ALBERT

Description: The role of aerial dispersal in shaping patterns of biodiversity remains poorly understood, mainly due to a lack of coordinated efforts in gathering data at appropriate temporal and spatial scales. It has been long known that the rate of dispersal to an ecosystem can significantly influence ecosystem dynamics, and that aerial transport has been identified as an important source of biological input to remote locations. With the considerable effort devoted in recent decades to understanding atmospheric circulation in the south-polar region, a unique opportunity has emerged to investigate the atmospheric ecology of Antarctica, from regional to continental scales. This concept note identifies key questions in Antarctic microbial biogeography and the need for standardized sampling and analysis protocols to address such questions. A consortium of polar aerobiologists is established to bring together researchers with a common interest in the airborne dispersion of microbes and other propagules in the Antarctic, with opportunities for comparative studies in the Arctic.

Description: Triples of GPS radio occultation (RO) temperature data are used to derive horizontal and vertical gravity wave (GW) parameters in the stratosphere between 20 km and 40 km from which the vertical flux of horizontal momentum is determined. Compared to previous studies using RO data, better limiting values for the sampling distance (Δd≤250 km) and the time interval (Δt≤15 min) are used. For several latitude bands the mean momentum fluxes (MFs) derived in this study are considerably larger than MF from other satellite missions based on horizontal wavelengths calculated between two adjacent temperature profiles along the satellite track. Error sources for the estimation of MF from RO data and the geometrical setup for the applied method are investigated. Another crucial issue discussed in this paper is the influence of different background separation methods to the final MF. For GW analysis a measured temperature profile is divided into a fluctuation and a background and it is assumed that the fluctuation is caused by GWs only. For the background separation, i.e., the detrending of large-scale processes from the measured temperature profile, several methods exist. In this study we compare different detrending approaches and for the first time an attempt is made to detrend RO data with ERA-Interim data from the European Centre for Medium-Range Weather Forecasts. We demonstrate that the horizontal detrending based on RO data and ERA-Interim gives more consistent results compared with a vertical detrending.

Description: Permafrost regions are highly sensitive to climate change. Bringing research data and metadata from diverse sources together and visualising them within a publicly available worldwide system would have an enormous impact on data accessibility and availability and would significantly promote scientific work. The CarboPerm WebGIS, a case study focusing on the Lena River Delta in the Laptev Sea Region (Siberia), shows how a WebGIS infrastructure can support scientific work, data management, data visualisation, and data publication. CarboPerm is an interdisciplinary German project with Russian cooperation, investigating the formation, turnover and release of carbon in Siberian permafrost landscapes. There, the Lena River formed the largest delta in the Arctic and is place of long-term Russian-German scientific cooperation in permafrost research. The CarboPerm WebGIS is being set up to visualise and emphasise the spatial context of local samples, measurements, and analyses versus the thematic background information (e.g., geomorphology, pedology, geology and vegetation), using the WebGIS infrastructure “maps@awi” at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI). The CarboPerm WebGIS database includes historical data from long-term Russian-German cooperation and recent field campaigns as well as environmental datasets that are freely available via the internet or research data repositories.

Description: Permafrost-Landschaften reagieren sehr sensibel auf den Klimawandel. Die Synthese von Forschungsdaten und Metadaten über diese Gebiete und deren Visualisierung in einem interoperablen, weltweit zugänglichen System ist von hohem Nutzen für Wissenschaft und Gesellschaft. Innerhalb des Permafrost-Forschungsprojektes CarboPerm wird für das Lena- Delta und die Laptevmeer-Region ein WebGIS-Projekt entwickelt, welches die wissenschaftliche Forschertätigkeit durch Datenmanagement, Datenvisualisierung und Datenpublikation unterstützt. CarboPerm ist ein interdisziplinäres deutsch-russisches Kooperationsprojekt, das die Bildung, den Umsatz und die Freisetzung von Kohlenstoff in sibirischen Permafrost-Landschaften untersucht. Der Fluss Lena hat das größte Delta in der Arktis ausgebildet und ist gleichzeitig ein Kerngebiet langjähriger russisch-deutscher Kooperation in der Permafrost-Forschung. Das CarboPerm WebGIS wurde ins Leben gerufen, um den räumlichen Bezug von lokalen Probennahmen, Messergebnissen und Analysen mit thematischen Hintergrundinformationen, wie z.B. Geomorphologie, Pedologie, Geologie und Vegetation zu visualisieren. Die CarboPerm-WebGIS-Datenbank entstand unter Nutzung der WebGIS-Infrastruktur „maps@awi“ am Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI). Sie beinhaltet sowohl historische Daten aus der langjährigen russisch-deutschen Kooperation als auch von aktuellen Geländekampagnen, sowie umweltrelevante räumliche Datensätze, die aus öffentlich zugänglichen Datenquellen und Daten-Repositorien stammen.

Description: Our knowledge of the origin of Love waves in the ambient seismic noise is extremely limited. This applies in particular to constraints on source locations and source mechanisms for Love waves in the secondary microseism. Here three‐component beamforming is used to distinguish between the differently polarized wave types in the primary and secondary microseismic noise fields, recorded at several arrays across Europe. We compare characteristics of Love and Rayleigh wave noise, such as source directions and frequency content, measure Love to Rayleigh wave ratios for different back azimuths, and look at the seasonal behavior of our measurements by using a full year of data in 2013. The beamforming results confirm previous observations that back azimuths for Rayleigh and Love waves in both microseismic bands mainly coincide. However, we observe differences in relative directional noise strength between both wave types for the primary microseism. At those frequencies, Love waves dominate on average, with kinetic Love‐to‐Rayleigh energy ratios ranging from 0.6 to 2.0. In the secondary microseism, the ratios are lower, between 0.4 and 1.2. The wave type ratio is directionally homogeneous, except for locations far from the coast. In the primary microseism, our results support the existence of different generation mechanisms. The contribution of a shear traction‐type source mechanism is likely.

Description: The application of thermo-sensitive tracers is a promising technique for evaluating the thermal state of geothermal reservoirs. To extend the compound spectrum for hydrolyzable compounds to reservoir temperatures between 100 and 200 °C carboxamides were studied. The kinetic parameters of 17 self-synthesized amides were determined in hydrothermal batch and autoclave experiments. The influence of the molecular structure and the role of pH/pOH on hydrolysis kinetics were studied. Additionally, the thermal stabilities of the hydrolysis products were evaluated. The results demonstrate the high potential of tracers based on amide hydrolysis for use in medium enthalpy reservoirs.

Description: Madagascar occupies a key position in the assembly and breakup of the supercontinent Gondwana. It has been used in numerous geological studies to reconstruct its original position within Gondwana and to derive plate kinematics. Seismological observations in Madagascar to date have been sparse. Using a temporary, dense seismic profile across southern Madagascar, we present the first published study of seismic anisotropy from shear wave splitting analyses of teleseismic phases. The splitting parameters obtained show significant small-scale variation of fast polarization directions and delay times across the profile, with fast polarization rotating from NW in the center to NE in the east and west of the profile. The delay times range between 0.4 and 1.5 s. A joint inversion of waveforms at each station is applied to derive hypothetical one-layer splitting parameters. We use finite-difference, full-waveform modeling to test several hypotheses about the origin and extent of seismic anisotropy. Our observations can be explained by asthenospheric anisotropy with a fast polarization direction of 50°, approximately parallel to the absolute plate motion direction, in combination with blocks of crustal anisotropy. Predictions of seismic anisotropy as inferred from global mantle flow models or global anisotropic surface wave tomography are not in agreement with the observations. Small-scale variations of splitting parameters require significant crustal anisotropy. Considering the complex geology of Madagascar, we interpret the change in fast-axis directions as a ~150 km wide zone of ductile deformation in the crust as a result of the intense reworking of lithospheric material during the Pan-African orogeny. This fossil anisotropic pattern is underlain by asthenospheric anisotropy induced by plate motion.

Description: In the present paper we describe the on-land field operations integrated in the TOMO-ETNA experiment carried out in June-November 2014 at Mt. Etna volcano and surrounding areas. This terrestrial campaign consists in the deployment of 90 short-period portable three-component seismic stations, 17 Broadband seismometers and the coordination with 133 permanent seismic station belonging to Italy’s Istituto Nazionale di Geofisica e Vulcanologia (INGV). This temporary seismic network recorded active and passive seismic sources. Active seismic sources were generated by an array of air-guns mounted in the Spanish oceanographic vessel “Sarmiento de Gamboa” with a power capacity of up to 5200 cubic inches. In total more than 26,000 shots were fired and more than 450 local and regional earthquakes were recorded. We describe the whole technical procedure followed to guarantee the success of this complex seismic experiment. We started with the description of the location of the potential safety places to deploy the portable network and the products derived from this search (a large document including full characterization of the sites, owners and indication of how to arrive to them). A full technical description of the seismometers and seismic sources is presented. We show how the portable seismic network was deployed, maintained and recovered in different stages. The large international collaboration of this experiment is reflected in the participation of more than 75 researchers, technicians and students from different institutions and countries in the on-land activities. The main objectives of the experiment were achieved with great success.

Description: Ground motion intensity measures such as the peak ground acceleration (PGA) and the pseudo-spectral acceleration (PSA) at two sites due to the same seismic event are correlated. The spatial correlation needs to be considered when modeling ground-motion fields for seismic loss assessments, since it can have a significant influence on the statistical moments and probability distribution of aggregated seismic loss of a building portfolio. Empirical models of spatial correlation of ground motion intensity measures exist only for a few seismic regions in the world such as Japan, Taiwan and California, since for this purpose a dense observation network of earthquake ground motion is required. The Istanbul Earthquake Rapid Response and Early Warning System (IERREWS) provides one such dense array with station spacing of typically 2 km in the urban area of Istanbul. Based on the records of eight small to moderate (Mw3.5–Mw5.1) events, which occurred since 2003 in the Marmara region, we establish a model of intra-event spatial correlation for PGA and PSA up to the natural period of 1.0 s. The results indicate that the correlation coefficients of PGA and short-period PSA decay rapidly with increasing interstation distance, resulting in correlation lengths of approximately 3–4 km, while correlation lengths at longer natural periods (above 0.5 s) exceed 6 km. Finally, we implement the correlation model in a Monte Carlo simulation to evaluate economic loss in Istanbul's district Zeytinburnu due to a Mw7.2 scenario earthquake.

Description: The International Geodynamics and Earth Tide Service (IGETS) was established in 2015 by the International Association of Geodesy. IGETS continues the activities of the Global Geodynamics Project (GGP) between 1997 and 2015 to provide support to geodetic and geophysical research activities using superconducting gravimeter (SG) data within the context of an international network. As a new addition to this network, the iGrav-027 superconducting gravimeter had been installed at the Borowa Gora Geodetic-Geophysical Observatory which has been established in late 1930s. Continuous time-varying gravity and atmospheric pressure data from the SGs at Borowa Gora are integrated in the IGETS data base hosted by ISDC (Information System and Data Center) at GFZ. Borowa Gora Geodetic-Geophysical Observatory is located in Poland, situated 50 km north of Warsaw (longitude: 21.0359 E, latitude: 52.2755 N, height above MSL: 109 m). The operation and maintenance of the Borowa Gora instrumentation is done by staff of the Institute of Geodesy and Cartography. The shortest distance to the Baltic Sea coastline is approx. 240 km. The area is located in a tectonically quiet zone. Geologically the situation is not well recognized, a significant size artificial reservoir is located within 1-2 km from the Observatory. The environment is a not significantly urbanized area with visible daily seismicity. The climate at this place has rough winters (up to -20 degrees Celsius) and hot summers (up to 35 degrees Celsius). The iGrav-027 is located in a specially prepared chamber in the basement of one of the Observatory buildings. It is separated from the compressor operating in a separate room. The location of the gravimeter ensures a relatively stable temperature of 21°C ±2°C throughout the year. The instrument is placed on a specially prepared concrete monument of 1.2 × 1.2 m horizontal and 1.5 m vertical dimensions (ca 1.3 m deep below floor level). The sensor of the instrument is located about 2 m below ground level, and the position and height of the instrument has been determined with a centimetre accuracy, before the installation. The iGrav-027 is co-located in the same building with the A10-020 absolute gravimeter. There are three well monumented pillars for absolute gravity determinations, which can be conducted along with the operating iGrav-027 (e.g. for the comparison with absolute gravimeters). In the vicinity of the observatory several further pillars were set up for various other geodetic antennas and instrumentation. Borowa Gora is a geodynamic observatory comprising space techniques and ground instruments. The iGrav-027 operation started at the end of April 2016, official start is assigned as from 1th of May 2016. Since that time the time series is carried out without interruption up to present. The time sampling of the raw gravity and barometric pressure data of IGETS Level 1 is 1 minute. Future plans include uploading 1s data sampling also. In addition, Borowa Gora is equipped with auxiliary data supporting the interpretation of the SG measurements, which is, however, not provided in the IGETS data base due to complexity. These are a local network of hydrological and meteorological sensors as well as two permanent GNSS (Global Navigation Satellite Systems) stations BOGO and BOGI. Additionally magnetic field variations are also recorded.

Description: To investigate temporal seismic velocity changes due to earthquake related processes and environmental forcing in Northern Chile, we analyse 8 yr of ambient seismic noise recorded by the Integrated Plate Boundary Observatory Chile (IPOC). By autocorrelating the ambient seismic noise field measured on the vertical components, approximations of the Green’s functions are retrieved and velocity changes are measured with CodaWave Interferometry. At station PATCX, we observe seasonal changes in seismic velocity caused by thermal stress as well as transient velocity reductions in the frequency range of 4–6 Hz. Sudden velocity drops occur at the time of mostly earthquake-induced ground shaking and recover over a variable period of time. We present an empirical model that describes the seismic velocity variations based on continuous observations of the local ground acceleration. The model assumes that not only the shaking of large earthquakes causes velocity drops, but any small vibrations continuously induce minor velocity variations that are immediately compensated by healing in the steady state. We show that the shaking effect is accumulated over time and best described by the integrated envelope of the ground acceleration over the discretization interval of the velocity measurements, which is one day. In our model, the amplitude of the velocity reduction as well as the recovery time are proportional to the size of the excitation. This model with two free scaling parameters fits the data of the shaking induced velocity variation in remarkable detail. Additionally, a linear trend is observed that might be related to a recovery process from one or more earthquakes before our measurement period. A clear relationship between ground shaking and induced velocity reductions is not visible at other stations. We attribute the outstanding sensitivity of PATCX to ground shaking and thermal stress to the special geological setting of the station, where the subsurface material consists of relatively loose conglomerate with high pore volume leading to a stronger nonlinearity compared to the other IPOC stations.

Description: We use the recorded seismicity, confined to the Dead Sea basin and its boundaries, by the Dead Sea Integrated Research (DESIRE) portable seismic network and the Israel and Jordan permanent seismic networks for studying the mechanisms of earthquakes in the Dead Sea basin. The observed seismicity in the Dead Sea basin is divided into nine regions according to the spatial distribution of the earthquakes and the known tectonic features. The large number of recording stations and the adequate station distribution allowed the reliable determinations of 494 earthquake focal mechanisms. For each region, based on the inversion of the observed polarities of the earthquakes, we determine the focal mechanisms and the associated stress tensor. For 159 earthquakes, out of the 494 focal mechanisms, we could determine compatible fault planes. On the eastern side, the focal mechanisms are mainly strike-slip mechanism with nodal planes in the N-S and E-W directions. The azimuths of the stress axes are well constrained presenting minimal variability in the inversion of the data, which is in agreement with the Eastern Boundary fault on the east side of the Dead Sea basin and what we had expected from the regional geodynamics. However, larger variabilities of the azimuthal and dip angles are observed on the western side of the basin. Due to the wider range of azimuths of the fault planes, we observe the switching of σ1 and σ2 or the switching of σ2 and σ3 as major horizontal stress directions. This observed switching of stress axes allows having dip-slip and normal mechanisms in a region that is dominated by strike-slip motion.

Description: We estimated the shear-wave velocity structure and Vp/Vs ratio of the crust beneath the Sumatra region by inverting stacked receiver functions from five three-component broadband seismic stations, located in diverse geologic setting, using a well known non-linear direct search approach, Neighborhood Algorithm (NA). Inversion results show significant variation of sediment layer thicknesses from 1 km beneath the backarc basin (station BKNI and PMBI) to 3–7 km beneath the coastal part of Sumatra region (station LHMI and MNAI) and Nias island (station GSI). Average sediment layer shear velocity (Vss) beneath all the stations is observed to be less (∼1.35 km/s) and their corresponding Vp/Vs ratio is very high (∼2.2–3.0). Crustal thickness beneath Sumatra region varies between 27 and 35 km, with exception of 19 km beneath Nias island, with average crustal Vs ∼3.1–3.4 km/s (Vp/Vs ∼1.8). It is well known that thick sediments with low Vs (and high Vp/Vs) amplify seismic waves even from a small-magnitude earthquake, which can cause huge damage in the zone. This study can provide the useful information of the crust for the Sumatra region. Since, Sumatra is an earthquake prone zone, which suffered the strong shaking of Great Andaman–Sumatra earthquake; this study can also be helpful for seismic hazard assessment.

Description: Als Voruntersuchung für das Forschungsprojekt DESMEX (Deep Electromagnetic Sounding for Mineral Exploration) werden ein -/ und zweidimensionale Modellierungen von LOTEM Daten durchgeführt. Mittels 1D Modellierung kann die optimale Sender-Empfänger Geometrie und die maximal benötigte Aufzeichnungszeit festgelegt werden, um eine gutleitfähige Schicht in einer Tiefe von ca. 1 km detektieren zu können. Mit der anschließenden 2D Modellierung wird die gutleitfähige Schicht als nicht durchgehend und verschiedene Neigungen der Schicht angenommen. Durch den Vergleich der synthetischen 2D Daten mit den synthetischen 1D Daten für verschiedene Sender-Empfänger Lokationen entlang des Profils, kann der 2D Effekt abgeschätzt werden. Mit einer abschließenden 1D Inversion können Aussagen über die Angemessenheit einer 1D Inversion von 2D beeinflussten Daten getroffen werden und mögliche Fehlinterpretationen eingeschätzt werden.

Description: The 2015 Mw8.3 Illapel, Chile earthquake is the latest megathrust event on the central segment of that subduction zone. It generated strong ground motions and a large (up to 11 m runup) tsunami which prompted the evacuation of more than 1 million people in the first hours following the event. Observations during recent earthquakes suggest that these phenomena can be associated with rupture on different parts of the megathrust. The deep portion generates strong shaking while slow, large slip on the shallow fault is responsible for the tsunami. It is unclear whether all megathrusts can have shallow slip during coseismic rupture and what physical properties regulate this. Here we show that the Illapel event ruptured both deep and shallow segments with substantial slip. We resolve a kinematic slip model using regional geophysical observations and analyze it jointly with teleseismic backprojection. We find that the shallow and deep portions of the megathrust are segmented and have fundamentally different behavior. We forward calculate local tsunami propagation from the resolved slip and find good agreement with field measurements, independently validating the slip model. These results show that the central portion of the Chilean subduction zone has accumulated a significant shallow slip deficit and indicates that, given enough time, shallow slip might be possible everywhere along the subduction zone.

Description: In this study we investigated conditions for loss of GPS signals observed by the Swarm satellites during a 2 year period, from December 2013 to November 2015. Our result shows that the Swarm satellites encountered most of the total loss of GPS signal at the ionization anomaly crests, between ±5° and ±20° magnetic latitude, forming two bands along the magnetic equator, and these low-latitude events mainly appear around postsunset hours from 19:00 to 22:00 local time. By further checking the in situ electron density measurements of Swarm, we found that practically, all the total loss of GPS signal events at low latitudes are related to equatorial plasma irregularities (EPIs) that show absolute density depletions larger than 10 × 1011 m−3; then, the Swarm satellites encountered for up to 95% loss of GPS signal for at least one channel and up to 45% tracked less than four GPS satellites (making precise orbit determination impossible). For those EPIs with density depletions less than 10 × 1011 m−3, the chance of tracked GPS signals less than four reduces to only 1.0%. Swarm also observed total loss of all GPS signal at high latitudes, mainly around local noon, and these events are related to large spatial density gradients due to polar patches or increased geomagnetic/auroral activities. We further found that the loss of GPS signals were less frequent after appropriate settings of the Swarm GPS receivers had been updated. However, the more recent period of the mission, e.g., after the GPS receiver settings have been updated, also coincides with less severe electron density depletions due to the declining solar cycle, making GPS loss events less likely. We conclude that both lower electron density gradients and appropriate GPS receiver settings reduce the probability for Swarm satellites loss of GPS signals.

Description: In this study we examine an interesting occurrence of miarolitic pegmatites in the Königshain granite of the Lusatia region of the Bohemian Massif. This granite is characterized by the extensive development of micro-sized miarolitic pegmatites (typically with diameters of 5 to 15 mm) irregularly distributed through its upper levels, and larger miarolitic pegmatites (up to 1 m) in the uppermost levels. This granite also shows evidence of varied forms of transport of extremely volatile rich residual melts/fluids, in the form of more or less discrete inter-granular melt bodies, and associated magmatic quartz veins formed in tectonic fissures. Together, these provide evidence for the origin of miarolitic pegmatites, both in the specific case of Königshain, and more generally. Our evidence suggests that miarolitic pegmatites form from volatile- and alkali-rich residual melts, ranging from 10 to 50% H2O, far more than typical granitic melts, but far more silicate components than aqueous fluids or vapor suggested by some authors. Using melt inclusions in quartz from the aplitic and graphic granite zones in miarolitic pegmatites in the Königshain granite, we show that two different inclusion populations are present. We provide evidence that the first inclusion population are those related to the primary granite at the level of intrusion, and the second were trapped during the re-crystallization of the granite wall rocks by silicate-rich supercritical fluids moving through the solid crystal framework with a porosity 〈 25 and a permeability 〉 0 (see Clarke et al., 2013). Our results show that a significant volume fraction of the miarolitic pegmatites was not created by a pegmatite-forming fluid, but formed in-situ by re-crystallization of wall-rocks, triggered by highly reactive volatiles exsolved from the pegmatite-forming melts. Evidence is also presented which suggests the nature and speed of emplacement of the Königshain granite. This evidence may explain the unusual form and abundance of miarolitic pegmatites in the studied area, and may have application to similar occurrences. Thus, there is a mixture of features which are applicable to miarolitic pegmatites in general, and others which help separate the overriding processes, from the variations produced by local or regional chemical or tectonic characteristics.

Description: Data publication is increasingly regarded as important scientific achievement and data publications are now fully citable in journal articles. This paper focuses on improving the reusability of data publications by providing comprehensive data descriptions complementary to standardized metadata. In this context, data reports proved to be a helpful tool to fill the gap between restricted ’README’ information on one hand and preparing an extended peer-reviewed data article on the other hand.

Description: A temporary seismic array was installed in combination with a meteorological station in the Dead Sea valley, Jordan. Within the scope of the HGF virtual institute DESERVE we operated 15 temporary seismic stations between February 2014 and February 2015 together with a nearby meteorological station close to the east coast of the Dead Sea. The main aim was to acquire data to study the influence of wind on seismic records and retrieve related meteorological parameters. The study area is scarcely populated and has ideal meteorological conditions to study periodically occurring winds.

Description: Widespread flooding in June 2013 caused damage costs of €6 to 8 billion in Germany, and awoke many memories of the floods in August 2002, which resulted in total damage of €11.6 billion and hence was the most expensive natural hazard event in Germany up to now. The event of 2002 does, however, also mark a reorientation toward an integrated flood risk management system in Germany. Therefore, the flood of 2013 offered the opportunity to review how the measures that politics, administration, and civil society have implemented since 2002 helped to cope with the flood and what still needs to be done to achieve effective and more integrated flood risk management. The review highlights considerable improvements on many levels, in particular (1) an increased consideration of flood hazards in spatial planning and urban development, (2) comprehensive property-level mitigation and preparedness measures, (3) more effective flood warnings and improved coordination of disaster response, and (4) a more targeted maintenance of flood defense systems. In 2013, this led to more effective flood management and to a reduction of damage. Nevertheless, important aspects remain unclear and need to be clarified. This particularly holds for balanced and coordinated strategies for reducing and overcoming the impacts of flooding in large catchments, cross-border and interdisciplinary cooperation, the role of the general public in the different phases of flood risk management, as well as a transparent risk transfer system. Recurring flood events reveal that flood risk management is a continuous task. Hence, risk drivers, such as climate change, land-use changes, economic developments, or demographic change and the resultant risks must be investigated at regular intervals, and risk reduction strategies and processes must be reassessed as well as adapted and implemented in a dialogue with all stakeholders.

Description: The 2014 April 1, Mw 8.1 Iquique (Chile) earthquake struck in the Northern Chile seismic gap. With a rupture length of less than 200 km, it left unbroken large segments of the former gap. Early studies were able to model the main rupture features but results are ambiguous with respect to the role of aseismic slip and left open questions on the remaining hazard at the Northern Chile gap. A striking observation of the 2014 earthquake has been its extensive preparation phase, with more than 1300 events with magnitude above ML 3, occurring during the 15 months preceding the main shock. Increasing seismicity rates and observed peak magnitudes accompanied the last three weeks before the main shock. Thanks to the large data sets of regional recordings, we assess the precursor activity, compare foreshocks and aftershocks and model rupture preparation and rupture effects. To tackle inversion challenges for moderate events with an asymmetric network geometry, we use full waveforms techniques to locate events, map the seismicity rate and derive source parameters, obtaining moment tensors for more than 300 events (magnitudes Mw 4.0–8.1) in the period 2013 January 1–2014 April 30. This unique data set of fore- and aftershocks is investigated to distinguish rupture process models and models of strain and stress rotation during an earthquake. Results indicate that the spatial distributions of foreshocks delineated the shallower part of the rupture areas of the main shock and its largest aftershock, well matching the spatial extension of the aftershocks cloud. Most moment tensors correspond to almost pure double couple thrust mechanisms, consistent with the slab orientation. Whereas no significant differences are observed among thrust mechanisms in different areas, nor among thrust foreshocks and aftershocks, the early aftershock sequence is characterized by the presence of normal fault mechanisms, striking parallel to the trench but dipping westward. These events likely occurred in the shallow wedge structure close to the slab interface and are consequence of the increased extensional stress in this region after the largest events. The overall stress inversion result suggests a minor stress rotation after the main shock, but a significant release of the deviatoric stress. The temporal change in the distribution of focal mechanisms can also be explained in terms of the spatial heterogeneity of the stress field: under such interpretation, the potential of a large megathrust earthquake breaking a larger segment offshore Northern Chile remains high.

Description: The International Continental Scientific Drilling Program (ICDP) performed a dual-phase scientific drilling project to investigate mountain-building processes called Collisional Orogeny in the Scandinavian Caledonides (COSC). The borehole COSC-1 was drilled through the Lower Seve Nappe, as the first of two 2.5 km deep drill holes close to Åre, central Sweden. The recovered rocks comprise a 1650 m thick suite of high grade gneisses and amphibolites with clear Seve Nappe affinities, while the lower 850 m comprise rather homogenous mylonitic gneisses with interfingered K-rich phyllonite bands of cm to several m size and some intercalated amphibolites. The different lithologies all crosscut the core in a subhorizontal direction with foliation of gneisses and phyllonites in the same direction. Albite and garnet porphyroblasts with pressure shadows show syn-deformational growth and the same sub-horizontal alignment. The focus of this thesis is to detect chemical and mineralogical differences in mylonitic and host rocks and to relate these differences to either metasomatism and deformation or inherited source rock variance. Another goal of this work is to compare chemical core scanning instruments. For this purpose two different μ-Energy-Dispersive X-Ray Fluorescence (μ-EDXRF), Laser Induced Breakdown Spectroscopy (LIBS) and hyperspectral imaging techniques served to measure seven samples from the lower 850 m of the COSC-1 core. The measurements reveal sharp borders between different rock types without indication of metasomatic changes, pointing to a heterogeneous protolith such as greywacke. Element and mineral maps show strong pervasive ductile deformation with mylonite recrystallization. The comparison of the scanning devices shows that the μ-EDXRF scanner with 50 μm resolution can be used perfectly for microstructural investigations and heavy element analysis. The XRF core scanner from AVAATECH is very useful and sufficiently precise for element profiles of line scans. The LIBS scanner is great to create distribution maps of elements from H to U with a resolution of 200 μm. The hyperspectral cameras are extremely fast in acquiring spectral mineral maps and structural information. However, several rock forming minerals in gneisses can currently not be identified and a calibration for metamorphic rocks is still needed.

Description: Measuring soil moisture with cosmic ray neutrons is a promising technique for intermediate spatial scales. To convert neutron counts to average volumetric soil water content a simple calibration function can be used (the N0-calibration of Desilets et al., 2010). The calibration is based on soil water content derived directly from soil samples taken within the footprint of the sensor. We installed a cosmic-ray neutron sensor (CRS) in a mixed forest in the lowlands of north-eastern Germany and calibrated it 10 times throughout one calendar year. Each calibration with the N0-calibration function resulted in a different CRS soil moisture time series, with deviations of up to 0.12 m3 m-3 for individual values of soil water content. Also, many of the calibration efforts resulted in time series that could not be matched with independent in situ measurements of soil water content. We therefore suggest a modified calibration function with a different shape that can vary from one location to another. A twopoint calibration proved to be adequate to correctly define the shape of the modified calibration function if the calibration points were taken during both dry and wet conditions spanning at least half of the total range of soil moisture. The best results were obtained when the soil samples used for calibration were linearly weighted as a function of depth in the soil profile and non-linearly weighted as a function of distance from the CRS, and when the depth-specific amount of soil organic matter and lattice water content was explicitly considered. The annual cycle of tree foliation was found to be a negligible factor for calibration because the variable hydrogen mass in the leaves was small compared to the hydrogen mass changes by soil moisture variations. We will also provide a best practice calibration guide for CRS in forested environments.

Description: Complex structures like the Carpathian Orogen and its neighbouring platforms and related inter-orogenic basin system can be understood only by complex integration of complementary investigative tools. A large wide angle refraction and reflection (WARR) survey was carried out in 2014 by a large international partnership in order to study the transition from the East European Platform to the northern part of the Romanian Eastern Carpathians, Transylvanian Basin and the Apuseni Mountains. The main scientific objectives of the WARR project relate to three main investigation domains: crustal architecture; affinity of crystalline basement and sedimentary basins architecture. The profile is about 700 km in total, in Ukraine and Romania. Recorders used were DSS Cubes and placed at 2.0 km intervals along an alignment forming the Romanian segment and the seismic sources were explosives, with shotpoints spaced at 20-65 km with a total of 800-1200 kg explosives/site in clusters of drill-holes loaded with 50 kg explosive/hole, average depth of 25 m. The main conclusions drawn from deep seismic data acquisition technology used is a clean technology, transient, short-lived and do not affect population health, the environmental factors flora and fauna.

Description: Bevölkerungswachstum und Klimawandel haben tiefgreifende Veränderungen im Mekong Delta verursacht. Eine dieser Veränderungen betrifft das zunehmende Auftreten extremer Hochwasserereignisse. Um das Leben der Menschen in den Küstenbereichen des Deltas während solcher Ereignisse zu schützen, ist es von großer Bedeutung, die Wasserstandhöhe in diesen Bereiche kontinuierlich zu überwachen. Standardmäßig kommen dafür Pegelmessstationen zum Einsatz. Sie ermöglichen die Bestimmung der Wasserstandhöhe mit großer Genauigkeit und hoher zeitlichen Auflösung. Ein Nachteil dieser Methode liegt in der lediglich punktuellen Verfügbarkeit von Messwerten. Aufgrund steigender Wartungskosten wird die Anzahl der Messstationen ferner kontinuierlicher verringert. Eine zukunftsträchtige Alternative stellt die Global Positioning System-Reflectometry (GPS-R) dar, da Wasseroberflächen eine hohe Reflektivität für GPS L-band Signale zeigen. Phasenbeobachtungen haben das Potenzial, genauere Ergebnisse zu liefern. Um die Möglichkeit des Einsatzes eines darauf beruhenden Verfahrens als Pegelmessinstrument zu prüfen, wurden zwei 14-tägige Messkampagnen, 2012 und 2013, im Mekong-Delta durchgeführt. Dabei kam eine neue Generation von GORS-Empfänger zum Einsatz. Um eine Aussage über den Einfluss der Antennenposition auf Qualität und Quantität der registrierten Phasenbeobachtungen treffen zu können, wurden zwei unterschiedliche Antennenhöhen verwendet. Die Ergebnisse der Analyse zeigen, dass hauptsächlich die Rauheit der Wasseroberfläche für den Verlust der Kohärenz der Phasenbeobachtungen verantwortlich ist. Bedingt durch die hohe Datenrate, ein neues Algorithmus zur automatisierte Extraktion von kohärente Phasenbeobachtungen wird vorgestellt. Dabei zeigen die Analyse der Ergebnisse eine Übereinstimmung von 82%. Die Analyse zeigte ferner die Präsenz von Mehrwegeffekte. Dieses bereits in anderen Veröffentlichungen festgestellte Phänomen stellt weiterhin eine offene Fragestellung dar. In der vorliegenden Arbeit werden diese Effekte durch die Anwendung einer adaptierten Version der empirischen Modenzerlegung Empirical Mode Decomposition reduziert, was zu einer deutlichen Erhöhung der Genauigkeit bei der Bestimmung der Wasserstandhöhen führt. Des Weiteren kann durch die Analyse der Daten das Vorhandensein einer Vielzahl von Phasensprüngen und deren hohes Maß an Korrelation mit der Umgebung der Antenne nachgewiesen werden. Um den Höhenunterschied zwischen Empfänger und Wasseroberfläche zu bestimmen, wird eine Ausgleichungsrechnung nach der Methode der kleinsten Quadrate durchgeführt. Da die Genauigkeit des geschätzten Höhenunterschieds von der Genauigkeit der berechnete Entfernungsdifferenz zwischen dem direkten und dem reflektierten Signal abhängig ist, muss der Einfluss von systematischen Fehlern, die die Signale beeinflussen, minimiert werden. Für diesen Zweck, werden zum einen verschiedene Strategien für die Korrektur der durch die Troposphäre verursachten Fehlers verglichen, wobei gezeigt wird, dass atmosphärische Höhenschicht und die Gesamtzenitverzögerung genau berechnet werden müssen. Zum anderen werden die Einflüsse des Phase Wind-up sowie von Antennenphasenzentrumvariationen und -offset analysiert und Korrekturverfahren vorgestellt. Für eine erfolgreiche Bestimmung der Wasserstandhöhe ist neben der Korrektur systematischer Fehler die korrekte Festsetzung der Mehrdeutigkeiten in den Phasenbeobachtungen erforderlich. Als Ergebnis dieser Arbeit kann festgehalten werden, dass unter diesen Voraussetzungen die Bestimmung der Wasserstandhöhen mit einer Auflösung von 10 Minuten und einer Genauigkeit im dm-Bereich möglich ist. Es konnte ferner gezeigt werden, dass bei gleichzeitigem Vorliegen von Daten mehrerer Satelliten Genauigkeiten im cm-Bereich erzielt werden. Während die größtenteils nicht vorhandene Redundanz den Hauptgrund für die eingeschränkte Genauigkeit darstellt, liegt dieser für die fehlende Kontinuität in dem häufig auftretenden Verlust der Kohärenz der Phasenbeobachtungen. Darüber hinaus, um die allgemeine Anwendbarkeit der in dieser Arbeit entwickeltes Algorithmus zu überprüfen, wurde die Methode auf Daten einer in 2014 durchgeführte Messung in Midelt, Marokko, angewandt. Die daraus resultierenden Wasserstandhöhen im dm-Bereich, zeigen die Anwendbarkeit des entwickelte Algorithmus auf andere grund- und phasenbasierte GPS-R Anwendungen.

Description: Ground-based gauge instrumentation enables a high altimetric accuracy with high temporal resolution, but for a point location only. However, their number is decreasing worldwide. GPS-R reveals new perspectives for water level monitoring, since water surfaces show a high reflectivity for the GPS L-band signal. To test the possibility of using this innovative technique, two field campaigns were conducted in Vietnam within the WISDOM project. As phase observations has the potential to offer more accurate results, a new generation of GORS receiver has been successfully tested. GPS-R phase-based altimetry imply continuous coherent phase observations. Due to the high sampling rate of the recorded data, a new automated algorithm, based on an ellipse fitting, is proposed to extract coherent observations. A hit rate of 82% could be reached. To test the geometrical impact of the antenna position on quality and quantity of the recorded observations, two antenna heights were used. A detailed analysis of the recorded observations was performed and correction techniques were developed. The results of the analysis show that the roughness of the water surface had a major influence on loss of coherency. Additionally, the surroundings of the antennas and the river geometry restrict the use of reflection events. The analysis also showed the presence of multipath effects other than the water, deteriorating the results. A phenomena already found in other research activities but not resolved. These multipath effects are mitigated and filtered based on an adjusted Empirical Mode Decomposition method showing an improvement of several centimetres in the obtained water level results. The data also reveals the strong presence of cycle slips that distort the results. A cycle slip detection strategy was therefore proposed. To extract water level changes, a LS method is used. As the accuracy of the extracted altimetric heights are strongly dependent on the accurate calculation of the geometrical excess paths between the direct and the reflected signal, effort was made to analyse the impact of systematic errors that influence the signals. Different tropospheric correction strategies are compared, showing that atmospheric height layer and total zenith delay have to be precisely calculated. Additionally, the impact of the mostly ignored phase wind-up effects in GPS-R applications is underlined. As the recorded coherent phase observations are ambiguous, an ambiguity fixing strategy for different satellite redundancy is proposed. Mostly, only L1 coherent phase observations from a single satellite are present. In this case, water level heights within the set goal of decimetre level of accuracy can be calculated with an interval of 10 min. In the most desirable case, with the presence of redundant satellites, water level heights could be estimated at the centimetre level of accuracy. To test the general applicability of the proposed algorithm, recorded observations during a measurement campaign, conducted 2014 within the PMARS project in Midelt, Morocco, were used. The obtained results within the decimetre level of accuracy, underline the applicability of the proposed algorithm to other ground and phase-based GPS-R altimetry applications. All the obtained results are verified by comparing them with tide gauge measurements in the vicinity of the antennas.

Description: We present the Neural-network-based Upper hybrid Resonance Determination (NURD) algorithm for automatic inference of the electron number density from plasma wave measurements made on board NASA's Van Allen Probes mission. A feedforward neural network is developed to determine the upper hybrid resonance frequency, fuhr, from electric field measurements, which is then used to calculate the electron number density. In previous missions, the plasma resonance bands were manually identified, and there have been few attempts to do robust, routine automated detections. We describe the design and implementation of the algorithm and perform an initial analysis of the resulting electron number density distribution obtained by applying NURD to 2.5 years of data collected with the Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) instrumentation suite of the Van Allen Probes mission. Densities obtained by NURD are compared to those obtained by another recently developed automated technique and also to an existing empirical plasmasphere and trough density model.

Description: During the past decade, the relevance of research data has been rising significantly and the free and open access not only to scientific results, but to research datasets has been identified as a key issue by the scientific community, funding agencies and the public. As a consequence, there is a dynamic coevolution of national and international guidelines on management of and open access to research data (e.g. Berlin Declaration on Open Access to Knowledge in the Sciences and Humanities, G8 Open Data Charter, EU Horizon 2020 Guidelines, etc.) and the development of concepts to make data persistently accessible and citable products of research. Especially in permafrost and climate research, longterm observatories and world-wide monitoring programmes are essential to understand the impact of, e.g., permafrost thaw on the Earth climate system and consequently of climate change. Many datasets are online available, via data portals or databases like, e.g. at the National Snow and Ice Datacentre, the GTN-P Database, NORPERM, Fluxnet, etc., but often without the possibility to give the data providers recognition and acknowledgement for contributing data to a global network. During the past years, the publication of research datasets with assigned digital object identifier (DOI) has emerged as best practice for citable and persistent open access research data together with the deserved recognition of the data providers. An important step for the international acceptance and recognition of DOI-referenced data publication is the‘Statement of Commitment’of the Coalition for Data Publication in the Earth and Space Sciences (COPDESS) that aims to promote joint policies and procedures for the publication and citation of data across Earth Science journals. Key commitments, signed by many publishers and data centres, are the acceptance of data citations within reference lists of research articles, the improvement of cross-references between journal articles and published datasets, and the strong recommendation to, whenever possible, store datasets in appropriate, theme-specific data repositories, in which data access and long-term preservation are guaranteed and datasets are accompanied by sufficient metadata to enable data reuse and discovery. A comprehensive data description is essential for data reuse. Data publication is mostly known as supplementary material to scientific articles. Very often, however, the data description in the journal article is not sufficient for data reuse leading to many published dataset not being used as much as they could be. To improve this, many disciplines have developed and are developing “Data Journals” that aim to publish scientific articles with the detailed description of datasets, data portals or data collections that will be published along with the datasets. There are different formats for articles in data journals, but all have in common that they lack of any scientific interpretation of the described datasets. For standalone publication of datasets where neither format is an option, accompanying data reports are a convenient and flexible tool for enhanced data description.

Description: Due to a strong Arctic warming trend, potentially large greenhouse gas emissions from Arctic and sub- Arctic areas are of concern. The Lena River Delta located in north-east Siberia is the largest delta within the Arctic Circle, characterized by wetland ecosystems and wet polygonal tundra environments. These environments are currently thought to be sinks for carbon dioxide and sources of methane. Tower-based eddy covariance is the most widely used direct method for quantifying exchanges of momentum, energy and trace gases between the surface and the atmosphere. However, they cover a relatively small footprint and constitute point measurements relative to the vast extend of tundra ecosystems. To improve spatial coverage and spatial representativeness of these direct flux measurements, airborne eddy covariance flux measurements across large areas are required. We used the helicopter-carried measurement system “Helipod” equipped with a turbulence probe, fast temperature and humidity sensors, and a fast response gas analyzer to measure turbulent fluxes of heat, carbon dioxide, and methane across the Lena River Delta in Russia in 2012 and 2014. The 2014 campaign covered several periods of the season from April to August 2014. Wavelet transforms are used to improve spatial resolution of the flux measurements and footprint analysis is applied to find relations between surface fluxes and biophysically relevant land cover properties. Strong regional differences in trace gas fluxes were detected, indicating a non-uniform distribution of sources especially in wet sedge-, moist grass-, and moss-dominated tundra. In contrast, the sensible heat flux showed less variability across the investigation area. The obtained results are essential in understanding the role of Arctic ecosystems in the greenhouse gas budgets and to evaluate regional scale model simulations.

Description: Knowledge of the quality factor of near-surface materials is of fundamental interest in various applications. Attenuation can be very strong close to the surface and thus needs to be properly assessed. In recent years, several researchers have studied the retrieval of attenuation coefficients from the cross correlation of ambient seismic noise. Yet, the determination of exact amplitude information from noise-correlation functions is, in contrast to the extraction oftraveltimes, not trivial. Most ofthe studies estimated attenuation coefficients on the regional scale and within the microseism band. In this paper, we investigate the possibility to derive attenuation coefficients from seismic noise at much shallower depths and higher frequencies (〉1 Hz). The Euroseistest area in northern Greece offers ideal conditions to study quality factor retrieval from ambient noise for different rock types. Correlations are computed between the stations of a small scale array experiment (station spacings 〈2 km) that was carried out in the Euroseistest area in 2011. We employ the correlation of the coda of the correlation (C3) method instead of simple cross correlations to mitigate the effect of uneven noise source distributions on the correlation amplitude. Transient removal and temporal flattening are applied instead of 1-bit normalization in order to retain relative amplitudes. The C3 method leads to improved correlation results (higher signal-to-noise ratio and improved time symmetry) compared to simple cross correlations. The C3 functions are rotated from the ZNE to the ZRT system and we focus on Love wave arrivals on the transverse component and on Love wave quality factors QL. The analysis is performed for selected stations being either situated on soft soil or on weathered rock. Phase slowness is extracted using a slant-stack method. Attenuation parameters are inferred by inspecting the relative amplitude decay ofLove waves with increasing interstation distance. We observe that the attenuation coefficient γ and QL can be reliably extracted for stations situated on soft soil whereas the derivation ofattenuation parameters is more problematic for stations that are located on weathered rock. The results are in acceptable conformance with theoretical Love wave attenuation curves that were computed using 1-D shear wave velocity and quality factor profiles from the Euroseistest area.

Description: We describe EnMAP-like imaging spectroscopy data files to be used for mineral mapping with the EnMAPBOX software. It is simulated EnMAP satellite data, which is based on hyperspectral flight cam-paign data with the AVIRIS-NG and HyMap sensors. In preparation of the EnMAP satellite mission, an EnMAPBOX software package provides tools for visualization and scientific analysis of the data. Among many applications, the EnMAPBOX contains geological mapping tools (EnGeoMAP). Here we apply these tools to several representative test cases (Boesche, 2015; Boesche et al., 2016; Mielke et al., 2016). The test data comprise two study sites. The first scene covers the Mountain Pass open pit mine - a carbonatite deposit in California, USA. It contains calcitic rock units and rare earth element (REE) bearing minerals of the bastnaesite group, also called fluorocarbonates (Olson et al., 1954). The REE concentrations at mountain pass are 9.2% on average, among the highest in the world (Brüning and Böhmer, 2011). The high concentration and the open pit activities make Mountain Pass an ideal test site to investigate the rare earth element distribution in the surface layer. The airborne image data were collected in 2014 by Jet Propulsion Laboratory (JPL), USA, with the AVIRIS-NG sensor and form the basis for EnMAP simulations (Segl et al., 2012; Thompson et al., 2015). The second HyMap spectral image data covers part of the Miocene Cabo de Gata-Nίjar volcanic field, in southeast Spain. It comprises a subset of (Chabrillat et al., 2016) covering the Rodalquilar and Lomilla Calderas, which host the economically relevant gold-silver, lead-zinc-silver-gold and alunite deposits. It is a hydrothermal alteration complex, representing the silicic alteration, the advanced argillic alter-ation zone, which grades into the argillic and propylitic zone (Arribas et al., 1995, 1989). The image data are part of the Cabo de Gata-Nίjar HyMap imagery which was collected during the DLR HyEurope airborne campaign 2005 in the frame of the GFZ land degradation program (Chabrillat et al., 2016, 2005). We use these datasets to simulate EnMAP-like images for classification and mapping using spectro-scopic remote sensing techniques in the EnGeoMAP tools. The EnMAP end-to-end Simulation (EeteS) tool produced simulated EnMAP like data with a spatial sampling distance of 30 x 30 m and 242 spectral bands (Guanter et al., 2015; Segl et al., 2012).

Description: The worlds 30 largest rivers represent half of the total runoff to the ocean and thus integrate the fluxes of Earth surface weathering and erosion over a large portion of global tectonic, geomorphic, and climatic zones. In-situ produced cosmogenic nuclides (10Be, 26Al) in detrital quartz sand can be used to constrain the mean millennial-scale denudation of these large basins. Yet cosmogenic nuclides have mostly been applied to small and intermediate size basins of significant relief. One reason is that in these settings, lowland sediment storage and burial are short compared to the half life of the nuclide (e.g. 1.4 Myr for 10Be). However, if sediment storage is long compared to the half-life, paired nuclides (e.g. 26Al/10Be), through their differential decay, allow to assess the duration of sediment transfer and burial ages from source to sink[1]. Here we present a new dataset of cosmogenic nuclides from 60 large rivers that integrate over ~30% of Earth’s terrestrial surface. 26Al/10Be ratios of around 6 to 7.5 for most rivers reveal burial durations shorter than the nuclides’ decay time scales, indicating high source-sink connectivity. In slowly-eroding basins such as the tectonically quiescent Australian Murray-Darling or the central African Okavango and Congo rivers, 26Al/10Be ratios of 〈6 indicate decay of nuclide concentrations. Such low nuclide ratios evolve during Myr-scale sediment burial during slow source to sink transfer. We converted denudation rates to sediment fluxes by estimating their actively eroding source areas. Extrapolating these millennial-scale sediment fluxes to global source areas provides an estimate of the global sediment flux. The comparison with estimates of modern sediment fluxes from river load gauging offers to deciphering the controls of sediment generation versus sediment transport across large basins.

Description: Deciphering the response of sediment routing systems to climatic forcing is fundamental for understanding theimpacts of climate change on landscape evolution and depositional systems. In the Sub-Himalaya, late Pleistoceneto Holocene alluvial fills and fluvial terraces record periodic fluctuations of sediment supply and transport capacityon timescale of 103to 105years, most likely related to past climatic fluctuations. To evaluate the climatic controlon sediment supply and transport capacity, we analyze remnant alluvial fans and terraces in the Kangra Basin ofthe northwestern Sub-Himalaya.Based on field observations and OSL and CRN-dating, we recognized two sedimentary cycles with ma-jor sediment aggradation and subsequent re-incision phases. The large one developed over the entire last glacialperiod with∼200 m high alluvial fan (AF1) and the second one during the latest Pleistocene/Holocene with∼50m alluvial fan (AF2) and its re-incision . Surface-exposure dating of six terrace levels with in-situ cosmogenic nu-clides (10Be) indicates the onset of channel abandonment and ensuing incision phases. Two terrace surfaces fromthe highest level (T1) sculpted into the oldest-preserved AF1 dates back to 48.9±4.1 ka and 42.1±2.7 ka (2σerror). T2 surfaces sculpted into the remnants of AF1 have exposure ages of 16.8±2 ka and 14.1±0.9 ka, whileterraces sculpted into the late Pleistocene- Holocene fan (AF2) provide ages of 8.4±0.8 ka, 6.6±0.7 ka, 4.9±0.4 ka and 3.1±0.3 ka. Together with previously-published ages on the timing of aggradation, we find a correla-tion between variations in sediment transport with oxygen-isotope records from regions affected by Indian SummerMonsoon. During stronger monsoon phases and post-LGM glacial retreat manifested by increased sediment de-livery (moraines and hillslope-derived) to the trunk streams, causing aggradation in the basin; whereas, weakenedmonsoon phases characterized by reduced sediment-delivery from the hillslope or moraines resulted into inci-sion of the transiently-stored sediments. Sediment cycles in the Kangra Basin are largely synchronous with thosedocumented from other NW Himalayan valleys.

Description: A temporary seismic array was installed in combination with a meteorological station in the Dead Sea valley, Jordan. Within the scope of the HGF virtual institute DESERVE we operated 15 temporary seismic stations between February 2014 and February 2015 together with a nearby meteorological station close to the east coast of the Dead Sea. The main aim was to acquire data to study the influence of wind on seismic records and retrieve related meteorological parameters. The study area is scarcely populated and has ideal meteorological conditions to study periodically occurring winds.

Description: Bei phreatischen Eruptionen fehlen häufig warnende Vorzeichen. Der plötzliche Ausbruch des japanischen Vulkans Ontake im Herbst 2014 traf viele unvorbereitet.

Description: Phreatic eruptions often occur without any forewarning. Many were unprepared for the sudden eruption of Ontake volcano, Japan in autumn 2014.

Description: In a chaotic system such as the Earth’s atmosphere, the differences between the members in an ensemble of global climate model simulations launched from different initial conditions initially grow in time until they reach the level of natural variability, indicating that member simulations become uncorrelated. In nested Regional Climate Models (RCMs), however, the growth of inter-member differences is quenched due to the control exerted by the lateral boundary conditions (LBCs), but it nevertheless exhibits episodes of large fluctuations. Earlier work has speculated that this puzzling behaviour may simply reflect remaining chaos allowed by the incomplete control exerted by LBC. In this work, two large ensembles of twenty simulations were performed over an Arctic domain with two different RCMs: the Canadian RCM (CRCM5) and the High-Resolution Limited-Area Model (HIRHAM5). The inter-member variability (IV) of each ensemble was methodically analysed in the framework of the potential temperature IV budget. The study reveals that, despite being simulated by models with entirely different formulation, the two ensembles exhibit nearly identical IV patterns and time evolution, and in both cases baroclinic processes trigger fluctuations of IV. These results confirm earlier speculations that IV in RCMs is not an artefact of specific model nesting technique, but rather a natural phenomenon arising from the chaotic nature of the atmosphere.

Description: Wird mit einem globalen Klimamodell ein Ensemble mit unterschiedlichen Anfangsbedingungen generiert, dann führt dies aufgrund des chaotischen Verhaltens der Atmosphäre dazu, dass die Differenzen zwischen den Ensemblemitgliedern mit der Zeit anwachsen, bis ein Zustand entsprechend der natürlichen Variabilität erreicht ist. Dies führt zu Simulationen, die sich zueinander unkorreliert verhalten. In genesteten regionalen Klimamodellen (RCM) ist das Anwachsen der Variabilität zwischen den Ensemblemitgliedern aufgrund der äußeren Randbedingungen (LBC) gedämpft. Dennoch können Episoden mit starken Schwankungen der Variabilität zwischen den Ensemblemitgliedern auftreten. In früheren Studien wird die Vermutung geäußert, dass dieses rätselhafte Verhalten durch mangelhafte LBC und das damit zusammenhängende verbleibende Chaos initiiert wird. In dieser Arbeit werden zwei große Ensemble mit je 20 Ensemblemitgliedern über der Arktis mit zwei verschiedenen RCMs erzeugt: dem kanadischen RCM (CRCM5) und dem „High-Resolution Limited-Area Model“ (HIRHAM5). Für diese Ensemble wird die Variabilität zwischen den Ensemblemitgliedern (inter-member Variability; IV) mit Hilfe einer IV Budgetstudie für die potentielle Temperatur analysiert. Die Studie ergab, dass trotz der sehr unterschiedlichen Modellformulierungen die räumlichen Muster und die zeitliche Entwicklung der IV in beiden RCM Ensembles sehr ähnlich sind. Außerdem werden in beiden Fällen die Schwankungen der IV durch barokline Prozesse ausgelöst. Diese Ergebnisse bestätigen die früheren Vermutungen, dass die IV in RCMs nicht durch die Nestingmethode bedingt, sondern eher ein natürliches Phänomen ist, dessen Ursache in der chaotischen Natur der Atmosphäre liegt.

Description: There is a long‐standing debate over how many and what types of plumes underlie the East African Rift and whether they do or do not drive its extension and consequent magmatism and seismicity. Here we present a new tomographic study of relative teleseismic S and SKS residuals that expands the resolution from previous regional studies below the northern East African Rift to image structure from the surface to the base of the transition zone. The images reveal two low‐velocity clusters, below Afar and west of the Main Ethiopian Rift, that extend throughout the upper mantle and comprise several smaller‐scale (about 100 km diameter), low‐velocity features. These structures support those of our recent P tomographic study below the region. The relative magnitude of S to P residuals is around 3.5, which is consistent with a predominantly thermal nature of the anomalies. The S and P velocity anomalies in the low‐velocity clusters can be explained by similar excess temperatures in the range of 100–200°C, consistent with temperatures inferred from other seismic, geochemical, and petrological studies. Somewhat stronger VS anomalies below Afar than west of the Main Ethiopian Rift may include an expression of volatiles and/or melt in this region. These results, together with a comparison with previous larger‐scale tomographic models, indicate that these structures are likely small‐scale upwellings with mild excess temperatures, rising from a regional thermal boundary layer at the base of the upper mantle.

Description: The data from seismic stations of the Arkhangelsk network and the networks in the neighboring territories are analyzed for refining the focal parameters of the tectonic earthquakes recorded in the north of the Russian plate on October 22, 2005 (M = 2.9) and March 28, 2013 (M = 3.4). The epicenters of the earthquakes are confined to the large NW–SE striking faults which border the Arkhangelsk bulge starting from the Kara–Pinega rift in the northeast and Onega–Kandalaksha paleorift in the southwest. The calculated focal mechanism of the earthquake of March 28, 2013 agrees with the distribution of neotectonic stresses characteristic of the north of the Russian plate, and specifically, with the submeridional compression and sublatitudinal extension.

Description: Bed load fluxes are typically calculated as a function of the reach averaged boundary shear stress and a representative bed grain size distribution. In steep, rough channels, heterogeneous bed surface texture and macro-roughness elements cause significant local deviations from the mean shear stress but this variability is often omitted in bed load calculations. Here we present a probabilistic bed load transport formulation that explicitly includes local variations in the flow field and grain size distribution. The model is then tested in a 10% gradient stream, to evaluate its predictive capability and to explore relations between surface grain size sorting and boundary shear stress. The boundary shear stress field, calculated using a quasi-3D hydraulic model, displayed substantial variability between patch classes, but the patch mean dimensionless shear stress varied inversely with patch median grain size. We developed an empirical relation between the applied shear stress on each patch class and the reach averaged shear stress and median grain size. Predicted sediment volumes using this relation in our bed load equation were as accurate as those using complete shear stress distributions and more accurate than current bed load transport equations. Our results suggest that when spatially variable grain size distributions (e.g., patches of sediment) are present they must be explicitly included in bed load transport calculations. Spatial variability in shear stress was relatively more important than grain size variations for sediment transport predictions.

Description: Abstract data objects are frequently transferred between a central computer (server) and one or more other computers (clients). The httpmsgbus (HMB) facilitates the transfer of these objects, functioning as a messaging service which runs over HTTP. These may be SeisComP data model items, or any other content. Messages sent by one client can be received by multiple clients connected to the same bus, using JSON and BSON formats for communication. Clients may limit what objects they wish to receive as part of the connection process. A bus may have multiple queues. Order of messages within a queue is preserved. A queue may have multiple topics; topic name is simply an attribute of a message. A receiving client subscribes to one or more queues and tells which topics it is interested in. Each message within a queue has a sequence number, so it is possible to resume connection without data loss, provided that the needed messages are still in the queue. A client can also select messages based on start- and end-time, and filter messages using a subset of MongoDB query language. HMB supports out-of-order messages by letting a sending client specify the sequence number when sending messages. Messages are received in order; a receiving client may ignore out-of-order messages or wait for missing messages until a timeout. httpmsgbus can be used as a standalone program or as an add-on to SeisComP 3 [1]; the code can be copied to SC3 source tree and compiled together with the rest of the SC3 using CMake or installed separately using the install.sh script. Go compiler [2] is required to compile the code; other requirements include Libpcre (pcre-devel, libpcre3-dev or similar Linux package), and Mongo DB for persistent storage. Source code is freely available for download; its use is governed by the GNU General Public License, version 3.

Description: The composition, structure and function of granules formed during process recovery with calcium oxide in a laboratory-scale fermenter fed with sewage sludge and rapeseed oil were studied. In the course of over-acidification and successful process recovery, only minor changes were observed in the bacterial community of the digestate, while granules appeared during recovery. Fluorescence microscopic analysis of the granules showed a close spatial relationship between calcium and oil and/or long chain fatty acids. This finding further substantiated the hypothesis that calcium precipitated with carbon of organic origin and reduced the negative effects of overloading with oil. Furthermore, the enrichment of phosphate minerals in the granules was shown, and molecular biological analyses detected polyphosphate-accumulating organisms as well as methanogenic archaea in the core. Organisms related to Methanoculleus receptaculi were detected in the inner zones of a granule, whereas they were present in the digestate only after process recovery. This finding indicated more favorable microhabitats inside the granules that supported process recovery. Thus, the granule formation triggered by calcium oxide addition served as a tool to influence the composition of the microbial community and to stabilize the process after overloading with oil.

Description: The Magnetotelluric (MT) method uses time variations of the Earth’s magnetic field which induce electrical currents in the conductive Earth [Simpson and Bahr, 2005; Chave and Jones, 2012; Viljanen, 2012]. By means of the relation between the resulting horizontal magnetic and electric fields one can estimate the conductivity as a function of spatial position. Electromagnetic fluctuations with periods higher than 1 s are caused by the interaction of the solar wind and the Earth’s magnetosphere and ionosphere. The fluctuations depend on variations in density, velocity and magnetic field intensity of the solar wind, whereupon the largest geomagnetic field variations occur during so called magnetic storms. Hereby an enhanced ring current is formed by ions and electrons located between 3–8RE. Variations of the magnetic fields caused by the dynamic variations of space plasma are defined as signal, whereas the fluctuations originated from artificial sources are termed as electromagnetic noise, since often they are undesired signals violating the plane wave assumption. Quiet geomagnetic periods are characterized by a low signal level which can lead to the degradation of response quality due to the increased uncertainty on spectral estimates. By means of MT data recorded during a field work in the Central Pyrenees we show how a time period of geomagnetic activity influences the horizontal magnetic fields and can dramatically improve the quality of impedances.

Description: In this study we report the structure of supercritical H2O–SiO2 fluid composed of 50 mol% H2O and 50 mol% SiO2 at 3000 K and 2400 K, investigated by means of ab initio molecular dynamics of models comprising 192 and 96 atoms. The density is set constant to 1.88 g/cm 3, which yields a pressure of 4.3 GPa at 3000 K and 3.6 GPa at 2400 K. Throughout the trajectories, water molecules are formed and dissociated via the network modifying reaction 2 SiOH = SiOSi + H2O. The calculation of the reaction constant K = [OH-]2/[H2O][O2-] is carried out on the basis of the experimentally relevant Qn species notation and agrees well with an extrapolation of experimental data to 3000 K. After quench from 3000 K to 2400 K, the degree of polymerization of the silicate network in the 192-atom models increases noticeably within several tens of picoseconds, accompanied by release of molecular H2O. An unexpected opposite trend is observed in smaller 96-atom models, due to a finite size effect, as several uncorrelated models of 192 and 96 atoms indicate. The temperature-dependent slowing down of the H2O–silica interaction dynamics is described on the basis of the bond autocorrelation function.

Description: We report the design, fabrication and application of a novel micro-electromechanical device coupled to a confocal Raman microscope that enables in situ molecular investigations of micro-fibers under uniaxial tensile load. This device allows for the mechanical study of micro-fibers with diameters in the range between 10 and 100 μm and lengths of several hundred micrometers. By exerting forces in the mN range, the device enables an important force range to be accessed between that of atomic force microscopy and macroscopic stress-strain measurement devices. The load is varied using a stiffness-calibrated glass micro-needle driven by a piezo-translator during simultaneous Raman microscopy imaging. The method enables experiments probing the molecular response of micro-fibers to external stress. This set-up was applied to biomimetic non-mineralized and mineralized collagen micro-fibers revealing that above 30% mineralization the proline-related Raman band shows a pronounced response to stress, which is not observed in non-mineralized collagen. This molecular response coincides with a strong increase in the Young’s modulus from 0.5 to 6 GPa for 0% and 70% mineralized collagen, respectively. Our results are consistent with a progressive interlocking of the collagen triple-helices by apatite nanocrystals as the degree of mineralization increases.

Description: The scope of the Science Plan is to describe the scientific background, applications, and activities related to the Environmental Mapping and Analysis Program (EnMAP) mission. Primarily, the document addresses scientists and funding institutions, but it may also be of interest for environmental stakeholders and governmental bodies. It is conceived to be a living document that will be updated throughout the entire mission. Chapter 1 provides a brief overview of the principles and current state of imaging spectroscopy. This is followed by an introduction to the EnMAP mission, including its objectives and potential impact on international programs as well as major environmental and societal challenges to their understanding and management EnMAP can contribute. Chapter 2 describes the EnMAP system together with data products and access, calibration/validation issues, and synergies with other missions. Chapter 3 gives an overview of the relevance, current lines of research, and potential contributions of EnMAP for major fields of application, such as vegetation, geology and soils, coastal and inland waters, cryosphere, urban areas, atmosphere and hazards to address the environmental and societal challenges presented in Chapter 1. Finally, Chapter 4 outlines the scientific exploitation strategy, which includes the strategy for community building and training, preparatory flight campaigns and software developments. A list of abbreviations is provided in the annex to this document, while an extended glossary of terms and abbreviations is available at the EnMAP website.

Description: The inner core boundary (ICB), where melting and solidification of the core occur, plays a crucial role in the dynamics of the Earth's interior. To probe temporal changes near the ICB beneath the eastern hemisphere, I analyze differential times of PKiKP (dt(PKiKP)), double differential times of PKiKP‐PKPdf, and PKiKP coda waves from repeating earthquakes in the southwest Pacific subduction zones. dt(PKiKP) values are mostly within ±30 ms of one another, without systematic temporal dependence. Some observations of PKiKP coda waves have absolute time shifts of 〉50 ms relative to their main phases. The combination of temporal changes in PKiKP coda arrivals and negligible changes in PKiKP arrivals favors a smooth ICB with fine‐scale structures in the upper inner core. dt(PKiKP) values are interpreted in the context of melting‐ or growth‐induced ICB topography, based on dynamic models. Uncertainties in dt(PKiKP) prevent verification of ICB melting or growth on decadal time scales.

Description: Understanding and quantification of phosphorus (P) fluxes are key requirements for predictions of future forest ecosystems changes as well as for transferring lessons learned from natural ecosystems to croplands and plantations. This review summarizes and evaluates the recent knowledge on mechanisms, magnitude, and relevance by which dissolved and colloidal inorganic and organic P forms can be translocated within or exported from forest ecosystems. Attention is paid to hydrological pathways of P losses at the soil profile and landscape scales, and the subsequent influence of P on aquatic ecosystems. New (unpublished) data from the German Priority Program 1685 “Ecosystem Nutrition: Forest Strategies for limited Phosphorus Resources” were added to provide up-to-date flux-based information. Nitrogen (N) additions increase the release of water-transportable P forms. Most P found in percolates and pore waters belongs to the so-called dissolved organic P (DOP) fractions, rich in orthophosphate-monoesters and also containing some orthophosphate-diesters. Total solution P concentrations range from ca. 1 to 400 µg P L−1, with large variations among forest stands. Recent sophisticated analyses revealed that large portions of the DOP in forest stream water can comprise natural nanoparticles and fine colloids which under extreme conditions may account for 40–100% of the P losses. Their translocation within preferential flow passes may be rapid, mediated by storm events. The potential total P loss through leaching into subsoils and with streams was found to be less than 50 mg P m−2 a−1, suggesting effects on ecosystems at centennial to millennium scale. All current data are based on selected snapshots only. Quantitative measurements of P fluxes in temperate forest systems are nearly absent in the literature, probably due to main research focus on the C and N cycles. Therefore, we lack complete ecosystem-based assessments of dissolved and colloidal P fluxes within and from temperate forest Systems.

Description: Mit der Modernisierung von GPS (Global Positioning System), Wiederherstellung von GLONASS (das russische Global Navigation Satellite System) und neu entstehende Konstellationen, wie das chinesische Beidou und dem europäischen Galileo-System, die Welt der Global Navigation Satellite Systems (GNSS) hat im Bereich der Multi-Konstellation GNSSerfahrendedramatische Veränderungen.Die schnelle Entwicklung des aktuellen GNSS Konstellation bringt eine vielversprechende Perspektive für die Echtzeit-Abfrage von der troposphärische Verzögerungsparameter wie Gesamtverzögerung im Zenit (ZTD) und niederschlagbarer Wasserdampf (PWV), die für die Unterstützung der zeitkritischen meteorologische Anwendungen von großem Nutzen ist wie Nowcasting oder Unwetter-Überwachung. Mit der schnelle Entwicklung des bestehenden GNSS und die Echtzeit-PPP (genaue Punkt-Positionierung) Technik, das Ziel dieser Arbeit ist es, eine Echtzeit-GNSS-PPP-Verarbeitung für zeitkritische meteorologische Anwendungen zu entwickeln. Die Kernforschung und die Beiträge dieser Arbeit sind wie folgt zusammengefasst: Wir entwickeln eine Echtzeit-ZTD/PWV-Verarbeitung basierend auf den Beobachtungen aus dem individuellen System: GPS, GLONASS und BeiDou. Die Leistung von ZTD und PWV, die von jedem System unter Verwendung von Echtzeit-PPP-Verfahren abgeleitet werden, wird untersucht. Der Beitrag der Kombination von BeiDou oder GLONASS mit GPS für die ZTD/PWV-Abfrage wird ebenfalls bewertet. Unsere Ergebnisse zeigen, dass die GLONASS ZTD-Zeitreihen insgesamt sehr gut mit der GPS ZTD-Zeitreihe übereinstimmt: Die Effektivwerte der ZTD-Differenzen betragen etwa 8 mm, was 1.2 mm PWV entspricht. Die nur mit BeiDou erzeugte ZTD-Zeitreihen zeigen ebenfalls gute Übereinstimmung mit den GPS: Die Effektivwerte betragen etwa 11-16 mm, entspricht etwa 2-3 mm im PWV. Die Echtzeit-ZTD/PWV aus GPS-einzelne, GLONASS-einzelne, BeiDou-einzelne, GPS/ GLONASS und GPS/BeiDou kombinierten Lösungen werden mit denen aus der Radiointerferometrie auf langen Basislinien (VLBI) und Radiosonden abgeleitet. Die Vergleiche zeigen, dass GLONASS zu echtzeit-meteorologischen Anwendungen mit nahezu der gleichen Genauigkeit wie GPS beitragen kann, ähnlich für BeiDou, die etwas weniger genau als GPS ist. Außerdem können genauere und zuverlässigere Wasserdampf-Schätzwerte erhalten werden, wenn die GLONASS- oder BeiDou-Beobachtungen mit den GPS-Beobachtungen in der Echtzeit-PPP-Datenverarbeitung kombiniert werden, etwa 1.5-2.3 mm in PWV. Außerdem wird ein Multi-GNSS-Modell (GLONASS + GPS + Galileo + BeiDou) zur vollständigen Nutzung aller verfügbaren Beobachtungen aus dem aktuellen GNSS zur Ableitung des Echtzeit-ZTD/PWV basierend auf der Echtzeit-PPP-Verarbeitung angeboten. Beobachtungen von Stationen, die die Multi-Konstellation verfolgen können, werden sowohl im Einzel- als auch im Multi-Systemmodus verarbeitet. Die aus dem einzelnen GNSS und den kombinierten Multi-GNSS-Lösungen abgerufenen ZTD/PWV werden durch Vergleich mit Daten aus den benachbarten Radiosonden-Stationen beurteilt. Das Nutzen der Multi-GNSS-Kombination für die Echtzeit-Wasserdampf-Schätzungen wird bewertet. Die Ergebnisse zeigen, dass eine Genauigkeit auf dem mm-Niveau, d.h. 1.2-1.3 mm, für die Echtzeit-PWV-Schätzungen mit der Multi-GNSS-Verarbeitung erreichbar ist. Die erhaltenen Wasserdampf-Schätzungen mit erhöhter Genauigkeit und Zuverlässigkeit zeigen die möglichen Vorteile der Multi-GNSS-Fusion für atmosphärische Überwachungssysteme, insbesondere für die zeitkritischen meteorologischen Anwendungen. Die troposphärischen horizontalen Gradienten mit hohen räumlich-zeitlichen Auflösungen liefern wichtige Informationen, um die azimutal asymmetrischen Verzögerungen zu beschreiben und die Fähigkeit von bodenbasiertem GNSS im Bereich der meteorologischen Studien signifikant zu erhöhen. Die neue schnelle Entwicklung von Multi-GNSS-Konstellationen hat das Potential, solche hochauflösenden Gradienten mit einem signifikanten Gradienten an Genauigkeit bereitzustellen. Wir entwickeln eine Multi-GNSS-Verarbeitung für die präzise Abfrage hochauflösender troposphärische Gradienten. Die troposphärischen Gradienten mit unterschiedlichen zeitlichen Auflösungen, die sowohl aus Einzelsystem- als auch aus Multi-GNSS-Lösungen gewonnen wurden, werden mit Hilfe von unabhängigen numerischen Wettermodellen (NWM) und Wasserdampfradiometern (WVR) validiert. Die Ergebnisse zeigen, dass die hochauflösenden Multi-GNSS-Gradienten gut mit denen aus dem NWM und dem WVR übereinstimmen, insbesondere für die sich schnell ändernden Spitzen, die meistens mit synoptischen Fronten assoziiert sind. Die Multi-GNSS-Gradienten verhalten sich viel stabiler als die Ein-System-Schätzungen, vor allem in Fällen hoher zeitlicher Auflösung, die von der erhöhten Anzahl beobachteter Satelliten und verbesserter Beobachtungsgeometrie profitieren. Weiterhin kann durch die Multi-GNSS-Fusion auch die Präzision der Stationspositionen merklich verbessert werden, und es lassen sich gesteigerte Ergebnisse erzielen, wenn die hochauflösende Gradientenschätzung statt der üblicherweise verwendeten täglichen Gradientenschätzung in der Multi-GNSS-Datenverarbeitung durchgeführt wird. Die genaue Positionierung mit dem aktuellen BeiDou erweist sich als mit GPS vergleichbar genau, was bei den horizontalen Komponenten und dem Sub-Dezimeter-Niveau für die vertikale Komponente im Zentimeter liegt. Aber das BeiDou-PPP zeigt seine Einschränkung bei der Erfordernis einer relativ langen Konvergenz-Zeit. Somit entwickeln wir einen NWM-erweiterten PPP-Verarbeitungsalgorithmus, um die genaue Positionierung von BeiDou zu verbessern. Troposphärische Verzögerungsparameter, d.h. Verzögerungen im Zenit, Abbildungsfunktionen und horizontale Verzögerungsgradienten, die aus Kurzbereichsprognosen des globalen Prognosesystems (GFS) der nationalen Zentren für Umweltvorhersage (NCEP) abgeleitet sind, werden in BeiDou-Echtzeit-PPP angewendet. Beobachtungsdaten von Stationen, die die BeiDou-Konstellation verfolgen können, werden sowohl mit dem Standard-PPP als auch mit der eingeführten NWM-erweiterten PPP-Verarbeitung verarbeitet. Die Positionierungsergebnisse zeigen, dass mit der NWM-erweiterten PPP-Lösung gegenüber den Standard-PPP-Lösungen eine Verbesserung der Konvergenz-Zeit bis zu 60.0 % bzw. 66.7 % für die Ost- und Vertikal-Komponenten erreicht werden kann, während nur eine geringe Verbesserung der Lösungskonvergenz erreicht für die Nordkomponente gefunden werden kann. Eine Positionierungsgenauigkeit von 2.0 cm für die Nordkomponente wird mit dem NWM-verstärkten PPP erreicht, im Vergleich zu 3.7 cm des Standard-PPP mit einer Verbesserung von 45.9 %. Verglichen mit der Genauigkeit von 5.7 cm für die Ost-Komponente, die von der Standard-PPP-Lösung abgeleitet ist, wird diejenige der NWM-verstärkten PPP-Lösung auf 3.5cm, um etwa 38.6 %, verbessert. Die Positionierungsgenauigkeit für die Up-Komponente verbessert sich von 11.4 cm mit der Standard-PPP-Lösung auf 8.0 cm mit der NWM-verstärkten PPP-Lösung, was einer Verbesserung von 29.8 % entspricht. Eine signifikante Verbesserung der Positionierungsgenauigkeit, Zuverlässigkeit sowie der Konvergenz-Zeit mit der Multi-GNSS-Fusion kann im Vergleich mit der einzelne System-Verarbeitung wie GPS beobachtet werden. In dieser Studie wurde ein NWM erweitert PPP-Verarbeitungssystem entwickelt, um die Multi-GNSS genaue Positionierung zu verbessern. Troposphärische Verzögerungsparameter, die aus der ECMWF-Analyse abgeleitet werden, werden auf das Multi-GNSS-PPP (eine Kombination von vier Systemen: GPS, GLONASS, Galileo und BeiDou) angewendet. Beobachtungen von Stationen aus dem IGS-Multi-GNSS-Experiment (MGEX)-Netzwerk werden verarbeitet, wobei sowohl das Standard-Multi-GNSS-PPP als auch die vorgeschlagene NWM eine mehrfache GNSS-PPP-Verarbeitung unterstützt. Die hohe Qualität und Genauigkeit der von ECMWF abgeleiteten troposphärischen Verzögerungsparameter werden durch Vergleich und Validierung mit den endgültigen troposphärischen IGS-Verzögerungsprodukten demonstriert. Im Vergleich zur Standard-PPP-Lösung wird die Konvergenz-Zeit mit der NWM-erweiterten PPP-Lösung um 20.0 %, 32.0 % bzw. 25.0 % für die Nord-, Ost- und Vertikalkomponenten verkürzt. Die Positionierungsgenauigkeit profitiert auch von der NWM-erweiterten PPP-Lösung, die sich um 2.5 %, 12.1 % bzw. 18.7 % für die Nord-, Ost- und Vertikal-Komponenten verbessert.

Description: With the modernization of GPS (Global Positioning System), recovery of GLONASS (the Russian GLObal NAvigation Satellite System), and newly emerging constellations, like the Chinese BeiDou Navigation Satellite System and the European Galileo system, the world of Global Navigation Satellite Systems (GNSS) has experienced dramatic changes within the field of multi-constellation GNSS. The rapid development of the current GNSS constellation brings a promising prospect for the real-time retrieval of tropospheric delay parameters like zenith total delay (ZTD) and precipitable water vapor (PWV), which is of great benefit for supporting the time-critical meteorological applications such as nowcasting or severe weather event monitoring. With the increasing development of the existing GNSS and the real-time PPP (precise point positioning) technique, the objective of this thesis is to develop a real-time GNSS PPP processing for time-critical meteorological applications. The core research and the contributions of this thesis are summarized as following: We develop a real-time ZTD/PWV processing based on the observations from individual system: GPS, GLONASS, and BeiDou. The performance of ZTD and PWV derived from each system using real-time PPP technique is investigated. The contribution of combining GLONASS or BeiDou with GPS for ZTD/PWV retrieving is evaluated as well. Our results show that the real-time GLONASS ZTD series agree quite well with the GPS ZTD series in general: the root mean square (RMS) values of ZTD differences are about 8 mm, which is equal to 1.2 mm in PWV. The real-time BeiDou-only ZTD series also show good agreement with the GPS-only ones: the RMS values are about 11-16 mm, of about 2-3 mm in PWV. The real-time ZTD/PWV derived from GPS-only, GLONASS-only, BeiDou-only, GPS/GLONASS and GPS/BeiDou combined solutions are compared with those derived from the Very Long Baseline Interferometry (VLBI) and radiosondes. The comparisons show that GLONASS can contribute to real-time meteorological applications, with almost the same accuracy as GPS, similar for BeiDou which is slightly less accurate than GPS. Besides, more accurate and reliable water vapor estimates can be obtained if the GLONASS or BeiDou observations are combined with the GPS observations in the real-time PPP data processing, about 1.5-2.3 mm in PWV. A multi-GNSS (GLONASS+GPS+Galileo+BeiDou) model is also presented to fully exploit all available observations from the current GNSS for deriving the real-time ZTD/PWV based on the real-time PPP processing. Observations from stations capable of tracking the multi-constellation are processed in both single- and multi-system modes. The ZTD/PWV retrieved from the individual GNSS and the combined multi-GNSS solutions are assessed by comparing with data from the nearby radiosonde stations. The benefit of the multi-GNSS combination for real-time water vapor derivation is evaluated. The results show that an accuracy at the mm-level, i.e. 1.2-1.3 mm, for the real-time PWV estimates is achievable with the multi-GNSS processing. The obtained water vapor estimates with enhanced accuracy and reliability reveal the potential benefits of multi-GNSS fusion for atmospheric monitoring systems, in particular for the time-critical meteorological applications. The tropospheric horizontal gradients with high spatiotemporal resolutions provide important information to describe the azimuthally asymmetric delays and significantly increase the ability of ground-based GNSS within the field of meteorological studies. The recent rapid development of multi-GNSS constellations has potential to provide such high-resolution gradients with a significant degree of accuracy. We develop a multi-GNSS processing for the precise retrieval of high-resolution tropospheric gradients. The tropospheric gradients with different temporal resolutions, retrieved from both single-system and multi-GNSS solutions, are validated using independent numerical weather model (NWM) and water vapor radiometer (WVR) data. The benefits of multi-GNSS processing for the retrieval of tropospheric gradients, as well as for the improvement of precise positioning, are demonstrated. The results show that the multi-GNSS high-resolution gradients agree well with those derived from the NWM and WVR, in particular for the fast-changing peaks, which are mostly associated with synoptic fronts. The multi-GNSS gradients behave in a much more stable manner than the single-system estimates, especially in cases of high temporal resolution, benefiting from the increased number of observed satellites and improved observation geometry. Furthermore, the precision of station positions can also be noticeably improved by the multi-GNSS fusion, and enhanced results can be achieved if the high-resolution gradient estimation is performed, instead of the commonly used daily gradient estimation in the multi-GNSS data processing. Precise positioning with the current BeiDou is proven to be of comparable accuracy to GPS, which is at centimeter level for the horizontal components and sub-decimeter level for the vertical component. But the BeiDou PPP shows its limitation in requiring a relatively long convergence time. Thus, we develop a NWM augmented PPP processing algorithm to improve BeiDou precise positioning. Tropospheric delay parameters, i.e., zenith delays, mapping functions, and horizontal delay gradients, derived from short-range forecasts from the Global Forecast System (GFS) of the National Centers for Environmental Prediction (NCEP) are applied into BeiDou real-time PPP. Observational data from stations that are capable of tracking the BeiDou constellation are processed with both the standard PPP and the introduced NWM augmented PPP processing. The positioning results show that an improvement of convergence time up to 60.0 % and 66.7 % for the east and vertical components, respectively, can be achieved with the NWM augmented PPP solution compared to the standard PPP solutions, while only slight improvement of the solution convergence can be found for the north component. A positioning accuracy of 2.0 cm for the north component is achieved with the NWM augmented PPP, in comparison to 3.7 cm of the standard PPP, showing an improvement of 45.9 %. Compared to the accuracy of 5.7 cm for the east component derived from the standard PPP solution, the one of the NWM augmented PPP solution is improved to 3.5 cm, by about 38.6 %. The positioning accuracy for the up component improves from 11.4 cm with the standard PPP solution to 8.0 cm with the NWM augmented PPP solution, an improvement of 29.8 %. Significant improvement on positioning accuracy, reliability, as well as convergence time with the multi-GNSS fusion can be observed in comparison with the single-system processing like GPS. In this study, a NWM augmented PPP processing system is developed to improve the multi-GNSS precise positioning. Tropospheric delay parameters which are derived from the ECMWF analysis are applied to the multi-GNSS PPP (a combination of four systems: GPS, GLONASS, Galileo, and BeiDou). Observations of stations from the IGS Multi-GNSS Experiments (MGEX) network are processed, with both the standard multi-GNSS PPP and the proposed NWM augmented multi-GNSS PPP processing. The high quality and accuracy of the tropospheric delay parameters derived from ECMWF are demonstrated through comparison and validation with the IGS final tropospheric delay products. Compared to the standard PPP solution, the convergence time is shortened by 20.0 %, 32.0 %, and 25.0 % for the north, east, and vertical components, respectively, with the NWM augmented PPP solution. The positioning accuracy also benefits from the NWM augmented PPP solution, which gets improved by 2.5 %, 12.1 %, and 18.7 % for the north, east, and vertical components, respectively.

Description: The mantle transition zone is delineated by seismic discontinuities around 410 and 660 km, which are generally related to mineral phase transitions. Study of the topography of the discontinuities further constrains which phase transitions play a role and, combined with their Clapeyron slopes, what temperature variations occur. Here we use P to S converted seismic waves or receiver functions to study the topography of the mantle seismic discontinuities beneath Europe and the effect of subducting and ponding slabs beneath southern Europe on these features. We combine roughly 28,000 of the highest quality receiver functions into a common conversion point stack. In the topography of the discontinuity around 660 km, we find broadscale depressions of 30 km beneath central Europe and around the Mediterranean. These depressions do not correlate with any topography on the discontinuity around 410 km. Explaining these strong depressions by purely thermal effects on the dissociation of ringwoodite to bridgmanite and periclase requires unrealistically large temperature reductions. Presence of several wt % water in ringwoodite leads to a deeper phase transition, but complementary observations, such as elevated Vp/Vs ratio, attenuation, and electrical conductivity, are not observed beneath central Europe. Our preferred hypothesis is the dissociation of ringwoodite into akimotoite and periclase in cold downwelling slabs at the bottom of the transition zone. The strongly negative Clapeyron slope predicted for the subsequent transition of akimotoite to bridgmanite explains the depression with a temperature reduction of 200–300 K and provides a mechanism to pond slabs in the first place.

Description: We present an analytical approach to compute the curvature effect by the new analytical solutions of coseismic deformation derived for the homogeneous sphere model. We consider two spheres with different radii: one is the same as earth and the other with a larger radius can approximate a half-space model. Then, we calculate the coseismic displacements for the two spheres and define the relative percentage of the displacements as the curvature effect. The near-field curvature effect is defined relative to the maximum coseismic displacement. The results show that the maximum curvature effect is about 4 per cent for source depths of less than 100 km, and about 30 per cent for source depths of less than 600 km. For the far-field curvature effect, we define it relative to the observing point. The curvature effect is extremely large and sometimes exceeds 100 per cent. Moreover, this new approach can be used to estimate any planet's curvature effect quantitatively. For a smaller sphere, such as the Moon, the curvature effect is much larger than that of the Earth, with an inverse ratio to the earth's radius.

Description: Modelling the development of soils in glacier forefields is necessary in order to assess how microbial and geochemical processes interact and shape soil development in response to glacier retreat. Furthermore, such models can help us predict microbial growth and the fate of Arctic soils in an increasingly ice-free future. Here, for the first time, we combined field sampling with laboratory analyses and numerical modelling to investigate microbial community dynamics in oligotrophic proglacial soils in Svalbard. We measured low bacterial growth rates and growth efficiencies (relative to estimates from Alpine glacier forefields) and high sensitivity of bacterial growth rates to soil temperature (relative to temperate soils). We used these laboratory measurements to inform parameter values in a new numerical model and significantly refined predictions of microbial and biogeochemical dynamics of soil development over a period of roughly 120 years. The model predicted the observed accumulation of autotrophic and heterotrophic biomass. Genomic data indicated that initial microbial communities were dominated by bacteria derived from the glacial environment, whereas older soils hosted a mixed community of autotrophic and heterotrophic bacteria. This finding was simulated by the numerical model, which showed that active microbial communities play key roles in fixing and recycling carbon and nutrients. We also demonstrated the role of allochthonous carbon and microbial necromass in sustaining a pool of organic material, despite high heterotrophic activity in older soils. This combined field, laboratory, and modelling approach demonstrates the value of integrated model–data studies to understand and quantify the functioning of the microbial community in an emerging High Arctic soil ecosystem.

Description: In this study we analyse eddy-covariance flux measurements of carbon dioxide and water vapour from 18 years at Waldstein-Weidenbrunnen (DE-Bay), a Norway spruce forest site in the Fichtelgebirge, Germany. Standard flux partitioning algorithms have been applied for separation of net ecosystem exchange NEE into gross ecosystem uptake GEE and ecosystem respiration Reco, and gap-filling. The annual NEE shows a positive trend, which is related to a strong increase in GEE, while Reco enhances slightly. Annual evapotranspiration increases as well, while atmospheric demand, i.e. potential evapotranspiration, shows inter-annual variability, but no trend. Comparisons with studies from other warm temperate needle-leaved forests show, that NEE is at the upper range of the distribution, and evapotranspiration in Budyko space is in a similar range, but with a large inter-annual variability. While this trends are generally in agreement with findings from other locations and expectations to climate change, the specific history at this site clearly has a large impact on the results: The forest was in the first years very much affected due to forest decline and convalesced after a liming. In the last ten years the site was much affected by beetles and windthrow. Thus the more recent positive trends may be related to increased heterogeneity at the site. As FLUXNET stations, built 10-20 years ago, often started with “ideal forest sites”, increasing heterogeneity might be a more general problem for trend analysis of long-term data sets.

Description: Stable metal (e.g. Li, Mg, Ca, Fe, Cu, Zn, and Mo) and metalloid (B, Si, Ge) isotope ratio systems have emerged as geochemical tracers to fingerprint distinct physicochemical reactions. These systems are relevant to many Earth Science questions. The benefit of in situ microscale analysis using laser ablation (LA) over bulk sample analysis is to use the spatial context of different phases in the solid sample to disclose the processes that govern their chemical and isotopic compositions. However, there is a lack of in situ analytical routines to obtain a samples' stable isotope ratio together with its chemical composition. Here, we evaluate two novel analytical routines for the simultaneous determination of the chemical and Si stable isotope composition (δ30Si) on the micrometre scale in geological samples. In both routines, multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) is combined with femtosecond-LA, where stable isotope ratios are corrected for mass bias using standard-sample-bracketing with matrix-independent calibration. The first method is based on laser ablation split stream (LASS), where the laser aerosol is split and introduced simultaneously into both the MC-ICP-MS and a quadrupole ICP-MS. The second method is based on optical emission spectroscopy using direct observation of the MC-ICP-MS plasma (LA-MC-ICP-MS|OES). Both methods are evaluated using international geological reference materials. Accurate and precise Si isotope ratios were obtained with an uncertainty typically better than 0.23‰, 2SD, δ30Si. With both methods major element concentrations (e.g., Na, Al, Si, Mg, Ca) can be simultaneously determined. However, LASS-ICP-MS is superior over LA-MC-ICP-MS|OES, which is limited by its lower sensitivity. Moreover, LASS-ICP-MS offers trace element analysis down to the μg g−1-range for more than 28 elements due to lower limits of detection, and with typical uncertainties better than 15%. For in situ simultaneous stable isotope measurement and chemical composition analysis LASS-ICP-MS in combination with MC-ICP-MS is the method of choice.

Description: Coloured Dissolved Organic Matter (CDOM) is one of the major light absorbing constituents in freshwaters. Supplied from degradation of components of the aquatic environment, it consists mainly of humic substances and its concentration is strongly related to primary production, often associated to macrophytes. It plays a central role in several biological and chemical processes affecting the bioavailability of nutrients in aquatic ecosystems. Therefore CDOM can be regarded as a water quality indicator. We used the spectral absorption and spectral slope for understanding CDOM dynamics in surface reservoirs in the Brazilian semiarid region. The analysis was based on water samples collected in three reservoirs in a total of ten sampling locations in the period June 2014 to November 2015 with monthly to bi-monthly intervals totaling 120 samples. The collected water samples were filtered through cellulose acetate membrane filters. Subsequently, spectral absorbance was measured in a Lambda 950 UV-VIS spectrometer in the spectral range 250 to 800 nm using a quartz cuvette with 5 cm optical path. From the absorbance measurement, we obtained CDOM content using the specific absorption coefficient at 440nm as well as spectral slope. The average slope for the entire period for all reservoirs is 0,018, but we found a considerable increase in spectral slope values after the wet period (between February 2014 and June 2014) for the reservoirs São Nicolau and Paus Branco while Marengo reservoir showed only slight variations during this period, but exhibited an increase only in the dry period. Regarding aCDOM(440), the average was equal to 2,55 for Marengo, 5,70 for São Nicolau, and 3,53 for Paus Branco reservoir indicating different characteristics of these reservoirs.We noticed a decrease in the absorption coefficient for São Nicolau and Paus Branco reservoirs at the end of the wet period whereas for Marengo reservoir this value showed a different behavior. Spectral slope and spectral absorption seem consistent and, among other possible factors, its dynamics were affected by high evaporation and low precipitation, typical conditions for semiarid regions in the tropics. The results show also evidence of the hysteresis phenomenon related to humic substance properties. However, it is important to consider also other water quality parameters in order to assess the whole interaction occurring in the reservoirs under eutrophic conditions. This is a first study of the application of spectral absorption and spectral slope of CDOM for small reservoirs in semiarid Brazil providing additional information to the traditional water quality measurements. In the future, we plan to relate the in-situ measurements to satellite imagery to study spatio-temporal water quality dynamics and relate them to land use changes.

Description: The 8–28 December 2013 Mw 5.0–5.8 Antalya Basin earthquake sequence in eastern Mediterranean is examined. Centroid moment tensors for 16 earthquakes with moment magnitudes (Mw) between 3.6 and 5.8 are determined by applying a waveform inversion method. All earthquakes are shallow focus thrust events at a depth of 40–45 km. The seismic moments (Mo) of the earthquakes are estimated as 4.10 × 1016–5.54 × 1017 N m and rupture durations of the mainshocks are 20–22 s. The focal mechanisms of the aftershocks are mainly thrust faulting with a strike-slip component and reveal NW–SE trending direction of T-axis in the entire activated region. According to high-resolution hypocenter relocation of the Antalya earthquake sequence, seven main clusters are revealed. The aftershock activity in the observation period between 1 December 2013 and 23 January 2015 extends in an N to S direction. A seismic cross-section indicates that a complex pattern of the hypocenter distribution with the activation of seven segments. The westernmost cluster (cluster 1) is associated with a fault plane trending mainly WNW–ESE and dipping vertical, while the cluster 5 is related to a fault plane trending NNE–SSW and dipping towards SSE. The best constrained focal depths indicate that the aftershock sequence is mainly confined in the crust (depth 〈 40 km) and are operating in the approximate depth range from 3 to 110 km. A stress tensor inversion of focal mechanism data is performed to obtain a more precise picture of the Antalya Basin stress field. The stress tensor inversion results indicate a predominant thrust stress regime with a NE–SW oriented maximum horizontal compressive stress (SH). According to variance of the stress tensor inversion, to first order, the Antalya Basin is characterized by a homogeneous interplate stress field. The Coulomb stress change associated with two mainshocks are also investigated to evaluate any significant enhancement of stresses along the Antalya Basin and surrounding regions. Positive lobes with stress of more than 0.4 bars are obtained for two mainshocks, indicating that these values are large enough to increase the Coulomb stress failure towards NE–SW and NW–SE directions, respectively.

Description: We present a deep electrical resistivity image from the passive continental margin in Namibia. The approximately 700 km long magnetotelluric profile follows the Walvis Ridge offshore, continues onshore across the Kaoko Mobile Belt and reaches onto the Congo Craton. Two-dimensional inversion reveals moderately resistive material offshore, atypically low for oceanic lithosphere, reaching depths of 15–20 km. Such moderate resistivities are consistent with seismic P wave velocity models, which suggest up to 35 km thick crust. The Neoproterozoic rocks of the Kaoko Mobile Belt are resistive, but NNW-striking major shear-zones are imaged as subvertical, conductive structures in the upper and middle crust. Since the geophysical imprint of the shear zones is intact, opening of the South Atlantic in the Cretaceous did not alter the middle crust. The transition into the cratonic region coincides with a deepening of the high-resistive material to depths of more than 60 km.

Description: The International Continental Scientific Drilling Program (ICDP) performed a dual-phase scientific drilling project to investigate mountain-building processes called Collisional Orogeny in the Scandinavian Caledonides (COSC). The borehole COSC-1 was drilled through the Lower Seve Nappe, as the first of two 2.5 km deep drill holes close to Åre, central Sweden. The recovered rocks comprise a 1650 m thick suite of high grade gneisses and amphibolites with clear Seve Nappe affinities, while the lower 850 m comprise rather homogenous mylonitic gneisses with interfingered K-rich phyllonite bands of cm to several m size and some intercalated amphibolites. The different lithologies all crosscut the core in a subhorizontal direction with foliation of gneisses and phyllonites in the same direction. Albite and garnet porphyroblasts with pressure shadows show syn-deformational growth and the same sub-horizontal alignment. The focus of this study was to detect chemical and mineralogical differences in mylonitic and host rocks and to relate these differences to either metasomatism and deformation or inherited source rock variance. Another goal of this work is to compare chemical core scanning instruments. For this purpose two different X-Ray Fluorescence (XRF) techniques, Laser Induced Breakdown Spectroscopy (LIBS) and hyperspectral imaging served to measure seven samples from the lower 850 m of the COSC-1 core. This data publication comprises the datasets gained in the course of this study. The metadata (OF WHAT?) will be presented in an additional file including XRF data from the Avaatech XRF core scanner in a txt.file as well as datasets of the other used devices in original file formats.

Description: In this paper, we discuss the scientific whether and clustering of time series based on RQA measures leads to an interpretable clustering structure when analyzed by human experts. We are not aware of studies answering this scientific question. Answering it is the crucial first step in the development of a Visual Analytics approach that support users to explore large sets of time series.

Description: The tectonic configuration of the Banda region in southeast Asia captures the spatial transition from subduction of Indian Ocean lithosphere to subduction and collision of the Australian continental lithosphere beneath the Banda Arc. An ongoing broadband seismic deployment funded by NSF is aimed at better understanding the mantle and lithospheric structure in the region and the relationship of the arc–continent collision to orogenesis. Here, we present results from ambient noise tomography in the region utilizing this temporary deployment of 30 broadband instruments and 39 permanent stations in Indonesia, Timor Leste, and Australia. We measure dispersion curves for over 21,000 inter-station paths resulting in good recovery of the velocity structure of the crust and upper mantle beneath the Savu Sea, Timor Leste, and the Nusa Tenggara Timur (NTT) region of Indonesia. The resulting three dimensional model indicates up to ∼25% variation in shear velocity throughout the plate boundary region; first-order velocity anomalies are associated with the subducting oceanic lithosphere, subducted Australian continental lithosphere, obducted oceanic sediments forming the core of the island of Timor, and high velocity anomalies in the Savu Sea and Sumba. The structure in Sumba and the Savu Sea is consistent with an uplifting forearc sliver. Beneath the island of Timor, we confirm earlier inferences of pervasive crustal duplexing from surface mapping, and establish a link to underlying structural features in the lowermost crust and uppermost mantle that drive upper crustal shortening. Finally, our images of the volcanic arc under Flores, Wetar, and Alor show high velocity structures of the Banda Terrane, but also a clear low velocity anomaly at the transition between subduction of oceanic and continental lithosphere. Given that the footprint of the Banda Terrane has previously been poorly defined, this model provides important constraints on tectonic reconstructions that formerly have lacked information on the lower crust and uppermost mantle.

Description: The experiments are performed down the Edward Bailey valley, in the Renland peninsula, Scoresby Sund, Greenland. General purpose: ambient seismic noise recordings are obtained to characterize the geometry/structure of the valley the geometry/structure of the glaciers the microseismicity of the glacier, the friction process, crack orientation and mechanisms the seismic activity of glacial rivers, the relation between hydrological flow and noise spectrum the localization and characterization of sub-glacial flow from surface recordings. Seismic stations were composed of 3C broadband Trillium compact seismometer, a Cube datalogger and a 12V (D-cell types, stacked) battery pack.The experiment splits into three surveys performed at three different sites, one after the other, from july to august 2016. In the first experiment, we deploy 11 stations, 9 of them on a flat sandy area covering, partly, immobile ice that seems to be blocked between the Bailey Glacier (upstream) and the Apusinikajik glacier (downstream). The 9 sensors are placed a few hundreds of meters from the Apusinikajik lateral front, the last 2 are placed on the glacier next to the collapsing front. In the second and third experiment (chronologically speaking), we deploy 10 and 8 stations, respectively. Each deployment is performed along a Bailey valley transect. The first one intercepts the front-end of the glacier and the sub-glacial river exit (flow of several m3/s). The second transect is performed some 850m upstream. Waveform data are available from the GEOFON data centre, under network code 3H, and are embargoed until summer of 2019.

Description: We present new experimental data of the low-temperature metastable region of liquid water derived from high-density synthetic fluid inclusions (996–916 kg m−3) in quartz. Microthermometric measurements include: (i) prograde (upon heating) and retrograde (upon cooling) liquid–vapour homogenisation. We used single ultrashort laser pulses to stimulate vapour bubble nucleation in initially monophase liquid inclusions. Water densities were calculated based on prograde homogenisation temperatures using the IAPWS-95 formulation. We found retrograde liquid–vapour homogenisation temperatures in excellent agreement with IAPWS-95. (ii) Retrograde ice nucleation. Raman spectroscopy was used to determine the nucleation of ice in the absence of the vapour bubble. Our ice nucleation data in the doubly metastable region are inconsistent with the low-temperature trend of the spinodal predicted by IAPWS-95, as liquid water with a density of 921 kg m−3 remains in a homogeneous state during cooling down to a temperature of −30.5 °C, where it is transformed into ice whose density corresponds to zero pressure. (iii) Ice melting. Ice melting temperatures of up to 6.8 °C were measured in the absence of the vapour bubble, i.e. in the negative pressure region. (iv) Spontaneous retrograde and, for the first time, prograde vapour bubble nucleation. Prograde bubble nucleation occurred upon heating at temperatures above ice melting. The occurrence of prograde and retrograde vapour bubble nucleation in the same inclusions indicates a maximum of the bubble nucleation curve in the ϱ–T plane at around 40 °C. The new experimental data represent valuable benchmarks to evaluate and further improve theoretical models describing the p–V–T properties of metastable water in the low-temperature region.

Description: Resolving robust source parameters of small‐moderate magnitude earthquakes is still a challenge in seismology. We infer directivity from apparent source time functions (ASTFs) at regional distance and quantify the associated uncertainties. ASTFs are used for (i) modeling a propagating 1‐D line source from the duration data and (ii) inverting the 2‐D slip distribution from the full signals. Slip inversion is performed through a Popperian scheme, where random trial models are either falsified on account of large misfit, or else become members of the solution set of the inverse problem. We assess the resolution of rupture directivity representing centroid shifts from the solution set in a rose diagram. Using as example an event with well‐studied rupture directivity, the 2011 Mw 5.2 Lorca (Spain) earthquake, 1‐D and 2‐D parameterizations yield similar estimates for direction (N213°E and N220°E, respectively) and asymmetry (67:33, 65:35) of rupture propagation, as well as rupture length (2.1 km, 2.7 km) and speed (3.5 km/s, 3.25 km/s). The high rupture velocity ≥ 90% vS may be held primarily responsible for the strong directivity effect of this earthquake. We show that inversion of apparent source durations is intrinsically unable to resolve highly asymmetric bilateral ruptures, while inversion of full ASTFs misses part of the signal's complexity, suggesting the presence of deconvolution artifacts. We extend the analysis to the Mw 4.6 foreshock of the Lorca earthquake, inferring similar directivity parameters and slip pattern as for the mainshock. The rupture toward SW of both earthquakes suggests that this direction could be inherent to the fault segment.

Description: The concept of the International GeoSample Number (IGSN) was introduced to uniquely identify and register geo-related sample material, and make it retrievable via electronic media (e.g., SESAR

Description: Geophysical measurements for monitoring the processes of CO2-sequestration or enhanced oil recovery usually take place on active or abandoned oil respectively gas fields. Considering the amount of steel infrastructure in the subsurface of these investigation sites it is crucial to take account of the effect of steel infrastructre on electromagnetic fields. Therefore we present three-dimensional finite element (FE) simulations of transient electromagnetic fields in the present of steel infrastructure. As a first approach we consider two common scenarios. The first scenario covers the case of surface transient electromagnetic measurements with a crossing pipeline beneath a receiver profile. The second scenario covers borehole transient electromagnetic measurements in a partially steel cased borehole. We demonstrate that steel infrastructure has a significant effect on the electromagnetic response.

Description: In this article we briefly describe the geomagnetic observatories operated or supported by the Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences (GFZ), their scientific and societal use in the light of a global approach, their main data products and their dissemination process, as well as their instrumentation. The geomagnetic observatories of GFZ are part of the 'Modular Earth Science Infrastructure' (MESI).

Description: The Gongga Shan batholith of eastern Tibet, previously documented as a ca. 32–12.8 Ma granite pluton, shows some of the youngest U-Pb granite crystallization ages recorded from the Tibetan Plateau, with major implications for the tectonothermal history of the region. Field observations indicate that the batholith is composite; some localities show at least seven crosscutting phases of granitoids that range in composition from diorite to leucocratic monzogranite. In this study we present U-Pb ages of zircon and allanite dated by laser ablation–inductively coupled plasma–mass spectrometry on seven samples, to further investigate the chronology of the batholith. The age data constrain two striking tectonic-plutonic events: a complex Triassic–Jurassic (ca. 215–159 Ma) record of biotite-hornblende granodiorite, K-feldspar megacrystic granite and leucogranitic plutonism, and a Miocene (ca. 14–5 Ma) record of monzonite-leucogranite emplacement. The former age range is attributed to widespread Indosinian tectonism, related to Paleo-Tethyan subduction zone magmatism along the western Yangtze block of south China. The younger component may be related to localized partial melting (muscovite dehydration) of thickened Triassic flysch-type sediments in the Songpan-Ganze terrane, and are among the youngest crustal melt granites exposed on the Tibetan Plateau. Zircon and allanite ages reflect multiple crustal remelting events; the youngest, ca. 5 Ma, resulted in dissolution and crystallization of zircons and growth and/or resetting of allanites. The young garnet, muscovite, and biotite leucogranites occur mainly in the central part of the batholith and adjacent to the eastern margin of the batholith at Kangding, where they are cut by the left-lateral Xianshui-he fault. The Xianshui-he fault is the most seismically active strike-slip fault in Tibet and is thought to record the eastward extrusion of the central part of the Tibetan Plateau. The fault obliquely cuts all granites of the Gongga Shan massif and has a major transpressional component in the Kangding-Moxi region. The course of the Xianshui Jiang river is offset by ∼62 km along the Xianshui-he fault and in the Kangding area granites as young as ca. 5 Ma are cut by the fault. Our new geochronological data show that only a part of the Gongga Shan granite batholith is composed of young (Miocene) melt, and we surmise that as most of eastern Tibet is composed of Precambrian–Triassic Indosinian rocks, there is no geological evidence to support regional Cenozoic internal thickening or metamorphism and no evidence for eastward-directed lower crustal flow away from Tibet. We suggest that underthrusting of Indian lower crust north as far as the Xianshui-he fault resulted in Cenozoic uplift of the eastern plateau.

Description: Permafrost regions are highly sensitive to climate changes. To monitor key variables and to identify environmentally relevant-processes is of topmost importance in these environments. Beside data analysis and map creation capabilities, Geographical Information Systems (GIS) also comprise functionalities for mobile data acquisition in the field, data transfer, data monitoring, data description, as well as data sharing and publication of data as WebGIS Services (Web Map/Feature Services (WMS, WFS)). Due to their excellent usability GIS technology and services are very common in many scientific disciplines all over the world, and since most data formats are standardized data re-use and data interchangeability are guaranteed. We visualize field-derived and remote sensing derived research data, collected within Russian and German cooperation projects in the Lena River Delta, Laptev Sea Region (Siberia) on a Web GIS Platform. We visualize the locations of long-term discharge measurements and of soil sampling for organic Carbon and Nutrients. Geormorphological feature classes derived from satellite data and publicly available environmental data layers (e.g. vegetation, soils, and digital elevation models) display the broader regional and thematic context. AWI offers WebGIS services published under http://maps.awi.de/awimaps/. The WebGIS core components are ArcGIS for Server 10.3 and PostgreSQL databases 9.3 including Spatial Database Engine (SDE).

Description: The Andean Orogeny is the result of the upper-plate crustal shortening during the Cenozoic Nazca plate subduction beneath South America plate. With up to ~300 km shortening, the Earths second highest Altiplano-Puna Plateau was formed with a pronounced N-S oriented deformation diversity. Furthermore, the tectonic shortening in the Southern Andes was much less intensive and started much later. The mechanism of the shortening and the nature of N-S variation of its magnitude remain controversial. The previous studies of the Central Andes suggested that they might be related to the N-S variation in the strength of the lithosphere, friction coupling at slab interface, and are probably influenced by the interaction of the climate and tectonic systems. However, the exact nature of the strength variation was not explored due to the lack of high numerical resolution and 3D numerical models at that time. Here we will employ large-scale subduction models with a high resolution to reveal and quantify the factors controlling the strength of lithospheric structures and their effect on the magnitude of tectonic shortening in the South America plate between 18-35S. These high-resolution models are performed by using the highly scalable parallel 3D code LaMEM (Lithosphere and Mantle Evolution Model). This code is based on finite difference staggered grid approach and employs massive linear and non-linear solvers within the PETSc library to complete high-performance MPI-based parallelization in geodynamic modeling. Currently, in addition to benchmark-models we are developing high-resolution (〈 1km) 2D subduction models with application to Nazca-South America convergence. In particular, we will present the models focusing on the effect of friction reduction in the Paleozoic-Cenozoic sediments above the uppermost crust in the Subandean Ranges. Future work will be focused on the origin of different styles of deformation and topography evolution in Altiplano-Puna Plateau and Central-Southern Andes through 3D modeling of large-scale interaction of subducting and overriding plates.

Description: The combination of multi-disciplinary sea ice science and the rising demand of society for up-to-date information and user customized products on climate change emphasis the need for addressing the challenges posed by environmental change in the Polar Regions by means of creating new ways of communication. The new knowledge platform “meereisportal.de” is a contribution to the cross-linking of scientifically qualified information on climate change and focuses deliberately on the theme: “sea ice” in both Polar Regions. With “meereisportal. de” the science opens to changing societal demands and goes new ways of communication between science and society. “meereisportal. de” is the first comprehensive German speaking knowledge platform on sea ice that went online 2013. It was developed in the frame of the Helmholtz Climate Initiative, Regional Climate Change (REKLIM) as a joint project of the University of Bremen (Institute of Environmental Physics) and the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research under the management of the Helmholtz Regional Climate Office for Polar Regions and Sea Level change. This paper describes the concept and the development of the knowledge platform, different usage examples and user-specific products. Moreover, an outlook on the planned activities in the future will be given.

Description: Die Kombination der zunehmend multi-disziplinären Meereisforschung und die steigende Nachfrage der Gesellschaft nach aktuellen Informationen und benutzerorientierten Produkten zum Thema Klimawandel erfordert neue Wege der Wissenskommunikation, um den Herausforderungen der zunehmenden Umweltveränderungen, insbesondere in den Polarregionen, zu begegnen. Die neue Wissensplattform “meereisportal.de” ist ein Beitrag zum Vernetzen von wissenschaftlich qualifizierten Fachinformationen zum Thema Klimawandel und fokussiert dabei bewusst auf ein Thema: “Meereis” in beiden Polargebieten. Mit “meereisportal.de” öffnet sich die Wissenschaft gegenüber sich verändernden gesellschaftlichen Anforderungen und geht neue Wege der Kommunikation zwischen Wissenschaft und Gesellschaft. “meereisportal. de” ist 2013 als erste umfassende, deutschsprachige Wissensplattform rund um das Thema Meereis in der Arktis und Antarktis online gegangen. Sie wurde im Rahmen des Helmholtz-Verbundes Regionale Klimaveränderungen (REKLIM) als Gemeinschaftsprojekt der Universität Bremen (Institut für Umweltphysik) und des Alfred-Wegener-Institutes, Helmholtz-Zentrum für Polar- und Meeresforschung unter der Federführung des regionalen Helmholtz Klimabüros für Polargebiete und Meeresspiegelanstieg entwickelt. Dieser Beitrag beschreibt die Entstehung, das Konzept und die Entwicklung der Wissensplattform, verschiedene Anwendungsbeispiele sowie nutzerspezifische Produkte. Darüber hinaus wird ein Ausblick über die in Zukunft geplanten Aktivitäten gegeben.

Description: This data collection contains a multitemporal series of six airborne hyperspectral image mosaics ac-quired during the growing season of 2012 over the Neusling test area near Landau a.d. Isar in Southern Germany. The airborne hyperspectral data is complemented by accompanying in-situ data acquired parallel to the overflights. The dataset is composed of a) four airborne hyperspectral image mosaics acquired during overflights on April 28th 2012, May 25th 2012, June 16th 2012 and September 8th 2012 with the AVIS-3 imaging spectrometer. The AVIS data consists of 197 spectral bands, ranging from VIS to SWIR (477 - 1704 nm); b) two airborne hyperspectral image mosaics acquired during overflights on May 8th 2012 and August 12th 2012 with a HySpex imaging spectrometer. The HySpex data consists of 332 spectral bands, ranging from VIS to SWIR (417 - 2496 nm); c) spatially comprehensive land use/land cover maps generated from in-situ observations for two time-windows during the growing season of 2012 (May and August); d) Flight-parallel in-situ point-measurements consisting of: i) non-destructively measured leaf area index of winter wheat, winter barley, sugar beet, maize and rapeseed (561 meas-urements incl. standard deviations), ii) SPAD chlorophyll measurements (522 measurements incl. standard deviations), iii) 557 soil moisture measurements incl. standard deviations iv) 539 phenological observations v) 499 measurements of canopy height incl. standard deviations and vi) 38 measurements of plant density. The dataset was collected in order to cover the seasonal dynamics in the development of agricultural crops in Southern Germany.

Description: Acoustic waves from volcanic eruptions are often observed as infrasound in near fields. Part of them propagate upward and disturb the ionosphere, and can be observed with Total Electron Content (TEC) data from Global Navigation Satellite System (GNSS) receivers. Here we report TEC variations after the 13 February 2014 Plinian eruption of the Kelud volcano, East Java, Indonesia, observed with regional GNSS networks. Significant disturbances in TEC were detected with six GNSS satellites, and wavelet analysis showed that harmonic oscillations started at ∼16:25 UT and continued for ∼2.5 h. The amplitude spectrum of the TEC time series showed peaks at 3.7 mHz, 4.8 mHz and 6.8 mHz. Long-wavelength standing waves with a wide range of wavelength trapped in the lower atmosphere are excited by the Plinian eruption. Amplitude spectra of the ground motion recorded by seismometers, however, had frequency components at discrete wave-periods. The condition for the resonant oscillations between the atmosphere and the solid Earth is satisfied only at these discrete wave-period and horizontal wavelength pairs, therefore efficient energy transfer from the atmospheric standing waves to the solid Earth Rayleigh waves occurred at discrete periods and resulted in the harmonic ground motion.

Description: The International Continental Scientific Drilling Program (ICDP) performed a dual-phase scientific drilling project to investigate mountain-building processes called Collisional Orogeny in the Scandinavian Caledonides (COSC). The borehole COSC-1 was drilled through the Lower Seve Nappe, as the first of two 2.5 km deep drill holes close to Åre, central Sweden. The recovered rocks comprise a 1650 m thick suite of high grade gneisses and amphibolites with clear Seve Nappe affinities, while the lower 850 m com-prise rather homogenous mylonitic gneisses with interfingered K-rich phyllonite bands of cm to several m size and some intercalated amphibolites. The different lithologies all crosscut the core in a subhorizontal direction with foliation of gneisses and phyllonites in the same direction. Albite and garnet porphyroblasts with pressure shadows show syn-deformational growth and the same sub-horizontal alignment. The focus was to detect chemical and mineralogical differences in mylonitic and host rocks and to relate these differences to either metasomatism and deformation or inher-ited source rock variance. Another goal of this work is to compare chemical core scanning instruments. For this purpose, two different μ-Energy-Dispersive X-Ray Fluorescence (μ-EDXRF), Laser Induced Breakdown Spectroscopy (LIBS) and hyperspectral imaging tech-niques served to measure seven samples from the lower 850 m of the COSC-1 core. This report will explain the data sets gained during this study. The metadata will be pre-sented in an additional file including XRF data from the AVAATECH XRF core scanner in a text file as well as data sets of the other used devices in original file formats.

Description: Fourier analyses of worldwide temperature proxy data show a multitude of spectral lines, indicating multi-periodic dynamics of the climate system. The proxy data investigated in this study all show an approximately 200 year period, which has been related to the solar De Vries/Suess cycle. This cycle is consistent with temperature measurements from about 1750 to present, suggesting that the solar De Vries/Suess cycle is of importance for the recent and near future climate variations.

Description: Fourier Analysen von weltweiten Temperatur-Proxydaten für verschiedene Regionen der Erde weisen eine große Zahl von Spektrallinien auf, die die Dynamik des Klimasystems auf unterschiedlichen Zeitskalen (multiperiodisch) widerspiegeln. Die in dieser Studie untersuchten Proxydaten zeigen durchweg eine Periodizität von ungefähr 200 Jahren, wie sie mit dem solaren De Vries/Suess-Zyklus in Verbindung gebracht werden kann. Diese Periodizität lässt sich auch in instrumentellen Temperaturmessungen ab etwa 1750 bis heute erkennen, was einen Einfluss des De Vries/ Suess-Zyklus’ auf die vergangene und zukünftige Temperaturentwicklung wahrscheinlich macht.

Description: Subduction zones around the world show the common pattern of a Double Seismicity Zone, where seismicity is organized in the form of two sub-parallel planes, one at the plate contact and the other one, 10 to 30 km below, in the mantle of the oceanic lithosphere (Lower Seismicity Zone, LSZ). A commonly held hypothesis states that dehydration processes and the associated mineral reactions promote the earthquakes of the LSZ. Fluids filling a porespace strongly alter the petropyhsical properties of a rock. Especially the seismic P- to S-wave velocity ratio (Vp/Vs) has been shown to be sensitive to the presence of fluid-filled porosity. It transforms uniquely to Poisson’s ratio. To test the mineral–dehydration-hypothesis, we use local earthquake data to measure Vp/Vs in the oceanic mantle of the subducting Nazca slab at 21 ◦ S. We determine it as the slope of the de-meaned differential P- vs. S-wave arrivaltimes of a dense seismicity cluster in the LSZ. This measurement yields a value for Vp/Vs of 2.10 ± 0.09, i.e. a Poisson’s ratio of ∼ 0.35. This value clearly exceeds the range of Vp/Vs values expected for oceanic mantle rocks in their purely solid form at ∼ 50km depth. We follow a poroelastic approach to model the rock’s elastic properties, including Vp/Vs, as a function of porosity and porespace-geometry. This results in a porespace model for the target volume having a vein-like porosity occu- pying only a minor volume fraction. Porosity is in the order of 0.1%. These findings are in very good agreement with field surveys and laboratory experiments of mantle dehydration. The pore-geometry is close to the geometrical percolation threshold, where long-ranged interconnectivity statistically emerges, suggesting good draining capa- bilities. Indeed, porosity is soft so that the amount of porosity and, consequently, permeability is very sensitive to local fluid pressure. We conclude that in the oceanic mantle of the subducting Nazca slab, mineral dehydration reactions are contin- uously releasing water into a transient, dynamically evolving vein-system. Permeability is most probably high enough to drain the rock at the rate of metamorphic fluid production.

Description: In the framework of the Collaborative Research Centre (CRC) 806 „Our way to Europe“, a 2D transient electromagnetic survey was conducted on three different sedimentary basins in southern and central Ethiopia. Combining geoscientific and archaeological methods, the CRC 806 is designed to reconstruct the passageway of Modern Man from eastern Africa to central Europe over the last 200,000 years. Geophysical measurements assist with the identification and definition of possible palaeoenvironmental archives such as sedimental deposits.

Description: Geomagnetic field data from four observatories and annual field surveys between 2005 and 2015 provide a detailed description of Earth’s magnetic field changes over South Africa, Namibia and Botswana on time scales of less than 1 year. The southern African area is characterized by rapid changes in the secular variation pattern and lies in close proximity to the South Atlantic Anomaly (SAA) where the geomagnetic field intensity is almost 30 % weaker than in other regions at similar latitudes around the globe. Several geomagnetic secular acceleration (SA) pulses (geomagnetic jerks) around 2007, 2010 and 2012 could be identified over the last decade in southern Africa. We present a new regional field model for declination and horizontal and vertical intensity over southern Africa (Southern African REGional (SAREG)) which is based on field survey and observatory data and covering the time interval from 2005 to 2014, i.e. including the period between 2010 and 2013 when no low Earth-orbiting vector field satellite data are available. A comparative evaluation between SAREG and global field models like CHAOS-5, the CHAMP, Orsted and SAC-C model of the Earth's magnetic field and International Geomagnetic Reference Field (IGRF-12) reveals that a simple regional field model based on a relatively dense ground network is able to provide a realistic representation of the geomagnetic field in this area. We particularly note that a global field model like CHAOS-5 does not always indicate similar short-period patterns in the field components as revealed by observatory data, while representing the general secular variation reasonably well during the time interval without near-Earth satellite vector field data. This investigation further shows the inhomogeneous occurrence and distribution of secular variation impulses in the different geomagnetic field components and at different locations in southern African.