of the greenhouse gas methane and therefore can contribute to climate change. In order to produce methane, the microorganisms have to transfer electrons between compounds in respiration processes. Only recently, it has been found that the peat itself can reversibly transfer electrons and that its capacities to reversibly accept electron accepting capacity (EAC) and reversibly donate electron donating capacity (EDC) electrons are large. We investigated which conditions favor large or small EAC and EDC of peat so that we can better explain methane formation. We argue that vegetation and decomposition control the amount of phenols and quinones—molecules in the peat that presumably are responsible for most of the peat's EAC and EDC. The EAC and EDC probably are largest for peat formed from vegetation rich in quinones and phenols, such as shrubs, and smaller for other vegetation types, for example, certain mosses. Intense decomposition may reduce both the EAC and EDC.

Description: Key Points: Peat particulate organic matter electron accepting and donating capacities per grams of carbon are smaller than for humic and fulvic acids. Both capacities are small in highly decomposed peat, unless it has larger amounts of quinones and phenols. We explain these patterns with parent vegetation chemistry and conditions during decomposition.

Description: Deutsche Forschungsgemeinschaft (DFG) http://dx.doi.org/10.13039/501100001659

Description: CAS | Youth Innovation Promotion Association (YIPA) http://dx.doi.org/10.13039/501100012492

Description: https://github.com/henningte/redoxpeat

Description: We developed a numerical thermodynamics laboratory called “Thermolab” to study the effects of the thermodynamic behavior of nonideal solution models on reactive transport processes in open systems. The equations of the state of internally consistent thermodynamic data sets are implemented in MATLAB functions and form the basis for calculating Gibbs energy. A linear algebraic approach is used in Thermolab to compute Gibbs energy of mixing for multicomponent phases to study the impact of the nonideality of solution models on transport processes. The Gibbs energies are benchmarked with experimental data, phase diagrams, and other thermodynamic software. Constrained Gibbs minimization is exemplified with MATLAB codes and iterative refinement of composition of mixtures may be used to increase precision and accuracy. All needed transport variables such as densities, phase compositions, and chemical potentials are obtained from Gibbs energy of the stable phases after the minimization in Thermolab. We demonstrate the use of precomputed local equilibrium data obtained with Thermolab in reactive transport models. In reactive fluid flow the shape and the velocity of the reaction front vary depending on the nonlinearity of the partitioning of a component in fluid and solid. We argue that nonideality of solution models has to be taken into account and further explored in reactive transport models. Thermolab Gibbs energies can be used in Cahn‐Hilliard models for nonlinear diffusion and phase growth. This presents a transient process toward equilibrium and avoids computational problems arising during precomputing of equilibrium data.

Description: Plain Language Summary: The behavior of Earth materials, rocks, minerals, melts, fluids, and gases is important to predict physical processes in the Earth with computer models. The purpose of this is to study how the changes of variables such as fluid and solid composition influence the diffusion, fluid flow, and reaction in rocks. Here, we present a set of computer codes, called Thermolab, to calculate important physical properties such as density and chemical composition of solids, fluids, and melts in chemical equilibrium. The calculations are based on the Gibbs energy that exists for every material. We use computer codes, written in MATLAB/OCTAVE language, to show how this Gibbs energy is calculated and used to compute chemical equilibrium and find the physical properties such as density and chemical composition. We discuss techniques for accurate calculation of chemical equilibrium and physical properties in real rocks. Finally, we use Thermolab to formulate a computer model of fluids reacting with rocks. We find that chemical composition of the fluid and rock strongly affects the speed and shape of the boundary between reacted and unreacted rock. Thermolab can be used in phase growth models to investigate the way in which rocks develop toward equilibrium.

Description: Key Points: Thermolab: a set of MATLAB codes is presented to perform equilibrium and nonequilibrium thermodynamic calculations. Local thermodynamic equilibrium is used to study effects of nonideality of solution models on nonlinear transport processes. Nonlinear diffusion processes are investigated with Thermolab providing a transient natural physical process toward equilibrium.

Description: Deutsche Forschungsgemeinschaft (DFG) http://dx.doi.org/10.13039/501100001659

Description: Russian Ministry of Science and Higher Education

Description: https://hansjcv.github.io/Thermolab/

Description: https://doi.org/10.5281/zenodo.6383253

Description: Since it is currently not understood how changes in 14C production rate (Q), and in the carbon cycle, can be combined to explain the reconstructed atmospheric Δ14C record, we discuss possible reasons for this knowledge gap. Reviewing the literature, we exclude that changes in the content of atoms in the atmosphere, which produce cosmogenic 14C after being hit by galactic cosmic rays, might be responsible for parts of the observed differences. When combining Q with carbon cycle changes, one needs to understand the changes in the atmospheric 14C inventory, which are partially counterintuitive. For example, during the Last Glacial Maximum, Δ14C was ∼400‰ higher compared with preindustrial times, but the 14C inventory was 10% smaller. Some pronounced changes in atmospheric Δ14C do not correspond to any significant changes in the atmospheric 14C inventory, since CO2 was changing simultaneously. Using two conceptually different models (BICYCLE‐SE and LSG‐OGCM), we derive hypothetical Qs by forcing the models with identical atmospheric CO2 and Δ14C data. Results are compared with the most recent data‐based estimates of Q derived from cosmogenic isotopes. Millennial‐scale climate change connected to the bipolar seesaw is missing in the applied models, which might explain some, but probably not all, of the apparent model‐data disagreement in Q. Furthermore, Q based on either data from marine sediments or ice cores contains offsets, suggesting an interpretation deficit in the current data‐based approaches.

Description: Key Points: No important change found in the level of precursor material, which produces cosmogenic radiocarbon after being hit by galactic cosmic rays. Transient changes in the bipolar seesaw are needed in applied carbon cycle models to improve interpretation of the radiocarbon cycle. Sediment core‐ and ice core‐based radiocarbon production rates differ systematically, suggesting missing processes.

Description: Bundesministerium für Bildung und Forschung (BMBF) http://dx.doi.org/10.13039/501100002347

Description: Swedish Research Concil

Description: Helmholtz Association (亥姆霍兹联合会致力) http://dx.doi.org/10.13039/501100009318

Description: https://doi.org/10.1594/PANGAEA.871273

Description: https://www.ncdc.noaa.gov/paleo-search/study/31772

Description: https://doi.org/10.1594/PANGAEA.914500

Description: https://www.iceandclimate.nbi.ku.dk/data/

Description: https://doi.org/10.1594/PANGAEA.932965

Description: The compound‐specific hydrogen isotopic composition (δ2H) of n‐alkanes is a valuable proxy to investigate hydrological conditions in lake sediments. While terrestrial n‐alkanes reflect the isotopic signal of the local precipitation, aquatic n‐alkanes incorporate the isotopic signal of the lake's water, which can be strongly modulated by evaporative enrichment. So far, the spatial distribution of the terrestrial and aquatic δ2H signal within lakes have not systematically been investigated. Here, we present compound‐specific δ2H results of terrestrial (δ2HC31) and aquatic (δ2HC23) n‐alkanes of surface sediment samples from Lake Khar Nuur, a semi‐arid and high‐altitude lake in the Mongolian Altai, and additionally investigate the δ2H signal of topsoils from the catchment. Our results show that the majority of the n‐alkane δ2H values from the catchment topsoils correspond well with modeled local growing season precipitation (JJAS). However, few samples in the northern catchment show more positive δ2H values possibly due to increased evapo(transpi)ration by southward exposition and shallower soils there. The only small variability of δ2HC31 in the surface sediments is in the range of most topsoils δ2H from the catchment, and thus, well reflects local growing season precipitation. δ2HC23 in surface sediment samples from the central and deepest parts of the lake, that is, the lake's sediment accumulation zones, shows distinctly more positive δ2HC23 values due to evaporative lake water enrichment. Consequently, Δaq‐terr, which is the isotopic offset between δ2HC23 and δ2HC31, indicates distinct lake water enrichment in the lake's accumulation zones and is a valuable proxy to investigate past hydrological changes.

Description: Key Points: The hydrogen isotopic composition of terrestrial C31 n‐alkanes reflects the local growing season precipitation at Lake Khar Nuur. Aquatic C23 n‐alkanes incorporate the isotopic signal of the lake's water, which is strongly modulated by evaporative enrichment. The isotopic offset between C23 and C31 is a valuable proxy for evaporation in the lake and past hydrological changes in the catchment.

Description: https://doi.pangaea.de/10.1594/PANGAEA.940115

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

Description: Large bell‐shaped calcite formations called “Hells Bells” were discovered underwater in the stratified cenote El Zapote on the Yucatán Peninsula, Mexico. Together with these extraordinary speleothems, divers found a white, cloudy turbid layer into which some Hells Bells partially extend. Here, we address the central question if the formation of the turbid layer could be based on microbial activity, more specifically, on microbially induced calcite precipitation. Metagenomic and metatranscriptomic profiling of the microbial community in the turbid layer, which overlaps with the pelagic redoxcline in the cenote, revealed chemolithoautotrophic Hydrogenophilales and unclassified β‐Proteobacteria as the metabolic key players. Bioinformatic and hydrogeochemical data suggest chemolithoautotrophic oxidation of sulfide to zero‐valent sulfur catalyzed by denitrifying organisms due to oxygen deficiency. Incomplete sulfide oxidation via nitrate reduction and chemolithoautotrophy are both proton‐consuming processes, which increase the pH in the redoxcline favoring authigenic calcite precipitation and may contribute to Hells Bells growth. The observed mechanism of microbially induced calcite precipitation is potentially applicable to many other stagnant sulfate‐rich water bodies.

Description: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659

Description: CONACYT‐FONCICYT‐DADC

Description: https://doi.org/10.11588/data/TMYLWS

Description: https://doi.org/10.11588/data/GYLDH5

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

Description: Key Points: Literature review of 7200 geoanalytical publications for the year 2020. 628 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. image

Description: This bibliographic review gives an overview of scientific publications in 2020 that contribute important data for geoanalytical reference materials (RMs).

Description: Due to their availability, low cost, nontoxicity, and tunability, polymeric carbon nitrides (CNx) represent one of the most attractive materials classes for the development of fully sustainable photo(electro)catalytic systems for solar‐driven water splitting. However, the development of CNx‐based photoanodes for visible light‐driven water oxidation to dioxygen is rather challenging, particularly due to issues related to photoelectrode stability and effective coupling of the light absorber with water oxidation catalysts. Herein, a triadic photoanode comprising a porous TiO2 electron collector scaffold sensitized by CNx coupled to a molecular cobalt polyoxometalate (CoPOM = [Co4(H2O)2(PW9O34)2]10) catalyst is reported. Complete water oxidation to dioxygen under visible (λ 〉 420 nm) light irradiation is demonstrated, with photocurrents down to relatively low bias potentials (0.2 V vs RHE). Furthermore, polyethyleneimine (PEI), a cationic polymer is shown to act as an effective and non‐sacrificial electrostatic linker for immobilization of the anionic CoPOM onto the negatively charged surface of CNx. The optimized deposition of CoPOM using the PEI linker translates directly into improved efficiency of the transfer of photogenerated holes to water molecules and to enhanced oxygen evolution. This work thus provides important design rules for effective immobilization of POM‐based catalysts into soft‐matter photoelectrocatalytic architectures for light‐driven water oxidation.

Description: A triadic photoanode comprised of a porous TiO2 electron collector scaffold sensitized by polymeric carbon nitride and coupled to a molecular cobalt polyoxometalate (CoPOM) catalyst exhibits visible (λ 〉 420 nm) light‐driven water oxidation to dioxygen. The beneficial role of the cationic polyethyleneimine polymer as an effective electrostatic linker for immobilization of CoPOM onto carbon nitride is highlighted.

Description: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659

Description: Vector Stiftung http://dx.doi.org/10.13039/501100013912

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

Description: Little research attention has been given to validating clusters obtained from the groundwater geochemistry of the waterworks' capture zone with a prevailing lake‐groundwater exchange. To address this knowledge gap, we proposed a new scheme whereby Gaussian finite mixture modeling (GFMM) and Spike‐and‐Slab Bayesian (SSB) algorithms were utilized to cluster the groundwater geochemistry while quantifying the probability of the resulting cluster membership against each other. We applied GFMM and SSB to 13 geochemical parameters collected during different sampling periods at 13 observation points across the Barnim Highlands plateau located in the northeast of Berlin, Germany; this included 10 observation wells, two lakes, and a gallery of drinking production wells. The cluster analysis of GFMM yielded nine clusters, either with a probability ≥0.8, while the SSB produced three hierarchical clusters with a probability of cluster membership varying from 〈0.2 to 〉0.8. The findings demonstrated that the clustering results of GFMM were in good agreement with the classification as per the principal component analysis and Piper diagram. By superimposing the parameter clustering onto the observation clustering, we could identify discrepancies that exist among the parameters of a certain cluster. This enables the identification of different factors that may control the geochemistry of a certain cluster, although parameters of that cluster share a strong similarity. The GFMM results have shown that from 2002, there has been active groundwater inflow from the lakes towards the capture zone. This means that it is necessary to adopt appropriate measures to reverse the inflow towards the lakes.

Description: Article impact statement: The probability of cluster membership quantified using an algorithm should be validated against another probabilistic‐based classifier.

Description: Federal Ministry of Education and Research http://dx.doi.org/10.13039/501100002347

Description: Internal water in cold‐water and tropical coral skeletons was extracted and measured for its oxygen and hydrogen isotope ratios. Water was extracted by crushing pieces of coral hard tissue in a percussion device connected to either a cavity ring‐down spectroscopy (CRDS) system or an isotope ratio mass spectrometry (IRMS) system. Despite most samples yielding sufficient water, each analytical system produces distinct isotope patterns. Experiments show that several characteristics specific to biominerals give rise to discrepancies and analytical artefacts that preclude the acquisition of reproducible isotope data. The main complication is that internal water in biogenic carbonates is distributed in an open interconnected micro‐network that readily exchanges with external water and potentially facilitates interaction with hydration water in the finely dispersed organic matrix in the coral skeleton. Furthermore, only an isotopically fractionated part of the internal water is released from the coral skeletons upon crushing. Altogether, isotope ratio measurement of internal water in corals with bulk crushing techniques does not give primary fluid isotope ratios useful for (palaeo‐)environmental or microbiological studies. As the resulting isotope patterns can show systematic behaviour per technique, isotope data may be erroneously interpreted to reflect the original calcifying fluid when using only a single technique to isotopically characterise internal fluids in coral skeletons.

Description: Key Points: Free water trapped inside coral skeletons was extracted and isotopically analyzed on two commonly used techniques for fluid inclusion isotope analysis. Measured oxygen and hydrogen isotope ratios do not reproduce between the techniques due to several analytical artefacts. The water extracted from coral skeletons is not of primary origin.

Description: Nederlandse Organisatie voor Wetenschappelijk Onderzoek http://dx.doi.org/10.13039/501100003246

Description: Western Indian Ocean Marine Science Association http://dx.doi.org/10.13039/501100009106

Description: Rapid and profound climatic and environmental changes have been predicted for the Antarctic Peninsula with so far unknown impact on the biogeochemistry of the continental shelves. In this study, we investigate benthic carbon sedimentation, remineralization and iron cycling using sediment cores retrieved on a 400 mile transect with contrasting sea ice conditions along the eastern shelf of the Antarctic Peninsula. Sediments at comparable water depths of 330–450 m showed sedimentation and remineralization rates of organic carbon, ranging from 2.5 to 13 and 1.8–7.2 mmol C m−2 d−1, respectively. Both rates were positively correlated with the occurrence of marginal sea ice conditions (5%–35% ice cover) along the transect, suggesting a favorable influence of the corresponding light regime and water column stratification on algae growth and sedimentation rates. From south to north, the burial efficiency of organic carbon decreased from 58% to 27%, while bottom water temperatures increased from −1.9 to −0.1°C. Net iron reduction rates, as estimated from pore‐water profiles of dissolved iron, were significantly correlated with carbon degradation rates and contributed 0.7%–1.2% to the total organic carbon remineralization. Tightly coupled phosphate‐iron recycling was indicated by significant covariation of dissolved iron and phosphate concentrations, which almost consistently exhibited P/Fe flux ratios of 0.26. Iron efflux into bottom waters of 0.6–4.5 μmol Fe m−2 d−1 was estimated from an empirical model. Despite the deep shelf waters, a clear bentho‐pelagic coupling is indicated, shaped by the extent and duration of marginal sea ice conditions during summer, and likely to be affected by future climate change.

Description: Plain Language Summary: The seafloor of the shallow shelf seas plays a significant role in the recycling of organic carbon and acts as a nutrient source for algae growth in the upper water layers. In Antarctic waters, the change in sea ice cover has a great impact on the growth of algae and the subsequent sinking of organic carbon to the seafloor. With global warming, profound changes in sea ice cover are expected for the Antarctic Peninsula. To better understand its imprint on the seafloor, we collected sediment samples from different locations along the eastern shelf of the Antarctic Peninsula and measured how changes in sea ice cover influence the accumulation and recycling of organic carbon. We found that moderate sea ice cover of 5%–35% increases the amount of organic carbon received by the seafloor and that the fraction that is buried in the sediments decreases from south (58%) to north (27%). We further measured that more iron, an important micro‐nutrient for algae growth, can be released from the seafloor the more organic carbon accumulates. Thus, sea ice conditions determine the organic carbon accumulation, turnover, and nutrient release at the seafloor, which are likely to be affected by future climate change.

Description: Key Points: Antarctic shelf sediments underlying marginal sea ice cover exhibit high sedimentation and remineralization rates of organic carbon. A high degree of sedimentary Fe‐recycling is found which scales with organic carbon remineralization rates. Coupling between P and Fe recycling is observed with a constant P/Fe flux ratio of 0.26 for sediments with high Fe and P recycling rates.

Description: Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research http://dx.doi.org/10.13039/501100003207

Description: https://doi.org/10.1594/PANGAEA.942455

Description: The Arctic Ocean is considered a source of micronutrients to the Nordic Seas and the North Atlantic Ocean through the gateway of Fram Strait (FS). However, there is a paucity of trace element data from across the Arctic Ocean gateways, and so it remains unclear how Arctic and North Atlantic exchange shapes micronutrient availability in the two ocean basins. In 2015 and 2016, GEOTRACES cruises sampled the Barents Sea Opening (GN04, 2015) and FS (GN05, 2016) for dissolved iron (dFe), manganese (dMn), cobalt (dCo), nickel (dNi), copper (dCu) and zinc (dZn). Together with the most recent synopsis of Arctic‐Atlantic volume fluxes, the observed trace element distributions suggest that FS is the most important gateway for Arctic‐Atlantic dissolved micronutrient exchange as a consequence of Intermediate and Deep Water transport. Combining fluxes from FS and the Barents Sea Opening with estimates for Davis Strait (GN02, 2015) suggests an annual net southward flux of 2.7 ± 2.4 Gg·a−1 dFe, 0.3 ± 0.3 Gg·a−1 dCo, 15.0 ± 12.5 Gg·a−1 dNi and 14.2 ± 6.9 Gg·a−1 dCu from the Arctic toward the North Atlantic Ocean. Arctic‐Atlantic exchange of dMn and dZn were more balanced, with a net southbound flux of 2.8 ± 4.7 Gg·a−1 dMn and a net northbound flux of 3.0 ± 7.3 Gg·a−1 dZn. Our results suggest that ongoing changes to shelf inputs and sea ice dynamics in the Arctic, especially in Siberian shelf regions, affect micronutrient availability in FS and the high latitude North Atlantic Ocean.

Description: Plain Language Summary: Recent studies have proposed that the Arctic Ocean is a source of micronutrients such as dissolved iron (dFe), manganese (dMn), cobalt (dCo), nickel (dNi), copper (dCu) and zinc (dZn) to the North Atlantic Ocean. However, data at the Arctic Ocean gateways including Fram Strait and the Barents Sea Opening have been missing to date and so the extent of Arctic micronutrient transport toward the Atlantic Ocean remains unquantified. Here, we show that Fram Strait is the most important gateway for Arctic‐Atlantic micronutrient exchange which is a result of deep water transport at depths 〉500 m. Combined with a flux estimate for Davis Strait, this study suggests that the Arctic Ocean is a net source of dFe, dNi and dCu, and possibly also dCo, toward the North Atlantic Ocean. Arctic‐Atlantic dMn and dZn exchange seems more balanced. Properties in the East Greenland Current showed substantial similarities to observations in the upstream Central Arctic Ocean, indicating that Fram Strait may export micronutrients from Siberian riverine discharge and shelf sediments 〉3,000 km away. Increasing Arctic river discharge, permafrost thaw and coastal erosion, all consequences of ongoing climate change, may therefore alter future Arctic Ocean micronutrient transport to the North Atlantic Ocean.

Description: Key Points: Fram Strait is the major gateway for Arctic‐Atlantic exchange of the dissolved micronutrients Fe, Mn, Co, Ni, Cu and Zn. The Arctic is a net source of dissolved Fe, Co, Ni and Cu to the Nordic Seas and toward the North Atlantic; Mn and Zn exchange are balanced. Waters of the Central Arctic Ocean, including the Transpolar Drift, are the main drivers of gross Arctic micronutrient export.

Description: German Research Foundation

Description: Netherlands Organization for Scientific Research

Description: https://doi.pangaea.de/10.1594/PANGAEA.859558

Description: https://doi.pangaea.de/10.1594/PANGAEA.871030

Description: https://doi.pangaea.de/10.1594/PANGAEA.868396

Description: https://doi.pangaea.de/10.1594/PANGAEA.905347

Description: https://dataportal.nioz.nl/doi/10.25850/nioz/7b.b.jc

Description: https://doi.pangaea.de/10.1594/PANGAEA.933431

Description: https://www.bco-dmo.org/dataset/718440

Description: https://doi.org/10.1594/PANGAEA.936029

Description: https://doi.org/10.1594/PANGAEA.936027

Description: https://doi.pangaea.de/10.1594/PANGAEA.927429

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

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

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

Description: Iron(II) (Fe(II)) can be formed by abiotic Fe(III) photoreduction, particularly when Fe(III) is organically complexed. Light‐influenced environments often overlap or even coincide with oxic or microoxic geochemical conditions, for example, in sediments. So far, it is unknown whether microaerophilic Fe(II)‐oxidizing bacteria are able to use the Fe(II) produced by Fe(III) photoreduction as electron donor. Here, we present an adaption of the established agar‐stabilized gradient tube approach in comparison with liquid cultures for the cultivation of microaerophilic Fe(II)‐oxidizing microorganisms by using a ferrihydrite‐citrate mixture undergoing Fe(III) photoreduction as Fe(II) source. We quantified oxygen and Fe(II) gradients with amperometric and voltammetric microelectrodes and evaluated microbial growth by qPCR of 16S rRNA genes. We showed that gradients of dissolved Fe(II) (maximum Fe(II) concentration of 1.25 mM) formed in the gradient tubes when incubated in blue or UV light (400–530 nm or 350–400 nm). Various microaerophilic Fe(II)‐oxidizing bacteria (Curvibacter sp. and Gallionella sp.) grew by oxidizing Fe(II) that was produced in situ by Fe(III) photoreduction. Best growth for these species, based on highest gene copy numbers, was observed in incubations using UV light in both liquid culture and gradient tubes containing 8 mM ferrihydrite‐citrate mixtures (1:1), due to continuous light‐induced Fe(II) formation. Microaerophilic Fe(II)‐oxidizing bacteria contributed up to 40% to the overall Fe(II) oxidation within 24 h of incubation in UV light. Our results highlight the potential importance of Fe(III) photoreduction as a source of Fe(II) for Fe(II)‐oxidizing bacteria by providing Fe(II) in illuminated environments, even under microoxic conditions.

Description: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659

Description: Ministerium für Wissenschaft, Forschung und Kunst Baden‐Württemberg http://dx.doi.org/10.13039/501100003542

Description: Bundesministerium für Bildung und Forschung http://dx.doi.org/10.13039/501100002347

Description: Biological nitrogen fixation is an important oceanic nitrogen source, potentially stabilizing marine fertility in an increasingly stratified and nutrient‐depleted ocean. Iron limitation of low latitude primary producers has been previously demonstrated to affect simulated regional ecosystem responses to climate warming or nitrogen cycle perturbation. Here we use three biogeochemical models that vary in their representation of the iron cycle to estimate change in the marine nitrogen cycle under a high CO2 emissions future scenario (RCP8.5). The first model neglects explicit iron effects on biology (NoFe), the second utilizes prescribed, seasonally cyclic iron concentrations and associated limitation factors (FeMask), and the third contains a fully dynamic iron cycle (FeDyn). Models were calibrated using observed fields to produce near‐equivalent nutrient and oxygen fits, with productivity ranging from 49 to 75 Pg C yr−1. Global marine nitrogen fixation increases by 71.1% with respect to the preindustrial value by the year 2100 in NoFe, while it remains stable (0.7% decrease in FeMask and 0.3% increase in FeDyn) in explicit iron models. The mitigation of global nitrogen fixation trend in the models that include a representation of iron originates in the Eastern boundary upwelling zones, where the bottom‐up control of iron limitation reduces export production with warming, which shrinks the oxygen deficient volume, and reduces denitrification. Warming‐induced trends in the oxygen deficient volume in the upwelling zones have a cascading effect on the global nitrogen cycle, just as they have previously been shown to affect tropical net primary production.

Description: Plain Language Summary: Phytoplankton need nutrients to grow. Two of those nutrients are nitrogen and iron. Climate change projections suggest that in the future there could be less nitrogen supplied to the surface ocean, which might reduce phytoplankton growth. Less phytoplankton growth could impact a wide range of ocean services, like fishing and fossil carbon draw‐down. However, some phytoplankton have the ability to add “new” nitrogen to the surface ocean directly from the atmosphere. In this study, we explore how this biological fixation of new nitrogen might change into the future using three models. These models differ in how iron is represented, but all do equally well in representing the observed nutrient and oxygen distribution. Biological nitrogen fixation slightly decreases with climate change in the very complex iron model and the moderately complex iron model, but it increases strongly (by more than 70% by the year 2100) in the model that does not include iron effects on biology. Our study addresses the importance of iron models and how they can change our view of how the ocean responds to climate change.

Description: Key Points: Models performing similarly with respect to global NO3, PO4, and O2 distributions yield diverse responses in marine N2 fixation to warming. Marine N2 fixation trends are sensitive to whether iron limits primary production in upwelling regions, for example, the Eastern Tropical Pacific.

Description: Helmholtz Research School for Ocean System Science and Technology

Description: New Zealand Ministry of Business, Innovation and Employment

Description: https://data.geomar.de/downloads/20.500.12085/673e7de0-20ab-4dd3-afe9-c4bfb00b1faf/

Description: Relationships between vegetation and air quality are intricate and still not fully understood. For regional air quality assessments, a better understanding of the diverse feedback mechanisms is crucial. The present article investigates the impact of land use data set detailedness on air quality predictions. Therefore, two different land use data sets were applied for simulations with COSMO‐MUSCAT for Germany in May 2014. One data set includes detailed information about tree species while the second one obtains generalized widely applied land use classes including mixed and coniferous forests. Moreover, we examined the role of agricultural NO soil emissions, agricultural biomass density enhancements, and model resolution. For a more comprehensive implementation of the secondary organic aerosol (SOA) formation, the SOA module was extended considering additional biogenic volatile organic compound (BVOC) precursor groups from isoprene, α‐pinene, limonene, and sesquiterpene oxidations. The model studies showed substantial differences in BVOC emission patterns between the two land use data sets. The application of detailed tree species information leads to complex BVOC emission patterns with high emission spots. In contrast, coarser forest information lead to standardized comprehensive emissions which result in 50% higher BVOC emissions. These differences affect both the atmospheric oxidizing potential and the production rates of SOA precursors. Land use induced regional differences (tree species minus forest information) in NOx (±2.5%), ozone (−2.5%), OH (±50%), NO3 radical (+70%) concentrations, and SOA (−60%) mass are modeled. Overall, the simulations demonstrate that detailed land use information, extended organic chemistry treatment, and high spatial resolution are mandatory for air quality assessments.

Description: Plain Language Summary: Trees are associated with being the lungs of the atmosphere as they filter out harmful substances from the air, they store CO2, and produce oxygen via photosynthesis. Other by‐products of photosynthesis are biogenic volatile organic compounds (BVOCs). BVOCs are chemical substances with a high vapor pressure already at room temperatures, so they quickly evaporate from the leaves into the surrounding air and are responsible for the characteristic forest smell. The amount and composition of BVOC emissions strongly depend on the tree species. Every plant has its own distinct emission properties. The chemical degradation of BVOCs impacts the chemical composition of the troposphere and is connected to ground level ozone production and the formation of secondary organic aerosols (SOA), contributing substantially to particulate matter (PM). On a global scale, standardized BVOC emission information on forest levels are often used, but for regional air quality assessments detailed plant specific information is crucial, but still often lacking. Therefore, two different land use data sets were applied in the present study to investigate the impact of standardized forest versus detailed tree‐species information for Germany in May 2014. The study reveals changes in NOx (±2.5%), ozone (−2.5%), OH (±50%), NO3 radical (+70%), and SOA (−60%) concentrations.

Description: Key Points: Detail of land use data sets crucial for biogenic volatile organic compound emission strength and composition. Composition and concentration variation of these organic compounds induce changes in regional air quality predictions. Detailed land use information, extended organic matter treatment, and high‐resolution simulations are mandatory for air quality assessments.

Description: Deutsche Bundesstiftung Umwelt (DBU) http://dx.doi.org/10.13039/100007636

Description: https://doi.org/10.5281/zenodo.4783106

Description: http://ebas.nilu.no/

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/

Description: Abundant volcanic activity occurs in the back‐arc region of the northern Tofua island arc where the Northeast Lau Spreading Center (NELSC) propagates southwards into older crust causing the formation of numerous seamounts at the propagating rift tip. An off‐axis volcanic diagonal ridge (DR) occurs at the eastern flank of the NELSC, linking the large rear‐arc volcano Niuatahi with the NELSC. New geochemical data from the NELSC, the southern propagator seamounts, and DR reveal that the NELSC lavas are tholeiitic basalts whereas the rear‐arc volcanoes typically erupt lavas with boninitic composition. The sharp geochemical boundary probably reflects the viscosity contrast between off‐axis hydrous harzburgitic mantle and dry fertile mantle beneath the NELSC. The new data do not indicate an inflow of Samoa plume mantle into the NELSC, confirming previously published He isotope data. The NELSC magmas form by mixing of an enriched and a depleted Indian Ocean‐type upper mantle end‐member implying a highly heterogeneous upper mantle composition in this area. Most NELSC lavas are little affected by a slab component implying that melting is adiabatic beneath the spreading center. The DR lavas show the influence of a component from the subducted Louisville Seamount Chain, which was previously thought to be restricted to the nearby arc volcanoes Niuatoputapu and Tafahi. This signature is rarely detected along the NELSC implying little mixing of melts from the low‐viscosity hydrous portion of the mantle wedge beneath the rear‐arc volcanoes into the melting region of the dry mantle beneath the NELSC.

Description: Plain Language Summary: Volcanic activity is abundant at subduction zones and the chemical analysis of the erupted rocks allows to determine the material transport in the Earth's mantle. The Northeast Lau Spreading Center (NELSC) forms by extension and volcanism behind the northern Tofua island arc. Several large volcanic structures occur east of the NELSC and the lavas of these off‐axis volcanoes are chemically and isotopically distinct implying little mixing with the magmas of the NELSC. The differences suggest decompression melting of relatively dry mantle beneath the NELSC whereas the off‐axis volcanoes reflect melting of water‐rich mantle affected by fluids from the subducting Pacific Plate. The sharp geochemical boundary between the NELSC and off‐axis volcanoes is probably due to a large viscosity contrast between hydrous harzburgitic mantle and dry fertile mantle. Element and isotope ratios indicate that the NELSC magmas form by mixing of enriched and depleted portions of the upper mantle, and we do not find evidence for inflow of the Samoa deep mantle plume from the north. Some of the off‐axis lavas contain a component from a volcanic chain that was subducted some 4 million years ago and that was previously only known in two volcanoes of the Tofua island arc.

Description: Key Points: Variably enriched mantle sources melt beneath the Northeast Lau Spreading Center (NELSC) but there is no evidence for Samoa mantle plume inflow. Relatively dry fertile mantle beneath NELSC causes sharp geochemical boundary with hydrous harzburgitic North Tonga mantle wedge. Subducted Louisville Seamount Chain material affects rear‐arc volcanism.

Description: Bundesministerium für Bildung und Forschung (BMBF) http://dx.doi.org/10.13039/501100002347

Description: Deutsche Forschungsgemeinschaft (DFG) http://dx.doi.org/10.13039/501100001659

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Description: Tropical forests contribute about one third to global annual CH4 uptake by soils. Understanding the factors that control the soil‐atmosphere exchange of CH4 at a large scale is a critical step to improve the CH4 flux estimate for tropical soils, which is presently poorly constrained. Since tropical forest degradation often involves shifts in nutrient availabilities, it is critical to evaluate how this will affect soil CH4 flux. Here, we report how nitrogen (N; 50 kg N ha−1 yr−1), phosphorus (P; 10 kg P ha−1 yr−1), and combined N + P additions affect soil CH4 fluxes across an elevation gradient of tropical montane forests. We measured soil CH4 fluxes in a nutrient application experiment at different elevations over a period of 5 years. Nutrient additions increased soil CH4 uptake after 4–5 years of treatment but effects were not uniform across elevations. At 1,000 m, where total soil P was high, we detected mainly N limitation of soil CH4 uptake. At 2,000 m, where total soil P was low, a strong P limitation of soil CH4 uptake was observed. At 3,000 m, where total P was low in the organic layer but high in mineral soil, we found N limitation of soil CH4 uptake. Our results show that projected increases of N and P depositions may increase soil CH4 uptake in tropical montane forests but the direction, magnitude, and timing of the effects will depend on forests' nutrient status and plant‐microbial competition for N and P.

Description: Plain Language Summary: CH4 is a potent greenhouse gas that contributes to global warming. Tropical forests are a natural sink of CH4 but increasing nutrient depositions due to industrialization may alter the sink strength of tropical forests. Our results show that projected increases of nitrogen and phosphorus depositions may increase soil CH4 uptake in tropical montane forests but the direction, magnitude, and timing of the effects will depend on forests' nutrients and plant‐microbial competition.

Description: Key Points: Projected increases in nitrogen and phosphorus depositions in the tropics will stimulate soil methane uptake in tropical montane forests. The direction, magnitude, and timing of nutrient deposition effects on soil methane uptake will depend on forests' nutrient status. Nutrient limitations on ecosystem processes have to be investigated in actual field conditions.

Description: Deutsche Forschungsgemeinschaft (DFG) http://dx.doi.org/10.13039/501100001659

Description: https://doi.org/10.25625/XLNKNK

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).

Description: Water isotope ratios of ice cores are a key source of information on past temperatures. Through fractionation within the hydrological cycle, temperature is imprinted in the water isotopic composition of snowfalls. However, this signal of climatic interest is modified after deposition when snow remains at the surface exposed to the atmosphere. Comparing time series of surface snow isotopic composition at Dome C with satellite observations of surface snow metamorphism, we found that long summer periods without precipitation favor surface snow metamorphism altering the surface snow isotopic composition. Using excess parameters (combining D,17O, and 18O fractions) allow the identification of this alteration caused by sublimation and condensation of surface hoar. The combined measurement of all three isotopic compositions could help identifying ice core sections influenced by snow metamorphism in sites with very low snow accumulation.

Description: Plain Language Summary: Water isotopes in ice core records are often used to reconstruct past climate temperature variations. Classically, the temperature signal is thought to be imprinted in water isotopes of precipitation, and then archived in the ice core as it falls, and in cold areas of Antarctica, piles up for very long period. Here, we show that the surface snow isotopic composition varies in between precipitation events, suggesting that there might be more than one contribution to the isotopic signal in ice core records. This is particularly important for low accumulation sites, where the snow at the surface remains exposed for very long time periods. The combined use of several isotopic ratios in surface snow helps us disentangle the processes that create this signal.

Description: Key Points: During summer without precipitation, intense snow metamorphism shows a strong water isotopic signature. During summer without precipitation, intense snow metamorphism shows a strong water isotopic signature. The d‐excess and 17O‐excess of the snow is a proxy of snow metamorphism for low accumulation regions.

Description: FP7 Ideas: European Research Council (FP7 Ideas) http://dx.doi.org/10.13039/100011199

Description: Foundation Prince Albert of Monaco

Description: Alexander von Humboldt‐Stiftung (Humboldt‐Stiftung) http://dx.doi.org/10.13039/100005156

Description: DFG project CLIMAIC

Description: https://doi.pangaea.de/10.1594/PANGAEA.934273

Description: The radiocarbon signature of respired CO2 (∆14C‐CO2) measured in laboratory soil incubations integrates contributions from soil carbon pools with a wide range of ages, making it a powerful model constraint. Incubating archived soils enriched by “bomb‐C” from mid‐20th century nuclear weapons testing would be even more powerful as it would enable us to trace this pulse over time. However, air‐drying and subsequent rewetting of archived soils, as well as storage duration, may alter the relative contribution to respiration from soil carbon pools with different cycling rates. We designed three experiments to assess air‐drying and rewetting effects on ∆14C‐CO2 with constant storage duration (Experiment 1), without storage (Experiment 2), and with variable storage duration (Experiment 3). We found that air‐drying and rewetting led to small but significant (α 〈 0.05) shifts in ∆14C‐CO2 relative to undried controls in all experiments, with grassland soils responding more strongly than forest soils. Storage duration (4–14 y) did not have a substantial effect. Mean differences (95% CIs) for experiments 1, 2, and 3 were: 23.3‰ (±6.6), 19.6‰ (±10.3), and 29.3‰ (±29.1) for grassland soils, versus −11.6‰ (±4.1), 12.7‰ (±8.5), and −24.2‰ (±13.2) for forest soils. Our results indicate that air‐drying and rewetting soils mobilizes a slightly older pool of carbon that would otherwise be inaccessible to microbes, an effect that persists throughout the incubation. However, as the bias in ∆14C‐CO2 from air‐drying and rewetting is small, measuring ∆14C‐CO2 in incubations of archived soils appears to be a promising technique for constraining soil carbon models.

Description: Plain Language Summary: Soils play a key role in the global carbon cycle by sequestering carbon from the atmosphere for decades to millennia. However, it is unclear if they will continue to do so as the climate changes. Microbial decomposition of soil organic matter returns carbon back to the atmosphere, and radiocarbon dating of this returning CO2 (∆14C‐CO2) can be used to quantify how long carbon is stored in ecosystems. Incubating archived soils could provide unique insight into soil carbon sequestration potential by quantifying the change in ∆14C‐CO2 over time. However, air‐drying, duration of archiving, and subsequent rewetting of soils may bias estimates of sequestration potential by altering the balance of younger versus older carbon leaving the soil. We compared ∆14C‐CO2 from soils incubated with and without air‐drying and archiving, and found that the air‐dried soils appeared to release slightly older carbon than soils that had never been air‐dried. The amount of time the soils were archived did not have an effect. Since the bias from air‐drying and rewetting was small, incubating archived soils appears to be a promising technique for improving our ability to model soil carbon cycling under global climate change.

Description: Key Points: ∆14C of CO2 measured in incubations of archived soils provides additional constraints for soil carbon models. Air‐drying and rewetting soils shifted the ∆14C of respired CO2 by 10‰–20‰ independent of the duration of storage. Differences in direction and magnitude of ∆14C‐CO2 shifts between forests and grasslands depended on sampling year and system C dynamics.

Description: EC, H2020, H2020 Priority Excellent Science, H2020 European Research Council (ERC) http://dx.doi.org/10.13039/100010663

Description: https://doi.org/10.5281/zenodo.4959705

Description: Temperate forest soils are often considered as an important sink for atmospheric carbon (C), thereby buffering anthropogenic CO2 emissions. However, the effect of tree species composition on the magnitude of this sink is unclear. We resampled a tree species common garden experiment (six sites) a decade after initial sampling to evaluate whether forest floor (FF) and topsoil organic carbon (Corg) and total nitrogen (Nt) stocks changed in dependence of tree species (Norway spruce—Picea abies L., European beech—Fagus sylvatica L., pedunculate oak—Quercus robur L., sycamore maple—Acer pseudoplatanus L., European ash—Fraxinus excelsior L. and small‐leaved lime—Tilia cordata L.). Two groups of species were identified in terms of Corg and Nt distribution: (1) Spruce with high Corg and Nt stocks in the FF developed as a mor humus layer which tended to have smaller Corg and Nt stocks and a wider Corg:Nt ratio in the mineral topsoil, and (2) the broadleaved species, of which ash and maple distinguished most clearly from spruce by very low Corg and Nt stocks in the FF developed as mull humus layer, had greater Corg and Nt stocks, and narrow Corg:Nt ratios in the mineral topsoil. Over 11 years, FF Corg and Nt stocks increased most under spruce, while small decreases in bulk mineral soil (esp. in 0–15 cm and 0–30 cm depth) Corg and Nt stocks dominated irrespective of species. Observed decadal changes were associated with site‐related and tree species‐mediated soil properties in a way that hinted towards short‐term accumulation and mineralisation dynamics of easily available organic substances. We found no indication for Corg stabilisation. However, results indicated increasing Nt stabilisation with increasing biomass of burrowing earthworms, which were highest under ash, lime and maple and lowest under spruce. Highlights We studied if tree species differences in topsoil Corg and Nt stocks substantiate after a decade. The study is unique in its repeated soil sampling in a multisite common garden experiment. Forest floors increased under spruce, but topsoil stocks decreased irrespective of species. Changes were of short‐term nature. Nitrogen was most stable under arbuscular mycorrhizal species.

Description: Deutsche Forschungsgemeinschaff (DFG)

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

Description: Carbonate‐associated sulfate (CAS) is an important proxy for reconstructing marine sulfur cycling throughout Earth's history. In order to assess the impact of carbonate neomorphism on δ34SCAS data, a mineralogical‐spatial transect from early diagenetic limestone into low‐temperature hydrothermal dolostone was analyzed in the middle Triassic Latemar platform interior, northern Italy. This study addresses the yet unconstrained question whether hydrothermal dolostone preserves a marine δ34SCAS signature and, hence, might represent an archive for past seawater sulfate. In this study, δ34SCAS values were measured in low‐temperature hydrothermal dolostone and compared with data from their corresponding precursor limestone. Results shown here reveal that δ34SCAS values for dolostone and precursor limestone are indistinguishable. This points to a rock‐buffered middle Triassic marine δ34S signature not affected by hydrothermal alteration. Hence, hydrothermal dolostone represents, under favorable conditions, an archive for unraveling past marine sulfur cycling.

Description: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659

Description: Fjords are recognized as hotspots of organic carbon (OC) burial in the coastal ocean. In fjords with glaciated catchments, glacier discharge carries large amounts of suspended matter. This sedimentary load includes OC from bedrock and terrigenous sources (modern vegetation, peat, soil deposits), which is either buried in the fjord or remineralized during export, acting as a potential source of CO2 to the atmosphere. In sub‐Antarctic South Georgia, fjord‐terminating glaciers have been retreating during the past decades, likely as a response to changing climate conditions. We determine sources of OC in surface sediments of Cumberland Bay, South Georgia, using lipid biomarkers and the bulk 14C isotopic composition, and quantify OC burial at present and for the time period of documented glacier retreat (between 1958 and 2017). Petrogenic OC is the dominant type of OC in proximity to the present‐day calving fronts (60.4 ± 1.4% to 73.8 ± 2.6%) and decreases to 14.0 ± 2.7% outside the fjord, indicating that petrogenic OC is effectively buried in the fjord. Beside of marine OC, terrigenous OC comprises 2.7 ± 0.5% to 7.9 ± 5.9% and is mostly derived from modern plants and Holocene peat and soil deposits that are eroded along the flanks of the fjord, rather than released by the retreating fjord glaciers. We estimate that the retreat of tidewater glaciers between 1958 and 2017 led to an increase in petrogenic carbon accumulation of 22% in Cumberland West Bay and 6.5% in Cumberland East Bay, suggesting that successive glacier retreat does not only release petrogenic OC into the fjord, but also increases the capacity of OC burial.

Description: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659

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

Description: Quantifying the anthropogenic fluxes of CO2 is important to understand the evolution of carbon sink capacities, on which the required strength of our mitigation efforts directly depends. For the historical period, the global carbon budget (GCB) can be compiled from observations and model simulations as is done annually in the Global Carbon Project's (GCP) carbon budgets. However, the historical budget only considers a single realization of the Earth system and cannot account for internal climate variability. Understanding the distribution of internal climate variability is critical for predicting the future carbon budget terms and uncertainties. We present here a decomposition of the GCB for the historical period and the RCP4.5 scenario using single‐model large ensemble simulations from the Max Planck Institute Grand Ensemble (MPI‐GE) to capture internal variability. We calculate uncertainty ranges for the natural sinks and anthropogenic emissions that arise from internal climate variability, and by using this distribution, we investigate the likelihood of historical fluxes with respect to plausible climate states. Our results show these likelihoods have substantial fluctuations due to internal variability, which are partially related to El Niño‐Southern Oscillation (ENSO). We find that the largest internal variability in the MPI‐GE stems from the natural land sink and its increasing carbon stocks over time. The allowable fossil fuel emissions consistent with 3 C warming may be between 9 and 18 Pg C yr−1. The MPI‐GE is generally consistent with GCP's global budgets with the notable exception of land‐use change emissions in recent decades, highlighting that human action is inconsistent with climate mitigation goals.

Description: Key Points: We use a single‐model large ensemble to estimate uncertainties from internal climate variability in the global carbon budget. The land sink accounts for most internal climate uncertainty which may permit 9–18 Pg C yr−1 in allowable emissions by 2050 (for 3°C warming).

Description: European Union's Horizon 2020

Description: There is still a paucity of hydrological data explaining the relationship between (rapid, millennial‐scale) climate forcing and Mediterranean rainfall since the Last Glacial. We show that distinct lake‐level fluctuations at Lake Trasimeno (Italy) are associated with changing aridity in the central Mediterranean during the last ~47 800 years. The lake‐level fluctuations are reconstructed based on carbonate mineral content and carbonate mineral species, as well as the stable oxygen and carbon isotope (δ18O and δ13C) geochemistry of endogenic carbonates. Low lake levels are linked to high carbonate, Mg‐calcite and aragonite contents, and high δ18O and δ13C values. Inferred hydrological changes are linked to glacial–interglacial and, tentatively within the limitations of our chronology, to millennial‐scale climate variability as well as the intensity of the Atlantic Meridional Overturning Circulation (AMOC). Prior to the Last Glacial Maximum (LGM), during intervals equivalent to Marine Isotope Stage 3 (MIS 3), a stronger AMOC associated with Greenland interstadial periods (Dansgaard/Oeschger (D/O) warm periods) and stronger Asian monsoon probably coincide with increased precipitation in central Italy as inferred from high lake levels at Lake Trasimeno. Periods of weak AMOC intensity such as during Greenland stadials (D/O cold periods), during Heinrich events, and weak Asian monsoons are correlated with lake level lowstands, which imply relatively dry conditions in central Italy. Lake Trasimeno’s water level during the LGM and the Lateglacial (MIS 2) is relatively stable, with recorded changes showing distinct similarities to orbital configurations. Although muted, high latitude climate forcing is still evident in the data during peak glacial conditions. The transition from D/O‐like hydrological variability at Lake Trasimeno during MIS 3 to orbitally controlled fluctuations during the Lateglacial to Holocene transition coincides with an increasing amplitude in local winter and summer insolation, probably indicating increasing seasonality and a larger temperature gradient between low‐ and high‐latitude settings.

Description: Deutscher Akademischer Austauschdienst http://dx.doi.org/10.13039/501100001655

Description: The early exhumation history of the Tauern Window in the European Eastern Alps and its surface expression is poorly dated and quantified, partly because thermochronological and provenance information are sparse from the Upper Austrian Northern Alpine Foreland Basin. For the first time, we combine a single‐grain double‐dating approach (Apatite Fission Track and U‐Pb dating) with trace‐element geochemistry analysis on the same apatites to reconstruct the provenance and exhumation history of the late Oligocene/early Miocene Eastern Alps. The results from 22 samples from the Chattian to Burdigalian sedimentary infill of the Upper Austrian Northern Alpine Foreland Basin were integrated with a 3D seismic‐reflection data set and published stratigraphic reports. Our highly discriminative data set indicates an increasing proportion of apatites (from 6% to 23%) with Sr/Y values 〈0.1 up‐section and an increasing amount of apatites (from 24% to 38%) containing 〉1,000 ppm light rare‐earth elements from Chattian to Burdigalian time. The number of U‐Pb ages with acceptable uncertainties increases from 40% to 59% up‐section, with mostly late Variscan/Permian ages, while an increasing number of grains (10%–27%) have Eocene or younger apatite fission track cooling ages. The changes in the apatite trace‐element geochemistry and U‐Pb data mirror increased sediment input from an ≥upper amphibolite‐facies metamorphic source of late Variscan/Permian age – probably the Ötztal‐Bundschuh nappe system – accompanied by increasing exhumation rates indicated by decreasing apatite fission track lag times. We attribute these changes to the surface response to upright folding and doming in the Penninic units of the future Tauern Window starting at 29–27 Ma. This early period of exhumation (0.3–0.6 mm/a) is triggered by early Adriatic indentation along the Giudicarie Fault System.

Description: Science Foundation Ireland http://dx.doi.org/10.13039/501100001602

Description: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659

Description: Preservation of organic carbon (OC) in marine sediments exerts a major control on the cycling of carbon in the Earth system. In these marine environments, OC preservation may be enhanced by diagenetic reactions in locations where deposition of fragmental volcanic material called tephra occurs. While the mechanisms by which this process occurs are well understood, site‐specific studies of this process are limited. Here, we report a study of sediments from the Bering Sea (IODP Site U1339D) to investigate the effects of marine tephra deposition on carbon cycling during the Pleistocene and Holocene. Our results suggest that tephra layers are loci of OC burial with distinct δ13C values, and that this process is primarily linked to bonding of OC with reactive metals, accounting for ∼80% of all OC within tephra layers. In addition, distribution of reactive metals from the tephra into non‐volcanic sediments above and below the tephra layers enhances OC preservation in these sediments, with ∼33% of OC bound to reactive phases. Importantly, OC‐Fe coupling is evident in sediments 〉700,000 years old. Thus, these interactions may help explain the observed preservation of OC in ancient marine sediments.

Description: Plain Language Summary: The burial of organic carbon (OC) in marine sediments is one of the major carbon sinks on Earth, meaning that it removes carbon dioxide from the ocean‐atmosphere system. However, the speed at which burial occurs varies across the globe, and is dependent on a range of factors, from the amount of nutrients in the water column, to the type of sediment. Despite evidence suggesting that when tephra is deposited to the seafloor carbon burial is enhanced, very little work has been done to investigate this process. We have therefore analyzed sediments from the Bering Sea, where volcanoes from the Aleutian Islands and Kamchatka regularly deposit tephra in the ocean. We found that OC burial is indeed associated with ash deposition, and importantly, that OC is preserved in the ash layers themselves. We show here that this carbon is preserved effectively because of chemical reactions between the OC and reactive iron, which is released by the ash, creating conditions which preserve carbon for hundreds of thousands of years.

Description: Key Points: Tephra layers are loci of marine organic carbon (OC) burial with distinct carbon isotopic compositions. Preservation primarily linked to association of OC with reactive iron phases, accounting for ∼80% of all OC in tephra layers. OC‐reactive Fe coupling is observed in sediments 〉700,000 years old, indicating long‐term persistence of these complexes.

Description: NERC

Description: The winter 2019/2020 showed the lowest ozone mixing ratios ever observed in the Arctic winter stratosphere. It was the coldest Arctic stratospheric winter on record and was characterized by an unusually strong and long‐lasting polar vortex. We study the chemical evolution and ozone depletion in the winter 2019/2020 using the global Chemistry and Transport Model ATLAS. We examine whether the chemical processes in 2019/2020 are more characteristic of typical conditions in Antarctic winters or in average Arctic winters. Model runs for the winter 2019/2020 are compared to simulations of the Arctic winters 2004/2005, 2009/2010, and 2010/2011 and of the Antarctic winters 2006 and 2011, to assess differences in chemical evolution in winters with different meteorological conditions. In some respects, the winter 2019/2020 (and also the winter 2010/2011) was a hybrid between Arctic and Antarctic conditions, for example, with respect to the fraction of chlorine deactivation into HCl versus ClONO2, the amount of denitrification, and the importance of the heterogeneous HOCl + HCl reaction for chlorine activation. The pronounced ozone minimum of less than 0.2 ppm at about 450 K potential temperature that was observed in about 20% of the polar vortex area in 2019/2020 was caused by exceptionally long periods in the history of these air masses with low temperatures in sunlight. Based on a simple extrapolation of observed loss rates, only an additional 21–46 h spent below the upper temperature limit for polar stratospheric cloud formation and in sunlight would have been necessary to reduce ozone to near zero values (0.05 ppm) in these parts of the vortex.

Description: Key Points: The Arctic stratospheric winter 2019/2020 showed the lowest ozone mixing ratios ever observed and was one of the coldest on record. Chemical evolution of the Arctic winter 2019/2020 was a hybrid between typical Arctic and typical Antarctic conditions. Only an additional 21–46 h below PSC temperatures and in sunlight would have been necessary to reduce ozone to near zero locally.

Description: International Multidisciplinary Drifting Observatory for the Study of the Arctic Climate (MOSAiC)

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

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

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

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

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

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

Description: The ungrouped iron meteorite Nedagolla is the first meteorite with bulk Mo, Ru, and Ni isotopic compositions that are intermediate between those of the noncarbonaceous (NC) and carbonaceous (CC) meteorite reservoirs. The Hf‐W chronology of Nedagolla indicates that this mixed NC–CC isotopic composition was established relatively late, more than 7 Myr after solar system formation. The mixed NC–CC isotopic composition is consistent with the chemical composition of Nedagolla, which combines signatures of metal segregation under more oxidizing conditions (relative depletions in Mo and W), characteristic for CC bodies, and more reducing conditions (high Si and Cr contents), characteristic for some NC bodies, in a single sample. These data combined suggest that Nedagolla formed as the result of collisional mixing of NC and CC core material, which partially re‐equilibrated with silicate mantle material that predominantly derives from the NC body. These mixing processes might have occurred during a hit‐and‐run collision between two differentiated bodies, which also provides a possible pathway for Nedagolla's extreme volatile element depletion. As such, Nedagolla provides the first isotopic evidence for early collisional mixing of NC and CC bodies that is expected as a result of Jupiter's growth.

Description: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659

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

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

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

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

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

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

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

Description: poster

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

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

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

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

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

Description: poster

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