ALBERT

Description: Paleoclimatic effects may still influence the present day subsurface temperature distribution and therefore the heatflow density calculated in affected depth levels. Cooling of several degrees Celsius into depths of up to 1.5 – 2km were reported for areas which were strongly affected by the Pleistocene ice ages (e.g. Canada, Poland, andDenmark). However, although this phenomenon is well known, not much research has been performed to quantifythese processes in Northern Germany, an area where Pleistocene ice margins of the last ice ages are located. Tofill that gap we compiled new data from two boreholes in the eastern part of the North German Basin, one locatedbeneath the former ice shield of the last glaciation, and one located in the foreland. We determined thermal rockproperties (thermal conductivity, thermal diffusivity, and specific heat capacity) on drill core samples and used itas calibrator for well-log based calculations of thermal parameter profiles along the borehole. The results wereused for heat-flow computations with depth and implemented as a base for an analytical solution of the heatequation as well as inversion modelling. By showing the discrepancy of observed and theoretical backgroundtemperature and heat flow density profiles, we aim to improve the understanding of the regional thermal responseto the last glaciations.

Description: The current assessments of the carbon turnover in the Arctic tundra are subject to large uncertainties. This problem can (inter alia) be ascribed to both the general shortage of flux data from the vast and sparsely inhabited Arctic region, as well as the typically high spatiotemporal variability of carbon fluxes in tundra ecosystems. Addressing these challenges, carbon dioxide fluxes on an active flood plain situated in the Siberian Lena River Delta were studied during two growing seasons with the eddy covariance method. The footprint exhibited a heterogeneous surface, which generated mixed flux signals that could be partitioned in such a way that both respiratory loss and photosynthetic gain were obtained for each of two vegetation classes. This downscaling of the observed fluxes revealed a differing seasonality in the net uptake of bushes (−0.89 µmol m−2 s−1) and sedges (−0.38 µmol m−2 s−1) in 2014. That discrepancy, which was concealed in the net signal, resulted from a comparatively warm spring in conjunction with an early snowmelt and a varying canopy structure. Thus, the representativeness of footprints may adversely be affected in response to prolonged unusual weather conditions. In 2015, when air temperatures on average corresponded to climatological means, both vegetation-class-specific flux rates were of similar magnitude (−0.69 µmol m−2 s−1). A comprehensive set of measures (e.g. phenocam) corroborated the reliability of the partitioned fluxes and hence confirmed the utility of flux decomposition for enhanced flux data analysis. This scrutiny encompassed insights into both the phenological dynamic of individual vegetation classes and their respective functional flux to flux driver relationships with the aid of ecophysiologically interpretable parameters. For comparison with other sites, the decomposed fluxes were employed in a vegetation class area-weighted upscaling that was based on a classified high-resolution orthomosaic of the flood plain. In this way, robust budgets that take the heterogeneous surface characteristics into account were estimated. In relation to the average sink strength of various Arctic flux sites, the flood plain constitutes a distinctly stronger carbon dioxide sink. Roughly 42 % of this net uptake, however, was on average offset by methane emissions lowering the sink strength for greenhouse gases. With growing concern about rising greenhouse gas emissions in high-latitude regions, providing robust carbon budgets from tundra ecosystems is critical in view of accelerating permafrost thaw, which can impact the global climate for centuries.

Description: In Northwest Anatolia, the dextral North Anatolian Fault Zone (NAFZ) goes through the Sea of Marmara and cre-ates a section which is known as the Main Marmara Fault (MMF). Due to the NAFZ activity, the Marmara regionis a major earthquake zone. This area hosts the Megacity of Istanbul in the vicinity of a seismic gap (∼150 kmlong) in the MMF which has not ruptured since 1766. There is an ongoing controversial debate regarding the causeof the seismic gap and if either the fault is locked to a certain depth or is creeping. The main question is if the faultis geomechanically segmented or if the energy will be released over a big single rupture surface. To contribute tothis discussion a detailed description and understanding of the lithosphere thermomechanical behaviour below theSea of Marmara is key. In this study, we present 3D lithospheric-scale thermal and rheological models of the Sea ofMarmara. These models are based on a 3D density model which is obtained from geological and geophysical dataintegration and constrained by gravity modelling. Accordingly, the lithosphere structure consists of six major lay-ers. Two layers of syn- and pre-kinematic sediments with respect to the Sea of Marmara formation with an averagedensity (ρ) of 2000 and 2490 kg.m−3, respectively. These sediments rest on a heterogeneous crust including a felsicupper crystalline crust (ρ= 2720 kg.m−3)and an intermediate to mafic lower crystalline crust (ρ= 2890 kg.m−3).The crystalline crustal units are crosscut by two thick dome-shaped mafic high-density bodies (ρ= 3050 kg.m−3),that spatially correlate with the bending segments of the MMF. Beneath these layers is a homogeneous lithosphericmantle (ρ= 3300 kg.m−3)down to the thermal Lithosphere-Asthenosphere boundary (LAB). Along the MMF,the thermomechanical model generally indicates that the brittle-ductile transition zone occurs within the uppercrystalline crust at a depth of around 18 km b.s.l, which is consistent with the 1999 Izmit earthquake. In contrast,the thermomechanical model indicates that the high-density bodies are colder and stronger than the surroundingcrystalline units. Consequently, the brittle-ductile transition zone occurs, closer to the Moho discontinuity, at thedepth around 23 km b.s.l. In conclusion, these results suggest that crustal heterogeneities significantly affect therheological behaviour of the MMF, and support the hypothesis that the fault is geomechanically segmented.

Description: Local earthquake activity can be employed to measure attenuation (the effective quality factor [Q]) and characterize production in the Delaware Basin, Texas, USA. To illustrate this, we employed data from the recently installed Texas Seismic Network (TexNet) seismic stations collected in the west Texas area between April 2017 and March 2018. Earthquake activity in the Delaware Basin has increased in comparison to the previous 20 years, which has resulted in numerous high-quality events suitable for this analysis. The high signal-to-noise ratio events were used to estimate effective Q factors using the peak frequency method on the sediments of the Delaware Basin. The effective attenuation of the sedimentary basin is 90 for P-waves and 140 for S-waves (both with uncertainty of approximately 30), indicating an unusually low attenuation (high Q) for S-waves relative to the P-waves. This is consistent with attenuation of a saturated sedimentary basin because the saturation results in less attenuation of S-waves. Additionally, we observe an increase of the effective Q factor with distance between the station and events consistent with rays sampling the deeper, less-attenuating, and less-saturated portions of the basin and even basement. Inverted effective attenuation coefficients were used to calculate moment magnitudes, which were consistent with those seen in the TexNet array.

Description: Understanding and quantifying total economic impacts of flood events is essential for flood risk management and adaptation planning. Yet, detailed estimations of joint direct and indirect flood-induced economic impacts are rare. In this study an innovative modeling procedure for the joint assessment of short-term direct and indirect economic flood impacts is introduced. The procedure is applied to 19 economic sectors in eight federal states of Germany after the flood events in 2013. The assessment of the direct economic impacts is object-based and considers uncertainties associated with the hazard, the exposed objects and their vulnerability. The direct economic impacts are then coupled to a supply-side Input-Output-Model to estimate the indirect economic impacts. The procedure provides distributions of direct and indirect economic impacts which capture the associated uncertainties. The distributions of the direct economic impacts in the federal states are plausible when compared to reported values. The ratio between indirect and direct economic impacts shows that the sectors Manufacturing, Financial and Insurance activities suffered the most from indirect economic impacts. These ratios also indicate that indirect economic impacts can be almost as high as direct economic impacts. They differ strongly between the economic sectors indicating that the application of a single factor as a proxy for the indirect impacts of all economic sectors is not appropriate.

Description: In summer 2017, the ICDP SUSTAIN project (Surtsey Underwater volcanic System for Thermophiles, Alteration processes and INnovative concretes), drilled three cored boreholes (Table 1) through Surtsey at sites ≤10 m from a cored hole obtained in 1979. Drilling through the still hot volcano was carried out with an Atlas Copco CS1000 drill rig, whose components were transported by helicopter to Surtsey and re-assembled on site. The first vertical borehole, SE-02a, was cored in HQ diameter to 152 meters below surface (m b.s.) during August 7-16. It was terminated due to borehole collapse. A second vertical (SE-02b) cored borehole was then drilled in HQ diameter to 192 m during August 19-26. Wireline borehole logging in SE-02b was performed August 26. The anodized NQ-sized aluminum tubing of the Surtsey Subsurface Observatory was installed in SE-02b to 181 m depth on August 27. A third borehole, SE-03, angled 35° from vertical and directed 264°, was drilled from August 28 to September 4 and reached a measured depth of 354 m (~290 m vertical depth) under the eastern crater. The core is HQ diameter to a measured depth of 213 m and NQ diameter from 213-354 m measured depth. The core traverses the deep conduit and intrusions of the volcano to a total vertical depth of 290 m b.s. Seawater drilling fluid for boreholes SE-02a and SE-02b was filtered and doubly UV-sterilized at the drill site. No mud products were employed while coring SE-02a, while small amounts of attapulgite mud were used in SE-02b and SE-03. Core samples for geochemical analyses of pore water and microbiological investigations were collected on site from all three boreholes. About 650 m of core was transported by helicopter to Heimaey, 18 km northeast of Surtsey, to a processing laboratory where the core was scanned, documented, and described. Additional core processing has taken place at the Náttúrufraedistofnun Íslands, the Icelandic Institute of Natural History in Gardabaer, where both the 1979 and 2017 cores are stored.

Description: Although crustal and sub-crustal structures in the Alps are some of the best studied of any orogen in the world,different hypotheses still exist regarding plate architecture and the nature of the subduction system. Additionally,rheological configurations of the different crustal units and of the lithospheric mantle, isostasy in the orogen-foreland system, and variations of flexural rigidity along and across the mountain belt are, at the present-day, poorlyconstrained with relation to spatial patterns of seismicity and deformation. The primary goal of INTEGRATE,a project in the DFG priority program Mountain Building in 4 Dimensions, a part of the AlpArray initiative,is to provide insights into these questions by integrating different 3D modelling techniques. Here we present agravity constrained, 3D, density differentiated, structural model of the Alps and their respective forelands derivedfrom integrating numerous existing geological and geophysical datasets. Results indicate the existence of lateralheterogeneities within the crust of the studied area, particularly in regards to the difference in thickness and densityof the European and Adriatic crusts. Within the plates, some density heterogeneities correspond to well-studiedtectonic features such as the Vosges, Black Forest and Bohemian massifs, along with the Ivrea geophysical body.However, in keeping with similar modelling works, the location of these density contrasts do not always correspondto present day tectonic structures, instead indicating older, inherited crustal features. A positive correlation betweenthese inherited crustal density contrasts and present day deformation maps of the region was identified, a trendnoted here for the first time. Additionally, we used the 3D density model together with information on seismicvelocities to derive lithologies for the different crustal units and calculate the 3D conductive field of the system. Astemperature is a key controlling factor for rock strength, we also assess the correlation of temperature variationsand deformation within the region.

Description: Spherical harmonic coefficients representing an estimate of Earth's mean gravity field during the specified timespan derived from GRACE-FO mission measurements. These coefficients represent the full magnitude of land hydrology, ice, and solid Earth processes. Further, they represent atmospheric and oceanic processes not captured in the accompanying GAC product.

Description: Dispersive delays due to the solar wind introduce excess noise in high-precision pulsar timing experiments, and must be removed in order to achieve the accuracy needed to detect, e.g., low-frequency gravitational waves. In current pulsar timing experiments, this delay is usually removed by approximating the electron density distribution in the solar wind either as spherically symmetric or with a two-phase model that describes the contributions from both high- and low-speed phases of the solar wind. However, no data set has previously been available to test the performance and limitations of these models over extended time-scales and with sufficient sensitivity. Here we present the results of such a test with an optimal data set of observations of pulsar J0034−0534, taken with the German stations of LOFAR. We conclude that the spherical approximation performs systematically better than the two-phase model at almost all angular distances, with a rms given by the two-phase model being up to 28 per cent larger than the result obtained with the spherical approximation. Never the less, the spherical approximation remains insufficiently accurate in modelling the solar wind delay (especially within 20 degrees of angular distance from the Sun), as it leaves timing residuals with rms values that reach the equivalent of 0.3 μs at 1400 MHz. This is because a spherical model ignores the large daily variations in electron density observed in the solar wind. In the short term, broad-band observations or simultaneous observations at low frequencies are the most promising way forward to correct for solar-wind-induced delay variations.

Description: In May 2018 a volcano-seismic sequence accompanied the upward migration of a magmatic intrusion from Moho depth to the seafloor led to the drainage of the deep magmatic reservoir and to the birth of a submarine volcano offshore the island of Mayotte, Comoro Islands. This process of magma transport was accompanied by an intense seismic swarm and peculiar long-duration very long period signals. Between 1 January 2018 and 1 May 2019 we detected 407 sources of very long period signals and 6990 volcano-tectonic earthquakes. This report collects detection, location and source parameters catalogs for these two sets of earthquake sources. This data publication provides the catalogues of very long period (VLP) signals and volcano-tectonic (VT) earthquakes, as discussed in Cesca et al. (2019). Here, methods and data used to create the different catalogues are only briefly discussed; a more accurate description is given in Cesca et al. (2019), which furthermore discusses the different processes of dike migration, undersea eruption, deep reservoir drainage and overburden sagging which are responsible for the seismic activity.

Description: The Australian plate has a long and complex tectonic history. The continental crust was accreted in three majorepisodes from the Archean cratons in the west to the Phanerozoic provinces in the east. The crust and upper mantleof Australia have been deeply investigated in the last two decades using a variety of geophysical methods. To dis-cern temperature and compositional variations in the Australian upper mantle, we apply an integrative technique,which jointly interprets seismic tomography and gravity data. In the first stage, we removed the effect of the crustfrom the observed gravity field and topography. In the second step, an initial thermal model has been constructedby inverting the seismic tomography model AusREM (http://rses.anu.edu.au/seismology/AuSREM/index.php),assuming a laterally and vertically uniform “fertile” mantle composition. After removing the effect of thetemperature variations from the total mantle anomalies, the residual “compositional” fields are obtained. Theresidual mantle gravity field and residual topography are inverted to obtain a 3-D density model of the uppermantle, which is supplementary to the initial thermally induced density variations. These density anomalies wereused to improve the initial thermal and compositional models by applying an iterative approach to account forthe effect of composition on the thermal model. The results obtained show that the Precambrian West and NorthAustralian Craton (WAC and NAC) each possess thick, relatively cool, lithosphere that has depleted composition(Mg# 〉 90). This observation is stronger in the older WAC than the younger NAC. Substantially hotter and lessdense lithosphere is seen fringing the eastern and southeastern margin of the continent, resolving the thermalperturbation of these regions in response to Mesozoic and Cenozoic events.Furthermore, we used the surface heat flow values recently published and the most updated crustal model ofAustralia (AusREM) to estimate temperature distribution in the crust, assuming steady state conditions, and weused the results obtained together with the mantle thermal model to construct two alternative models of strengthand effective elastic thickness (EET) of the lithosphere. The first model (Model I) assumes a constant value of 10−15 s−1for the strain rates. In the second model (Model II), we used the strain rates obtained from a global mantleflow model. In both models we assumed a stiff rheology, on account of the mafic composition of the Australiancrust. The results of Model II show larger variability of the rigidity of the plate within the cratonic areas, reflectingthe long tectonic history of the Australian plate. On the other hand, the younger eastern terranes are uniformlyweak, due to the higher temperatures.

Description: Length: 32 min What forms the landscapes of the Earth with its mountains, rivers, soils, the places we live in? Is Earth’s surface shaped when rocks are uplifted by geologic forces, and are then destroyed by rain, ice, and wind; or do plants with their roots, animals that dig into soil and the vast number of microorganisms shape the landscapes? Watch the scientists of the German-Chilean “EarthShape” project study these questions along a fascinating landscapes in Chile, and in their home laboratories. A science movie designed and produced by Friedhelm von Blanckenburg from GFZ Potsdam, Germany, Kirstin Übernickel from Universität Tübingen, and Wolfgang Dümcke from Filmbüro Potsdam, Germany, within the DFG-funded research network “EarthShape – Earth Surface Shaping by Biota” which is coordinated by Todd Ehlers (Universität Tübingen) und Friedhelm von Blanckenburg (GFZ Potsdam).

Description: The Cretaceous Niobrara Formation is one of the latest unconventional exploration targets in North America. In this paper, an overall Type-II marine organofacies with some variability is present within a core which consists of alternating marls and chalks, covering a maturity range of 0.8–1.0 %Rc (calculated vitrinite reflectance). Enhanced oil saturation index (OSI) values have previously been reported for the chalk, and here a positive trend (R2 = 0.92) between the OSI and the percentage of saturates in gross fractions is present. Thus, the saturate fraction gradually increases from 40% to above 60% as the OSI increases from 40 to 550 mg HC/g TOC (total organic carbon). Extremely high OSI values (〉300 mg HC/g TOC) are characteristic of Niobrara chalks. Therefore, the chalk intervals represent primary sweet spots. Using a combined analytical approach, petroleum has been shown to migrate from the organic-rich marls into juxtaposed chalks, and that this has fractionated oils into higher quality liquids. Extractable organic matter in the chalks is clearly enriched in saturate hydrocarbons, while the NSO-containing polar compounds are preferentially retained in the shale and marl units. Compared with the significant fractionation effects between these gross fractions, fractionation within a given compound class is nevertheless indistinct.

Description: Understanding the natural microbiological mechanismsthat promote iron cycling in iron ore mine environmentsmay provide novel tools for the remediation of the fragile,iron-rich duricrust ecosystems associated with these envir-onmentsaswellasprovide asolutionforthestabilisation ofhillslopes and tailings (waste) dams. A diverse array ofmicrofossils is frequently identified throughout metre-scale duricrusts (canga;〉50 wt.% Fe) that cap iron oredeposits in Brazil, shedding light on the intimate role ofmicroorganisms in the evolution of these crusts. Nanoscalesecondary ion mass spectrometry revealed that carbon andnitrogen biosignatures are occasionally preserved, and typ-ically associated with the cell envelope structures of micro-fossils. The microfossils are 1–5mm in length, withfilamentous and rod-shaped morphologies commonly pre-served1,2. When examined using backscatter electron scan-ning electron microscopy, canga shows a complexmicrostructure from repeated dissolution and re-precipita-tion of iron oxide minerals. Geochronology3, geochemis-try4and microbiology5provide insights into the past andpresent-day role of microorganisms in the evolution ofcanga. These dynamic biogeochemical processes in cangacontribute to the continuous formation of new ironcements, preserving some of world’s longest-lived contin-uously exposed surfaces. Harnessing and accelerating thebiogeochemical cycling of iron may contribute to the de-velopment of novel technologies for mine remediation andwaste stabilisation.

Description: This dataset provides friction data from ring-shear tests (RST) for a quartz sand used in analogue experiments at the Institute of Geophysics of the Czech Academy of Science (IGCAS) (Kratinová et al., 2006; Zavada et al., 2009; Lehmann et al., 2017; Krýza et al., 2019). It is characterized by means of internal friction coefficients µ and cohesion C. According to our analysis the materials show a Mohr-Coulomb behaviour characterized by a linear failure envelope. Peak friction coefficients µP of the tested material is ~0.75, dynamic friction coeffi-cients µD is ~0.60 and reactivation friction coefficients µR is ~0.64. Cohesions of the material range between 90 and 130 Pa. The material shows a minor rate-weakening of 〈1% per ten-fold change in shear velocity v.

Description: Velocity updates have been proven to be important for constraining motion-sensor-based dead-reckoning (DR) solutions in indoor unmanned aerial vehicle (UAV) applications. The forward velocity from a mass flow sensor and the lateral and vertical non-holonomic constraints (NHC) can be utilized for three-dimensional (3D) velocity updates. However, it is observed that (a) the quadrotor UAV may have a vertical velocity trend when it is controlled to move horizontally; (b) the quadrotor may have a pitch angle when moving horizontally; and (c) the mass flow sensor may suffer from sensor errors, especially the scale factor error. Such phenomenons degrade the performance of velocity updates. Thus, this paper presents a multi-sensor integrated localization system that has more effective sensor interactions. Specifically, (a) the barometer data are utilized to detect height changes and thus determine the weight of vertical velocity update; (b) the pitch angle from the inertial measurement unit (IMU) and magnetometer data fusion is used to set the weight of forward velocity update; and (c) an extra mass flow sensor calibration module is introduced. Indoor flight tests have indicated the effectiveness of the proposed sensor interaction strategies in enhancing indoor quadrotor DR solutions, which can also be used for detecting outliers in external localization technologies such as ultrasonics.

Description: Redox-sensitive elements (Mo, V, U, Re, Cd, Co, As, Sb, Tl, Ni, Cr, Mn, Fe, Pb, Cu, Zn, Se) and proxies for detrital clastic sedimentation (Al, Ti, Sc, Th) along with total organic carbon (TOC) and total sulfur (TS) were analysed to constrain the paleoredox conditions of the Middle-Upper Jurassic black shales in the Blue Nile (Abay) Basin, Ethiopia. These samples were collected from the deep marine Antalo Limestone (Oxfordian-Kimmeridgian), Gohatsion Formation (Bathonian) and glauconitic shale-mudstone unit (Aalenian-Toarcian). Significant variations in redox-sensitive elements concentration within and between these shales were evident for variable redox conditions. In general, the concentration of proxies for detrital clastic sedimentation increases from the Antalo Limestone to Gohatsion Formation and further to glauconitic shale-mudstone unit shales, respectively. The Antalo Limestone shales show slightly higher enrichment in redox-sensitive elements than the Gohatsion Formation and glauconitic shale-mudstone unit shales. The Antalo Limestones shales have higher TOC content than the glauconitic shale-mudstone unit shales and become very low in the Gohatsion Formation shales. The TS content in contrast, is relatively lower in the Antalo Limestone shales, intermediate in the Gohatsion Formation shales and becomes higher in the glauconitic shale-mudstone unit shales. The Antalo Limestone shales were deposited under anoxic-suboxic conditions whereas the Gohatsion Formation and glauconitic shale-mudstone unit shales were deposited under suboxic-oxic conditions. The TOC content and redox conditions of the Antalo Limestone shales implies favourable organic matter preservation and future source rock explorations in the basin should be targeted there.

Description: Magmatic-hydrothermal systems form a variety of ore deposits at different proximities to upper-crustal hydrous magma chambers, ranging from greisenization in the roof zone of the intrusion, porphyry mineralization at intermediate depths to epithermal vein deposits near the surface. The physical transport processes and chemical precipitation mechanisms vary between deposit types and are often still debated. For this study, we investigate the fluid evolution from proximal to distal settings at the Pirquitas and Chinchillas Mines in NW Argentina and the Sweet Home Mine, Colorado. New results from fluid inclusion and isotopic analyses indicate a contribution of magmatic fluids in the formation of the SnAg Pirquitas Mine, even though no direct association to a magmatic intrusion is visible. Therefore, this deposit may represent a rather distal setting. In contrast, the Ag-Pb-Zn Chinchillas Mine is hosted in volcanic extrusive units and is directly associated to an underlying dacite diatreme. In that respect, this deposit is proximal to a volcanic complex, but due to its shallow emplacement is distal to an inferred magmatic intrusion at depth. The Ag-polymetallic Sweet Home Mine (currently mined for gemmy rhodochrosite) is related to an assumed hidden Mo porphyry, but may be located more proximal to a magmatic intrusion as compared to the other deposits. Performing fluid inclusion analysis, Raman spectroscopy, noble gas isotopic compositions and LA-ICPMS measurements as well as the analysis of stable (H, O, S) and radiogenic (Pb, Sr) isotopic compositions, we aim to reconstruct the evolution and P-T-x properties of the ore-forming fluids in the respective ore deposits. As all studied deposits are characterized by a distinct sulfide mineralization stage, we also investigate whether this stage has formed by mixing of magmatic fluids with variable amounts of externally derived fluids. Furthermore, numerical modelling of the transition from a porphyry to an epithermal environment, considering country rock permeability, fluid pressure distribution, fluid temperatures, and varying locations of the magmatic plume, is used to build a quantitative model for the formation of these types of epithermal deposits.

Description: At extensional volcanic arcs, faulting often acts to localize magmatism. Santorini is located on the extended continental crust of the Aegean microplate and is one of the most active volcanoes of the Hellenic arc, but the relationship between tectonism and magmatism remains poorly constrained. As part of the Plumbing Reservoirs Of The Earth Under Santorini experiment, seismic data were acquired across the Santorini caldera and the surrounding region using a dense amphibious array of 〉14,300 marine sound sources and 156 short‐period seismometers, covering an area 120 km by 45 km. Here a P wave velocity model of the shallow, upper‐crustal structure (〈3‐km depth), obtained using travel time tomography, is used to delineate fault zones, sedimentary basins, and tectono‐magmatic lineaments. Our interpretation of tectonic boundaries and regional faults are consistent with prior geophysical studies, including the location of basin margins and E‐W oriented basement faults within the Christiana Basin west of Santorini. Reduced seismic velocities within the basement east of Santorini, near the Anydros and Anafi Basins, are coincident with a region of extensive NE‐SW faulting and active seismicity. The structural differences between the eastern and western sides of Santorini are in agreement with previously proposed models of regional tectonic evolution. Additionally, we find that regional magmatism has been localized in NE‐SW trending basin‐like structures that connect the Christiana, Santorini, and Kolumbo volcanic centers. At Santorini itself, we find that magmatism has been localized along NE‐SW trending lineaments that are subparallel to dikes, active faults, and regional volcanic chains. These results show strong interaction between magmatism and active deformation.

Description: Power-to-Gas (PtG) is a chemical energy storage technology that converts electrical energy into a high-energy density combustible gas. This technology alleviates the contradiction between power supply and demand due to the intermittent electricity production from environment-friendly renewable energy. Hydrogen (H2), produced by electrolysis, can be used to produce synthetic methane (CH4) by reacting with carbon dioxide (CO2) that is captured from carbon emission sources. Subsurface gas storage is one of the most important processes in a PtG system. However, nearly a half of the total stored gas is used as cushion gas to maintain a suitable reservoir pressure, indicating large amounts of CH4 might be wasted and trapped in geological formations. Based on a PtG system, CO2 can be a promising choice as a cushion gas due to its high effective compressibility near its critical conditions. In this paper, a numerical model is established based on the theory of the fluid flow and molecular diffusion to study the role of CO2 as a cushion gas in increasing the gas storage capacity. The accuracy of this model is verified by comparing with that of Curtis M. Oldenburg. However, because of the declining purity of recovered gas induced by the convection and diffusion of two kinds of gases in the same reservoir. The influences of reservoir thickness on the distribution of mixed region are discussed. The results show that thicker reservoir would be a better choice for the geological storage of CH4 with CO2 as a cushion gas.

Description: QuantumFrontiers_HLSST_SLR_COMB2019s is a series of monthly gravity field models based on high-low satellite-to-satellite (HLSST) tracking and satellite laser ranging (SLR) data up to degree and order 60. The combination of HLSST and SLR data is done on the normal equation level using Variance Component Estimation. The series spans from 2003 to 2018 and thus covers the entire period between GRACE and GRACE Follow-On. It is therefore a prime candidate to bridge the data gap between these two satellite mission considering long-wavelength features on a global scale. The model has been developed with data contributions from the Astronomical Institute, University Bern (AIUB), the Institute of Geodesy, Theoretical Geodesy and Satellite Geodesy, Graz University of Technology, the Institute for Geodesy, Leibniz University Hannover and the European Space Agency. More details on the processing can be found in "Time-Variable Gravity Signal in Greenland Revealed by High-Low Satellite-to-Satellite Tracking" (Weigelt et al, 2013, https://doi.org/10.1002/jgrb.50283) Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy – EXC-2123 QuantumFrontiers – 390837967.

Description: Magmatic-hydrothermal systems form a variety of ore deposits at different proximities to upper-crustal hydrous magma chambers, ranging from greisenization in the roof zone of the intrusion, porphyry mineralization at intermediate depths to epithermal vein deposits near the surface. The physical transport processes and chemical precipitation mechanisms vary between deposit types and are often still debated. For this study, we investigate the fluid evolution from proximal to distal settings at the Pirquitas and Chinchillas Mines in NW Argentina and the Sweet Home Mine, Colorado. New results from fluid inclusion and isotopic analyses indicate a contribution of magmatic fluids in the formation of the SnAg Pirquitas Mine, even though no direct association to a magmatic intrusion is visible. Therefore, this deposit may represent a rather distal setting. In contrast, the Ag-Pb-Zn Chinchillas Mine is hosted in volcanic extrusive units and is directly associated to an underlying dacite diatreme. In that respect, this deposit is proximal to a volcanic complex, but due to its shallow emplacement is distal to an inferred magmatic intrusion at depth. The Ag-polymetallic Sweet Home Mine (currently mined for gemmy rhodochrosite) is related to an assumed hidden Mo porphyry, but may be located more proximal to a magmatic intrusion as compared to the other deposits. Performing fluid inclusion analysis, Raman spectroscopy, noble gas isotopic compositions and LA-ICPMS measurements as well as the analysis of stable (H, O, S) and radiogenic (Pb, Sr) isotopic compositions, we aim to reconstruct the evolution and P-T-x properties of the ore-forming fluids in the respective ore deposits. As all studied deposits are characterized by a distinct sulfide mineralization stage, we also investigate whether this stage has formed by mixing of magmatic fluids with variable amounts of externally derived fluids. Furthermore, numerical modelling of the transition from a porphyry to an epithermal environment, considering country rock permeability, fluid pressure distribution, fluid temperatures, and varying locations of the magmatic plume, is used to build a quantitative model for the formation of these types of epithermal deposits.

Description: Samples of the Cu2Cd x Zn1−x SnS4 solid solution series were synthesized by a mechanochemical process, exhibiting high crystallinity due to an annealing step under flowing H2S gas. The composition-dependent structural transition between the kesterite- and stannite-type phases was determined for Cd content close to x Cd ≈ 0.4 by means of x-ray diffraction and Raman spectroscopic probes, in excellent agreement with earlier investigations. Our DFT calculations predicted a critical Cd concentration value of x Cd = 0.5 as the 'border' between the stannite- and kesterite-type structure in the Cu2Cd x Zn1−x SnS4 solid solution series. The somewhat higher calculated Cd content value compared to the experimental case can be accounted by partial Cu/Zn disorder present in the synthesized samples. The measured optical band gaps E g of the Cu2Cd x Zn1−x SnS4 solid solution series decrease by ~0.3 eV upon immediate introduction of Cd into the lattice, with E g being almost constant with varying Cd concentration. All of our observations are interpreted within the framework of earlier reports on composition-dependent kesterite-to-stannite transition, where local structural variations due to the Zn2+ substitution by the larger Cd2+ cations appear to dictate the transition process.

Description: Skarn deposits are found on every continents and were formed at different times from Precambrian to Tertiary. Typically, the formation of a skarn is induced by a granitic intrusion in carbonates-rich sedimentary rocks. During contact metamorphism, fluids derived from the granite interact with the sedimentary host rocks, which results in the formation of calc-silicate minerals at the expense of carbonates. Those newly formed minerals generally develop in a metamorphic zoned aureole with garnet in the proximal and pyroxene in the distal zone. Ore elements contained in magmatic fluids are precipitated due to the change in fluid composition. The temperature decrease of the entire system, due to the cooling of magmatic fluids and the entering of meteoric water, allows retrogression of some prograde minerals. The Hämmerlein skarn deposit has a multi-stage history with a skarn formation during regional metamorphism and a retrogression of primary skarn minerals during the granitic intrusion. Tin was mobilized during both events. The 340 Ma old tin-bearing skarn minerals show that tin was present in sediments before the granite intrusion, and that the first Sn enrichment occurred during the skarn formation by regional metamorphism fluids. In a second step at ca. 320 Ma, tin-bearing fluids were produced with the intrusion of the Eibenstock granite. Tin, which has been added by the granite and remobilized from skarn calc-silicates, precipitated as cassiterite. Compared to clay or marl, the skarn is enriched in Sn, W, In, Zn, and Cu. These metals have been supplied during both regional metamorphism and granite emplacement. In addition, the several isotopic and chemical data of skarn samples show that the granite selectively added elements such as Sn, and that there was no visible granitic contribution to the sedimentary signature of the skarn The example of Hämmerlein shows that it is possible to form a tin-rich skarn without associated granite when tin has already been transported from tin-bearing sediments during regional metamorphism by aqueous metamorphic fluids. These skarns are economically not interesting if tin is only contained in the skarn minerals. Later alteration of the skarn (the heat and fluid source is not necessarily a granite), however, can lead to the formation of secondary cassiterite (SnO2), with which the skarn can become economically highly interesting.

Description: Skarn-Lagerstätten befinden sich auf allen Kontinenten und wurden zu unterschiedlichen Zeiten vom Präkambrium bis zum Tertiär gebildet. Typischerweise wird die Bildung eines Skarns durch die Intrusion eines Granits in karbonatreiche Sedimentgesteine induziert. Während der Kontaktmetamorphose reagieren die Fluide aus dem Granit mit dem sedimentären Wirtgestein, was zur Bildung von Kalksilikaten auf Kosten von Karbonaten führt. Diese neu gebildeten Minerale entwickeln sich im Allgemeinen in einer metamorph zonierten Aureole mit Granat im proximalen und Pyroxen im distalen Bereich. Erzelemente die in magmatischen Fluiden enthalten sind werden aufgrund der veränderten Fluidzusammensetzung ausgefällt. Die Temperaturabsenkung des gesamten Systems, hervorgerufen durch die Abkühlung von magmatischen Fluiden sowie durch das Eindringen meteorischen Wassers, führen zu teilweisen oder vollständigen Umwandlung prograder Minerale. Die Skarn-Lagerstätte Hämmerlein hat eine mehrstufige Geschichte mit Skarnsbildung während der regionalen Metamorphose und Retrogression der primären Skarn-Minerale während der Intrusion von Graniten. Zinn wurde während beiden Ereignissen mobilisiert. Die 340 Ma alten zinnhaltigen Skarnminerale zeigen, dass Zinn in Sedimenten bereits vor dem Graniteintrag vorhanden war, und dass die erste Sn-Anreicherung während der Bildung des Skarns durch Fluide der Regionalmetamorphose stattfand. In einem zweiten Schritt um 320 Ma wurden Zinn-haltige Fluide durch die Intrusion des Eibenstockgranits freigesetzt. Diese Fluide überprägten den Skarn. Das freisetzen und das neu zugefügte Zinn ist in Kassiterit gebunden und führten dem System zusätzliches Zinn zu, wobei Zinn aus den Skarn-Kalksilikaten remobilisiert wurde. Im Vergleich zu Tonstein oder Mergel sind die Skarn mit Sn, W, In, Zn, und Cu angereichet. Diese Metalle sind während der Regionalmetamorphose und der Granitplatznahme zu unterschiedlichen Teilen zugeführt worden. Darüber hinaus zeigen die verschiedenen isotopen und chemischen Daten der Skarn-Proben, dass der Granit selektiv einige Elemente wie Sn hinzugefügt, und dass es keinen sichtbar granitischen Beitrag zur sedimentären Signatur des Skarns gab. Das Beispiel Hämmerlein zeigt, dass es möglich ist einen zinnreichen Skarn ohne zugehörigen Granit zu bilden, wenn Zinn von zinnhaltigen Sedimenten während einer Regionalmetamorphose mit wässrigen metamorphen Fluiden transportiert worden ist. Diese Skarne sind wirtschaftlich uninterssant wenn das Zinn nur in den Skarn-Mineralen enthalten ist. Spätere Umwandlung des Skarns (die Quelle der Wärme und Fluiden ist nicht unbedingt ein Granit) kann jedoch zur Bildung von sekundärem Kassiterite (SnO2) führen, womit der Skarn plötzlich wirtschaftlich hoch interessant sein kann.

Description: Earthquake swarms are characterized by large numbers of events occurring in a short period of time within a confined source volume and without significant mainshock aftershock pattern as opposed to tectonic sequences. Intraplate swarms in the absence of active volcanism usually occur in continental rifts as for example in the Eger Rift zone in North West Bohemia, Czech Republic. A common hypothesis links event triggering to pressurized fluids. However, the exact causal chain is often poorly understood since the underlying geotectonic processes are slow compared to tectonic sequences. The high event rate during active periods challenges standard seismological routines as these are often designed for single events and therefore costly in terms of human resources when working with phase picks or computationally costly when exploiting full waveforms. This methodological thesis develops new approaches to analyze earthquake swarm seismicity as well as the underlying seismogenic volume. It focuses on the region of North West (NW) Bohemia, a well studied, well monitored earthquake swarm region. In this work I develop and test an innovative approach to detect and locate earthquakes using deep convolutional neural networks. This technology offers great potential as it allows to efficiently process large amounts of data which becomes increasingly important given that seismological data storage grows at increasing pace. The proposed deep neural network trained on NW Bohemian earthquake swarm records is able to locate 1000 events in less than 1 second using full waveforms while approaching precision of double difference relocated catalogs. A further technological novelty is that the trained filters of the deep neural network’s first layer can be repurposed to function as a pattern matching event detector without additional training on noise datasets. For further methodological development and benchmarking, I present a new toolbox to generate realistic earthquake cluster catalogs as well as synthetic full waveforms of those clusters in an automated fashion. The input is parameterized using constraints on source volume geometry, nucleation and frequency-magnitude relations. It harnesses recorded noise to produce highly realistic synthetic data for benchmarking and development. This tool is used to study and assess detection performance in terms of magnitude of completeness Mc of a full waveform detector applied to synthetic data of a hydrofracturing experiment at the Wysin site, Poland. Finally, I present and demonstrate a novel approach to overcome the masking effects of wave propagation between earthquake and stations and to determine source volume attenuation directly in the source volume where clustered earthquakes occur. The new event couple spectral ratio approach exploits high frequency spectral slopes of two events sharing the greater part of their rays. Synthetic tests based on the toolbox mentioned before show that this method is able to infer seismic wave attenuation within the source volume at high spatial resolution. Furthermore, it is independent from the distance towards a station as well as the complexity of the attenuation and velocity structure outside of the source volume of swarms. The application to recordings of the NW Bohemian earthquake swarm shows increased P phase attenuation within the source volume (Qp 〈 100) based on results at a station located close to the village Luby (LBC). The recordings of a station located in epicentral proximity, close to Nový Kostel (NKC), show a relatively high complexity indicating that waves arriving at that station experience more scattering than signals recorded at other stations. The high level of complexity destabilizes the inversion. Therefore, the Q estimate at NKC is not reliable and an independent proof of the high attenuation finding given the geometrical and frequency constraints is still to be done. However, a high attenuation in the source volume of NW Bohemian swarms has been postulated before in relation to an expected, highly damaged zone bearing CO 2 at high pressure. The methods developed in the course of this thesis yield the potential to improve our understanding regarding the role of fluids and gases in intraplate event clustering.

Description: Erdbebenschwärme zeichnen sich durch eine große Anzahl an Ereignissen in einem relativ kleinen Zeitraum und Volumen aus. Im Gegensatz zu tektonischen Sequenzen ist in der Regel keine signifikantes Muster von Vor- und Nachbeben erkennbar. In Abwesenheit aktiven Vulkanismusses, kommen Erdbebenschwärme innerhalb kontinentaler Platten häufg an kontinentalen Verwerfungen vor, wie Beispielsweise im Bereich des Egergrabens im nordböhmischen Becken (Tschechien). Eine übliche Hypothese verbindet den Erdbebenentstehungsprozess mit Hochdruckfluiden. Der exakte kausale Zusammenhang ist jedoch häufig enigmatisch, da die zugrundeliegenden geotektonischen Prozesse im Vergleich zu tektonischen Sequenzen relativ langsam sind. Die hohe Erdbebenrate während aktiver Phasen stellt hohe Anforderungen an etablierte seismologische Routinen da diese häufg für Einzelereignisse konzipiert sind. So können sie einen hohen Aufwand bei manueller Selektion seismischer Phasen (picking) bedeuten oder rechenerisch aufwändig sein wenn volle Wellenformen verarbeitet werden sollen. Im Rahmen dieser methodologischen Thesis werden neue Ansätze zur Analyse seismischer Schwärme, sowie des zugrundeliegenden seismogenen Volumens entwickelt. Der Fokus liegt hierbei auf der gut untersuchten und überwachten nordböhmischen Schwarmregion. Ich entwickle und teste in dieser Arbeit einen innovativen Ansatz zur Detektion und Lokalisation von Erdbeben basierend auf einem tiefen konvolvierenden neuronalen Netzwerk. Diese Technologie bietet großes Potential da sie es erlaubt große Datenmengen effizient zu verarbeiten was durch die zunehmenden Datenmengen seismologischer Datenzentren immer weiter an Bedeutung gewinnt. Das entwickelte tiefe neuronale Netzwerk, trainiert auf Aufnahmen nordböhmischer Erdbebenschwärme, ist in der Lage 1000 Eregnisse in weniger als 1 Sekunde bei Verwendung voller Wellenformen zu lokalisieren und erreicht eine Präzision die vergleichbar ist mit der Genauigkeit eines Katalogs, der mittels Doppelte Differenzen Methode relokalisiert wurde. Eine weitere technologische Neuheit ist, dass die trainierten Filter der ersten Schicht des tiefen neuronalen Netzwerkes als Mustererkennungsfilter umfunktioniert werden und damit als Ereignisdetektor dienen können, ohne, dass zuvor explizit auf Rauschdaten trainiert werden muss. Für die weitere technologische Entwicklung stelle ich ein neues, automatisiertes Werkzeug für die synthetisierung realistischer Erdbebenschwarmkataloge, sowie hierauf basierender synthetischer voller Wollenform vor. Die Eingabeparameter werden durch die Geometrie des Quellvolumens, der Nukleationscharakteristik und Magnitude-Häufigkeitsverteilung definiert. Weiter können Rauschsignale realer Daten verwendet werden um äußerst realistische synthetische Daten zu generieren. Dieses Werkzeug wird verwendet um die Vollständigkeitmagnitude eines Detektors für volle Wellenformen anhand synthetischer Daten zu evaluieren. Die synthetisierten Daten sind Motiviert durch ein Hydrofrackingexperiment in Wysin (Polen). Des Weiteren stelle ich einen neuen Ansatz vor, der die Effekte der Wellenausbreitung zwischen Erdbeben und Stationen ausblendet und die Bestimmung der Dämpfung unmittelbar im Quellvolumen von Schwarmerdbeben erlaubt. Diese neue Methode benutzt das hochfrequente spektrale Verhältnis von Ereignispaaren mit gemeinsamen Strahlenwegen. Synthetische Tests zeigen, dass die Methode in der Lage ist die Dämpfung innerhalb des Quellvolumens mit hoher räumlicher Genauigkeit zu bestimmen. Weiter ist sie im Einzelnen unabhängig von der Entfernung zwischen Ereignis und Station als auch von der Komplexität der Dämpfungs und Geschwindigkeitsstruktur außerhalb des Quellvolumens. Die Anwendung auf Daten des nordböhmischen Erdbebenschwarms zeigt eine erhöhte P Phasen Dämpfung im Quellvolumen (Qp 〈 100) basierend auf Daten einer Station in der Nähe des Dorfes Luby (LBC). Die Wellenformen einer Station in unmittelbarer epizentraler Nähe, bei Novy Kostel (NKC), weisen eine relativ hohe Komplexität auf, was darauf hindeutet, dass seismische Wellen, die diese Station erreichen relativ stark gestreut werden im Vergleich zu anderen Stationen. Das hohe Maß an Komplexität destabilisiert die Methode und führt zu ungenauen Schätzungen an der Station NKC. Daher bedarf es einer weiteren unabhängigen Validierung der hohen Dämpfung bei gegebenen geometrischen und spektralen Voraussetzungen. Nichtsdestoweniger wurde bereits eine hohe Dämpfung im Quellvolumen der nordböhmischen Schwärme postuliert und erwartet, insbesondere im Zusammenhang mit einer Zone hoher Brüchigkeit die CO2 bei hohen Drücken beinhaltet. Die Methoden die im Rahmen dieser Thesis entwickelt werden haben das Potential unser Verständnis bezüglich der Rolle von Fluiden und Gasen bei Erdbebenschärmen innerhalb kontinentaler Platten zu verbessern.

Description: Partial melting is a first order process for the chemical differentiation of the crust (Vielzeuf et al., 1990). Redistribution of chemical elements during melt generation crucially influences the composition of the lower and upper crust and provides a mechanism to concentrate and transport chemical elements that may also be of economic interest. Understanding of the diverse processes and their controlling factors is therefore not only of scientific interest but also of high economic importance to cover the demand for rare metals. The redistribution of major and trace elements during partial melting represents a central step for the understanding how granite-bound mineralization develops (Hedenquist and Lowenstern, 1994). The partial melt generation and mobilization of ore elements (e.g. Sn, W, Nb, Ta) into the melt depends on the composition of the sedimentary source and melting conditions. Distinct source rocks have different compositions reflecting their deposition and alteration histories. This specific chemical “memory” results in different mineral assemblages and melting reactions for different protolith compositions during prograde metamorphism (Brown and Fyfe, 1970; Thompson, 1982; Vielzeuf and Holloway, 1988). These factors do not only exert an important influence on the distribution of chemical elements during melt generation, they also influence the volume of melt that is produced, extraction of the melt from its source, and its ascent through the crust (Le Breton and Thompson, 1988). On a larger scale, protolith distribution and chemical alteration (weathering), prograde metamorphism with partial melting, melt extraction, and granite emplacement are ultimately depending on a (plate-)tectonic control (Romer and Kroner, 2016). Comprehension of the individual stages and their interaction is crucial in understanding how granite-related mineralization forms, thereby allowing estimation of the mineralization potential of certain areas. Partial melting also influences the isotope systematics of melt and restite. Radiogenic and stable isotopes of magmatic rocks are commonly used to trace back the source of intrusions or to quantify mixing of magmas from different sources with distinct isotopic signatures (DePaolo and Wasserburg, 1979; Lesher, 1990; Chappell, 1996). These applications are based on the fundamental requirement that the isotopic signature in the melt reflects that of the bulk source from which it is derived. Different minerals in a protolith may have isotopic compositions of radiogenic isotopes that deviate from their whole rock signature (Ayres and Harris, 1997; Knesel and Davidson, 2002). In particular, old minerals with a distinct parent-to-daughter (P/D) ratio are expected to have a specific radiogenic isotope signature. As the partial melting reaction only involves selective phases in a protolith, the isotopic signature of the melt reflects that of the minerals involved in the melting reaction and, therefore, should be different from the bulk source signature. Similar considerations hold true for stable isotopes.

Description: Partielle Schmelzbildung ist ein zentraler Prozess für die geochemische Differentiation der Erdkruste (Vielzeuf et al., 1990). Die Umverteilung chemischer Elemente während der Schmelzbildung beeinflusst die Zusammensetzung der oberen und unteren Erdkruste entscheidend und stellt einen Mechanismus zur Konzentration und zum Transport chemischer Elemente dar. Das Verständnis der diversen Prozesse und der kontrollierenden Faktoren ist deshalb nicht nur von wissenschaftlichem Interesse sondern auch von ökonomischer Bedeutung um die Nachfrage für seltene Metalle zu decken. Die Umverteilung von Haupt- und Spurenelementen während des partiellen Aufschmelzens ist ein entscheidender Schritt für das Verständnis wie sich granitgebundene Lagerstätten bilden (Hedenquist and Lowenstern, 1994). Die Schmelzbildung und die Mobilisierung von Erz-Elementen (z. B. Sn, W, Nb, Ta) in die Schmelze hängt von der Zusammensetzung der sedimentären Ausgangsgesteine und den Schmelzbedingungen ab. Verschiedene Ausgangsgesteine haben aufgrund ihrer Ablagerungs- und Verwitterungsgeschichte unterschiedliche Zusammensetzungen. Dieses spezifische geochemische „Gedächtnis“ resultiert in unterschiedlichen Mineralparagenesen und Schmelzreaktionen in verschiedenen Ausgangsgesteinen während der prograden Metamorphose. (Brown and Fyfe, 1970; Thompson, 1982; Vielzeuf and Holloway, 1988). Diese Faktoren haben nicht nur einen wichtigen Einfluss auf die Verteilung chemischer Elemente während der Schmelzbildung, sie beeinflussen auch das Volumen an Schmelze, die Extraktion der Schmelze aus dem Ausgangsgestein und deren Aufstieg durch die Erdkruste (Le Breton and Thompson, 1988). Auf einer grösseren Skala unterliegen die Verteilung der Ausgangsgesteine und deren chemische Alteration (Verwitterung), die prograde Metamorphose mit partieller Schmelzbildung, Schmelzextraktion und die Platznahme granitischer Intrusionen einer plattentektonischen Kontrolle. Das Verständnis der einzelnen Schritte und deren Wechselwirkungen ist entscheidend um zu verstehen wie granitgebunden Lagerstätten entstehen und erlaubt es, das Mineralisierungspotential bestimmter Gebiete abzuschätzen. Partielles Aufschmelzen beeinflusst auch die Isotopensystematik der Schmelze und des Restites. Die Zusammensetzungen radiogener und stabiler Isotopen von magmatischen Gesteinen werden im Allgemeinen dazu verwendet um deren Ursprungsgesteine zu identifizieren oder um Mischungsprozesses von Magmen unterschiedlichen Ursprunges zu quantifizieren (DePaolo and Wasserburg, 1979; Lesher, 1990; Chappell, 1996). Diese Anwendungen basieren auf der fundamentalen Annahme, dass die Isotopenzusammensetzung der Schmelze derjenigen des Ausgangsgesteines entspricht. Unterschiedliche Minerale in einem Gestein können unterschiedliche, vom Gesamtgestein abweichende, Isotopenzusammensetzungen haben (Ayres and Harris, 1997; Knesel and Davidson, 2002). Insbesondere für alte Minerale, mit einem unterschiedlichen Mutter-Tochter Nuklidverhältnis, ist eine spezifische Isotopenzusammensetzung zu erwarten. Da im partiellen Schmelzprozess nur bestimmte Minerale eines Gesteines involviert sind, entspricht die Isotopenzusammensetzung der Schmelze derjenigen der Minerale welche an der Schmelzreaktion teilnehmen. Daher sollte die Isotopenzusammensetzung der Schmelze von derjenigen des Ursprungsgesteines abweichen. Ähnliche Überlegungen treffen auch für stabile Isotopen zu.

Description: The Central Andes host large reserves of base and precious metals. The region represented, in 2017, an important part of the worldwide mining activity. Three principal types of deposits have been identified and studied: 1) porphyry type deposits extending from central Chile and Argentina to Bolivia, and Northern Peru, 2) iron oxide-copper-gold (IOCG) deposits, extending from central Peru to central Chile, and 3) epithermal tin polymetallic deposits extending from Southern Peru to Northern Argentina, which compose a large part of the deposits of the Bolivian Tin Belt (BTB). Deposits in the BTB can be divided into two major types: (1) tin-tungsten-zinc pluton-related polymetallic deposits, and (2) tin-silver-lead-zinc epithermal polymetallic vein deposits. Mina Pirquitas is a tin-silver-lead-zinc epithermal polymetallic vein deposit, located in north-west Argentina, that used to be one of the most important tin-silver producing mine of the country. It was interpreted to be part of the BTB and it shares similar mineral associations with southern pluton related BTB epithermal deposits. Two major mineralization events related to three pulses of magmatic fluids mixed with meteoric water have been identified. The first event can be divided in two stages: 1) stage I-1 with quartz, pyrite, and cassiterite precipitating from fluids between 233 and 370 °C and salinity between 0 and 7.5 wt%, corresponding to a first pulse of fluids, and 2) stage I-2 with sphalerite and tin-silver-lead-antimony sulfosalts precipitating from fluids between 213 and 274 °C with salinity up to 10.6 wt%, corresponding to a new pulse of magmatic fluids in the hydrothermal system. The mineralization event II deposited the richest silver ores at Pirquitas. Event II fluids temperatures and salinities range between 190 and 252 °C and between 0.9 and 4.3 wt% respectively. This corresponds to the waning supply of magmatic fluids. Noble gas isotopic compositions and concentrations in ore-hosted fluid inclusions demonstrate a significant contribution of magmatic fluids to the Pirquitas mineralization although no intrusive rocks are exposed in the mine area. Lead and sulfur isotopic measurements on ore minerals show that Pirquitas shares a similar signature with southern pluton related polymetallic deposits in the BTB. Furthermore, the major part of the sulfur isotopic values of sulfide and sulfosalt minerals from Pirquitas ranges in the field for sulfur derived from igneous rocks. This suggests that the main contribution of sulfur to the hydrothermal system at Pirquitas is likely to be magma-derived. The precise age of the deposit is still unknown but the results of wolframite dating of 2.9 ± 9.1 Ma and local structural observations suggest that the late mineralization event is younger than 12 Ma.

Description: Die zentralen Anden beherbergen große Reserven von unedlen und Edelmetallen. Die Region war 2017 ein wichtiger Teil der weltweiten Bergbautätigkeit. Bisher wurden drei Hauptlagerstätten identifiziert und untersucht: 1) Porphyr-Lagerstätten, die sich von Zentralchile und Argentinien bis Bolivien und Nord-Peru erstrecken; 2) Eisenoxid-Kupfer-Gold-Lagerstätten (IOCG), die sich von Zentralperu bis Zentralchile ausdehnen, sowie 3) polymetallische epithermale Zinnlagerstätten, die sich von Südperu bis nach Nordargentinien erstrecken und einen Großteil der Lagerstätten des bolivianischen Zinngürtels (Bolivian Tin Belt - BTB) bilden. Lagerstätten im BTB können in zwei Haupttypen unterteilt werden: (1) polymetallische Lagerstätten aus Zinn-Wolfram-Zink im Zusammenhang mit Plutonen und (2) polymetallische Zinn-Silber-Blei-zink Anlagerungen in epithermalen gangförmigen Lagerstätten. Mina Pirquitas ist eine epithermale Zinn-Silber-Blei-Zink-Polymetallvenenlagerstätte im Nordwesten Argentiniens, die früher eine der wichtigsten Zinnsilber-Mine meines Landes war. Es wurde als Teil der BTB interpretiert und hat ähnliche Mineralstoffverbände mit südlichen Pluton-bezogenen BTB-Epithermalvorkommen. Es wurden zwei bedeutende Mineralisierungsereignisse identifiziert, die sich auf drei mit meteorischem Wasser gemischte magmatische Fluide beziehen. Das erste Ereignis kann in zwei Stufen unterteilt werden: 1) Stufe I-1, wobei Quarz, Pyrit und Cassiterit aus Fluiden zwischen 233 und 370 ° C und einem Salzgehalt zwischen 0 und 7,5 Gew .-% ausfallen, entsprechend einem ersten Flüssigkeitsimpuls, und 2) Stufe I-2 mit Sphalerit und Zinn-Silber-Blei-Antimonsulfosalzen, die aus Fluiden zwischen 213 und 274 ° C mit einem Salzgehalt von bis zu 10,6 Gew .-% ausfallen, was einem neuen Impuls magmatischer Fluiden im hydrothermalen System entspricht. Durch die Mineralisierung II wurden die reichsten Silbererze bei Pirquitas abgelagert. Die Temperaturen und Salzgehalte von Event II liegen zwischen 190 und 252 ° C bzw. zwischen 0,9 und 4,3 Gew .-%. Dies entspricht der abnehmenden Versorgung mit magmatischen Fluiden. Edelgasisotopenzusammensetzungen und -konzentrationen in mit Erz beherbergten Flüssigkeitseinschlüssen zeigen einen signifikanten Beitrag magmatischer Fluiden zur Pirquitas-Mineralisierung, obwohl keine intrusiven Gesteine im Minengebiet exponiert sind. Messungen von Blei- und Schwefelisotopen an Erzmineralien zeigen, dass Pirquitas eine ähnliche Signatur mit südlichen Pluton-verwandten polymetallischen Lagerstätten in der BTB teilt. Darüber hinaus liegt der größte Teil der Schwefelisotopenwerte von Sulfid- und Sulfosaltmineralien aus Pirquitas im Bereich von Schwefel aus magmatischem Gestein. Dies deutet darauf hin, dass der Hauptbeitrag von Schwefel zum hydrothermalen System bei Pirquitas wahrscheinlich aus Magma stammt. Das genaue Alter der Lagerstätte ist noch nicht bekannt, aber die Ergebnisse der Wolframit-Datierung von 2,9 ± 9,1 Ma und lokalen Strukturbeobachtungen legen nahe, dass die späten Mineralisierungsereignisse jünger als 12 Ma sind.

Description: EnMAP (Environmental Mapping and Analysis Program, www.enmap.org) is a German, Earth observing, imaging spectroscopy, spaceborne mission planned for launch in 2020. The data products will cover the spectral range from 420 nm to 2450 nm with a spectral sampling distance between 5 and 12 nm with an expected signal-to-noise-ratio of 400:1 in the visible near-infrared and 180:1 in the shortwave infrared parts of the electro-magnetic spectrum. The resulting images will cover an area of 30 km in the across- track direction with a ground sampling distance of 30 m. The across-track tilt-capability of 30° enables revisit times of less than four days. The resulting data products will be freely available to the scientific user community for measuring, deriving, and analyzing diagnostic parameters, which describe vital processes on the Earth's surface comprising agriculture, forestry, soil and geological environments, as well as coastal zones and inland waters. This work concentrates on the description of activities performed and facilities involved for the preparation of these products. It starts out by the description of the User Portals for observation requests and acquisition planning, touches the aspects of creating the time-lines, the commanding and controlling of the satellite, the downlink of the telemetry and payload data, the design of the processing chain and the archiving of data plus a set of activities flanking the above for the provision of high-quality data products.

Description: In this study we derive the stress tensor and its local variations throughout the Marmara region, Turkey. Based on a recently compiled 10-year earthquake catalogue, we directly invert first-motion polarity data and quantify confidence intervals for the principal stress orientations. We find a combined strike-slip and normal faulting stress field for the Marmara region generally reflecting the overall transtensional setting. However, the results clearly show moderate local variations of the stress field. The largest (σ1) and intermediate (σ2) principal stresses show an average regional trend of N125∘E and locally varying plunges. The least principal stress (σ3) is well resolved in its confidence interval and consistent throughout the region with an average trend of ∼ N35∘E and a subhorizontal plunge. The eastern Sea of Marmara shows local stress field orientations with pronounced strike-slip (northern part) and normal faulting (southern part) components. Along the central Marmara region, normal faulting tends to dominate, while a well resolved strike-slip stress regime is found in the western Sea of Marmara region. Regarding the faulting mechanism of an earthquake with magnitude up to 7.4 which is expected in this area in direct vicinity of the Istanbul metropolitan region, our results imply that neither strike-slip nor normal faulting kinematics can be excluded.

Description: Deliverable D5.2 presents the experimental outcome of jetting experiments at simulated reservoir conditions. Different rock types are tested under various conditions with the use of three different types of test bench. At first jetting experiments are conducted under submerged conditions in order to derive a better understanding of the governing erosion mechanism. Therefore pitting tests are combined with PIV measurements in order to derive and explain the erosion pattern of the occurring cavitation erosion and why the rock is more like to be eroded by the stagnation pressure of the impinging jet. Second, jetting experiments under pressure controlled conditions are performed. Rate of penetrations (ROP) of up to 100 m/h can be achieved which proofs the successful application of RJD technology especially in sand stone reservoir rock types. Especially the rotating nozzle design bears the highest potential for jetting operations where the static nozzle designs tend to fail, especially when pore pressure increases. The third experimental series under application of a bi- axial stress field show that the current RJD technology, as being used by project partner WSG, is not able to penetrate harder sandstone rock types (e.g. Dortmund sandstone) when field operating conditions are applied. The induced stress in the specimen does not initiate or enhance ROP. A second experiment thereby shows that higher nozzle exit speeds can lead to massive breakouts. Fourth, experiments are performed under a tri-axial stress field in collaboration with TU DELFT. Rock cubes are tested under different and very severely stress regimes while jetting into them. Compared to tests at atmospheric conditions it can be stated that the application of a stress field does not enhance the erosion of rock. At last experiments are conducted with the project partner WSG in order to determine the jetability of the Icelandic Basalt rock type and Icelandic inter basalt sediment layer. The experiments show that already higher pump pressures result in higher jetting performance, hence making them jetable as previously not expected. Furthermore the experiments approved the feasibility of the planned field test in Iceland when the soft sediment layer is the target zone. All in all the experiments conducted with the RJD technology show different results at simulated reservoir conditions compared to those at atmospheric which are described in deliverable D5.1 (Hahn & Wittig, 2017). Therefor, further testing at conditions representing the reservoir conditions more closer are needed in order to better understand and analyze the jetting process downhole.

Description: In this deliverable, the objectives of the Imperial College team are to consider jetted boreholes in the context of conventional borehole wall-rock stability analysis and to utilise an in-house advanced combined finite-discrete element code to examine the wall-rock failure process for jetted holes. The geomechanical modelling of Lateral Stability in D7.2 presented here is in addition to the main focus on modelling the water-jetting breakdown of the rock itself, reported in D7.1.

Description: The aim of this research is to investigate the failure mechanism for different types of rock in the context of water jet drilling and to predict the jet-ability or assess the radial jet drilling (RJD) performance prior to drilling and at the well petrophysical analysis stage. The main approach is to numerically simulate the water jet drilling for different types of rock using ICL’s in-house fluid-solid coupling codes. The rock properties, CT-scan data and jetting results obtained from D4.1 (Bakker et al., 2018) and D5.1 (Hahn et al., 2017) provide a good foundation for the related numerical results.

Description: The climate is a complex dynamical system involving interactions and feedbacks among different processes at multiple temporal and spatial scales. Although numerous studies have attempted to understand the climate system, nonetheless, the studies investigating the multiscale characteristics of the climate are scarce. Further, the present set of techniques are limited in their ability to unravel the multi-scale variability of the climate system. It is completely plausible that extreme events and abrupt transitions, which are of great interest to climate community, are resultant of interactions among processes operating at multi-scale. For instance, storms, weather patterns, seasonal irregularities such as El Niño, floods and droughts, and decades-long climate variations can be better understood and even predicted by quantifying their multi-scale dynamics. This makes a strong argument to unravel the interaction and patterns of climatic processes at different scales. With this background, the thesis aims at developing measures to understand and quantify multi-scale interactions within the climate system. In the first part of the thesis, I proposed two new methods, viz, multi-scale event synchronization (MSES) and wavelet multi-scale correlation (WMC) to capture the scale-specific features present in the climatic processes. The proposed methods were tested on various synthetic and real-world time series in order to check their applicability and replicability. The results indicate that both methods (WMC and MSES) are able to capture scale-specific associations that exist between processes at different time scales in a more detailed manner as compared to the traditional single scale counterparts. In the second part of the thesis, the proposed multi-scale similarity measures were used in constructing climate networks to investigate the evolution of spatial connections within climatic processes at multiple timescales. The proposed methods WMC and MSES, together with complex network were applied to two different datasets. In the first application, climate networks based on WMC were constructed for the univariate global sea surface temperature (SST) data to identify and visualize the SSTs patterns that develop very similarly over time and distinguish them from those that have long-range teleconnections to other ocean regions. Further investigations of climate networks on different timescales revealed (i) various high variability and co-variability regions, and (ii) short and long-range teleconnection regions with varying spatial distance. The outcomes of the study not only re-confirmed the existing knowledge on the link between SST patterns like El Niño Southern Oscillation and the Pacific Decadal Oscillation, but also suggested new insights into the characteristics and origins of long-range teleconnections. In the second application, I used the developed non-linear MSES similarity measure to quantify the multivariate teleconnections between extreme Indian precipitation and climatic patterns with the highest relevance for Indian sub-continent. The results confirmed significant non-linear influences that were not well captured by the traditional methods. Further, there was a substantial variation in the strength and nature of teleconnection across India, and across time scales. Overall, the results from investigations conducted in the thesis strongly highlight the need for considering the multi-scale aspects in climatic processes, and the proposed methods provide robust framework for quantifying the multi-scale characteristics.

Description: Das Klima ist ein komplexes Zusammenspiel verschiedener Mechanismen und Rückkopplungen auf mehreren zeitlichen und räumlichen Skalen. Viele Studien beschäftigten sich mit dem diesem System, nur wenige jedoch konzentrierten sich auf das Multiskalenverhalten des Klimas. Vor allem die bis dato verfügbaren Techniken schränkten eine vertiefte Analyse der Klimavariabilität auf unterschiedlichen Skalen ein. Von großen Interesse in der aktuellen Klimaforschung sind Extremereignisse und plötzliche Veränderungen, welche höchstwahrscheinlich aus dem Zusammenwirken von Prozessen auf unterschiedlichen Skalen hervorgehen. Um Stürme, wiederkehrende Wetterlagen, jahreszeitliche Phänomene wie El Niño, Fluten, Dürren oder Klimaschwankungen über Jahrzehnte besser zu verstehen oder sogar vorhersagen zu können, müssen wir deren Dynamik auf unterschiedlichen Skalen quantifizieren. In der vorliegenden Arbeit werden Mittel und Wege präsentiert um das Zusammenwirken auf verschiedenen Skalen im Klimasystem besser zu verstehen und zu quantifizieren. Im ersten Teil dieser Arbeit stelle ich zwei Methoden, multi-scale event synchronization (MSES) und wavelet multi-scale correlation (WMC) vor, welche skalenspezifischen Eigenschaften in klimatischen Prozessen abbilden. Die vorgestellte Methode wurde mit mehreren synthetischen und realen Zeitreihen getestet um ihre Anwendbarkeit und Reproduzierbarkeit zu überprüfen. Die Ergebnisse zeigen, dass beide Methoden Beziehungen auf unterschiedlichen zeitlichen Skalen detaillierter als traditionelle Ansätze abbilden können. Im zweiten Teil dieser Arbeit bilde ich klimatische Netzwerke mithilfe eines Maßes zur Ähnlichkeit auf Multiskalen. Dabei untersuche ich die Entwicklung von räumlichen Beziehungen um klimatische Prozesse auf mehreren Zeitskalen zu verstehen. Die Methoden WMC und MSES werden zusammen mit komplexen Netzwerken auf zwei Datensätze angewendet. In der ersten Anwendung werden klimatische Netzwerke mit WMC für univariate globale Meeresoberflächentemperaturen gebildet. Auf unterschiedlichen Zeitskalen sollen dabei kurze und lange Fernwirkungen, welche andernfalls auf einer einzigen Zeitskale unerkannt blieben, entdeckt werden. In diesem Klimanetzwerk ließ sich eine starke Variabilität über die Zeit feststellen, was auf eine skalenfreie und kleinräumige Netzstruktur auf großem, beziehungsweise kleinem Maßstab schließen lässt. Weitere Untersuchungen von Klimanetzwerken auf unterschiedlichen Zeitskalen zeigte (i) hohe Variabilität und Co-Variabilität in Regionen, und (ii) Fernbeziehungen auf kurzen und langen Entfernungen mit variabler räumlicher Distanz. Die Ergebnisse bestätigen bekannte physikalischen Wechselwirkungen und daher auch die Stärken meines Ansatzes. Dadurch ergeben sich neue Einblicke in die Klimatologie von Ozeanen, sodass beispielsweise konvektive Prozesse in der Atmosphäre eine Abhängigkeit über weite Entfernungen aufweisen können. In der zweiten Anwendung verwendeten wir das von mir entwickelte, nicht-lineare MSES Ähnlichkeitsmaß um multivariate Fernbeziehungen zwischen Starkniederschlägen und klimatischen Mustern über Indien zu quantifizieren. Unsere Ergebnisse bestätigen signifikante, nicht-lineare Einflüsse, welche von traditionellen Methoden bisher unzureichend abgebildet wurden. Des Weiteren fanden wir deutliche Schwankungen in der Stärke und in der Ausprägung von Fernbeziehungen über Indien und über Zeitskalen. Zusammenfassend zeigen die Ergebnisse dieser Fallstudien, dass Multiskalen in Klimaprozessen entschieden berücksichtigt werden müssen und dass der entwickelte methodische Rahmen adäquat die charakteristischen Prozesse quantifizieren kann.

Description: The C-band synthetic aperture radar (SAR) satellites of Sentinel-1 with capability to obtain acquisition in Terrain Observation with Progressive Scan (TOPS) mode have brought new opportunities for large-scale monitoring of the ground surface deformation using interferometric SAR (InSAR) technique. However, despite the potential to generate large-scale interferograms, the highly spatiotemporal variability in troposphere, limits InSAR measurements accuracy. In addition, the measurement accuracy might be degraded by the signals due to the ionosphere, which is not negligible even at C-band data. One way for the atmospheric delay correction in interferograms is using external sources such as the global navigation satellite system (GNSS). The total electron content (TEC) and the zenith total delay (ZTD) values measured from a dense network of the GNSS receivers can be used to retrieve the ionospheric and tropospheric contributions to the interferometric phase, respectively. However, interpolation of the data is a big challenge, as we need to find a suitable function to predict the delay for the whole interferogram, which is challenging for large-scale Sentine-1 interferograms. In this study, we propose a new technique based on machine learning (ML) regression approach using the combination of small-baseline interferograms and the GNSS derived TEC and ZTD values to mitigate the atmospheric contributions. The technique produces the differential atmospheric (using the TEC and ZTD values) map for short-interval intergerograms based on the phase-atmosphere relation by this assumption that the deformation contribution to the interferometric phase is negligible in the short intervals. It then estimates the differential atmospheric maps for the longer-interval interferograms using the atmospheric maps with short intervals. The technique facilitates the corrections, as we do not need to deal with finding a suitable function for interpolation of distributed external observations. We implement our method on 12 concatenated frames of Sentinel-1 images acquired between May-October 2016 along a track over Norway to correct the interferograms from the atmospheric effects. Then, we apply the small baseline subset (SBAS) approach on the atmospherically corrected interferograms. The results on the stack of large-scale Sentinel-1 interferograms show that the ML-based method largely removes the ionospheric and tropospheric effects and thus improves the InSAR time series analysis results. To validate the results we compare the displacement time-series derived by small-baseline interferograms corrected by our method with the displacement time-series observed by GNSS receivers.

Description: Calcium sulfate minerals are found in nature as three hydrates: gypsum (CaSO4·2H2O), bassanite (CaSO4·0.5H2O), and anhydrite (CaSO4). Due to their relevance in natural and industrial processes, the formation pathways of calcium sulfates from aqueous solution have been the subject of intensive research, and there is a growing body of literature, suggesting that calcium sulfates form through nonclassical nanoparticle-mediated crystallization processes. We showed earlier (Stawski et al. Nat. Commun.2016, 7, 11177) that at the early stages in the precipitation reaction, calcium sulfate nanocrystals nucleate through the reorganization and coalescence of aggregates rather than through classical unit addition. Here, we used low-dose dark field (DF) transmission electron microscopy (TEM) and electron diffraction and document that these restructuring processes do not continue until a final near-perfectly homogeneous single crystal is obtained. Instead, we show that the growth process yields a final imperfect mesocrystal with an overall morphology resembling that of a single crystal, yet composed of smaller nanodomains. Our data reveal that organic-free calcium sulfate mesocrystals grown by a particle mediated-pathway may preserve in the final crystal structure a “memory” or “imprint” of their nonclassical nucleation process, something that has been overlooked until now. Furthermore, the nanoscale misalignment of the structural subunits within these crystals might propagate through the length-scales, which is potentially expressed macroscopically as misaligned zones/domains in large single crystals. This is akin to observations in some of the giant crystals from the Naica Mine, Chihuahua, Mexico.

Description: Jasmine Kaur Sandhu, Maria-Theresia Walach, Hayley Allison and Clare Watt report on the RAS meeting The Global Response of the Terrestrial Magnetosphere during Storms and Substorms.

Description: Abstract Observations of the electron radiation belts have shown links between increases in the low-energy seed population and enhancements in the 〉1-MeV flux. During active times, low-energy electrons are introduced to the radiation belt region before being accelerated to higher energies via a range of mechanisms. The impact of variations in the seed population on the 1-MeV flux level were explored using the British Antarctic Survey Radiation Belt Model. We find that, for a period from the 21 April to 9 May 2013, the increase in the low-energy electron flux was vital to recreate the observed 1-MeV flux enhancement on the 1 May but was less important for the 1-MeV enhancement on the 27 April 2013. To better understand the relationships between the different energy populations, a series of idealized experiments with the 2-D British Antarctic Survey Radiation Belt Model were performed, which highlight a careful balance between losses and acceleration from chorus waves. Seed population enhancements alter this balance by increasing the phase space density gradient, and consequently, the rate of energy diffusion, allowing acceleration to surpass loss. Additionally, we demonstrate that even with the same chorus diffusion coefficients and the same low-energy boundary condition, the flux of ∼500-keV to 1-MeV electrons increased when starting with a hard spectrum but decreased for a soft initial spectrum. This suggests that initial energy gradients in the phase space density were important to determine whether 〉500-keV electrons were enhanced due to chorus wave acceleration.

Description: Understanding the gypsum (CaSO4·2H2O) formation pathway from aqueous solution has been the subject of intensive research in the past years. This interest stems from the fact that gypsum appears to fall into a broader category of crystalline materials whose formation does not follow classical nucleation and growth theories. The pathways involve transitory precursor cluster species, yet the actual structural properties of such clusters are not very well understood. Here, we show how in situ high-energy X-ray diffraction experiments and molecular dynamics (MD) simulations can be combined to derive the structure of small CaSO4 clusters, which are precursors of crystalline gypsum. We fitted several plausible structures to the derived pair distribution functions and explored their dynamic properties using unbiased MD simulations based on both rigid ion and polarizable force fields. Determination of the structure and (meta)stability of the primary species is important from both a fundamental and applied perspective; for example, this will allow for an improved design of additives for greater control of the nucleation pathway.

Description: GRACE/GRACE-FO Level-3 product based on GFZ RL06 Level-2B products (Dahle & Murböck, 2019) representing Ocean Bottom Pressure (OBP) variations provided at 1° latitude-longitude grids as defined over ocean areas. The OBP grids are provided in NetCDF format divided into yearly batches. The files each contain seven different variables: 1) 'barslv': gravity-based barystatic sea-level pressure 2) 'std_barslv': gravity-based barystatic sea-level pressure uncertainties 3) 'resobp': gravity-based residual ocean circulation pressure resobp 4) 'std_resobp': gravity-based residual ocean circulation pressure uncertainties 5) 'leakage': apparent gravity-based bottom pressure due to continental leakage 6) 'model_ocean': background-model ocean circulation pressure 7) 'model_atmosphere': background-model atmospheric surface pressure These Level-3 products are visualized at GFZ's web portal GravIS (http://gravis.gfz-potsdam.de). Link to data products: ftp://isdcftp.gfz-potsdam.de/grace/GravIS/GFZ/Level-3/OBP

Description: The GEOFON program consists of a global seismic network (GE Network), a seismological data centre (GEOFON DC) and a global earthquake monitoring system (GEOFON EQinfo). These three pillars are part of the MESI research infrastructure of the Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences aiming at facilitating scientific research. GEOFON provides real-time seismic data, access to its own and third party data from the archive facilities as well as global and rapid earthquake information. The GEOFON Seismological Software can be considered a fourth cross-cutting module of the GEOFON Program. Data, services, products and software openly distributed by GEOFON are used by hundreds of scientists and data centres worldwide. Its earthquake information service is accessed directly by tens of thousands of visitors. The SeisComP software package is the flagship software provided to the community, which is geared for seismic observatory and data centre needs and used extensively to support our internal operations. Like all other MESI (Modular Earth Science Infrastructure) modules GEOFON has the majority of users outside the GFZ as well as an external advisory committee that provides advice to the GFZ Executive Board and to the GEOFON team. This report describes the main activities carried out within the three GEOFON pillars and the software development group.

Description: Advancements in the Global Geodetic Observing System (GGOS) have enabled us to investigate the effects of lateral heterogeneities in the internal Earth structure on long-term surface deformations caused by the Glacial Isostatic Adjustment (GIA). Many theories have been developed so far to consider such effects based on analytical and numerical approaches, and 3D viscosity distributions have been inferred. On the other hand, fewer studies have been conducted to assess the effects of lateral heterogeneities on short-term, elastic deformations excited by surface fluids, with 1D laterally homogeneous theories being frequently used. In this paper, we show that a spectral finite-element method is applicable to calculate the elastic deformation of an axisymmetric spherical Earth. We demonstrate the effects of laterally heterogeneous moduli with horizontal scales of several hundred kilometers in the upper mantle on the vertical response to a relatively large-scale surface load. We found that errors due to adopting a 1D Green’s function based on a local structure could amount to 2–3% when estimating the displacement outside the heterogeneity. Moreover, we confirmed that the mode coupling between higher-degree spherical harmonics needs to be considered for simulating smaller-scale heterogeneities, which agreed with results of previous studies.

Description: One of the lowest geoid anomalies on Earth lies in the Indian Ocean just south of the Indian peninsula. Several theories have been proposed to explain this negative geoid anomaly, most of which invoke past subduction. Some recent studies have argued that high-velocity anomalies in the lower mantle coupled with low-velocity anomalies in the upper mantle are responsible for these geoid lows. However, there is no general agreement regarding the source of the geoid low in the Indian Ocean. We investigate the source of this anomaly by using instantaneous models of density-driven mantle convection. Our study is the first to successfully explain the presence of this anomaly using a global convection model driven by present-day density anomalies derived from seismic tomography. We test various tomography models in our flow calculations using different radial and lateral viscosity variations. Although quite a few of them produce a fairly high correlation to the observed geoid globally, only a few (SMEAN2, GyPSuM, SEMUCB, and LLNL-JPS) could match the exact location and pattern of the geoid low in the Indian Ocean. The source of this low is a low-density anomaly stretching from a depth of 300 km down to ∼900 km in the northern Indian Ocean region. This density anomaly potentially originates from plume material rising along the edge of the African Large Low Shear Velocity Province, which moves toward the northeast, along with the movement of the Indian plate in the same direction.

Description: Volcanic and seismic activities produce a variety of phenomena that put population at risk. In order to assess the seismic and volcanic hazard, many instruments are deployed around active volcanoes and seismic fault zones. Their records are useful to observe the activity of the volcanoes and faults in order to understand better their behaviour and issue warnings to authorities in charge of the public security. In this study, we used optical cables around Etna volcano to observe seismic and pressure signals associated with volcanic activity. The 2018 expedition consisted of three experiments. Firstly, we used a 4-km long telecom line in Zafferana and recorded all geodynamic and other activities for about 20 days. At this site, the fibre is known to cross active faults that are linked to the eastern volcano flank slowly sliding towards the sea. Secondly, we tested a 40 km-long cable from an internet provider at the western side of the volcano. Thirdly, we used a fibre cable deployed at the summit area of the volcano to test its ability to detect small volcanic events. In each of the three parts, a DAS system (iDASTM interrogator provided by Silixa) sent repeatedly coherent light pulses with a gauge length of 10 m and deduced the strain rate from interferometric measurements of the back-scattered light. We were able to measure every 2 metres the strain rate associated with several volcanic event types, earthquakes and many other signals from human activity. We validated the optical records with records from additional sensors such as seismic broadband stations, geophones and infrasound sensors. We present results from all experiments.

Description: In natural coastal wetlands, high supplies of marine sulfate suppress methanogenesis. Coastal wetlands are, however, often subject to disturbance by diking and drainage for agricultural use and can turn to potent methane sources when rewetted for remediation. This suggests that preceding land use measures can suspend the sulfate-related methane suppressing mechanisms. Here, we unravel the hydrological relocation and biogeochemical S and C transformation processes that induced high methane emissions in a disturbed and rewetted peatland despite former brackish impact. The underlying processes were investigated along a transect of increasing distance to the coastline using a combination of concentration patterns, stable isotope partitioning, and analysis of the microbial community structure. We found that diking and freshwater rewetting caused a distinct freshening and an efficient depletion of the brackish sulfate reservoir by dissimilatory sulfate reduction (DSR). Despite some legacy effects of brackish impact expressed as high amounts of sedimentary S and elevated electrical conductivities, contemporary metabolic processes operated mainly under sulfate-limited conditions. This opened up favorable conditions for the establishment of a prospering methanogenic community in the top 30–40 cm of peat, the structure and physiology of which resemble those of terrestrial organic-rich environments. Locally, high amounts of sulfate persisted in deeper peat layers through the inhibition of DSR, probably by competitive electron acceptors of terrestrial origin, for example Fe(III). However, as sulfate occurred only in peat layers below 30–40 cm, it did not interfere with high methane emissions on an ecosystem scale. Our results indicate that the climate effect of disturbed and remediated coastal wetlands cannot simply be derived by analogy with their natural counterparts. From a greenhouse gas perspective, the re-exposure of diked wetlands to natural coastal dynamics would literally open up the floodgates for a replenishment of the marine sulfate pool and therefore constitute an efficient measure to reduce methane emissions.

Description: We propose to investigate the structure and evolution of the Main Pamir Thrust (MPT) with a high-density seismological array. The MPT, with its surface expression along the east-west trending Alai Valley, marks the northern boundary of the Pamir. The Alai Valley, separating the Pamir and the Tien Shan, constitutes the last vestige of a formerly continuous basin that linked the Tarim and the Tajik Basins. The MPT manifests itself as a place of high seismic activity with frequently occurred disastrous earthquakes. The array is about 50 km long, consisted of 90 three-component geophones (stations G?? and C??) and 10 Trillium-Compact seismometers (stations T??), and equipped with 100 CUBE dataloggers. We will construct a high-resolution receiver function profile to image the MPT and accurately locate the local earthquakes associated with the MPT. Funded by BMBF, within the framework of CaTeNA project – Climatic and Tectonic Natural Hazards in Central Asia. Waveform data are available from the GEOFON data centre, under network code 7A and are embargoed until Jan 2024.

Description: Despite its unique properties the diffracted seismic wavefield is still rarely exploited in common practice. Although the first works on seismic diffraction date back at least as far as the 1950s, a first rigorous theoretical framework for diffraction imaging only evolved decades later and many important questions still remain unanswered until the present day. While this comparably slow progression can partly be explained by the lack of densely sampled high quality recordings, recent advances in acquisition and dedicated processing suggest we might be at the door step to a paradigm shift in which seismic diffraction could play an important role. Despite the fact that most major progress—in terms of data acquisition and processing—has been achieved for the reflected wavefield, upon closer inspection it becomes obvious that the concept of diffraction is deeply ingrained in migration-type seismic imaging. With the aim of complementing existing contributions on the topic, this chapter is an attempt to provide an intuitive introduction to the process of seismic diffraction. Discussed are the deep conceptual roots in optics, physical links to the Kirchhoff integral as well as diffraction types and their importance in different contexts of application. By means of controlled synthetic and academic as well as industry-scale field data examples, I suggest a simple integrated framework for noninvasive diffraction separation and high-resolution imaging, which remains computationally affordable and can be reproduced by the reader. Different applications suggest that the faint diffracted background wavefield is surprisingly rich and, once it is given a voice, it announces highly resolved features such as faults, fractures, and erosional unconformities, which remain notoriously hard to image conventionally. Extending the dominant theme of high-resolution seismic imaging, I illustrate how the superior illumination due to the uniform radiation of diffraction carries the additional potential for drastically reduced acquisitions and discuss the possibility of a systematic extraction of inter-scatterer traveltimes from coda waves.

Description: Glacial-isotactic adjustment (GIA) is one of the key processes considering relative sea-level (RSL) and paleo-topography during the last glacial cycle. Especially in former ice-covered regions the subsidence of the solid Earth due to ice loads can reach more than 500 m and contributes to the stability of ice-sheets (e.g. position of grounding line and ice-sheet elevation), whereas at the coasts of the world oceans the deformation is governed by global RSL fall of more than 100 m. Because the viscoelastic response of the solid Earth is governed by its viscosity structure, the effect of lateral viscosity variations on deformations due to GIA has to be estimated. The importance was already shown for the differences in earth structure below the glacial ice sheets of Fennoscandia and Laurentide, as well as for a number of peripheral and far-field regions. One open question arises: Can the 3D earth properly be parameterized by locally optimized 1D earth structures? In this study, we apply a 3D Earth structure which we derived from seismic tomography and further geodynamic constraints as an a priori estimation of the Earth viscosity distribution. Applying a standard glaciation history, we compare the response characteristics of 1D and 3D earth parameterizations and discuss the limits of optimized 1D earth parametrizations. We will focus on reconstructions of RSL during the last deglaciation in view of sea level index points which are generally used for validating the GIA process.

Description: Enclosed topographic depressions are characteristic of karst landscapes on Earth. The developmental relationship between depression types, such as sinkholes (dolines) and uvalas, has been the subject of debate, mainly because the long developmental timescales in classical limestone karst settings impede direct observation. Here we characterize the morphometric properties and spatio-temporal development of ∼1150 sinkholes and five uvalas formed from ∼1980 to 2017 in an evaporite karst setting along the eastern coast of the hypersaline Dead Sea (at Ghor Al-Haditha, Jordan). The development of sinkhole populations and individual uvalas is intertwined in terms of onset, evolution and cessation. The sinkholes commonly develop in clusters, within which they may coalesce to form compound or nested sinkholes. In general, however, the uvalas are not defined by coalescence of sinkholes. Although each uvala usually encloses several clusters of sinkholes, it develops as a larger-scale, gentler and structurally distinct depression. The location of new sinkholes and uvalas shows a marked shoreline-parallel migration with time, followed by a marked shoreline-perpendicular (i.e. seaward) growth with time. These observations are consistent with theoretical predictions of karstification controlled by a laterally migrating interface between saturated and undersaturated groundwater, as induced by the 35 m fall in the Dead Sea water level since 1967. More generally, our observations indicate that uvalas and the sinkhole populations within them, although morphometrically distinct, can develop near-synchronously by subsidence in response to subsurface erosion.

Description: The CNES/GRGS RL04 Earth gravity models are a set of gravity field solutions based on GRACE and SLR data, provided at different time samplings: (A) CNES/GRGS RL04 time series (A/1) A monthly GRACE+SLR time series of gravity field models (A/2) A 10-day GRACE+SLR time series of gravity field models (B) A mean gravity model EIGEN-GRGS.RL04.MEAN-FIELD, computed from the monthly RL04 GRACE+SLR time series and from GOCE data. (A) CNES/GRGS RL04 time series DATA: The data from the Star Camera Assembly (SCA), Accelerometer (ACC), K-Band Ranging (KBR) and GPS receiver are used. The KBR data is processed in the form of the relative velocity between the spacecrafts: K-Band Range-Rate (KBRR). In addition to the data from GRACE, the data from 5 SLR satellites are also used (Lageos, Lageos-2, Starlette, Stella and Ajisai), in order to provide an accurate and consistent description of the very low degrees of the gravity field (mainly degrees 1 and 2). The version of the GRACE data used for RL04 is L1B-v2 for the ACC and GPS data, L1B-v3 for the SCA and KBR data. INVERSION METHOD: By contrast with the GRACE solutions in spherical harmonics provided by other groups, the CNES/GRGS solutions are not obtained by a simple Cholesky inversion. The normal matrices are first diagonalized, ordered by decreasing order of the Eigen values and only the best defined sets of linear combinations of the spherical harmonics are solved. More details can be found here: https://grace.obs-mip.fr/variable-models-grace-lageos/grace-solutions-release-04/rl04-products-description/ (B) EIGEN-GRGS.RL04.MEAN-FIELD mean model EIGEN-GRGS.RL04.MEAN-FIELD is a mean model of Earth's gravity field spherical harmonics coefficients, based on the RL04 version of the CNES/GRGS time series of monthly gravity field determinations from GRACE & SLR data. EIGEN-GRGS.RL04.MEAN-FIELD is complete to degree and order 300. Between degrees 1 and 90, it contains time-variable gravity (TVG) coefficients ; above degree 90, it is a static field. EIGEN-GRGS.RL04.MEAN-FIELD is based on GOCE-DIR5 for the part between degree 91 and 300. The TVG coefficients between degrees 1 and 90 are obtained from a regression on the GRGS-RL04-v1 monthly time series of solutions (2002/09 – 2016/06). For degrees 1 and 2 this TVG part is temporally extended to 1993/01-2019/02 through the use of a GRGS SLR-only solution based on the data of 5 SLR satellites (Lageos, Lageos-2, Starlette, Stella, Ajisai). Outside of the measurements period (1993/01-2019/02 for degrees 1 and 2, 2002/09-2016/06 for degrees 3 to 90), the gravity field is extrapolated in the following way: - for degrees 1 and 2, before 1993/01 : average slope based on historical SLR data, mean annual and semi-annual periodic signals based on their average value between 1993 and 2019 - for degrees 1 and 2, after 2019/02 : average slope & mean annual and semi-annual periodic signals (based on their average value between 1993 and 2019) - for degrees 3 to 90, before 2002/09 : zero-slope extrapolation, mean annual and semi-annual periodic signals based on their average value between 2002 and 2016 - for degrees 3 to 90, after 2016/06 : average slope & mean annual and semi-annual periodic signals (based on their average value between 1993 and 2019) More details can be found here: https://grace.obs-mip.fr/variable-models-grace-lageos/mean-fields/release-04/

Description: The software package “ClassifyStorms” version 1.0.1 performs a classification of geomagnetic storms according to their interplanetary driving mechanisms based exclusively on magnetometer measurements from ground. In this version two such driver classes are considered for storms dating back to 1930. Class 0 contains storms driven by Corotating or Stream Interaction Regions (C/SIRs) and class 1 contains storms driven by Interplanetary Coronal Mass Ejections (ICMEs). The properties and geomagnetic responses of these two solar wind structures are reviewed, e.g., by Kilpua et al. (2017, http://doi.org/10.1007/s11214-017-0411-3). The classification task is executed by a supervised binary logistic regression model in the framework of python's scikit-learn library. The model is validated mathematically and physically by checking the driver occurrence statistics in dependence on the solar cycle phase and storm intensity. A detailed description of the classification model is given in Pick et al. (2019) to which this software is supplementary material. Under “Files” you can download ClassifyStorms-V1.0.1.zip, which contains the jupyter notebook “ClassifyStorms.ipynb” (https://jupyter.org/) and the python modules “Imports.py”, “Modules.py” and “Plots.py”. Check for an up-to-date release of the software on GitLab via https://gitext.gfz-potsdam.de/pick/public/ClassifyStorms (under Project, Releases). The “Readme.md” file provides all information needed to run or modify “ClassifyStorms” from the GitLab source. The software depends on the input data set “Input.nc”, an xarray Dataset (http://xarray.pydata.org/en/stable) saved in NetCDF format (https://www.unidata.ucar.edu/software/netcdf), which you can also download under “Files”. It contains 1. the HMC index: a three-hour running mean with weights [0.25,0.5,0.25] of the original Hourly Magnetospheric Currents index (HMC index, http://doi.org/10.5880/GFZ.2.3.2018.006). 2. the geomagnetic observatory data: vector geomagnetic disturbances from 34 mid-latitude observatories during 1900-2015 in the Cartesian Centered Dipole coordinate system. The original observatory data was downloaded from the WDC for Geomagnetism, Edinburgh (http://www.wdc.bgs.ac.uk/) and processed as described in section 2.1 of Pick et al. (2019). 3. the “reference” geomagnetic storms: universal time hours of 868 geomagnetic storm peaks together with their interplanetary drivers (class labels 0 or 1, see above) as described in section 2.2 of Pick et al., 2019. These events are taken from published lists (Jian et al., 2006a, 2006b, 2011; Shen et al., 2017; Turner et al., 2009), which are gathered in the separate ASCII file “ReferenceEvents.txt” (under “Files”) for a quick overview. 4. additional quantities for plotting: time series of Kp (since 1932) and Dst (since 1957) geomagnetic indices from the WDC for Geomagnetism, Kyoto (http://wdc.kugi.kyoto-u.ac.jp/wdc/Sec3.html) as well as the yearly mean total sunspot number from WDC-SILSO, Royal Observatory of Belgium, Brussels (http://sidc.be/silso/datafiles). The output of ClassifyStorms is "StormsClassified.csv" (under “Files”). This table lists the Date (Year-Month-Day) and Time (Hour:Minutes:Seconds) of 7546 classified geomagnetic storms together with the predicted interplanetary driver class label (0 or 1) and the corresponding probability (between 0 and 1). Version history: 20 Sep 2019: Version 1.0.1: Correction of plotting mistake in Figure m / Figure S4 (see gitlab repository for details)

Description: Surrogate playground is an automated machine learning approach written for rapidly screening a large number of different models to serve as surrogates for a slow running simulator. This code was written for a reactive transport application where a fluid flow model (hydrodynamics) is coupled to a geochemistry simulator (reactions in time and space) to simulate scenarios such as underground storage of CO2 or hydrogen storage for excess energy from wind farms. The challenge for such applications is that the geochemistry simulator is typically slow compared to fluid dynamics and constitutes the main bottleneck for producing highly detailed simulations of such application scenarios. This approach attempts to find machine learning models that can replace the slow running simulator when trained on input-output data from the geochemistry simulator. The code may be of more general interest as this prototype can be used to screen many different machine learning models for any regression problem in general. To illustrate this it also includes a demonstration example using the Boston housing standard data-set.

Description: Oxygen isotope ratios were measured in zircon by laser fluorination and by SIMS from in over 50 silicic (dacite–rhyolite) volcanic rocks of Triassic to Cretaceous (230-98 Ma) age from the Sierra Nevada batholith, White-Inyo Mountains, and Mojave Desert. These data give broad geographic and temporal context of volcanism in the Mesozoic California arcs system that was previously unobtainable because of secondary hydrothermal exchange that routinely alters original magmatic δ18O values in these rocks (c.f., Sorensen et al. GSAB 1998). SIMS analysis of δ18O using 10 µm spot size, augmented by U-Pb dating by LA-ICP-MS, further allows appraisal of variability within zircon grains and grain populations as potential evidence of assimilation or magma mixing within caldera systems, including mixing during eruptions. Values of δ18O(zircon) in most rocks studied are 5.0–7.5‰, and overlap with values of δ18O in plutonic rocks (6.80±1.85‰, S.D., Lackey et al. 2005,2006,2008,2012). A subset of Late Jurassic (152-148 Ma) tuffs distributed from the Mojave Desert to Mt. Goddard pendant that contain zircons whose δ18O values commonly are 〈5.0‰; such low values are not found in coeval plutonic rocks or dikes of the ca. 148 Ma Independence Dike Swarm. Among these rocks, δ18O values are as low as 2.6‰ and average 4.4±0.8‰; porphyries associated with caldera complexes in the Mojave Desert are similarly low. The restriction of these lower values to volcanic rocks of Late Jurassic age suggests that caldera systems at this time interacted with low-δ18O surface water (meteoric or marine). Such infiltration into caldera environments has not been recognized before or after. The Late Jurassic corresponds to a pronounced but brief transtension event in the arc, which is hypothesized to have impelled mafic mantle melts high into the crust, and also encouraged low-δ18O surface water exchange with arc wall rocks (especially volcanic crust). These two factors thus created a period of low-δ18O magmatism in the upper arc crust that is strikingly mismatched with the δ18O record in coeval plutons. Moreover, the volcanic δ18O record may provide previously unrecognized information about tectonic stress regimes in arc systems as they respond to plate-tectonic reorganizations.

Description: Weltweit stiegen die Temperaturen im Permafrost um durchschnittlich 0,30 °C zwischen 2007 bis 2016, dies vor allem im Norden Russlands. Die Erwärmung des Permafrosts hat drastische Folgen für das globale Klima, aber auch für die Infrastruktur in der Arktis und das Auskommen der vier Millionen dort lebenden Menschen.

Description: Worldwide permafrost temperatures rose on average by 0.30°C over a ten year period from 2007 to 2016 most notably in the Russia North. Permafrost warming has drastic consequences for global climate but also for infrastructure in arctic communities and for the livelihood of the four million people that live there.

Description: The evolution of the Philippine Sea Plate (PSP) since Jurassic is one of the key issues in the dynamics of lithosphere and mantle. The related studies benefited mostly from seismic tomography which provides velocity structures in the upper mantle. However, the upper-mantle structure is not well resolved compared to the continental areas due to the lack of seismic data in the Philippine Sea. We employ a 3-D gravity inversion constrained by an initial model based on the S-wave tomography (SL2013sv; Schaeffer & Lebedev 2013) to image the density structure of the upper mantle of the PSP and adjacent region. The resulting model shows a three-layer pattern of vertical high-low-high density variation in the upper mantle under the PSP. The thin high-density layer evidences for strong oceanic lithosphere in the West Philippine Sea. The relatively low dense mantle located below the PSP possibly originates from the asthenosphere. The PSP differs from the Pacific and the Indian-Australian plates in the whole depth range, while its structure is similar to the eastern Eurasian and Sunda plates. In the depth range, 200–300 km, the relative high-density zone beneath PSP extends to the Sunda Plate and to the eastern Eurasian Plate. We further estimated the conversion factor of our density model and the velocity model (SL2013sv; Schaeffer & Lebedev 2013) in order to locate the changes of compositional effects in the upper mantle. The negative conversion factor indicates that the compositional changes primarily affect the density anomalies beneath the PSP. We, therefore, describe the layered density structures as ‘sandwich’ pattern, which is unique and different from adjacent regions.

Description: The characterization of the crustal structure of the plates involved in a subduction system is a crucial step towardsthe understanding of potentially associated geohazards. Despite the low current seismic activity in the Lesserand Leeward Antilles (compared with other subduction zones), several historical M〉7 earthquakes have beenregistered in both regions. In the Lesser Antilles, the oceanic floor of the North and South American plates subductsbeneath the Caribbean plate. In contrast, in the Leeward Antilles, the Caribbean plate subducts under the continentalSouth American plate. In regions where the seismic records do not extend far back in time, or where the frequencyof such large earthquakes is low, alternative indirect methods for delimiting seismogenic zones may be applied.In those cases, it would be valuable to characterize in detail the regional continental-oceanic boundary and thebackstop edge location. The tectonic history of the Lesser Antilles includes a variety of allochthonous slightly orhigh buoyant fragments, which have been either subducted or accreted to the backstop, and which can influence thespatial seismicity patterns. Moreover, previous studies suggest that the north central region of the Lesser Antillesforearc is composed of two different crustal units: an inner and an outer forearc domains, characterized by high andlow seismic velocity gradients, respectively. Such crustal domains interact spatially with the down-going plate, forexample, acting as backstops. Nevertheless, the seismic experiments carried out in the Lesser Antilles have focusedonly on a relatively narrow region; thus, much of the structure of the currently active volcanic arc remains poorlyconstrained.

Description: The stability and sensitivity of scanning transmission electron microscopes as well as detectors collecting e.g. electrons which suffered different scattering processes, or secondary radiation, have increased tremendously during the last decade. In order to fully exploit capabilities of simultaneously recording various signals with up to 1000 px/s acquisition rates the central issue is their synchronization. The latter is frequently a non-trivial problem without commercially available solution especially if detectors of different manufacturers are involved. In this paper, we present a simple scanning pattern enabling a posteriori synchronization of arbitrarily many signals being recorded entirely independently. We apply the approach to the simultaneous atomic-scale acquisition of signals from an annular dark-field detector and electron energy loss as well as energy-dispersive x-ray spectrometers. Errors emerging in scanning direction due to the independence of the respective processes are quantified and found to have a standard deviation of roughly half the pixel spacing. Since there are no intermediate waiting periods to maintain synchronicity, the proposed acquisition process is, in fact, demonstrated to be 12% faster than a commercial hardware-synchronized solution for identical sub-millisecond signal integration times and hence follows the trend in electron microscopy to extract more information per irradiating electron.

Description: The sampling strategy for mapping soil properties from remote sensing imagery entails making decisions aboutsampling pattern, size and location. The availability of a consistent number of ancillary data strongly related to thetarget variable allows applying sampling strategies that optimally cover the feature space. This study aims at eval-uating the capability of multispectral (Sentinel-2) and hyperspectral (EnMAP) satellite data to select the samplinglocations in order to collect a calibration dataset as basis for multivariate statistical modelling of the Soil OrganicCarbon (SOC) content. Remote sensing spectra can be exploited first to set the sampling strategy and then as inde-pendent variables for the prediction models of the target variables. We tested different sampling strategies based onthe feature space, where the ancillary data are the spectral bands of the Sentinel-2 and of simulated EnMAP satellitedata acquired in Demmin (north-Est Germany). Some selection algorithms require to set the number of samples inadvance (random, Kennard-Stones and conditioned Latin Hypercube algorithm) and others automatically providethe ideal number of sampling units (Puchwein, SELECT and Puchwein+SELECT algorithm). The SOC contentand the spectra extracted at the sampling locations were used to build random forest (RF) models. The accuracyof the RF estimation models was evaluated on an independent dataset. The highest Sentinel-2 ratio of performanceto deviation (RPD) for the validation set was obtained using Puchwein (RPD: 2.5), and Kennard-Stones (RPD:2.4) algorithm. A strong positive correlation was detected between the standard deviation of the calibration datasetand the validation accuracy. The efficiency of the sampling strategies, as ratio between accuracy and number ofsamples per hectare, is highest using Puchwein with EnMAP and Puchwein+SELECT algorithm with Sentinel-2 data. The achieved results demonstrated that Sentinel-2 and EnMAP data can be exploited to build a reliablecalibration dataset for SOC mapping; moreover the efficiency of the sampling strategy selection can be improvedusing algorithms that provide the number of sampling units. For EnMAP, the different selection algorithms pro-vided very similar results. On the other hand, using Puchwein and Kennard-Stones algorithms, Sentinel-2 provideda more accurate estimation than the EnMAP. The calibration datasets provided by EnMAP data provided in thiscase lower SOC variability and lower prediction accuracy than compared to Sentinel-2. This was probably due toEnMAP coarser spatial resolution (30 m) less adequate for linkage to the sampling performed at 10 m scale.

Description: The GeoDataNode project, funded by the Federal Ministry for Research and Education (BMBF) conducted a survey of data management practices at GFZ. The aim was to assess the state of current practices and needs, and their alignment to institutional and national guidelines for data management. The target audience included scientific and technical employees at all levels. A response rate of 24% of the target demographic was achieved. The survey revealed a general need for improvement and structuring of research data handling. This includes provision of adequate storage space, back-up schedules, and the familiarization of young researchers with good scientific practice.

Description: Global spherical harmonic paleomagnetic field model LSMOD.2 describes the magnetic field evolution from 50 to 30 ka BP based on published paleomagnetic sediment records and volcanic data. It is an update of LSMOD.1, with the only difference being a correction to the geographic locations of one of the underlying datasets. The time interval includes the Laschamp (~41 ka BP) and Mono Lake (~34 ka BP) excursions. The model is given with Fortran source code to obtain spherical harmonic magnetic field coefficients for individual epochs and to obtain time series of magnetic declination, inclination and field intensity from 49.95 to 30 ka BP for any location on Earth. For details see M. Korte, M. Brown, S. Panovska and I. Wardinski (2019): Robust characteristics of the Laschamp and Mono lake geomagnetic excursions: results from global field models.

Description: This is a Level 3 data daily file product from various scientific and utility sensors on board of the `LEO' satellite 'CHAMP' with magnetic field data given by a time resolution of 1 Hz. Thise Level 3 data type is build to hold and merge finally corrected data, focusing on mature data calibration and corrections -- as well as internal consistency. This Level 3 data product is intended to supersede the various Level 2 versions with calibrated magnetic field readings from the CHAMP mission distributed hitherto and should be fitted for scientific use, assembling time series of scalar magnetic field values (but not directly readings from the scalar Overhauser sensor), vector magnetic field data from the boom-mounted Fluxgate 'FGM' sensors and attitude data from the ('ASC') boom-mounted Star Cameras. The vector data are given both in the satellite-bound sensor ('FGM') system and the Earth Centered Earth Fixed local 'NEC' (North-East-Center) system. The attitude time series, processed and cleaned, are represented by quaternions describing the satellite attitude related to the celestial system. The readings of the scalar OVM (Overhauser) absolute magnetometer at the top of the boom are not supplied directly, but were used during calibration of the vector magnetometer readings. The files with daily time coverage are in the (binary and self-describing) 'CDF' file format and accompanied, beside the generic 'CDF'-format timestamp, by the satellite's geocentric positions and utility information like quality flags.

Description: Reasons for injectivity decline were investigated at a geothermal site located in SE Hungary. Due to low injectivities, production rates have to be reduced and the site faces negative commercial implications.In addition to historical operation data, fluid and rock samples were sampled on-site and further investigated in the laboratory. Analysis and experiments focus on physical, chemical and biological processes and their interaction.Results show fivemain processes being responsible for injection-triggered occlusion of flow pathways: Reservoir thickness, low permeability in the reservoir, precipitation of minerals, microbiological activity and fines migration. The reservoir geometry indicates unfavorable conditions like low sandstone thickness and low permeability. Fines migration is caused by washouts in loosely cemented rocks, from where fine sand or clay particles are transported and injected into lower aquifer layers. Precipitation of minerals is caused by cooling or oxygen exposure. Biofilm is a result of sulfate-reducing bacteria being present at injection depth. Biofilm and physicochemical conditions also cause corrosion in pipelines and wells.In order to fully understand the processes taking place in the injection well, borehole measurements will bedone in 2019. After evaluating the results, a specially tailored stimulation concept willbe applied in the injection well. A combined chemical-mechanical treatment will takeplace at different depth. Borehole measurements and hydraulic tests willbe done again after the stimulation to show the effect of the stimulation. A multiple monitoring and sampling program comesalong with activities onsite.

Description: Post-processed GRACE/GRACE-FO spherical harmonic coefficients of GFZ RL06 Level-2 GSM products representing an estimate of Earth's gravity field variations during the specified timespan. Post-processing steps comprise: (1) subtraction of a long-term mean field; (2) optionally, decorrelation and smoothing with VDK filter (anisotropic filter taking the actual error covariance information of the underlying GSM coefficients into account, see Horvath et al. (2018)); (3) replacement of coefficient C20 and its uncertainty by values estimated from Satellite Laser Ranging (SLR); (4) subtraction of linear trend caused by Glacial Isostatic Adjustment (GIA) as provided by a numerical model; (5) insertion of coefficients of degree 1; and (6) removal of estimated signal with 161 days period. These coefficients represent signals caused by water mass redistribution over the continents and in the oceans. These post-processed GRACE/GRACE-FO GSM products are denoted as Level-2B products.

Description: These data are supplementary material to "3D Modelling of Vertical Gravity Gradients and the delimitation of tectonic boundaries: The Caribbean oceanic domain as a case study" (Gómez-García et al., 2019). This dataset contains information about the structure of the Caribbean oceanic crust, based on the modelling of the Vertical Gravity Gradients, which are gravity derivatives especially sensitive to density contrasts in the upper layers of the Earth.

Description: The distribution of data records for the maximum horizontal stress orientation S_Hmax in the Earth’s crust is sparse and very unequally. To analyse the stress pattern and its wavelength and to predict the mean S_Hmax orientation on regular grids, statistical interpolation as conducted e.g. by Coblentz and Richardson (1995), Müller et al. (2003), Heidbach and Höhne (2008), Heidbach et al. (2010) or Reiter et al. (2014) is necessary. Based on their work we wrote the Matlab® script Stress2Grid that provides several features to analyse the mean S_Hmax pattern. The script facilitates and speeds up this analysis and extends the functionality compared to the publications mentioned before. This script is the update of Stress2Grid v1.0 (Ziegler and Heidbach, 2017). It provides two different concepts to calculate the mean S_Hmax orientation on regular grids. The first is using a fixed search radius around the grid points and computes the mean S_Hmax orientation if sufficient data records are within the search radius. The larger the search radius the larger is the filtered wavelength of the stress pattern. The second approach is using variable search radii and determines the search radius for which the standard deviation of the mean S_Hmax orientation is below a given threshold. This approach delivers mean S_Hmax orientations with a user-defined degree of reliability. It resolves local stress perturbations and is not available in areas with conflicting information that result in a large standard deviation. Furthermore, the script can also estimate the deviation between plate motion direction and the mean S_Hmax orientation. The script is fully documented by the accompanying WSM Technical Report 19/02 (Ziegler and Heidbach, 2019) which includes a changelog in the beginning.

Description: The accurate interpretation of Si isotope signatures in natural systems requires knowledge of the equilibrium isotope fractionation between Si-bearing solids and the dominant Si-bearing aqueous species. Aqueous silicon speciation is dominated by silicic acid (H4SiO4o) in most natural aqueous fluids at pH 〈 8.5, but forms H3SiO4−, H2SiO42−, and polymeric Si species in more alkaline fluids. In this study isotope exchange experiments were performed at bulk chemical equilibrium between amorphous silica (SiO2∙0.32 H2O) and inorganic aqueous fluids at pH ranging from 5.8 to 9.9 at 25° and 75 °C with experiments running as long as 375 days. The three-isotope method was used to quantify the equilibrium Si isotope fractionation, Δeq30Si, between amorphous silica and aqueous Si; at pH ∼ 6 this equilibrium fractionation factor was found to be 0.45 ± 0.2‰ at 25 °C, and 0.07 ± 0.6‰ at 75 °C. At more basic pH (〉9), equilibrium Si isotope fractionation factors between solid and aqueous solution are higher, at 1.63 ± 0.23‰ at 25 °C, and 1.06 ± 0.13‰ at 75 °C. Taking account of the distribution of the aqueous Si species, equilibrium Si isotope fractionation factors between H3SiO4− and H4SiO4o of −2.34 ± 0.13‰ and −2.21 ± 0.05‰ at 25 and 75 °C, respectively, were determined. The distinct equilibrium isotope fractionation factors of H3SiO4− and H4SiO4o, and its variation with temperature can be used to establish paleo-pH and temperature proxies. The application of the three-isotope method also provides insight into the rates of isotopic exchange. For the solid grain size used (∼20 nm), these rates match closely the measured bulk dissolution rates for amorphous silica for most of the isotope exchange process, suggesting the dominant and rate controlling isotope exchange mechanism in the experiments is detachment and reattachment of material at the amorphous silica surface.

Description: We report five new Rb‐Sr muscovite‐based isochron ages, which are the first to constrain the timing of amphibolite‐facies mylonitization of the Alpine Schist in the Southern Alps of New Zealand. The ages range from 13.1 ± 4.3 to 8.9 ± 3.2 Ma (2σ uncertainties) for mylonite directly above the Alpine Fault. The weighted mean age of 10.74 ± 0.57 Ma is within uncertainty of a published 40Ar/39Ar illite/mica upper‐intercept age of 11.5 ± 0.5 Ma measured at the same locality. The end of amphibolite‐facies mylonitization occurred at metamorphic conditions of ~560–570 °C and ~0.9–1.1 GPa as derived from pseudosection analysis in the NCTiKFMASH system. We interpret Miocene metamorphism to reflect transpressional crustal thickening and formation of a thick crustal root supporting early Southern Alps topography at or prior to 10.74 ± 0.57 Ma. Additional ~2–1 Ma Rb‐Sr biotite, 40Ar/39Ar muscovite, and 40Ar/39Ar biotite ages reflect isotopic closure during rapid cooling along the Alpine Fault in the Pleistocene. The Miocene mylonitization ages and the Pleistocene cooling ages define a distinct two‐stage cooling and exhumation history for the Alpine Schist with initial cooling of ~10 °C/Myr and exhumation rates of 2–4 km/Myr. Final cooling since ~2 Ma was 〉100 °C/Myr at exhumation rates of ~5–6 km/Myr. We interpret the two‐phase cooling history by movement of the mylonite through a strongly nonlinear thermal structure. An older 60.5 ± 0.7 Ma metamorphic event is also preserved as a Rb‐Sr crystallization age of a predeformational muscovite‐plagioclase assemblage in a sheared pegmatite.

Description: ESA’s Swarm constellation mission consisting of three identical satellites, successfully launched on 22 November 2013, provides the excellent opportunity of reliable electric current density estimates in the ionosphere based on multi-satellite magnetic field measurements. The final constellation with Swarm A/C orbiting the Earth at about 470 km (flying side-by-side) and Swarm B at about 520 km altitude was achieved on 17 April 2014. Swarm satellites need a period of about 130 days to cover all local times; therefore the coverage of all local times and local seasons can be achieved in 5 years from the final constellation when the dual-satellite current density estimations have been started. We present the climatology of field-aligned currents (FACs) at polar cap, cusp and auroral regions, radial, interhemispheric (IHFACs) and F region dynamo currents at mid-latitude and equatorial regions, using the single and dual satellite approaches for the current density estimations. Also, the higher-flying Swarm B satellite provides from time to time well-matched observations with the 50 km lower Swarm A/C pair that gives the possibility for zonal current estimates by using Ampère’s ring integral for determining the mean current density passing through the encircled area.

Description: The auroral oval is the region receiving most magnetospheric particle precipitations and its boundaries can be highly dynamic and influenced by the solar wind and geomagnetic conditions. Polar orbiting Low Earth Orbit (LEO) satellites carrying high-precision magnetometers are suitable to derive Field-Aligned Currents (FACs) with tens of km-scale lengths flowing between the magnetosphere and ionosphere. Our previous work has used nearly 10 years FAC data from the CHAMP mission to construct an empirical model (called CH-Aurora-204) for estimating the location of the auroral oval boundaries. The model has been recently updated by taking nearly 5 years FAC data from the three Swarm satellites. Furthermore, magnetic data from other non-dedicated magnetic LEO missions, like Cryosat or e-PoP, are also used for improving the model predicts of the auroral oval boundaries.

Description: The question of how human-environment interactions help constitute society is an integral part of social scientific research. The social sci-ences and humanities have taken several “turns” to explore the role of materiality or the body and the human senses in order to understand how humans make sense of and socially construct their environment. In this rugged landscape, an emerging interdisciplinary research field is currently developing into a promising test bed for exploring the social dimension of human-environment interactions. The shared focus is on ALAN—artificial light at night. While astronomers, biologists, ecolo-gists, physicians, and psychologists explore primarily the visual and nonvisual effects of light and darkness on flora, fauna, and humans as well as ecosystems (Falchi et al. 2016; Gaston et al. 2015; Roenneberg et al. 2013),1 there is also an increasing interest in day and night rhythms, artificial lighting, dark skies, and their social and cultural implications in the social sciences, historical studies, and humanities. As outlined in the following, this research is perfectly suited to challenging the persistent dichotomous notions of nature and culture and add to a better under-standing of how our sense making relates to our senses.