ALBERT

Description: Van Allen Probes measurements revealed the presence of the most unusual structures in the ultra-relativistic radiation belts. Detailed modeling, analysis of pitch angle distributions, analysis of the difference between relativistic and ultra-realistic electron evolution, along with theoretical studies of the scattering and wave growth, all indicate that electromagnetic ion cyclotron (EMIC) waves can produce a very efficient loss of the ultra-relativistic electrons in the heart of the radiation belts. Moreover, a detailed analysis of the profiles of phase space densities provides direct evidence for localized loss by EMIC waves. The evolution of multi-MeV fluxes shows dramatic and very sudden enhancements of electrons for selected storms. Analysis of phase space density profiles reveals that growing peaks at different values of the first invariant are formed at approximately the same radial distance from the Earth and show the sequential formation of the peaks from lower to higher energies, indicating that local energy diffusion is the dominant source of the acceleration from MeV to multi-MeV energies. Further simultaneous analysis of the background density and ultra-relativistic electron fluxes shows that the acceleration to multi-MeV energies only occurs when plasma density is significantly depleted outside of the plasmasphere, which is consistent with the modeling of acceleration due to chorus waves.

Description: The spatial and angular emission patterns of artificial and natural light emitted, scattered, and reflected from the Earth at night are far more complex than those for scattered and reflected solar radiation during daytime. In this commentary, we use examples to show that there is additional information contained in the angular distribution of emitted light. We argue that this information could be used to improve existing remote sensing retrievals based on night lights, and in some cases could make entirely new remote sensing analyses possible. This work will be challenging, so we hope this article will encourage researchers and funding agencies to pursue further study of how multi-angle views can be analyzed or acquired.

Description: Organic soil amendments such as modified lignite and biostimulants like arbuscular mycorrhizal fungi (AMF) may have the potential to improve soil biological conditions of agricultural soils. The aim of the study was to test if nitrogen-modified lignite granules (NH) are beneficial for mycorrhization, root and shoot development compared to common mineral nitrogen (Nmin) in a nitrogen and phosphorus limited soil. A greenhouse experiment with Secale cereale L. was carried out using non-sterilized and sterilized sand substrate treated with NH, AMF or Nmin and AMF+NH and AMF+Nmin and was compared to an untreated substrate (control). 7.5 t ha−1 NH and 120 kg Nmin ha−1 led to a similar increase of AMF colonization compared to the control; however, Nmin had a more positive influence on biomass development. Significantly highest mycorrhizal colonization intensity was found for AMF+NH. The co-application of AMF+NH revealed that shoot and root development and shoot nutrient concentrations were significantly higher or were among the significantly highest values, when compared to the other treatments. AMF+NH may be a suitable soil amendment for nutrient-limited soils and may be more sustainable than Nmin due to a combined increase of nitrogen, AMF and carbon/humic acids in the soil that comes with the NH.

Description: In both seismic and electromagnetic imaging the diffracted wavefield has gained importance in recent years. While seismic data is often acquired for a large range of different source-receiver offsets, ground-penetrating radar (GPR) acquisitions are mostly (near-) zero-offset. This characteristic inhibits the use of reflected waves for the estimation of depth velocities, which in turn increases the importance of a reliable imaging and characterization of the diffracted wavefield. In this study, we adapt a coherence-based workflow originally designed for seismic wavefields to ground-penetrating radar (GPR) data, which often exhibit similar wave propagation phenomena. The first step of the proposed workflow is the coherence-based imaging of the often predominant reflected wavefield, which in the second step is adaptively subtracted from the original data, resulting in an approximation of the diffracted wavefield. In the third step, we characterize the previously revealed diffracted wavefield by means of wavefront attributes, namely slopes and curvatures. In the fourth and final step, these wavefront attributes can be used for the estimation of depth velocities by means of wavefront tomography, an inversion scheme that provides both the localization of scatterers and a smooth velocity model of the subsurface. We demonstrate the wide applicability of the suggested workflow on two GPR field data examples provided by the USGS – one recorded in the aftermath of Hurricane Sandy on the shores of Long Beach Island, New Jersey, the other capturing the internal structure of Wolverine Glacier, Alaska.

Description: Seismic monitoring refers to the measurement of time-lapse changes of seismic wave velocities and is a frequently used technique to detect dynamic changes in the Earth‘s crust. Its applications include a broad range of topics, such as natural hazard assessment and structural health monitoring. To obtain reliable measurements, results are usually stacked over time. Thereby, temporal resolution is lost, which makes the measurement less sensitive to short-term environmental processes. Another problem is that conventional datasets often lack spatial density and velocity changes can only be attributed to large areas. Recently, distributed acoustic sensing (DAS) has gained a lot of attention as a way to achieve high spatial resolution at low cost. DAS is based on Rayleigh-scattering of photons within an optical fibre. Because measurements can be taken every few meters along the cable, the fibre is turned into a large seismic array that provides information about the Earth’s crust at unprecedented resolution. In our study, we explore the potential of DAS for monitoring studies. Specifically, we investigate how spatial stacking of DAS traces affects the measurements of velocity variations. We use data recorded by a 21-km-long dark fibre located on Reykjanes Pensinsula, Iceland. The cable is sampled with a channel spacing of 4 meters. We analyze the energy of the oceans microseism continuously recorded between March and September 2020. At first, we stack adjacent traces on the fibre in space. We then cross correlate the stacks to obtain approximations of the Green’s functions between different DAS-channels. By measuring changes in the coda waveform of the extracted seismograms, velocity variations can be inferred. Our analysis shows that spatial stacking improves the reliability of our measurements considerably. Because of that, less temporal stacking is required and the time resolution of our measurements can be increased. In addition, the enhancement of the data quality helps resolve velocity variations in space, allowing us to observe variations propagating along the cable over time. These velocity changes are likely linked to magmatic intrusions associated with a series of repeated uplifts on the Peninsula. Our results highlight the potential of DAS for improving the localization capabilities and accuracy of seismic monitoring studies.

Description: Volcanic explosions produce energy that propagates both in the subsurface as seismic waves and in the atmosphere as acoustic waves. We analyse thousands of explosions which occurred at different craters at Etna volcano (Italy) in 2018 and 2019. We recorded signals from infrasound sensors, geophones (GPH), broadband seismometers (BB) and Distributed Acoustic Sensing (DAS) with fibre optic cable. The instruments were deployed at Piano delle Concazze at about 2 to 2.5 km from the active craters, within (or onto) a ~300,000 m2 scoria layer deposited by recent volcanic eruptions. The DAS interrogator was setup inside the Pizzi Deneri Volcanic Observatory (~2800 m elevation). Infrasonic explosion records span over a large range of pressure amplitudes with the largest one reaching 130 Pa (peak to peak), with an energy of ca. 2.5x1011 J. In the DAS and the BB records, we find a 4-s long seismic “low frequency” signal (1-2 Hz) corresponding to the seismic waves, followed by a 2-s long “high-frequency” signal (16-21 Hz), induced by the infrasound pressure pulse. The infrasound sensors contain a 1-2 Hz infrasound pulse, but surprisingly no high frequency signal. At locations where the scoria layer is very thin or even non-existent, this high frequency signal is absent from both DAS strain-rate records and BB/GPH velocity seismograms. These observations suggest that the scoria layer is excited by the infrasound pressure pulse, leading to the resonance of lose material above more competent substratum. We relate the high frequency resonance to the layer thickness. Multichannel Analysis of Surface Wave from jumps performed along the fibre optic cable provide the structure of the subsurface, and confirm thicknesses derived from the explosion analysis. As not all captured explosions led to the observation of these high frequency resonance, we systematically analyze the amplitudes of the incident pressure wave versus the recorded strain and find a non-linear relationship between the two. This non-linear behaviour is likely to be found at other explosive volcanoes. Furthermore, our observations suggest it might also be triggered by other atmospheric pressure sources, like thunderstorms. This analysis can lead to a better understanding of acoustic-to-seismic ground coupling and near-surface rock response from natural, but also anthropogenic sources, such as fireworks and gas explosions.

Description: Recently, many sports stadiums have begun using high power lighting systems to help the grass grow on the playing surfaces. These lights supplement winter sunlight, which is sometimes insufficient due to the low elevation of the sun and shading from the surrounding walls. In many stadiums, grow lights are operated at night, and the waste light emissions from these stadiums are extraordinary in comparison to most other areas in the cities in which they are located. Here we present space-based observations of the radiance of fourteen stadiums located in towns and cities of varying sizes and in varying geographical locations across England which each have a Premier League football stadium. We show that stadiums have dramatically brightened (typically by factors of 2-5) in recent years compared to the situation in 2012. We also show that stadiums are often responsible for an important fraction of the total light emission of the cities they are in (often 10% or more, and in one case up to 30%). Because the light emissions from many English towns have been reducing in recent years, the overall fraction of light due to the stadiums is increasing. In some cases, total city emissions have actually increased due to the stadiums, undermining the environmental impact of reductions in radiance in the rest of the community. We believe that stadium grow lights are an excellent target for sustainable lighting initiatives, both because of their considerable environmental impact (especially when located near sensitive areas) and the possibility of high profile and successful waste light mitigation projects.

Description: Over the past decades, ground-penetrating radar (GPR) has become a fundamental tool in glaciological studies thanks to its tremendous capacity to provide high-resolution images in snow and ice. 3D acquisitions in particular can give detailed information on the internal structure, properties, and dynamics of glaciers. For imaging and highlighting important englacial and subglacial features such as meltwater tunnels and voids, an analysis of the spatial distribution of diffractions in the data holds great potential. However, the diffracted wavefield typically has low amplitude and is often masked by more prominent arrivals. Diffraction separation and imaging procedures have already become topics of significant interest in the field of exploration seismology, and may potentially open new possibilities for the analysis of glacier GPR data. Here, we explore the potential of recent advances in diffraction imaging for the analysis of alpine glacier GPR data. To this end, we consider a 3D data set acquired on the Haut Glacier d’Arolla (Valais, Switzerland) using a 70-MHz single-antenna real-time-sampling GPR system. The approach we use coherently approximates the dominant reflected wavefield and subtracts it from the data. The remaining diffracted wavefield is then enhanced using local coherent stacking. We find that this methodology is highly effective at isolating diffractions in glacier GPR data and provides clean images of the diffracting structures. Current work includes investigation of the correlation between these structures and the englacial and subglacial hydrological network.

Description: Cassiterite, the economically most important tin mineral, typically has moderate U and variable common Pb contents, making it amenable for U-Pb dating. Cassiterite has extremely low Th/U ratios (Th/U 〈 0.01) and its 208Pb is dominantly common Pb. This is particularly helpful as there is significant interference of tungsten oxides on 202Hg and 204Pb. The feasibility of the 208Pb correction procedure is discussed in detail. The 208Pb corrected LA-SF-ICP-MS data are in good agreement with intercept ages in the Tera-Wasserburg diagram and 207Pb corrected ages. Twelve cassiterite samples were investigated using the ID-TIMS and LA-SF-ICP-MS methods. The ID-TIMS results of Pit-AB, Rond-A, RG-114, BB#7 and 19GX cassiterite are reported for the first time in this study. RG-114, BB#7 and 19GX cassiterite have very low common Pb contents and are recommended for use as primary reference materials for in situ cassiterite. Pit-AB, Rond-A and Yankee cassiterite contain a small amount of common Pb, produce reliable and consistent ages and are suitable as primary reference materials. The remaining five cassiterite samples (Kard, Zinnwald, Els, XBD-W and Y724) were only investigated using the LA-SF-ICP-MS method and produce ages consistent with published age data from the host rocks associated with the tin deposits and with published U-Pb ages of cassiterite from the same deposits. We present an ID-TIMS Usingle bondPb of 154.3 ± 0.7 Ma for the commonly used cassiterite reference material AY-4. This age differs from previously reported ID-TIMS ages. This age discrepancy is caused by different initial common Pb compositions rather than age heterogeneity.

Description: Tungsten and Sn display similar behavior during magmatic processes and are commonly associated spatially and genetically with highly evolved granites. Nonetheless, they typically form separate deposits, even if their associated granites have the same protolith. This separation may be due to the fractionation of the metals at the magmatic-hydrothermal transition or their differential mobility during partial melting of the metasedimentary protolith. If this separation occurred at the magmatic-hydrothermal transition, the ages of the W and Sn deposits would be very similar, whereas if it occurred during partial melting, the deposits are likely to have different ages because of the concentration of the metals in different magma batches and, in extreme cases, during different magmatic events. New age data from the Wangxianling ore field in the western part of the world-class Nanling W-Sn metallogenic province demonstrate that the W and Sn mineralization took place at different times. The W mineralization (219.5 ± 3.4 Ma) is related to Triassic granites (224.9–217.8 Ma), whereas the Sn mineralization is related to granites of Late Jurassic age (154.7 ± 1.1 Ma). This difference in ages rules out fractionation at the magmatic-hydrothermal transition as an explanation for the spatial separation of the W and Sn deposits and implies that the separation was due to differences in the mobility of W and Sn during partial melting. Both suites of granite originated from the partial melting of the same metasedimentary rocks, and both are reduced and highly evolved. The W granites, however, have a lower zircon saturation temperature (~750°C) than the Sn granites (~800°C), which indicates that the magma forming the W granites was mainly the product of muscovite-dehydration melting, whereas that forming the Sn granites was largely the result of biotite-dehydration melting. The different melting paths indicate that W released during muscovite breakdown dissolved in the magma, whereas Sn was sequestered by restite biotite. At the higher melting temperature, the residual W and Sn, released during the subsequent breakdown of biotite, dissolved in the magma. Thus, the magma that generated at low temperature was enriched in W, leading to subsequent W mineralization, whereas the magma that generated at high temperature was enriched in Sn and produced an Sn-mineralized granite. The whole-rock Sr-Nd isotope data for the Triassic W granites plot in the compositional field of the regional basement rocks and are consistent with partial melting of an orogenically thickened crust by internal heating in a collisional setting. In contrast, the Sr-Nd isotope data for the Late Jurassic Sn(-W) granites are displaced toward a mantle composition, likely reflecting contributions from mantle-derived material. Given the emplacement of many of the Late Jurassic Sn(-W) granites close to the Chenzhou-Linwu fault, we propose that this structure was the focus of decompression melting of the mantle and the injection of mantle-derived melts into the crust during the Late Jurassic, which supplied the additional heat for the melting at higher temperature needed to generate magmas enriched in Sn. This model, which is based on differences in the behavior of Sn and W during crustal melting, is potentially applicable to other Sn-W metallogenic provinces where Sn and W deposits are temporally separated.

Description: In nature, light is a key driver of animal behaviour and physiology. When studying captive or laboratory animals, researchers usually expose animals to a period of darkness, to mimic night. However, ‘darkness’ is often poorly quantified and its importance is generally underappreciated in animal research. Even small differences in nocturnal light conditions can influence biology. When light levels during the dark phase are not reported accurately, experiments can be impossible to replicate and compare. Furthermore, when nocturnal light levels are unrealistically dark or bright, the research is less ecologically relevant. Such issues are exacerbated by huge differences in the sensitivity of different light meters, which are not always described in study methods. We argue that nocturnal light levels need to be reported clearly and precisely, particularly in studies of animals housed indoors (e.g. ‘〈0.03 lux’ rather than ‘0 lux’ or ‘dark’), and that these light levels should reflect conditions that the animal would experience in a natural context.

Description: Quantitative continental climate reconstructions covering the last glacial cycle from the Iberian Peninsula are scarce. In order to fill this gap, we obtained for the first time a high-resolution mean annual air temperature (MAAT) record based on the distribution of specific bacterial membrane lipids (i.e., branched glycerol dialkyl glycerol tetraethers; brGDGTs) from the last 36.0–4.7 kyr palaeolake record recovered by the Padul-15-05 sedimentary core (Padul, Sierra Nevada, southern Iberia). The fractional abundance of the three major groups of GDGTs present in the Padul sediments, GDGT-0, crenarchaeol and the summed brGDGTs, is comparable with that of other shallow and small (〈10 km2) European lakes. Despite variations in the lithology in the studied section, the GDGT composition remains relatively stable, except for the uppermost 116 cm of the record, representing the ephemeral/emerged lake stage, which is characterized by higher crenarchaeol fractional abundances. The identification of a specific brGDGT that has only been detected in anoxic lakes provides evidence for in-situ brGDGT production in the water column and/or sediments in the Padul palaeolake. Its presence/absence probably denotes a succession of periods with a variable oxygen content in the bottom waters of the palaeolake. MAAT was reconstructed based on the distribution of brGDGTs using an African lake calibration and ranged between 12 and 20 °C. A new Bayesian calibration to mean temperature of Months Above Freezing (MAF) depicts similar temperature variations with a mean absolute difference of 0.7 °C. The MAAT reconstruction in the Padul palaeolake for the 36.0–4.7 kyr period reveals similarities with climate variability described at high-latitudes and in the westernmost Mediterranean area during this interval, showing cold conditions during the last three Heinrich Stadials and the Younger Dryas and warm conditions during the Dansgaard–Oeschger interstadials (7–1) and the Bölling-Alleröd period. Despite the more stable and warm general climate conditions during the Early and Mid-Holocene, rapid centennial-scale temperature changes are registered in the Padul palaeolake in good agreement with variations observed in the Mediterranean forest record.

Description: Organic carbon (OC) stored in Arctic permafrost represents one of Earth's largest and most vulnerable terrestrial carbon pools. Amplified climate warming across the Arctic results in widespread permafrost thaw. Permafrost deposits exposed at river cliffs and coasts are particularly susceptible to thawing processes. Accelerating erosion of terrestrial permafrost along shorelines leads to increased transfer of organic matter (OM) to nearshore waters. However, the amount of terrestrial permafrost carbon and nitrogen as well as the OM quality in these deposits is still poorly quantified. We define the OM quality as the intrinsic potential for further transformation, decomposition and mineralisation. Here, we characterise the sources and the quality of OM supplied to the Lena River at a rapidly eroding permafrost river shoreline cliff in the eastern part of the delta (Sobo-Sise Island). Our multi-proxy approach captures bulk elemental, molecular geochemical and carbon isotopic analyses of Late Pleistocene Yedoma permafrost and Holocene cover deposits, discontinuously spanning the last ∼52 kyr. We showed that the ancient permafrost exposed in the Sobo-Sise cliff has a high organic carbon content (mean of about 5 wt %). The oldest sediments stem from Marine Isotope Stage (MIS) 3 interstadial deposits (dated to 52 to 28 cal ka BP) and are overlaid by last glacial MIS 2 (dated to 28 to 15 cal ka BP) and Holocene MIS 1 (dated to 7–0 cal ka BP) deposits. The relatively high average chain length (ACL) index of n-alkanes along the cliff profile indicates a predominant contribution of vascular plants to the OM composition. The elevated ratio of iso- and anteiso-branched fatty acids (FAs) relative to mid- and long-chain (C ≥ 20) n-FAs in the interstadial MIS 3 and the interglacial MIS 1 deposits suggests stronger microbial activity and consequently higher input of bacterial biomass during these climatically warmer periods. The overall high carbon preference index (CPI) and higher plant fatty acid (HPFA) values as well as high ratios point to a good quality of the preserved OM and thus to a high potential of the OM for decomposition upon thaw. A decrease in HPFA values downwards along the profile probably indicates stronger OM decomposition in the oldest (MIS 3) deposits of the cliff. The characterisation of OM from eroding permafrost leads to a better assessment of the greenhouse gas potential of the OC released into river and nearshore waters in the future.

Description: Assessing the timing of great megathrust earthquakes is together crucial for seismic hazard analysis and deemed impossible. Geodetic instrumentation of subduction zones has revealed unexpected deformation patterns at subduction segments adjacent to those that hosted recent mega-earthquakes: coastal sites move landward with faster velocities than before the earthquake. Here, we show observations from the largest and best-monitored megathrust earthquakes, and from a scaled analog model, to reveal that these events create coseismic and postseismic deformation patterns typical of a complete gear-like rotation about a vertical axis, hereafter called twisting. We find that such twisting alters the interseismic velocity field of adjacent subduction segments depending on the time since the last earthquake. Early interactions accelerate while late interactions decelerate local kinematics. This finding opens the possibility of using megathrust earthquakes, the characteristics of the twisting pattern, and the ensuing geodetic velocity changes, as a proxy for estimating the timing of the seismic cycle at unruptured segments along the margin.

Description: Spatially explicit monitoring of tropical forest aboveground carbon is an important prerequisite for better targeting and assessing forest conservation efforts and more transparent reporting of carbon losses. Here, we combine near-real-time forest disturbance alerts based on all-weather radar data with aboveground carbon stocks to provide carbon loss estimates at high spatial and temporal resolution for the rainforests of Africa. We identified spatial and temporal hotspots of carbon loss for 2019 and 2020 for the 23 countries analyzed, led by different drivers of forest disturbance. We found that 75.7% of total annual carbon loss in the Central African Republic happened within the first three months of 2020, while 89% of the annual carbon loss in Madagascar occurred within the last five months of 2020. Our detailed spatiotemporal mapping of carbon loss creates opportunities for much more transparent, timely, and efficient assessments of forest carbon changes both at the level of specific activities, for national-level GHG reporting, and large area comparative analysis.

Description: Tectonic plate motions predominantly result from a balance between the potential energy change of the subducting slab and viscous dissipation in the mantle, bending lithosphere and slab–upper plate interface. A wide range of observations from active subduction zones and exhumed rocks suggest that subduction interface shear zone rheology is sensitive to the composition of subducting crustal material—for example, sediments versus mafic igneous oceanic crust. Here we use 2-D numerical models of dynamically consistent subduction to systematically investigate how subduction interface viscosity influences large-scale subduction kinematics and dynamics. Our model consists of an oceanic slab subducting beneath an overriding continental plate. The slab includes an oceanic crustal/weak layer that controls the rheology of the interface. We implement a range of slab and interface strengths and explore how the kinematics respond for an initial upper mantle slab stage, and subsequent quasi-steady-state ponding near a viscosity jump at the 660-km-discontinuity. If material properties are suitably averaged, our results confirm the effect of interface strength on plate motions as based on simplified viscous dissipation analysis: a ∼2 order of magnitude increase in interface viscosity can decrease convergence speeds by ∼1 order of magnitude. However, the full dynamic solutions show a range of interesting behaviour including an interplay between interface strength and overriding plate topography and an end-member weak interface-weak slab case that results in slab break-off/tearing. Additionally, for models with a spatially limited, weak sediment strip embedded in regular interface material, as might be expected for the subduction of different types of oceanic materials through Earth’s history, the transient response of enhanced rollback and subduction velocity is different for strong and weak slabs. Our work substantiates earlier suggestions as to the importance of the plate interface, and expands the range of quantifiable links between plate reorganizations, the nature of the incoming and overriding plate and the potential geological record.

Description: Pegmatite fields within granite plutons are commonly considered to have formed from residual melts of their host. This is not always true as demonstrated by the Tysfjord granite gneiss and its two groups of pegmatites. The Tysfjord granite gneiss, exposed in a tectonic window of the Caledonides of northern Norway, is part of the transscandinavian igneous belt (TIB) that includes several phases of granitic magmatism. In the northern Hamarøy area (Drag-Finnøy), where most rare-element pegmatites occur, Paleoproterozoic and metamorphosed Group 1 allanite–(Ce)–fluorite metapegmatites have similar bulk rock chemical composition as the TIB granite gneiss rocks, indicating that these pegmatites are residual melts. Group 1 metapegmatites, which are up to 400 m in size, are among the largest known intra-plutonic pegmatites with Nb–Y–F (NYF) signature. The formation of these unusually large granite-hosted NYF pegmatites may have been facilitated by the overall high F content of TIB granite gneisses. Undeformed Group 2 amazonite–tourmaline pegmatites yield columbite and zircon U–Pb ages in the range 400–379 Ma. These pegmatites are interpreted to be anatectic melts that formed from the partial melting of Tysfjord granite gneiss. Group 2 pegmatites, including those from Træna Island and the Sjona tectonic window (400 and 414 Ma), formed during late Caledonian ductile shearing and incipient unroofing of the central Scandinavian Caledonides and record progressively younger ages of this event from SW to NE.

Description: Analysis of forest disturbance patterns in relation to precipitation seasonality is important for understanding African tropical forest dynamics under changing climate conditions and different levels of human activities. Newly available radar-based forest disturbance information now enables an investigation of the intra-annual relationship between precipitation and forest disturbance in a spatially and temporally explicit manner, especially in the tropics, where frequent cloud cover hinders the use of optical-based remote sensing products. In this study, we applied cross-correlation on monthly precipitation and forest disturbance time series for 2019 and 2020 at a 0.5° grid in the African rainforest. We used the magnitude of the correlation and time lag to assess the intra-annual relationship between precipitation and forest disturbance, and introduced accessibility proxies to analyse the spatial variation of the relationship. Results revealed that a significant negative correlation between forest disturbance and precipitation dominates the study region. We found that significant negative correlations appear on average closer to settlements with overall smaller variations in travel time to settlements compared to grid cells with non-significant and significant positive correlation. The magnitude of the negative correlation increases as the travel time to settlements increases, implying that forest disturbances in less accessible areas are more affected by precipitation seasonality and that in particular human-induced disturbance activities are predominantly carried out in the drier months. Few areas showed a significant positive correlation, mainly resulting from natural causes such as flooding. These new insights in the interaction between forest disturbance, precipitation and accessibility provide a step forward in understanding the complex interactions that underlie the complexity of forest loss patterns that we can increasingly capture with Earth Observation approaches. As such, they can support forest conservation and management in coping with climate change induced changes of precipitation patterns in African rainforest countries.

Description: A striking feature of the seismicity in the Ibero-Maghrebian region is a narrow band of intermediate-depth earthquakes (50 〈 h 〈 100 km) beneath the western part of the Alboran Sea, with epicenters following a NNE-SSW alignment. The origin and characteristics of this seismicity are debated, and an accurate analysis of this seismic scenario is provided despite the low to moderate magnitude of these earthquakes. In this study, we collect 20 years of seismic data from permanent and temporary installations and reprocess these data with the aid of advanced seismological techniques, including non-linear probabilistic relocation with a 3D-Earth velocity model and a probabilistic moment tensor inversion scheme, to shed new light on intermediate-depth seismicity in Southern Spain and the Alboran Sea. We relocated 238 intermediate-depth earthquakes (M ≥ 3) using a nonlinear probabilistic approach and a recent regional 3D tomography lithospheric velocity model for the Alboran-Betic Rif Zone. Maximum likelihood hypocenters confirm the NNE-SSW distribution in a depth range between 50 and 100 km, depicting three clusters of epicenters with a seismic gap that may be correlate to the boundary between the sunken slabs of the Iberian and African plates around Gibraltar. We simultaneously determined the focal mechanisms of 25 mb 〉 3.9 earthquakes using P-waves and moment tensors by fitting body-wave amplitude spectra and waveform cross-correlations. We performed an accurate resolution study by repeating the inversion using different 1-D velocity models. The results show predominant horizontal T axes with a rotation on the direction from NE-SW in southern Spain to E-W near the African coast. The distribution of intermediate-depth earthquakes and their source geometries provide new evidence of the seismotectonic complexity of the region, which is possibly controlled by the stopping or slowing down of subduction.

Description: The societal importance of geothermal energy is significantly increasing because of its low carbon-dioxide footprint. However, geothermal exploration is also subject to high risks. For a better assessment of these risks, extensive parameter studies are required that improve the understanding of the subsurface. This yields computationally demanding analyses. Often, this is compensated by constructing models with a small vertical extent. This paper demonstrates that this leads to entirely boundary-dominated and hence uninformative models. It demonstrates the indispensable requirement to construct models with a large vertical extent to obtain informative models with respect to the model parameters. For this quantitative investigation, global sensitivity studies are essential since they also consider parameter correlations. To compensate for the computationally demanding nature of the analyses, a physics-based machine learning approach is employed, namely the reduced basis method, instead of reducing the physical dimensionality of the model. The reduced basis method yields a significant cost reduction while preserving the physics and a high accuracy, thus providing a more efficient alternative to considering, for instance, a small vertical extent. The reduction of the mathematical instead of physical space leads to less restrictive models and, hence, maintains the model prediction capabilities. The combination of methods is used for a detailed investigation of the influence of model boundary settings in typical regional-scale geothermal simulations and highlights potential problems.

Description: Serpentinization plays an important role in fluid and mass transfer between the ocean, the crust, and the mantle, in biogeochemical processes, and CO2 sequestration within oceanic and continental settings. The physical-chemical conditions of serpentinization, such as temperature and fluid source, are often investigated using oxygen isotopes. However, the ability to precisely constrain such parameters is limited by the accuracy of calibrations for oxygen isotope fractionation between serpentine and water – i.e. 1000 lnα(Srp-w) – which disagree by up to 20‰ when extrapolated to T 〈 200 °C [1-5]. In this study, we present a new empirical calibration of 1000 lnα(Srp-w) aiming to improve applications of oxygen isotope thermometry to very low-T serpentinization (T 〈 100 °C). We used the high-spatial resolution capabilities of Secondary Ion Mass Spectrometry (SIMS) to analyze oxygen isotope ratios in mineral pairs of calcite+serpentine, quartz+serpentine and talc+serpentine co-crystallized at scales ≤ 50 μm in six serpentinite samples from the Samail ophiolite (Oman). SIMS analysis shows that the mineral pairs are relatively homogeneous in oxygen isotope ratios with variability in δ18O values ≤ 2‰ (2s). Clumped isotope thermometry and petrological constraints indicate crystallization temperatures from ~20 to 90 °C for the investigated samples [6,7]. These independent constraints on temperature allowed us to derive 1000 lnα(Srp-w) by combining mineral-serpentine oxygen isotope fractionations measured by SIMS with published mineral-water oxygen isotope fractionations. Our empirical calibration of 1000 lnα(Srp-w) = 1.12±0.42 × 106/T2 (T in K), from T = 20 to 90 °C, is within uncertainty of former high-temperature empirical calibrations [1,4] extrapolated to T 〈 100 °C. The new 1000 lnα(Srp-w) calibration enables more accurate reconstructions of fluid-rock interactions occurring during low-temperature serpentinization processes in various tectonic settings.

Description: Permafrost regions store between 1.100 and 1.500 gigatons of organic carbon and account for about 50 % of the world’s soil carbon storage. About 10–20 % of near-surface permafrost has been lost due to increases in surface temperatures between 1960 and 2000, and between 10–65 % of near-surface permafrost is expected to disappear by the year 2100. The organic matter in permafrost is only weakly protected and most of it is therefore available for microbial degradation. Microorganisms thus play a central role for the permafrost carbon feedback.

Description: Specular meteor radars (SMRs) and partial reflection radars (PRRs) have been observing mesospheric winds for more than a solar cycle over Germany (∼ 54∘ N) and northern Norway (∼ 69∘ N). This work investigates the mesospheric mean zonal wind and the zonal mean geostrophic zonal wind from the Microwave Limb Sounder (MLS) over these two regions between 2004 and 2020. Our study focuses on the summer when strong planetary waves are absent and the stratospheric and tropospheric conditions are relatively stable. We establish two definitions of the summer length according to the zonal wind reversals: (1) the mesosphere and lower-thermosphere summer length (MLT-SL) using SMR and PRR winds and (2) the mesosphere summer length (M-SL) using the PRR and MLS. Under both definitions, the summer begins around April and ends around middle September. The largest year-to-year variability is found in the summer beginning in both definitions, particularly at high latitudes, possibly due to the influence of the polar vortex. At high latitudes, the year 2004 has a longer summer length compared to the mean value for MLT-SL as well as 2012 for both definitions. The M-SL exhibits an increasing trend over the years, while MLT-SL does not have a well-defined trend. We explore a possible influence of solar activity as well as large-scale atmospheric influences (e.g., quasi-biennial oscillation (QBO), El Niño–Southern Oscillation (ENSO), major sudden stratospheric warming events). We complement our work with an extended time series of 31 years at middle latitudes using only PRR winds. In this case, the summer length shows a breakpoint, suggesting a non-uniform trend, and periods similar to those known for ENSO and QBO.

Description: The symbiotic relationship between corals and photosynthetic algae is the foundation of coral reef ecosystems. This relationship breaks down, leading to coral death, when sea temperature exceeds the thermal tolerance of the coral-algae complex. While acclimation via phenotypic plasticity at the organismal level is an important mechanism for corals to cope with global warming, community-based shifts in response to acclimating capacities may give valuable indications about the future of corals at a regional scale. Reliable regional-scale predictions, however, are hampered by uncertainties on the speed with which coral communities will be able to acclimate. Here we present a trait-based, acclimation dynamics model, which we use in combination with observational data, to provide a first, crude estimate of the speed of coral acclimation at the community level and to investigate the effects of different global warming scenarios on three iconic reef ecosystems of the tropics: Great Barrier Reef, South East Asia, and Caribbean. The model predicts that coral acclimation may confer some level of protection by delaying the decline of some reefs such as the Great Barrier Reef. However, the current rates of acclimation will not be sufficient to rescue corals from global warming. Based on our estimates of coral acclimation capacities, the model results suggest substantial declines in coral abundances in all three regions, ranging from 12% to 55%, depending on the region and on the climate change scenario considered. Our results highlight the importance and urgency of precise assessments and quantitative estimates, for example through laboratory experiments, of the natural acclimation capacity of corals and of the speed with which corals may be able to acclimate to global warming.

Description: The scattering and absorption of high-frequency seismic waves in the oceanic lithosphere is to date only poorly constrained by observations. Such estimates would not only improve our understanding of the propagation of seismic waves, but also unravel the small-scale nature of the lithosphere and its variability. Our study benefits from two exceptional situations: (1) we deployed over 10 months a mid-aperture seismological array in the central part of the Eastern North Atlantic in 5 km water depth and (2) we could observe in total 340 high-frequency (up to 30 Hz) Po and So arrivals with tens to hundreds of seconds long seismic coda from local and regional earthquakes in a wide range of backazimuths and epicentral distances up to 850 km with a travel path in the oceanic lithosphere. Moreover, the array was located about 100 km north of the Gloria fault, defining the plate boundary between the Eurasian and African plates at this location which also allows an investigation of the influence of an abrupt change in lithospheric age (20 Ma in this case) on seismic waves. The waves travel with velocities indicating upper-mantle material. We use So waves and their coda of pre-selected earthquakes to estimate frequency-dependent seismic scattering and intrinsic attenuation parameters. The estimated scattering attenuation coefficients are between 10−4 and 4 × 10−5 m−1 and are typical for the lithosphere or the upper mantle. Furthermore, the total quality factors for So waves below 5 Hz are between 20 and 500 and are well below estimates from previous modelling for observations in the Pacific Ocean. This implies that the Atlantic Ocean is more attenuative for So waves compared to the Pacific Ocean, which is inline with the expected behaviour for the lithospheric structures resulting from the slower spreading rates in the Atlantic Ocean. The results for the analysed events indicate that for frequencies above 3 Hz, intrinsic attenuation is equal to or slightly stronger than scattering attenuation and that the So-wave coda is weakly influenced by the oceanic crust. Both observations are in agreement with the proposed propagation mechanism of scattering in the oceanic mantle lithosphere. Furthermore, we observe an age dependence which shows that an increase in lithospheric age is associated with a decrease in attenuation. However, we also observe a trade-off of this age-dependent effect with either a change in lithospheric thickness or thermal variations, for example due to small-scale upwellings in the upper mantle in the southeast close to Madeira and the Canaries. Moreover, the influence of the nearby Gloria fault is visible in a reduction of the intrinsic attenuation below 3 Hz for estimates across the fault. This is the first study to estimate seismic scattering and absorption parameters of So waves for an area with several hundreds of kilometres radius centred in the Eastern North Atlantic and using them to characterize the nature of the oceanic lithosphere.

Description: The subsidence history of forearc and back-arc basins reflects the relationship between subduction kinematics, mantle dynamics, magmatism, crustal tectonics, and surface processes. The distinct contributions of these processes to the topography variations of active margins during subduction initiation, oceanic subduction, and collision are less understood. We ran 2D elasto-visco-plastic numerical models including surface and hydration processes. The models show the evolution of wedge-top and retro-forearc basins on the continental overriding plate, separated by a forearc high. They are affected by repeated compression and extension phases. Compression-induced subsidence is recorded in the syncline structure of the retro-forearc basin from the onset of subduction. The 2–4 km upper plate negative residual topography is produced by the gradually steepening slab, which drags down the upper plate. Trench retreat leads to slab unbending and decreasing slab dip angle that leads to upper plate trench-ward tilting. Back-arc basins are either formed along inherited weak zones at a large distance from the arc or are created above the hydrated mantle wedge originating from arc rifting. Back-arc subsidence is primarily governed by crustal thinning that is controlled by slab roll-back and supported by the underlying mantle convection. High subduction and mantle convection velocities result in large wavelength negative dynamic topography. Collision and continental subduction are linked to the uplift of the forearc basins; however, the back-arc records ongoing extension during a soft collision. During the hard collision, both the forearc and back-arc basins are ultimately affected by the compression. Our modeling results provide insights into the evolution of Mediterranean subduction zones.

Description: Für eine erfolgreiche Umsetzung der Wärmewende sind unter anderem kom- munale Energieversorger in der Verant- wortung. Deutschlands größte und 2021 in Betrieb genommene Geothermiean- lage »Schäftlarnstraße« der Stadtwerke München (SWM) mit drei geothermalen Dubletten in München-Sendling soll dazu beitragen, bis 2035 eine Klimaneutralität zu erreichen und den Bedarf an Wärme in München CO2-neutral zu decken. Zur strukturellen Überwachung der Bohrloch- konstruktion und zur Unterstützung einer sicheren und nachhaltigen Bewirtschaf- tung der Wärmequelle wurde bereits im Jahr 2019 ein Glasfaserkabel in einer der Produktionsbohrungen bis Endteufe eingebracht.

Description: We use a fully coupled hydro-thermal model (TH) to quantify changes in the pore pressure and temperature distribution following the Last Glacial Maximum (LGM) in the intracontinental basins in Central and Northern Europe. We demonstrate that even without considering a direct mechanical coupling from the visco-elastic lithosphere rebound, the system is, at present-day, in a state of hydrogeologic and thermal disequilibrium as a result of the past ice sheet dynamics. We find that the local geology exerts an additional control on the subsurface response to imposed glacial loading, as evidenced by a contrasting thermal and pore pressure configuration in time and space. Highest rates of pore pressure dissipation are restricted to crustal domains that underwent substantial glacial loading, while the majority of the sedimentary sub-basins show a prominent signature of hydraulic disequilibrium (overpressure) at present. Groundwater-driven convective cooling and heating during the advance and retreat of the ice cap occurred mainly within sedimentary rocks, domains where thermal equilibration is ongoing. The spatial correlation between modeled pore pressure dissipation rates and postglacial uplift rates is indicative of a complex and transient hydrogeological system structurally connected to the viscous tail of the ongoing isostatic adjustment after the LGM, with important implications for assessing the long-term mechanical stability of this intraplate setting.

Description: Two novel satellite LiDAR missions —GEDI and ICESat-2— are currently operational and combined provide near-global measurements of forest height and structure. Such data underpin a new era of large-area approaches for measuring forest height in regrowing forests of different ages and assessing associated regrowth rates. Two LiDAR missions further allow for comparing independently derived forest heights and regrowth rates. This study utilized both GEDI and ICESat-2 measurements to assess regrowth rates in regrowing forests of different ages for the Brazilian state Rondônia. We considered 19 data subgroups stratified by beam strength, light condition, beam sensitivity, and waveform processing algorithm to assess the retrieval uncertainty and identify data subgroups associated with the most reliable regrowth estimates. The quality assessment of GEDI and ICESat-2 forest heights over four 50 km long airborne LiDAR strips determined a root mean square error of 4.14 m (CV = 17%) and 5.91 m (CV = 19%) and a mean error of 0.04 m and −2.81 m, respectively. A linear calibration model between satellite- and airborne-LiDAR heights was then derived for each data subgroup and used to calibrate satellite heights. Forest regrowth rates were subsequently estimated for each satellite mission using a space-for-time imputation with forest heights’ medians per stand age class. The total growth of GEDI and ICESat-2 median forest heights after 33 years was 20.17 m (SE = 1.3 m) and 20.13 m (SE = 2.8 m), respectively. However, when growth was approximated with different non-linear models, the total growth differed by up to 6%, and the average regrowth rate even by up to 23%. The study revealed that omitting either the calibration step or the removal of secondary-forest-border pixels would result in an underestimation of the regrowth rate by more than 20%. Furthermore, the ICESat-2 weak beams were found unreliable for regrowth retrieval. The study showed that the novel satellite LiDAR data and the proposed methods could assess median forest height growth over large areas. However, forest age errors should also be accounted for in the retrieval uncertainty before comparing the growth estimates across different regions. Code and data necessary to reproduce the results are freely available on GitHub and Zenodo.

Description: The immense advances in computer power achieved in the last decades have had a significant impact in Earth science, providing valuable research outputs that allow the simulation of complex natural processes and systems, and generating improved forecasts. The development and implementation of innovative geoscientific software is currently evolving towards a sustainable and efficient development by integrating models of different aspects of the Earth system. This will set the foundation for a future digital twin of the Earth. The codification and update of this software require great effort from research groups and therefore, it needs to be preserved for its reuse by future generations of geoscientists. Here, we report on Geo-Soft-CoRe, a Geoscientific Software & Code Repository, hosted at the archive DIGITAL.CSIC. This is an open source, multidisciplinary and multiscale collection of software and code developed to analyze different aspects of the Earth system, encompassing tools to: 1) analyze climate variability; 2) assess hazards, and 3) characterize the structure and dynamics of the solid Earth. Due to the broad range of applications of these software packages, this collection is useful not only for basic research in Earth science, but also for applied research and educational purposes, reducing the gap between the geosciences and the society. By providing each software and code with a permanent identifier (DOI), we ensure its self-sustainability and accomplish the FAIR (Findable, Accessible, Interoperable and Reusable) principles. Therefore, we aim for a more transparent science, transferring knowledge in an easier way to the geoscience community, and encouraging an integrated use of computational infrastructure.

Description: We experimentally determined the hydraulic properties of fractures within various rock types, focusing on a variety of Variscan rocks. Flow-through experiments were performed on slate, graywacke, quartzite, granite, natural fault gouge, and claystone samples containing an artificial fracture with a given roughness. For slate samples, the hydraulic transmissivity of the fractures was measured at confining pressures, pc, at up to 50 MPa, temperatures, T, between 25 and 100 °C, and differential stress, σ, acting perpendicular to the fracture surface of up to 45 MPa. Fracture transmissivity decreases non-linearly and irreversibly by about an order of magnitude with increasing confining pressure and differential stress, with a slightly stronger influence of pc than of σ. Increasing temperature reduces fracture transmissivity only at high confining pressures when the fracture aperture is already low. An increase in the fracture surface roughness by about three times yields an initial fracture transmissivity of almost one order of magnitude higher. Fractures with similar surface roughness display the highest initial transmissivity within slate, graywacke, quartzite and granite samples, whereas the transmissivity in claystone and granitic gouge material is up to several orders of magnitude lower. The reduction in transmissivity with increasing stress at room temperature varies with composition and uniaxial strength, where the deduction is lowest for rocks with a high fraction of strong minerals and associated high brittleness and strength. Microstructural investigations suggest that the reduction is induced by the compaction of the matrix and crushing of strong asperities. Our results suggest that for a given surface roughness, the fracture transmissivity of slate as an example of a target reservoir for unconventional EGS, is comparable to that of other hard rocks, e.g., granite, whereas highly altered and/or clay-bearing rocks display poor potential for extracting geothermal energy from discrete fractures.

Description: Dense hydrous magnesium silicates (DHMSs) with large water content and wide stability fields are a potential H2O reservoir in the deep Earth. Al-bearing superhydrous phase B (shy-B) with a wider stability field than the Al-free counterpart can play an important role in understanding H2O transport in the Earth’s transition zone and topmost lower mantle. In this study, a nominally Al-free and two different Al-bearing shy-B with 0.47(2) and 1.35(4) Al atoms per formula unit (pfu), were synthesized using a rotating multi-anvil press. The single-crystal structures were investigated by X-ray diffraction (XRD) complemented by Raman spectroscopy, and Fourier-transform infrared spectroscopy (FTIR). Single-crystal XRD shows that the cell parameters decrease with increasing Al-content. By combining X-ray diffraction and spectroscopy results, we conclude that the Al-poor shy-B crystallizes in the Pnn2 space group with hydrogen in two different general positions. Based on the results of the single crystal X-ray diffraction refinements combined with FTIR spectroscopy, three substitutions mechanisms are proposed: 2 Al3+ = Mg2+ + Si4+; ☐Mg2+ = 2H+; Si4+ = Al3+ + H+. Thus, in addition to the two general H positions, hydrogen is incorporated into the hydrous mineral via point defects. The elastic stiffness coefficients were measured for the Al-shy-B with 1.35 pfu Al by Brillouin scattering (BS). Al-bearing shy-B shows lower C11, higher C22 and similar C33 when compared to Al-free shy-B. The elastic anisotropy of Al-bearing shy-B is also higher than that of the Al-free composition. Such different elastic properties are due to the effect of lattice contraction as a whole and the specific chemical substitution mechanism that affect bonds strength. Al-bearing shy-B with lower velocity, higher anisotropy and wider thermodynamic stability can help to understand the low velocity zone and high anisotropy region in the subducted slab located in Tonga.

Description: de-climate-change-analysis provides statistical analysis and plotting functions to determine absolute and relative changes in climate variables. It is used by the Digital Earth Climate Change Backend Module as part of the Digital Earth Flood Event Explorer. It is developed at the Helmholtz-Zentrum Hereon (https://www.hereon.de) in collaboration with the GFZ German Research Centre for Geosciences (https://www.gfz-potsdam.de) and funded by the Initiative and Networking Fund of the Helmholtz Association through the Digital Earth project (https://www.digitalearth-hgf.de/).

Description: de-smart-monitoring-backend-module provides geo-data acquisition and processing functions, exposed through the DASF RPC messaging protocol. It is used by the Smart Monitoring Workflow (Tocap) as part of the Digital Earth Flood Event Explorer. It is developed at the Helmholtz Centre for Environmental Research - UFZ Leipzig (https://www.ufz.de) in collaboration with the GFZ German Research Centre for Geosciences (https://www.gfz-potsdam.de) and funded by the Initiative and Networking Fund of the Helmholtz Association through the Digital Earth project (https://www.digitalearth-hgf.de/). The module contains three major submodules: data acquisition submodule provided through downloader.py data processing submodule provided through rasterprocessing.py routing submodule provided through rasterrouter.py Detailed submodule descriptions can be found in the git repository readme.

Description: de-change-backend-module wraps the de-climate-change-analysis library and exposes it's statistical analysis and plotting functions to determine absolute and relative changes in climate variables via the DASF RPC messaging protocol. It is used by the Climate Change Workflow as part of the Digital Earth Flood Event Explorer. It is developed at the GFZ German Research Centre for Geosciences (https://www.gfz-potsdam.de) in collaboration with the Helmholtz-Zentrum Hereon (https://www.hereon.de) and funded by the Initiative and Networking Fund of the Helmholtz Association through the Digital Earth project (https://www.digitalearth-hgf.de/).

Description: Subduction zones, where one tectonic plate slides underneath the other, host the largest earthquakes on Earth. These zones are characterized by intense earthquake activity and are responsible for 95 % of all moment releases on Earth. The shallow portion of the subduction zone interface (i.e., megathrust) generated the largest ever recorded earthquakes, such as the 1960 Valdivia earthquake in Chile, the 2004 Sumatra earthquake in Indonesia, and the 2011 Tohoku-Oki earthquake in Japan on the Earth. Unwrapping the behavior of this portion of the subduction zone, which generates the most significant earthquakes and devastating tsunamis, is a vital step forward in earthquake geoscience. Monitoring only a fraction of a single megathrust earthquake cycle and the offshore location of the source of these earthquakes are the foremost reasons for the insufficient understanding. The insufficient offshore observation and the interseismic data incompleteness led earthquake scientists to employ analog and numerical modeling approaches to unfold the linkage between short-term elastic (i.e., coseismic) and long-term permanent (i.e., several seismic cycles) deformation of the subduction zones. Revealing these relationships allows us to identify which long and short-term signals earthquake scientists should look for remotely or in the field to unwrap the subduction zone’s seismic cycle history. In this research, I investigate a simplified analog model of a subduction zone from trench to the location of volcanic arc and 240 km along strike using elastoplastic granular material and stick-slip analog material at a laboratory scale. Establishing generic seismotectonic scale models enables me to generate hundreds of megathrust seismic cycles and monitor the earthquake-related surface and cross-sectional deformation pattern at high resolution in both space and time. I attempt to demonstrate what surface deformation signals the frictional and mechanical changes on the interface generates over coseismic and early postseismic stages and interseismic intervals. Additionally, at a more extended time scale (tens to hundreds of earthquake cycles), I study what surface strain pattern in the forearc from the trench to the coastal region can be permanently preserved. This provides critical observations for earthquake geoscientists to tie forearc surface deformation to subsurface elastoplastic processes at the shallow portion of the subduction interface. I apply a geodetic slip inversion technique to analog trench-breaking and non-trench-breaking megathrust earthquakes to demonstrate how limited offshore geodetic coverage affects coseismic slip models. The slip models derived from analog earthquakes show quantitative and qualitative changes as a function of offshore coverage: 1) Shallow slip cannot be resolved if the observation coverage of the offshore segment is 〈50%. 2) the slip pattern of shallow event flips from landward to trenchward skewed as offshore coverage reduces to 〈40%. 3) In the case of no offshore coverage, the slip pattern for both event types converges to a similar unimodal pattern. Additionally, I infer 5-20% slip overestimation when the observations are above the high slipping zone during trench-breaking events versus 5-10% underestimation during non-trench-breaking events if observations are land-limited. Moreover, the moment magnitude derived for trench-breaking ruptures might be affected. Furthermore, I mimic homogenous and heterogeneous megathrust interfaces at the laboratory scale to monitor the strain relaxation on the two elastically non-identical plates by establishing analog velocity weakening and strengthening materials. I propose a sequential elastic rebound that follows the coseismic shear-stress drop in the elastic-frictional models: a fast rebound of the upper plate and the delayed and smaller rebound on the slab. The delayed rebound of the slab, along with the rapid relaxation of the upper plate after an elastic overshooting, accelerates the relocking of the megathrust. This acceleration triggers/antedates the failure of a nearby asperity and enhances the early backslip in the rupture area. The long-term frictional-elastoplastic interaction between the interface and its overlying wedge causes variable surface strain signals. I establish two coseismically compressional and extensional wedge configurations to explore the mechanical and kinematic interaction between the shallow wedge and the interface. The results demonstrate that this interaction can partition the wedge into different segments. I highlight that a more segmented upper plate represents a subduction megathrust that generates more characteristic and periodic events. Moreover, the results illustrate that different wedge segments may switch their state from compression/extension to extension/compression domains. Additionally, the strain time series of the coastal zone reveals that the strain state may remain quasi-stable over a few seismic cycles before switching to the opposite mode. These observations are key for evaluating earthquake-related morphotectonic markers (i.e., marine terraces) and short-term interseismic GPS time-series onshore (coastal region).

Description: In Subduktionszonen, in denen sich eine tektonische Platte unter die andere schiebt, ereignen sich die größten Erdbeben der Erde. Diese Zonen zeichnen sich durch eine starke Erdbebentätigkeit aus und sind für 95 % der Energiefreisetzung durch Erdbeben auf der Erde verantwortlich. Der obere Teil der Subduktionszone (d. h. die Megathrust) erzeugte die größten jemals aufgezeichneten Erdbeben wie das Valdivia-Erdbeben von 1960 in Chile, das Sumatra-Erdbeben von 2004 in Indonesien und das Tohoku-Oki-Erdbeben von 2011 in Japan. Die Entschlüsselung des Verhaltens dieses Teils der Subduktionszone, der die bedeutendsten Erdbeben und verheerenden Tsunamis hervorruft, ist ein entscheidender Schritt nach vorn in der Erdbebengeowissenschaft. Die Beobachtung von nur einem Bruchteil eines einzelnen Megathrust-Erdbebenzyklus und die Offshore-Lage der Quelle dieser Erdbeben sind die Hauptgründe für das unzureichende Verständnis. Die unzureichende Offshore-Beobachtung und die Unvollständigkeit der interseismischen Daten haben die Erdbebenforscher dazu veranlasst, analoge und numerische Modellierungsansätze anzuwenden, um den Zusammenhang zwischen kurzfristiger elastischer (d. h. koseismischer) und langfristiger permanenter (d. h. mehrere seismische Zyklen umfassender) Verformung der Subduktionszonen aufzudecken. Die Aufdeckung dieser Beziehungen ermöglicht es uns, zu ermitteln, nach welchen lang- und kurzfristigen Signalen Erdbebenforscher suchen sollten, um die seismische Zyklusgeschichte der Subduktionszone zu entschlüsseln. In dieser Forschungsarbeit untersuche ich ein vereinfachtes analoges Modell einer Subduktionszone vom Tiefseegraben bis zum Vulkanbogen und etwa 240 km entlang des Streichens der Subduktionszone unter Verwendung von elastoplastischem granularem Material und analogem Stick-Slip-Material im Labormaßstab. Die Erstellung allgemeiner seismotektonischer Modelle ermöglicht es mir, Hunderte von seismischen Megathrust-Erdbebenzyklen zu erzeugen und die erdbebenbedingten Oberflächen- und Querschnittsverformungsmuster mit hoher räumlicher und zeitlicher Auflösung zu überwachen. Ich versuche zu demonstrieren, welche Oberflächendeformationssignale die Reibung und die mechanischen Veränderungen an der Grenzfläche über koseismische und frühe postseismische Phasen und interseismische Intervalle hinweg erzeugen. Darüber hinaus untersuche ich auf einer längeren Zeitskala (Dutzende bis Hunderte von Erdbebenzyklen), welche Oberflächendeformationsmuster im Forearc, vom Graben bis zur Küstenregion, dauerhaft erhalten werden können. Dies liefert den Erdbebengeowissenschaftlern wichtige Beobachtungen, um die Oberflächendeformation des Plattenrandes mit den elastoplastischen Prozessen unter der Oberfläche im flachen Teil der Subduktionsgrenze zu verbinden. Ich wende eine geodätische Inversionstechnik zur Ableitung des koseismischen Versatzes entlang der Megathrust auf analoge grabenbrechende und nicht grabenbrechende Megathrust Erdbeben an, um zu demonstrieren, wie eine begrenzte geodätische Offshore-Abdeckung koseismische Versatzmodelle beeinflusst. Die aus analogen Erdbeben abgeleiteten Versatzmodelle zeigen quantitative und qualitative Veränderungen in Abhängigkeit von der Offshore-Abdeckung: 1) Flacher Versatzkann nicht aufgelöst werden, wenn die Beobachtungsabdeckung des Offshore-Segments 〈50% ist. 2) Das Versatzsmuster eines flachen Ereignisses kippt von landwärts zu grabenwärts vergent, wenn die Offshore-Abdeckung auf 〈40% sinkt. 3) Im Falle keiner küstennahen Abdeckung konvergiert das Versatzmuster für beide Ereignistypen zu einem ähnlichen unimodalen Muster. Darüber hinaus schließe ich auf eine 5-20%ige Überschätzung des Versatzes, wenn die Beobachtungen oberhalb der flachen Versatzzone während grabenbrechenden Ereignissen liegen, gegenüber einer 5-10%igen Unterschätzung während nicht grabenbrechenden Ereignissen, wenn die Beobachtungen landgebunden sind. Außerdem kann die für grabenbrechende Brüche abgeleitete Momentgröße beeinflusst werden. Darüber hinaus ahme ich homogene und heterogene Megathrust-Grenzflächen im Labormaßstab nach, um die Dehnungsrelaxation an den beiden elastisch nicht identischen Platten zu überwachen, indem ich analoge Materialien einsetze, die ratenabhängige Festigkeiten zeigen. Ich schlage einen sequentiellen elastischen Rebound vor, der dem koseismischen Scherspannungsabfall in den elastischen Reibungsmodellen folgt: einen schnellen Rebound der oberen Platte und den verzögerten und kleineren Rebound an der abtauchenden Platte. Der verzögerte Rebound der abtauchenden Platte, zusammen mit der schnellen Entspannung der oberen Platte nach einem elastischen Überschießen, beschleunigt die Wiederkopplung der Megathrust. Diese Beschleunigung löst/begünstigt das Versagen einer nahe gelegenen Asperity und verstärkt das frühe Rückgleiten im Bruchbereich. Die langfristige reibungs-elastoplastische Wechselwirkung zwischen der Grenzfläche und dem darüber liegenden Keil verursacht variable Oberflächendehnungssignale. Ich habe zwei Keilkonfigurationen mit koseismischer Kompression und Dehnung erstellt, um die mechanische und kinematische Wechselwirkung zwischen dem flachen Keil und der Grenzfläche zu untersuchen. Die Ergebnisse zeigen, dass diese Wechselwirkung den Keil in verschiedene Segmente aufteilen kann. Ich hebe hervor, dass eine stärker segmentierte obere Platte eine Subduktions-Megathrust darstellt, die mehr charakteristische und periodische Ereignisse erzeugt. Darüber hinaus veranschaulichen die Ergebnisse, dass verschiedene Keilsegmente ihren Zustand von Kompressions-/Dehnungs- zu Extensions-/Kompressionsbereichen wechseln können. Darüber hinaus zeigt die Zeitreihe der Dehnungen in der Küstenzone, dass der Dehnungszustand über einige seismische Zyklen quasistabil bleiben kann, bevor er in einen entgegengesetzten Verkürzuungs-Modus übergeht. Diese Beobachtungen sind von entscheidender Bedeutung für die Bewertung erdbebenbedingter morphotektonischer Marker (z. B. Meeresterrassen) und kurzfristiger interseismischer GPS-Zeitserien an Land (Küstenregion).

Description: Gypsum crystals are found at the well perforation of observation well Ktzi 202 of the test site for CO2 storage at Ketzin, Germany. XRD analysis confirms pure gypsum. Fluid samples before and after CO2 injection are analyzed. Geochemical modeling is conducted to identify the mechanisms that lead to gypsum formation. The modeling is carried out with PHREEQC and Pitzer database due to the high salinity of up to 5 mol per kg water. Due to their significantly higher reactivity compared to other minerals like silicates, calcite, dolomite, magnesite, gypsum, anhydrite, and halite are considered as primary mineral phases for matching the observed brine compositions in our simulations. Calcite, dolomite, and gypsum are close to saturation before and after CO2 injection. Dolomite shows the highest reactivity and mainly contributes to buffering the brine pH that initially decreased due to CO2 injection. The contribution of calcite to the pH-buffering is only minor. Gypsum and anhydrite are no geochemically active minerals before injection. After CO2 injection, gypsum precipitation may occur by two mechanisms: (i) dissociation of CO2 decreases activity of water and, therefore, increases the saturation of all minerals and (ii) dolomite dissolution due to pH-buffering releases Ca2+ ions into solution and shifts the mass action to gypsum. Gypsum precipitation decreases with increasing temperature but increases with increasing partial CO2 pressure. Our calculations show that calcium sulfate precipitation increases by a factor of 5 to a depth of 2000 m when Ketzin pressure and temperature are extrapolated. In general, gypsum precipitation constitutes a potential clogging hazard during CO2 storage and could negatively impact safe site operation. In the presented Ketzin example, this threat is only minor since the total amount of gypsum precipitation is relatively small.

Description: Strain NGK65T, a novel hexadecane degrading, non-motile, Gram-positive, rod-to-coccus shaped, aerobic bacterium, was isolated from plastic polluted soil sampled at a landfill. Strain NGK65T hydrolysed casein, gelatin, urea and was catalase-positive. It optimally grew at 28 °C, in 0–1% NaCl and at pH 7.5–8.0. Glycerol, d-glucose, arbutin, aesculin, salicin, potassium 5-ketogluconate, sucrose, acetate, pyruvate and hexadecane were used as sole carbon sources. The predominant membrane fatty acids were iso-C16:0 followed by iso-C17:0 and C18:1 ω9c. The major polar lipids were phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and hydroxyphosphatidylinositol. The cell-wall peptidoglycan type was A3γ, with ll-diaminopimelic acid and glycine as the diagnostic amino acids. MK 8 (H4) was the predominant menaquinone. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NGK65T belongs to the genus Nocardioides (phylum Actinobacteria), appearing most closely related to Nocardioides daejeonensis MJ31T (98.6%) and Nocardioides dubius KSL-104T (98.3%). The genomic DNA G+C content of strain NGK65T was 68.2%. Strain NGK65T and the type strains of species involved in the analysis had average nucleotide identity values of 78.3–71.9% as well as digital DNA–DNA hybridization values between 22.5 and 19.7%, which clearly indicated that the isolate represents a novel species within the genus Nocardioides. Based on phenotypic and molecular characterization, strain NGK65T can clearly be differentiated from its phylogenetic neighbours to establish a novel species, for which the name Nocardioides alcanivorans sp. nov. is proposed. The type strain is NGK65T (=DSM 113112T=NCCB 100846T).

Description: It is well established that nighttime radiance, measured from satellites, correlates with economic prosperity across the globe. In developing countries, areas with low levels of detected radiance generally indicate limited development – with unlit areas typically being disregarded. Here we combine satellite nighttime lights and the world settlement footprint for the year 2015 to show that 19% of the total settlement footprint of the planet had no detectable artificial radiance associated with it. The majority of unlit settlement footprints are found in Africa (39%), rising to 65% if we consider only rural settlement areas, along with numerous countries in the Middle East and Asia. Significant areas of unlit settlements are also located in some developed countries. For 49 countries spread across Africa, Asia and the Americas we are able to predict and map the wealth class obtained from ~2,400,000 geo-located households based upon the percent of unlit settlements, with an overall accuracy of 87%.

Description: Die Muschelkalk-Gruppe ist in der STD 2016 in die Zeit vom frühen Anisium (Bithynium) bis zum frühen Ladinium (Fassanium) eingestuft. Nach Beschlüssen der Subkommission Perm-Trias der Deutschen Stratigraphischen Kommission werden die Grenzen der Muschelkalk-Gruppe gegen die Buntsandstein- und die Keuper-Gruppe an weit aus- haltenden Leitbänken gezogen, die annähernd isochron sind. Leitbänke liegen auch der internen Gliederung in die Folgen m1 bis m9, regionalen geochronologischen Einheiten, zugrunde. Für den Unteren Muschelkalk wurden von verschiedenen Autoren 19 bis 29 kleinmaßstäbliche Zyklen angegeben. Der STD 2016 wurden 21 Zyklen zugrunde gelegt, denen je 100 ka zugerechnet wurden. Die in die STD eingegangenen 11 Zyklen im Mittleren und 38 Zyklen im Oberen Muschelkalk bedür- fen vertiefender Untersuchungen. Neben den an Leitbänke gelegten nahezu isochronen Grenzen verlaufen Grenzziehungen an Fazieswechseln regional diachron: (1) So beginnt die für den Muschelkalk typische Karbonatsedimentation im östlichen Beckenteil (Polen) mit der Unteren Gogolin-Formation, in deren zeitlichem Äquivalent im westlichen Beckenteil (Dorn- burg-Subformation der Röt-Formation, früher: Myophorienschichten) über Karbonatfazies noch einmal bunte und sandige Tonsteinfazies auftritt und deshalb in Deutschland zur Buntsandstein-Gruppe gestellt wird, und (2) endet im polnischen und nordostdeutschen Beckenteil mit Einsetzen der von Norden vorrückenden feinklastischen und z. T. bunten Fazies bereits im frühesten Ladinium. Im weitaus größten Teil des Mitteleuropäischen Beckens werden im Muschelkalk sieben Formationen ausgehalten, die z. T. weitflächig durch Leitbänke und damit annähernd isochron begrenzt sind. Die Folgen m1 bis m9 wer- den durch Leitbänke begrenzt. Wo die Grenzen von Formationen und Folgen identisch sind, erleichtern sie eine zeitliche Sicht auf die Erdentwicklung. Wo sich die Fazies hin zu den Beckenrändern stark ändert, wurden regional begrenzte, z. T. gruppenübergreifende Formationen mit überwiegend diachronen Grenzen aufgestellt. Die Muschelkalk-Gruppe wird bio- stratigraphisch anhand von Cephalopoden und Conodonten und daneben auch mit weiteren Invertebraten, Vertebraten und Palynomorphen in Zonen gegliedert. Da für die Muschelkalk-Gruppe selbst keine radio-isotopischen Altersbestimmungen (RIA) vorliegen, basieren alle Altersschätzungen auf der Annahme, dass die sedimentären Zyklen orbital-klimatisch indu- ziert sind, sowie auf der Integration globaler RIA in die Muschelkalkabfolge mithilfe biostratigraphischer Korrelationen mit der tethyalen Trias. Die Anisium-Ladinium-Grenze, datiert in der STD 2016 auf ca. 241 Ma, ist die einzige globale Stufen- grenze innerhalb des Muschelkalks und liegt im Bereich der Cycloidesbank im oberen Teil des Oberen Muschelkalks. Für die STD 2016 wurde für den Muschelkalk mit 7 Ma eine maximale Dauer gewählt. Diskutiert wird hier eine verkürzte Ab- schätzung der Muschelkalk-Dauer von 5,2 Ma bzw. 4,8 Ma, die weithin konsistent mit den RIA ist. In the Stratigraphic Table of Germany 2016 (STG 2016, STD 2016) the Muschelkalk Group has been assessed as early Anisian (Bithynian) through early Ladinian (Fassanian). Following decisions of the Permian-Triassic Subcommission (SKPT) in the German Stratigraphic Commission (DSK), the boundaries of the Muschelkalk Group against the Buntsand- stein and Keuper groups have been fixed at widespread marker beds that are nearly isochronous. The internal subdivision into the regional geochronological units Folge m1 to m9 is also based on marker beds. The number of Lower Muschelkalk small-scale cycles has been estimated by different authors as 19 to 29. In the STG 2016, 21 cycles of 100 ka duration are assessed, whereas the numbers of 11 cycles for the Middle and 38 for the Upper Muschelkalk still require additional re- search. While marker bed-based boundaries are nearly isochronous, unit boundaries based on facies changes are diachronous on a regional scale: (1) in the eastern part of the basin (Poland), the typical Muschelkalk carbonate sedimentation com- mences with the Lower Gogolin Formation, time equivalent of the carbonatic Dornburg Subformation (Member) of the Röt Formation (former Myophoria Beds) in the western basin parts, which is overlain by variegated and sandy claystone and hence attributed to the Buntsandstein Group, and (2) in the Polish and northeast German basin parts the carbonatic facies ended already in earliest Ladinian times. In the largest parts of the Central European Basin, the Muschelkalk Group is con- stituted according to SKPT decisions of seven formations which are mostly delimited by nearly isochronous and widespread marker beds. Identical boundaries of formations and allostratigraphic marker bed-based Folgen (m1 through m9) are favour- able for understanding the basin history. Where significant facies changes occur towards the basin margins, regional forma- tions with mostly diachronous boundaries were established, some of which are covering the equivalents of more than one group of the basinal facies. The Muschelkalk Group is biostratigraphically subdivided in biozones by means of cephalopods and conodonts and also by additional invertebrate and vertebrate groups, and palynomorphs. Since no radio-isotopic age determinations (RIA) are available for the Muschelkalk Group itself, all age estimates have to be based on the hypothesis that Muschelkalk sedimentary cycles are caused orbital-climatically and by integration of global RIA into the Muschelkalk succession using biostratigraphic correlations with the Tethyan Triassic. The Anisian-Ladinian boundary, dated in the STG 2016 at ca. 241 Ma, is the only global stage boundary within the Muschelkalk Group, located in the vicinity of the Cycloides- bank in the upper part of the Upper Muschelkalk. In the STG 2016, a maximum estimate of 7 Ma for the Muschelkalk Group was chosen. Additional estimations are discussed which indicate shorter Muschelkalk durations of 5.2 Ma or 4.8 Ma respec- tively and are nearly consistent with the RIA.

Description: The demand for mobile applications in agriculture is increasing as smartphones are continuously developed and used for many purposes; one of them is managing pests and diseases in crops. Using mobile applications, farmers can detect early infection and improve the specified treatment and precautions to prevent further infection from occurring. Furthermore, farmers can communicate with agricultural authorities to manage their farm from home, and efficiently obtain information such as the spectral signature of crops. Therefore, the spectral signature can be used as a reference to detect pests and diseases with a hyperspectral sensor more efficiently than the conventional method, which takes more time to monitor the entire crop field. This review aims to show the current and future trends of mobile computing based on spectral signature analysis for pest and disease management. In this review, the use of mobile applications for pest and disease monitoring is evaluated based on image processing, the systems developed for pest and disease extraction, and the structure of steps outlined in developing a mobile application. Moreover, a comprehensive literature review on the utilisation of spectral signature analysis for pest and disease management is discussed. The spectral reflectance used in monitoring plant health and image processing for pest and disease diagnosis is mentioned. The review also elaborates on the integration of a spectral signature library within mobile application devices to obtain information about pests and disease in crop fields by extracting information from hyperspectral datasets. This review demonstrates the necessary scientific knowledge for visualising the spectral signature of pests and diseases using a mobile application, allowing this technology to be used in real-world agricultural settings.

Description: In the global methane budget, the largest natural source is attributed to wetlands, which encompass all ecosystems composed of waterlogged or inundated ground, capable of methane production. Among them, northern peatlands that store large amounts of soil organic carbon have been functioning, since the end of the last glaciation period, as long-term sources of methane (CH4) and are one of the most significant methane sources among wetlands. To reduce uncertainty of quantifying methane flux in the global methane budget, it is of significance to understand the underlying processes for methane production and fluxes in northern peatlands. A methane model that features methane production and transport by plants, ebullition process and diffusion in soil, oxidation to CO2, and CH4 fluxes to the atmosphere has been embedded in the ORCHIDEE-PEAT land surface model that includes an explicit representation of northern peatlands. ORCHIDEE-PCH4 was calibrated and evaluated on 14 peatland sites distributed on both the Eurasian and American continents in the northern boreal and temperate regions. Data assimilation approaches were employed to optimized parameters at each site and at all sites simultaneously. Results show that methanogenesis is sensitive to temperature and substrate availability over the top 75 cm of soil depth. Methane emissions estimated using single site optimization (SSO) of model parameters are underestimated by 9 g CH4 m−2 yr−1 on average (i.e., 50 % higher than the site average of yearly methane emissions). While using the multi-site optimization (MSO), methane emissions are overestimated by 5 g CH4 m−2 yr−1 on average across all investigated sites (i.e., 37 % lower than the site average of yearly methane emissions).

Description: Based on a viscoelastic earthquake‐cycle deformation model, we revisit the fault locking of the central Himalayan thrust using geodetic data acquired in the past three decades. By incorporating the viscoelastic relaxation effect induced by stress buildup and release, our viscoelastic model is capable of explaining the far‐field observation with similar fault locking width obtained in previous studies. Elastic models underestimate the far‐field deformation and consequently underestimate the fault slip rate by attributing the far‐field deformation to stable intraplate deformation. A steady‐state viscosity of ∼1019  Pa⋅s is required for the lower crust beneath south Tibet to best fit the crustal velocity. The optimal slip rate and locking width of the central Main Himalayan Thrust are estimated to 18.8 ± 1.6 mm/a and 85 ± 2.1 km, respectively. The inferred fault locking width, along with the down‐dip rupture extension of the 2015 Gorkha earthquake, agrees well with the identified mid‐crustal ramp, which leads to an interpretation that the fault geometry of the central Himalayan thrust plays an important role on fault kinematics. Our results highlight that viscoelastic relaxation during the earthquake cycle should be incorporated for robust estimation of fault locking parameters and reasonable data fitting.

Description: We present a new procedure for U–Pb dating of vesuvianite using laser ablation sector field inductively coupled plasma mass spectrometry (LA-SF-ICP-MS). Vesuvianite is a common mineral in skarn ore deposits and in metamorphic and metasomatic argillaceous carbonate rocks. The age of vesuvianite growth directly dates the formation of skarn mineralization, possibly also the metamorphism and metasomatism of argillaceous limestones. Vesuvianite U–Pb dating may provide age information for hydrothermal, metamorphic, and metasomatic processes that may be hard to get by zircon U–Pb dating. We analyzed eleven vesuvianite samples. Matrix effects were corrected by using Ti-bearing andradite (schorlomite) of known age as no well-characterized vesuvianite was available as a U–Pb reference material. The robustness of the analytical protocol was assessed by additional U–Pb dating of four vesuvianite samples by ID-TIMS. The U–Pb ages determined by ID-TIMS and LA-SF-ICP-MS agree well within uncertainties. An additional seven vesuvianite samples yielded in situ U–Pb ages that agree with previously published zircon, cassiterite, or wolframite U–Pb ages from the same area. Therefore, U–Pb dating of vesuvianite by LA-SF-ICP-MS represents a fast, relatively low-cost approach with high spatial resolution that may be particularly suited to date skarn mineralization.

Description: This paper reports microthermometric and noble gas isotope data for fluid inclusion assemblages (FIAs) with evidence of phase separation, i.e. coexisting vapor-rich and halite-saturated inclusions, hosted in the early-formed quartz stockwork veins and post-magmatic quartz eye crystals in two economic porphyry Cu deposits (PCDs; Sar Cheshmeh and Miduk) and two sub-economic prospects (Sar Kuh and Abdar) from the Kerman porphyry copper belt (KPCB), Iran. The multiphase halite-saturated inclusions (i.e., Type I) in all studied PCDs and prospects had the highest homogenization temperature (Th = 525–594 °C) and salinities (63–73 wt% NaClequiv), whereas vapor-rich inclusions (Type II) had lower Th (362–460 °C). Fluid inclusion data show that like economic PCDs, the sub-economic prospects were formed in a fertile hydrothermal system and benefited from a mineralizing fluid, which evolved from a primary hot (mostly 〉 400 °C), metal-rich and oxidized fluid (as evidenced by the presence of opaque- and hematite-bearing fluid inclusions) of unknown salinity, which underwent a phase separation process to form both brine and vapor phases in the early stage of mineralization. The helium abundance and its isotopic composition document a mantle-derived magmatic source for the primary ore fluid in the formation of the studied PCDs and prospects (3He/4He ratios ranging from 0.46 to 2.8 Ra, corresponding to a mantle He contribution in ore fluids between ~ 7 and 45%). However, subsequent hydrothermal processes, i.e., vapor–brine phase separation, fluid-rock interaction with crustal rocks, and mixing with meteoric pore water containing dissolved atmospheric (e.g., Ne and Xe) and some crustal noble gases (e.g., Ar), changed the initial noble gas composition of the magmatic ore fluid to predominantly atmospheric- and crustal-like compositions. A significant proportion of mantle-derived He (up to 45%) in high-temperature (513–594 °C) and high-salinity (61.5–73 wt% NaClequiv) FIAs may indicate the existence of buried, economic, porphyry Cu mineralization in the Abdar prospect; therefore, it is suggested to be a possible target for further exploration. Comparing the He and Ar noble gas isotope composition in porphyry copper systems of different size and economic importance in this study showed that the ore-forming fluids of the outsized PCD (i.e., Sar Cheshmeh) have higher contributions of crustal-derived fluids characterized by predominantly radiogenic noble gas signatures (4He and 40Ar) than the smaller PCDs. This could have been achieved by a prolonged hydrothermal circulation in a large volume of crustal rocks containing radiogenic noble gases under a long-lived heat regime resulting from a deeply emplaced and slowly cooled composite intrusive body.

Description: Women constitute a minority in the geoscience professional environment (around 30 %; e.g. UNESCO, 2015; Gonzales, 2019; Handley et al., 2020), and as a consequence, they are underrepresented in disaster risk reduction (DRR) planning. After examining the Sendai framework documents and data outputs, Zaidi and Fordham (2021) pointed out that the Sendai Framework for Disaster Risk Reduction 2015–2030 (SFDRR) has failed to promote women and girls' inclusion in disaster policy effectively. In addition, it represents a missed opportunity to tackle gender-based issues in DRR (even beyond the female–male dichotomy). Nevertheless, practical actions have been promoted and applied in several contexts with promising results, but often they only remain lessons learned in localised environments (Zaidi and Fordham, 2021). Instead, the global gender gap index, which includes political empowerment, economic participation and opportunity, educational attainment, health, and survival, reveals that the average distance completed to parity is only 68 % in 2019. Although the gap closing rate has constantly improved, it will take about 135.6 years to close it completely (WEF, 2021). These numbers do not yet account for 2020–2021 data, where the global pandemic has more strongly impacted women, their career, their opportunities, and their health in comparison with men (e.g. Alon et al., 2020; Chandler et al., 2021; Yildirim and Eslen-Ziya, 2021).

Description: Several severe flood events hit Germany in recent years, with events in 2013 and 2016 being the most destructive ones, although dynamics and flood processes were very different. While the 2013 event was a slowly rising widespread fluvial flood accompanied by some severe dike breaches, the events in 2016 were fast-onset pluvial floods, which resulted in surface water flooding in some places due to limited capacities of the drainage systems and in destructive flash floods with high sediment loads and clogging in others, particularly in small steep catchments. Hence, different pathways, i.e. different routes that the water takes to reach (and potentially damage) receptors, in our case private households, can be identified in both events. They can thus be regarded as spatially compound flood events or compound inland floods. This paper analyses how differently affected residents coped with these different flood types (fluvial and pluvial) and their impacts while accounting for the different pathways (river flood, dike breach, surface water flooding and flash flood) within the compound events. The analyses are based on two data sets with 1652 (for the 2013 flood) and 601 (for the 2016 flood) affected residents who were surveyed around 9 months after each flood, revealing little socio-economic differences – except for income – between the two samples. The four pathways showed significant differences with regard to their hydraulic and financial impacts, recovery, warning processes, and coping and adaptive behaviour. There are just small differences with regard to perceived self-efficacy and responsibility, offering entry points for tailored risk communication and support to improve property-level adaptation.

Description: A fourth of the global seabed sediment volume is buried at depths where temperatures exceed 80 °C, a previously proposed thermal barrier for life in the subsurface. Here, we demonstrate, utilizing an extensive suite of radiotracer experiments, the prevalence of active methanogenic and sulfate-reducing populations in deeply buried marine sediment from the Nankai Trough subduction zone, heated to extreme temperature (up to ~120 °C). The small microbial community subsisted with high potential cell-specific rates of energy metabolism, which approach the rates of active surface sediments and laboratory cultures. Our discovery is in stark contrast to the extremely low metabolic rates otherwise observed in the deep subseafloor. As cells appear to invest most of their energy to repair thermal cell damage in the hot sediment, they are forced to balance delicately between subsistence near the upper temperature limit for life and a rich supply of substrates and energy from thermally driven reactions of the sedimentary organic matter.

Description: In this pilot study, microplastic beads (5–50 μm) were tagged with fluorescent dye and introduced to the soil of potted Betula pendula Roth. (silver birch) saplings during the growing season. After five months, root samples were examined using fluorescence- and confocal laser scanning microscopy. This paper presents the first documented indication of the incorporation of microplastic into root tissues of woody plants and discusses the phytoremediation potential of birch in soil with microplastic contamination.

Description: Information provided by satellite data is becoming increasingly important in the field of agriculture. Estimating biomass, nitrogen content or crop yield can improve farm management and optimize precision agriculture applications. A vast amount of data is made available both as map material and from space. However, it is up to the user to select the appropriate data for a particular problem. Without the appropriate knowledge, this may even entail an economic risk. This study therefore investigates the direct relationship between satellite data from six different optical sensors as well as different soil and relief parameters and yield data from cereal and canola recorded by the thresher in the field. A time series of 13 years is considered, with 947 yield data sets consisting of dense point data sets and 755 satellite images. To answer the question of how well the relationship between remote sensing data and yield is, the correlation coefficient r per field is calculated and interpreted in terms of crop type, phenology, and sensor characteristics. The correlation value r is particularly high when a field and its crop are spatially heterogeneous and when the correct phenological time of the crop is reached at the time of satellite imaging. Satellite images with higher resolution, such as RapidEye and Sentinel-2 performed better in comparison with lower resolution sensors of the Landsat series. The additional Red Edge spectral band also has advantage, especially for cereal yield estimation. The study concludes that there are high correlation values between yield data and satellite data, but several conditions must be met which are presented and discussed here.

Description: Carbonate minerals are ubiquitous in most sediment-hosted mineral deposits. These deposits can contain a variety of carbonate types with complex paragenetic relationships. When normalized to chondritic values (CN), rare-earth elements and yttrium (REE+YCN) can be used to constrain fluid chemistry and fluid-rock interaction processes in both low- and high-temperature settings. Unlike other phases (e.g., pyrite), the application of in situ laser ablation-inductively coupled plasma-mass spectroscopy (LA-ICP-MS) data to the differentiation of pre-ore and hydrothermal carbonates remains relatively untested. To assess the potential applicability of carbonate in situ REE+Y data, we combined transmitted light and cathodoluminescence (CL) petrography with LA-ICP-MS analysis of carbonate mineral phases from (1) the Proterozoic George Fisher clastic dominated (CD-type) massive sulfide deposit and from (2) correlative, barren host rock lithologies (Urquhart Shale Formation). The REE+YCN composition of pre-ore calcite suggests it formed during diagenesis from diagenetic pore fluids derived from ferruginous, anoxic seawater. Hydrothermal and hydrothermally altered calcite and dolomite from George Fisher is generally more LREE depleted than the pre-ore calcite, whole-rock REE concentrations, and shale reference values. We suggest this is the result of hydrothermal alteration by saline Cl--rich mineralizing fluids. Furthermore, the presence of both positive and negative Eu/Eu* values in calcite and dolomite indicates that the mineralizing fluids were relatively hot (〉250°C) and cooled below 200–250°C during ore formation. This study confirms the hypothesis that in situ REE+Y data can be used to differentiate between pre-ore and hydrothermal carbonate and provide important constraints on the conditions of ore formation.

Description: The main objectives of this study were to evaluate the Cu, Zn, Pb, Cr and Ni mobility using modified Tessier sequential extraction procedure and to study the functional group changes affected by each extraction step using FTIR analysis in the soil of a former sewage farm sedimentation basin. Tessier extraction revealed element dependent fractionation of studied metals: Pb was mostly discovered in the residual fraction (77%) followed by Cr (53%), Cu (8%), and Zn (5%), while Ni was not extracted in this fraction. The organic matter-bound was the dominant species of Cu (77%). Zn and Ni exhibited the highest affinity for Fe/Mn oxides fraction (55% and 39%, respectively). The average recovery rate was 62–111%, whereas the lowest rate was obtained for Ni (62%) and the highest for Cu/Pb (110–111%). Results indicated elevated concentrations of studied elements, with the following order of mobility factor: Ni 〉 Zn 〉 Cu 〉 Pbdouble bondCr. The preliminary interpretation of the sequential extraction FTIR spectral response revealed that DRIFT is applicable to interpret the sequential metal extraction and revealed three most profound changes correlated to the carbonate, Fe/Mn oxides, and OM fraction.

Description: Sewage disposal onto agricultural land may result in the high accumulation of organic wastes, which questions the applicability of typical elemental analysis used for the soil components. To monitor the contamination status of agricultural soils at a former sedimentation basin, after the long-term cessation of wastewater irrigation, 110 locations (15–20 cm depth) and 4 boreholes (up to 100 cm depth) were sampled to determine pH, loss on ignition, and concentration of Ni, Cu, Pb, Zn, and Cr. Additionally, the applicability of portable X-ray fluorescence (pXRF) for the soil samples highly influenced by the organic wastes was evaluated. The study revealed the presence of a relatively homogenous sewage waste layer (depth of 20 cm), characterized by slightly acidic to neutral pH (6.3–7.5), high organic matter (OM) accumulation (up to 49%), and elevated concentration (mg kg −1) ranges between: Pb (5–321), Cu (31–2828), Ni (10–193), Cr (14–966), and Zn (76–6639). The pXRF analysis revealed metal concentration increase in mineral samples (up to 50%). The regression models and correction factors demonstrated high correlation and significance of pXRF measurement with response to increasing OM content, with the lowest r 2 = 0.86 obtained for Ni. Correlation of pXRF and AES measurement illustrated element-dependent response for soils high in organics. Zn, Cu, and Cr pXRF analysis led to a slight underestimation in lower values, but overall good correlations (0.87; 0.89; and 0.88 respectively). Pb and Ni pXRF measurement revealed higher deviation from the reference in both lower and higher concentrations (0.74 and 0.70, respectively).

Description: 1: Body size is a decisive functional trait in many organisms, especially for phytoplankton, which span several orders of magnitude in cell volume. Therefore, the analysis of size as a functional trait driving species’ performance has received wide attention in aquatic ecology, amended in recent decades by studies documenting changes in phytoplankton size in response to abiotic or biotic factors in the environment. 2. We performed a systematic literature review to provide an overarching, partially quantitative synthesis of cell size as a driver and sentinel of phytoplankton ecology. We found consistent and significant allometric relationships between cell sizes and the functional performance of phytoplankton species (cellular rates of carbon fixation, respiration, and exudation as well as resource affinities, uptake, and content). Size-scaling became weaker, absent or even negative when addressing C- or volume-specific rates or growth. C-specific photosynthesis and population growth rate peaked at intermediate cell sizes around 100 µm³. 4: Additionally, we found a rich literature on sizes changing in response to warming, nutrients and pollutants. Whereas small cells tended to dominate under oligotrophic and warm conditions, there are a few notable exceptions, which indicates that other environmental or biotic constraints alter this general trend. Grazing seems a likely explanation, which we reviewed to understand both how size affects edibility and how size structure changes in response to grazing. Cell size also predisposes the strength and outcome of competitive interactions between algal species. Finally, we address size in a community context, where size-abundance scaling describes community composition and thereby the biodiversity in phytoplankton assemblages. 5: We conclude that i) size is a highly predictive trait for phytoplankton metabolism at the cellular scale, with less strong and non-linear implications for growth and specific metabolism, and ii) size structure is a highly suitable sentinel of phytoplankton responses to changing environments.

Description: Accurately quantifying tree and forest structure is important for monitoring and understanding terrestrial ecosystem functioning in a changing climate. The emergence of laser scanning, such as Terrestrial Laser Scanning (TLS) and Unoccupied Aerial Vehicle Laser Scanning (UAV-LS), has advanced accurate and detailed forest structural measurements. TLS generally provides very accurate measurements on the plot-scale (a few ha), whereas UAV-LS provides comparable measurements on the landscape-scale (〉10 ha). Despite the pivotal role dense tropical forests play in our climate, the strengths and limitations of TLS and UAV-LS to accurately measure structural metrics in these forests remain largely unexplored. Here, we propose to combine TLS and UAV-LS data from dense tropical forest plots to analyse how this fusion can further advance 3D structural mapping of structurally complex forests. We compared stand (vertical point distribution profiles) and tree level metrics from TLS, UAV-LS as well as their fused point cloud. The tree level metrics included the diameter at breast height (DBH), tree height (H), crown projection area (CPA), and crown volume (CV). Furthermore, we evaluated the impact of point density and number of returns for UAV-LS data acquisition. DBH measurements from TLS and UAV-LS were compared to census data. The TLS and UAV-LS based H, CPA and CV measurements were compared to those obtained from the fused point cloud. Our results for two tropical rainforest plots in Australia demonstrate that TLS can measure H, CPA and CV with an accuracy (RMSE) of 0.30 m (Haverage =27.32 m), 3.06 m2 (CPAaverage =66.74 m2), and 29.63 m3 (CVaverage =318.81 m3) respectively. UAV-LS measures H, CPA and CV with an accuracy (RMSE) of 〈0.40 m, 〈5.50 m2, and 〈30.33 m3 respectively. However, in dense tropical forests single flight UAV-LS is unable to sample the tree stems sufficiently for DBH measurement due to a limited penetration of the canopy. TLS can determine DBH with an accuracy (RMSE) of 5.04 cm, (DBHaverage =45.08 cm), whereas UAV-LS can not. We show that in dense tropical forests stand-alone TLS is able to measure macroscopic structural tree metrics on plot-scale. We also show that UAV-LS can be used to quickly measure H, CPA, and CV of canopy trees on the landscape-scale with comparable accuracy to TLS. Hence, the fusion of TLS and UAV-LS, which can be time consuming and expensive, is not required for these purposes. However, TLS and UAV-LS fusion opens up new avenues to improve stand-alone UAV-LS structural measurements at the landscape-scale by applying TLS as a local calibration tool.

Description: Defintion of metadata fields used in the GFZ Metadata Editor and recommendations

Description: Rainfall–runoff models are valuable tools for flood forecasting, management of water resources, and drought warning. With the advancement in space technology, a plethora of satellite precipitation products (SPPs) are available publicly. However, the application of the satellite data for the data-driven rainfall–runoff model is emerging and requires careful investigation. In this work, two satellite rainfall data sets, namely Global Precipitation Measurement-Integrated Multi-Satellite Retrieval Product V6 (GPM-IMERG) and Climate Hazards Group Infrared Precipitation with Station (CHIRPS), are evaluated for the development of rainfall–runoff models and the prediction of 1-day ahead streamflow. The accuracy of the data from the SPPs is compared to the India Meteorological Department (IMD)-gridded precipitation data set. Detection metrics showed that for light rainfall (1–10 mm), the probability of detection (POD) value ranges between 0.67 and 0.75 and with an increasing rainfall range, i.e., medium and heavy rainfall (10–50 mm and 〉50 mm), the POD values ranged from 0.24 to 0.45. These results indicate that the satellite precipitation performs satisfactorily with reference to the IMD-gridded data set. Using the daily precipitation data of nearly two decades (2000–2018) over two river basins in India's Eastern part, artificial neural network, extreme learning machine (ELM), and long short-time memory (LSTM) models are developed for rainfall–runoff modelling. One-day ahead runoff prediction using the developed rainfall–runoff modelling confirmed that both the SPPs are sufficient to drive the rainfall–runoff models with a reasonable accuracy estimated using the Nash–Sutcliffe Efficiency coefficient, correlation coefficient, and the root-mean-squared error. In particular, the 1-day streamflow forecasts for the Vamsadhara river basin (VRB) using LSTM with GPM-IMERG inputs resulted in NSC values of 0.68 and 0.67, while ELM models for Mahanadhi river basin (MRB) with the same input resulted in NSC values of 0.86 and 0.87, respectively, during training and validation stages. At the same time, the LSTM model with CHIRPS inputs for the VRB resulted in NSC values of 0.68 and 0.65, and the ELM model with CHIRPS inputs for the MRB resulted in NSC values of 0.89 and 0.88, respectively, in training and validation stages. These results indicated that both the SPPs could reliably be used with LSTM and ELM models for rainfall–runoff modelling and streamflow prediction. This paper highlights that deep learning models, such as ELM and LSTM, with the GPM-IMERG products can lead to a new horizon to provide flood forecasting in flood-prone catchments.

Description: Thermodynamic models predict that H2 is energetically favorable for seafloor microbial life, but how H2 affects anabolic processes in seafloor-associated communities is poorly understood. Here, we used quantitative 13C DNA stable isotope probing (qSIP) to quantify the effect of H2 on carbon assimilation by microbial taxa synthesizing 13C-labeled DNA that are associated with partially serpentinized peridotite rocks from the equatorial Mid-Atlantic Ridge. The rock-hosted seafloor community was an order of magnitude more diverse compared to the seawater community directly above the rocks. With added H2, peridotite-associated taxa increased assimilation of 13C-bicarbonate and 13C-acetate into 16S rRNA genes of operational taxonomic units by 146% (±29%) and 55% (±34%), respectively, which correlated with enrichment of H2-oxidizing NiFe-hydrogenases encoded in peridotite-associated metagenomes. The effect of H2 on anabolism was phylogenetically organized, with taxa affiliated with Atribacteria, Nitrospira, and Thaumarchaeota exhibiting the most significant increases in 13C-substrate assimilation in the presence of H2. In SIP incubations with added H2, an order of magnitude higher number of peridotite rock-associated taxa assimilated 13C-bicarbonate, 13C-acetate, and 13C-formate compared to taxa that were not associated with peridotites. Collectively, these findings indicate that the unique geochemical nature of the peridotite-hosted ecosystem has selected for H2-metabolizing, rock-associated taxa that can increase anabolism under high H2 concentrations. Because ultramafic rocks are widespread in slow-, and ultraslow-spreading oceanic lithosphere, continental margins, and subduction zones where H2 is formed in copious amounts, the link between H2 and carbon assimilation demonstrated here may be widespread within these geological settings.

Description: Rivers regulate the global carbon cycle by transferring particulate organic carbon (POC) from terrestrial landscapes to marine sedimentary basins, but the processes controlling the amount and composition of fluvially exported POC are poorly understood. We propose that hydrodynamic sorting processes modify POC fluxes during fluvial transit. We test this hypothesis by studying POC transported along a ∼1,200 km reach of the Rio Bermejo, Argentina. Nanoscale secondary ion mass spectrometry revealed that POC was either fine, mineral-associated organic matter, or coarse discrete organic particles. Mineral-associated POC is more resistant to oxidation and has a lower particle settling velocity than discrete POC. Consequently, hydraulic sorting and downstream fining amplify the proportion of fine, mineral-associated POC from ∼55% to ∼78% over 1,220 km of downstream transit. This suggests that mineral-associated POC has a greater probability of export and preservation in marine basins than plant detritus, which may be oxidized to CO2 during transit.

Description: Tephra layers from explosive eruptions can provide valuable isochronous marker horizons for paleoenvironmental studies across large regions. East Asia and Southeast Asia are host to more than half of the Earth's subaerial volcanoes, and tephras from these volcanoes offer significant numbers of widely distributed marker layers. However, the integrated tephrostratigraphic framework of this region is less refined because only limited (crypto-) tephra sequences have been established. In this study, we present a cryptotephra sequence covering the period ∼60–50 ka in East Asia from a lacustrine sediment from Huguangyan Maar Lake, southern China. Four cryptotephra layers were identified, one of which can be correlated with the ∼53.8 ka Unnan eruption (SUn) of Sambe volcano, Japan. This tephra provides a critical isochronous marker horizon for linking paleoenvironmental records from central Japan to southern China, illustrating a consistent environmental shift during early MIS 3 across this region. The three other tephras cannot be correlated with known eruptions, but glass geochemical compositions suggest that they may be from Japan or surrounding areas, implying that they too may be widely distributed around East Asia. Importantly, two of them feature at the start of MIS 3, and thus can be potentially be used to establish the synchroneity of the onset of MIS 3 around East Asia, overcoming challenges that presently hinder the dating of early MIS 3 in this region.

Description: Instrumental data show that the groundwater and lake levels in Northeast Germany have decreased over the past decades, and this process has accelerated over the past few years. In addition to global warming, the direct influence of humans on the local water balance is suspected to be the cause. Since the instrumental data usually go back only a few decades, little is known about the multidecadal to centennial-scale trend, which also takes long-term climate variation and the long-term influence by humans on the water balance into account. This study aims to quantitatively reconstruct the surface water areas in the Lower Havel Inner Delta and of adjacent Lake Gülpe in Brandenburg. The analysis includes the calculation of surface water areas from historical and modern maps from 1797 to 2020. The major finding is that surface water areas have decreased by approximately 30% since the pre-industrial period, with the decline being continuous. Our data show that the comprehensive measures in Lower Havel hydro-engineering correspond with groundwater lowering that started before recent global warming. Further, large-scale melioration measures with increasing water demands in the upstream wetlands beginning from the 1960s to the 1980s may have amplified the decline in downstream surface water areas.

Description: Several holistic approaches are based on the description of socio-ecological systems to address the sustainability challenge. Essential Variables (EVs) have the potential to support these approaches by describing the status of the Earth system through monitoring and modeling. The different classes of EVs can be organized along the environmental policy framework of Drivers, Pressures, States, Impacts and Responses. The EV concept represents an opportunity to strengthen monitoring systems by providing observations to seize the fundamental dimensions of the Earth system The Group on Earth Observation (GEO) is a partnership of 113 nations and 134 participating organizations in 2021 that are dedicated to making Earth Observation (EO) data available globally to inform about the state of the environment and enable data-driven decision processes. GEO is building the Global Earth Observation System of Systems, a set of coordinated and independent EO, information and processing systems that interoperate to provide access to EO for users in the public and private sectors. The progresses made in the development of various classes of EVs are described with their main policy targets, Internet links and key references The paper reviews the literature on EVs and describes the main contributions of the EU GEOEssential project to integrate EVs within the work plan of GEO in order to better address selected environmental policies and the SDGs. A new GEO-EVs community has been set to discuss about the current status of the EVs, exchange knowledge, experiences and assess the gaps to be solved in their communities of providers and users. A set of four traits characterizing an EV was put forward to describe the entire socio-ecological system of planet Earth: Essentiality, Evolvability, Unambiguity, and Feasibility. A workflow from the identification of EO data sources to the final visualization of SDG 15.3.1 indicators on land degradation is demonstrated, spanning through the use of different EVs, the definition of the knowledge base on this indicator, the implementation of the workflow in the VLab (a cloud-based processing infrastructure), the presentation of the outputs on a dedicated dashboard and the corresponding narrative through a story map. The concept of EV started in the climate sphere and spread to other domains of the earth system but less so in socio-economic activities. More work is therefore needed to converge on a common definition and criteria in order to complete the implementation of EVs in all GEO focus areas. EVs should screen the entire Earth's social-ecological system, providing a trusted and long-term foundation for interdisciplinary approaches such as ecological footprinting, planetary boundaries, disaster risk reduction, and nexus frameworks, as well as many other policy frameworks such as the SDGs

Description: Lake sediments are a valuable archive to document past flood occurrence and magnitude, and their evolution over centuries to millennia. This information has the potential to greatly improve current flood design and risk assessment approaches, which are hampered by the shortness and scarcity of gauge records. For this reason, paleoflood hydrology from lake sediments received fast-growing attention over the last decade. This allowed an extensive development of experience and methodologies and, thereby, the reconstruction of paleoflood series with increasingly higher accuracy. In this review, we provide up-to-date knowledge on flood sedimentary processes and systems, as well as on state-of-the-art methods for reconstructing and interpreting paleoflood records. We also discuss possible perspectives in the field of paleoflood hydrology from lake sediments by highlighting the remaining challenges. This review intends to guide the research interest in documenting past floods from lake sediments. In particular, we offer here guidance supported by the literature in how: to choose the most appropriate lake in a given region, to find the best suited sedimentary environments to take the cores, to identify flood deposits in the sedimentary sequence, to distinguish them from other instantaneous deposits, and finally, to rigorously interpret the flood chronicle thus produced.

Description: A volcanic eruption is usually preceded by seismic precursors, but their interpretation and use for forecasting the eruption onset time remain a challenge. A part of the eruptive processes in open conduits of volcanoes may be similar to those encountered in geysers. Since geysers erupt more often, they are useful sites for testing new forecasting methods. We tested the application of Permutation Entropy (PE) as a robust method to assess the complexity in seismic recordings of the Strokkur geyser, Iceland. Strokkur features several minute-long eruptive cycles, enabling us to verify in 63 recorded cycles whether PE behaves consistently from one eruption to the next one. We performed synthetic tests to understand the effect of different parameter settings in the PE calculation. Our application to Strokkur shows a distinct, repeating PE pattern consistent with previously identified phases in the eruptive cycle. We find a systematic increase in PE within the last 15 s before the eruption, indicating that an eruption will occur. We quantified the predictive power of PE, showing that PE performs better than seismic signal strength or quiescence when it comes to forecasting eruptions.

Description: This work analyzes temporal variations of seismic velocities at Mt. Etna from August 2018 to February 2019. During this time period, a strong flank eruption accompanied by intense seismicity and ground deformation took place along a fracture that opened on 24 December 2018 at the base of the New South-East summit crater. Furthermore, two moderate earthquakes—the 6 October 2018 ML 4.7 and 26 December 2018 ML 4.8—associated with the volcanic activity were recorded. In this study, we computed cross-correlation functions (CCFs) between windows of seismic ambient noise to identify seismic velocity variations within the volcano edifice. We calculated daily CCFs at 16 stations for 120 interstation pairs using the vertical component in the 1.0–1.5 Hz frequency band. We observe that dv/v starts to decrease rapidly from the beginning of October 2018 and reaches approximately −0.45% in the pre-eruption period. The spatio-temporal distribution of seismic velocities shows that the reduction of dv/v mostly occurs in the vicinity of the summit and close to the flank area and is interpreted to be affected by magmatic intrusion at 0–3 km depth. To infer the source mechanism of this eruption, we compared these observations with volcano-tectonic earthquakes, volcanic tremor, volcanic degassing, gravity, and ground deformation data. Our study suggests that a relationship between magma intrusion and associated crack opening is responsible for the decrease of dv/v.

Description: The airborne hyperspectral image was acquired by the AVIRIS-Next Generation (AVIRIS-NG) instrument during the AVIRIS-NG Europe 2021 HyperSense campaign that has been conducted as a joint effort of ESA, NASA/JPL and the University of Zurich. Acquired was an agricultural area near Irlbach, Germany on May 30th, 2021. The data was preprocessed (radiometrically, geometrically and atmospherically corrected) to contain 419 bands in the 402 - 2495 nm spectral range. Metadata was acquired on the same day for the variables Leaf Area Index (LAI), Leaf Chlorophyll content, crop height and phenology. An overview of metadata acquisition and processing can be found in the HYPERedu YouTube videos on ground reference data acquisition in the field and ground reference data acquisition in the lab. More details on LAI and chlorophyll acquisition can be found in the field data guides assembled by the authors of this dataset via enmap.org (Danner et al., 2015; Süß et al., 2015). The dataset is made publically available within the massive open online course (MOOC) "Beyond the Visible - Introduction to Imaging Spectroscopy for Agricultural Applications", available from December 2022.

Description: This dataset provides friction data from ring-shear tests on feldspar sand FS900S used for the simulation of brittle behaviour in crust- and lithosphere-scale analogue experiments at the Tectonic Modelling Laboratory of the University of Bern (Zwaan et al. in prep; Richetti et al. in prep). The materials have been characterized by means of internal friction parameters as a remote service by the Helmholtz Laboratory for Tectonic Modelling (HelTec) at the GFZ German Research Centre for Geosciences in Potsdam (Germany). According to our analysis both materials show a Mohr-Coulomb behaviour characterized by a linear failure envelope. Peak, dynamic and reactivation friction coefficients of the feldspar sand are μP = 0.65, μD = 0.57, and μR = 0.62, respectively, and the Cohesion of the feldspar sand is in the order of 5-20 Pa. An insignificant rate-weakening of less than 1% per ten-fold rate change is registered for the feldspar sand. Granular healing is also minor.

Description: This dataset includes five stations of an Ocean Bottom Seismometer (OBS) experiment conducted at the southern end of the Fonualei Rift and Spreading Center in the Lau Basin, southwestern Pacific. The OBS recorded continuously for 32-days on 4 components, including a hydrophone and a 3-component 4.5 Hz geophone. The experiment was conducted during RV Sonne cruise SO267, project ARCHIMEDES I. In the article, the authors report an increasing trend of methane emissions for June and July at a permafrost site in Siberia (Lena River Delta). Using the longest set of observational methane flux data in the Arctic, the authors demonstrate that the continuous warming has begun to trigger the projected enhancement of methane release in Arctic permafrost ecosystems. This software is written in MATLAB. Running the codes ([.m files](Code)) and loading the data files ([.mat files](Data)) requires the pre-installation of [MATLAB](/https://de.mathworks.com/products/matlab.html). IMPORTANT: The repository only contains dummy data. The data that is needed to run the code can be requested by Torsten Sachs and Christian Wille (contact authors). Although the scripts and the data files have been tested for newer versions of MATLAB (〉= MATLAB R2017a). The code might also run in older versions of MATLAB, but this has not been tested.

Description: Orbital products describe positions and velocities of satellites, be it the Global Navigation Satellite System (GNSS) satellites or Low Earth Orbiter (LEO) satellites. These orbital products can be divided into the fastest available ones, the Near Realtime Orbits (NRT), which are mostly available within 15 to 60 minutes delay, followed by Rapid Science Orbit (RSO) products with a latency of two days and finally the Precise Science Orbit (PSO) which, with a latency of up to a few weeks, are the most delayed. The absolute positional accuracy increases with the time delay. This dataset compiles the RSO products for various LEO missions and the appropriate GNSS constellation in sp3 format. The individual solutions for each satellite mission are published with individual DOI as part of this compilation. GNSS Constellation: • GNSS 24h (v01) • GNSS 30h (v02) LEO Satellites: • CHAMP • GRACE • GRACE-FO • SAC-C • TanDEM-X/ TerraSAR-X Each solution is given in the Conventional Terrestrial Reference System (CTS). • The GNSS RSOs are 30-hour long arcs starting at 21:00 the day before the actual day and ending at 03:00 the day after. The accuracy of the GPS RSO sizes at the 3-cm level in terms of RMS values of residuals after Helmert transformation onto IGS combined orbit solutions (Version 1 GNSS RSOs are 24-hour long arcs starting at 00:00 and ending at 24:00 the actual day). • The LEO RSOs are generated based on these 30-hour GNSS RSOs in two pieces for the actual day with arc lengths of 14 hours and overlaps of 2 hours. One starting at 22:00 and ending at 12:00, one starting at 10:00 and ending at 24:00. The accuracy of the LEO RSOs is at the level of 1-2 cm in terms of SLR validation. The exact time covered by an arc is defined in the header of the files and indicated as well as in the filename. This dataset compiles RSO products for various LEO missions and the corresponding GNSS constellation in sp3 format in a revised processing version 2. The switch from previous version 1 to 2 was performed on 18-Feb-2019. Major changes from version 1 to 2 are the change from IERS 2003 to IERS 2010 conventions and ITRF 2008 to ITRF-2014, as well as the temporal extension of the GNSS constellation from previous 24 hours (version 1) to 30 hours (version 2) arcs. This temporal expansion eliminates the chaining of two consecutive 24-hour GNSS constellation solutions previously used to process day-overlapping LEO arcs in Version 1. This 24h GNSS constellation (Version 1) will continue to operate and be stored on the ISDC ftp server, as discussed in more detail in Section 8.1. All RSO LEO arcs will no longer be continued in version 1 after the changeover date and will only be available in version 2 since then.

Description: Meteorite impact processes are ubiquitous on the surfaces of rocky and icy bodies in the Solar System, including the Moon. One of the most common accessory minerals, zircon, when shocked, produces specific micro-structures that may become indicative of the age and shock conditions of these impact processes. To better understand the shock mechanisms in zircon from Apollo 15 and 16 impact breccias, we applied transmission electron microscopy (TEM) and studied nano-structures in eight lunar zircons displaying four different morphologies from breccias 15455, 67915, and 67955. Our observations revealed a range of shock-related features in zircon: (1) planar and non-planar fractures, (2) “columnar” zircon rims around baddeleyite cores, (3) granular textured zircon, in most cases with sub-µm-size inclusions of monoclinic ZrO2 (baddeleyite) and cubic ZrO2 (zirconia), (4) silica-rich glass and metal inclusions of FeS and FeNi present at triple junctions in granular zircon and in baddeleyite, (5) inclusions of rutile in shocked baddeleyite, (6) amorphous domains, (7) recrystallized domains. In many grain aggregates, shock-related micro-structures overprint each other, indicating either different stages of a single impact process or multiple impact events. During shock, some zircons were transformed to diaplectic glass (6), and others (7) were completely decomposed into SiO2 and Zr-oxide, evident from the observed round shapes of cubic zirconia and silica-rich glass filling triple junctions of zircon granules. Despite the highly variable effect on textures and Zr phases, shock-related features show no correlation with relatively homogeneous U–Pb or 207Pb/206Pb ages of zircons. Either the shock events occurred very soon after the solidification or recrystallization of the different Zr phases, or the shock events were too brief to result in noticeable Pb loss during shock metamorphism.

Description: Most natural resources are distributed within the uppermost layer of the lithosphere and their exploitation is limited by the transition from brittle to ductile rocks' deformation (BDT), which coincides with a strong reduction in rocks permeability. Therefore, knowledge of the physical and mechanical crustal properties is crucial for improving our understanding of the exploitable potential. Previous studies have showcased the existence of a relation between rocks' seismic attenuation and their viscous modes of deformations, considering that both depend on intrinsic rocks characteristics (e.g., grain size, fluid content) and background P-T conditions. In this study, we investigate such quantitative relationships between seismic attenuation and viscous rocks' rheology across the domain where rocks transition from a dominant brittle to a more ductile deformation mode. We rely on the Burgers and Gassmann mechanical model to derive shear wave attenuation (1/Qs), for several dry and wet crustal rheology, thermal conditions, and different strain rates. This allows us to establish geothermal and mechanical conditions at which the BDT occurs and cross-correlate this transition to computed shear seismic wave attenuation values. In particular, we observe that Qs variation with depth is more sensitive to the input strain rate than to the adopted rock‘s rheology and thermal conditions, so that a fixed amount of the Qs reduction can be used to identify the average BDT depths for each strain rate used. Below the BDT depth, we observe a significant drop in Qs (up to 10-4 % of the surface value), being also influenced by the background temperature and rock rheology. Since the greatest Qs reduction is estimated for the highest input strain rate (10-13 s-1), our results have implications for tectonically active/geothermal areas. Ongoing and future works will focus on a further validation of the modelling implications by systematic analyses of observations derived from rocks’ laboratory experiments. The last ones can add constraints on the relationship found in this study between seismic attenuation and adopted rheological flow law.

Description: East Asia currently has the largest SO2 and NOx emissions in the world. The long-range transport (LRT) of acidic pollutants in this region is of great concern but the extent is not well understood. Here results from combined long-term (⩾20 years) atmospheric deposition monitoring and air trajectory analysis in East Asia were reported. The results showed that despite the large decrease of SO2 and NOx emissions in Taiwan, annual deposition of non-sea-salt sulfate (nss-${\text{SO}}_4^{2 - }$) in northern Taiwan showed no decreasing trend during 1994–2020. However, when divided seasonally, both nss-${\text{SO}}_4^{2 - }$ and nitrate (${\text{NO}}_3^ - $) deposition had a significant decreasing trend in the summer but not in the winter. Similar patterns were found for Japan and Korea. Air trajectory models in combination with a regional emission map indicate that LRT from eastern China contributed up to 70% of the winter deposition of nss-${\text{SO}}_4^{2 - }$ and ${\text{NO}}_3^ - $ in Taiwan and up to 50% in Japan and Korea. The results indicate that LRT obscured the efficacy of local pollution control measures in East Asia and suggest that transboundary air pollution regulations are required to combat acid deposition.

Description: The most profound consequences of the presence of Ca–Mg carbonates (CaCO3–MgCO3) in the Earth’s upper mantle may be to lower the melting temperatures of the mantle and control the melt composition. Low-degree partial melting of a carbonate-bearing mantle produces CO2-rich, silica-poor melts compositionally imposed by the melting relations of carbonates. Thus, understanding the melting relations in the CaCO3–MgCO3 system facilitates the interpretation of natural carbonate-bearing silicate systems. We report the melting relations of the CaCO3–MgCO3 system and the partition coefficient of trace elements between carbonates and carbonate melt from experiments at high pressure (6 and 9 GPa) and temperature (1300–1800 C) using a rocking multi-anvil press. In the absence of water, Ca–Mg carbonates are stable along geothermal gradients typical of subducting slabs. Ca–Mg carbonates (~Mg0.1–0.9Ca0.9–0.1CO3) partially melt beneath mid-ocean ridges and in plume settings. Ca–Mg carbonates melt incongruently, forming periclase crystals and carbonate melt between 4 and 9 GPa. Furthermore, we show that the rare earth element (REE) signature of Group-I kimberlites, namely strong REE fractionation and depletion of heavy REE relative to the primitive mantle, is resembled by carbonate melt in equilibrium with Ca-bearing magnesite and periclase at 6 and 9 GPa. This suggests that the dolomite–magnesite join of the CaCO3–MgCO3 system might be useful to approximate the REE signature of carbonate-rich melts parental to kimberlites.

Description: Assessing post-seismic damage on an urban/regional scale remains relatively difficult owing to the significant amount of time and resources required to acquire information and conduct a building-by-building seismic damage assessment. However, the application of new methods based on artificial intelligence, combined with the increasingly systematic availability of field surveys of post-seismic damage, has provided new perspectives for urban/regional seismic damage assessment. This study analyzes the effectiveness and relevance of a number of machine learning techniques for analyzing spatially distributed seismic damage after an earthquake at the regional scale. The basic structural parameters of a portfolio of buildings and the postearthquake damage surveyed after the Nepal 2015 earthquake are analyzed and combined with macro-seismic intensity values provided by the United States Geological Survey ShakeMap tool. Among the methods considered, the random forest regression model provides the best damage predictions for specified ground motion intensity values and structural parameters. For traffic-light-based damage classification (three classes: green-, amber-, and red-tagged buildings based on post-earthquake damage grade), a mean accuracy of 0.68 is obtained. This study shows that restricting learning to basic features of buildings (i.e. number of stories, height, plinth area, and age), which could be readily available from authoritative databases (e.g. national census) or field-surveyed databases, yields a reliable prediction of building damage (4 features/3 damage grade accuracy: 0.64).

Description: Soil hydrologic processes play an important role in the hydro-pedo-geomorphological feedback cycle of landscape evolution. Soil properties and subsurface flow paths both change over time, but due to a lack of observations, subsurface water flow paths are often not properly represented in soil and landscape evolution models. We investigated the evolution of subsurface flow paths across a soil chronosequence in the calcareous glacier forefield at the Griessfirn glacier in the Swiss Alps. Young soils developed from calcareous parent material usually have a high pH value, which likely affects vegetation development and pedogenesis and thus the evolution of subsurface flow paths. We chose four glacial moraines of different ages (110, 160, 4 900, and 13 500 years) and conducted sprinkling experiments with the dye tracer Brilliant Blue on three plots at each moraine. Each plot was divided into three equal subplots, and dyed water was applied with three different irrigation intensities (20, 40, and 60 mm h−1) and an irrigation amount of 40 mm. Subsequent excavation of soil profiles enabled the tracing of subsurface flow paths. A change in flow types with increasing moraine age was observed from a rather homogeneous matrix flow at 110 and 160 years to heterogeneous matrix and finger-shaped flow at 4 900 and 13 500 years. However, the proportion of preferential flow paths is not necessarily directly related to the moraine age but rather to soil properties such as texture, soil layering, organic matter content, and vegetation characteristics such as root length density and biomass. Irrigation intensity had an effect on the number of finger-shaped flow paths at the two old moraines. We also found that flow paths in this calcareous material evolved differently compared to a previous study in siliceous material, which emphasizes the importance of parent material for flow path evolution. Our study provides a rare systematic dataset and observations on the evolution of vertical subsurface flow paths in calcareous soils, which is useful to improve their representation in the context of landscape evolution modeling.

Description: Late Cretaceous granitic rocks occur in the Gejiu ore district to the east and west of the N-S striking Gejiu Fault, whereas major Sn deposits are only known to occur to the east of the Gejiu Fault. Comparison of the whole-rock chemistry, the apatite trace-element chemistry, and zircon Hf and O isotope data of the various granites demonstrates that fertile granites occur to both sides of the Gejiu fault. The results demonstrate that the c. 83 Ma old granitic intrusions (i) have similar magma sources, which are dominated by metasedimentary rocks that had experienced intense chemical weathering, resulting in reduced melts, (ii) had similar melting conditions, i.e., high temperature biotite dehydration melting, and (iii) in part had experienced large extents of fractional crystallization. The most evolved granites to both sides of the Gejiu Fault have the characteristics typical of tin granites. Therefore, the absence of major deposits to the west of the Gejiu Fault is not due to the absence of fertile granites. The areas to the east and the west of the Gejiu Fault, however, have fundamentally different fault pattern, which indicates different orientation of the stress field to both sides of the Gejiu Fault at the time of the emplacement of the Cretaceous granites. Late Cretaceous dextral movement along the Ailaoshan Fault Zone resulted in a (trans)tensional setting in areas to the east of the Gejiu Fault and in a (trans)pressional setting to the west of that fault. We speculate that the tectonic setting influences the potential for mineralization because the Sn bearing fluids need efficient pathways to transporting metals from the roof zone of the batholith into the wall rocks. In contrast to regional compression, hydraulic fracturing in an overall extensional setting has the potential to develop efficient fluid pathways and, thus, may lead to major ore deposits. To the west of the Gejiu Fault, however, granite intrusions in an overall compressional setting are likely to develop no or only small mineralization.

Description: Spectroscopic measurements of soil samples are reliable because they are highly repeatable and reproducible. They characterise the samples' mineral–organic composition. Estimates of concentrations of soil constituents are inevitably less precise than estimates obtained conventionally by chemical analysis. But the cost of each spectroscopic estimate is at most one-tenth of the cost of a chemical determination. Spectroscopy is cost-effective when we need many data, despite the costs and errors of calibration. Soil spectroscopists understand the risks of over-fitting models to highly dimensional multivariate spectra and have command of the mathematical and statistical methods to avoid them. Machine learning has fast become an algorithmic alternative to statistical analysis for estimating concentrations of soil constituents from reflectance spectra. As with any modelling, we need judicious implementation of machine learning as it also carries the risk of over-fitting predictions to irrelevant elements of the spectra. To use the methods confidently, we need to validate the outcomes with appropriately sampled, independent data sets. Not all machine learning should be considered ‘black boxes’. Their interpretability depends on the algorithm, and some are highly interpretable and explainable. Some are difficult to interpret because of complex transformations or their huge and complicated network of parameters. But there is rapidly advancing research on explainable machine learning, and these methods are finding applications in soil science and spectroscopy. In many parts of the world, soil and environmental scientists recognise the merits of soil spectroscopy. They are building spectral libraries on which they can draw to localise the modelling and derive soil information for new projects within their domains. We hope our article gives readers a more balanced and optimistic perspective of soil spectroscopy and its future.

Description: Handling multiple scales efficiently is one avenue for processing big remote sensing imagery data. Unfortunately, imagery is also affected by the infamous modifiable areal unit problem, which creates unpredictable errors at different scales. We developed a downsampling method that attempts to keep the data distribution in a downsampled image constant, reducing the modifiable areal unit problem. We tested our method against classic downsampling methods (mean, central pixel selection, random) under a range of typical remote sensing scenarios. Under our experimental conditions, our downsampling method consistently outperformed the classical downsampling methods within a 95% confidence level. The downsampling method can be used in most typical situations where downsampling is needed, but it is likely to shine when used as a pyramid building policy in geocomputing platforms, such as Google Earth Engine.

Description: The Earth's mass redistribution due to deglaciation and recent ice sheet melting causes changes in the Earth's gravity field and vertical land motion in Greenland. The changes are because of ongoing mass redistribution and related elastic (on a short time scale) and viscoelastic (on time scales of a few thousands of years) responses. These signatures can be used to determine the mantle viscosity. In this study, we infer the mantle viscosity associated with the glacial isostatic adjustment (GIA) and long-wavelength geoid beneath the Greenland lithosphere. The viscosity is determined based on a spatio-spectral analysis of the Earth's gravity field and the land uplift rate in order to find the GIA-related gravity field. We used different land uplift data, that is, the vertical land motions obtained by the Greenland Global Positioning System (GPS) Network (GNET), gravity recovery and climate experiment (GRACE) and glacial isostatic adjustment (GIA) data, and also combined them using the Kalman filtering technique. Using different land uplift rates, one can obtain different GIA-related gravity fields.

Description: Floods are the most frequent, costliest natural disasters having devastating consequences on people, infrastructure, and the ecosystem. During flood events near real-time satellite imagery has proven to be an efficient management tool for disaster management authorities. However one of the challenges is accurate classification and segmentation of flooded water. The generalization ability of binary segmentation using threshold split-based method, is limited due to the effects of backscatter, geographical area, and time of image collection. Recent advancements in deep learning algorithms for image segmentation has demonstrated excellent potential for improving flood detection. However, there have been limited studies in this domain due to the lack of large scale labeled flood event dataset. In this paper, we present two deep learning approaches, first using a UNet and second, using a Feature Pyramid Network (FPN), both based on a backbone of EfficientNet-B7, by leveraging publicly available Sentinel-1 dataset provided jointly by NASA Interagency Implementation and Advanced Concepts Team, and IEEE GRSS Earth Science Informatics Technical Committee. The dataset covers flood events from Nebraska, North Alabama, Bangladesh, Red River North, and Florence. The performances of both networks were evaluated with multiple training, testing, and validation. During testing, the UNet model achieved the meanIOU score of 75.06% and the FPN model achieved the meanIOU score of 75.76%.

Description: The integration of imaging spectroscopy and aeromagnetics provides a cost-effective and promising way to extend the initial analysis of a mineral deposit. While imaging spectroscopy retrieves surface spectral information, magnetic responses are used to determine magnetization at both shallower and greater depths using 2D and 3D modeling. Integration of imaging spectroscopy and magnetics improves upon knowledge concerning lithology with magnetic properties, enhances understanding of the geological origin of magnetic anomalies, and is a promising approach for analyzing a prospective area for minerals having a high iron-bearing content. To combine iron diagnostic information from airborne hyperspectral and magnetic data, we (a) used an iron absorption feature ratio to model pseudo-magnetic responses and compare them with the measured magnetic data and (b) estimated the apparent susceptibility along the surface by some equivalent source modeling, and compared them with iron ratios along the surface. For this analysis, a Modified Iron Feature Depth index was developed and compared to the surface geochemistry of the rock samples in order to validate the spectral information of iron. The comparison revealed a linear increase in iron absorption feature depths with iron content. The analysis was performed by empirically modeling the statistical relationship between the diagnostic absorption features of hyperspectral (HS) image spectra of selected rock samples and their corresponding geochemistry. Our results clearly show a link between the spectral absorption features and the magnetic response from iron-bearing ultra/-mafic rocks. The iron absorption feature ratio of Fe3+/Fe2+ integrated with aeromagnetic data (residual magnetic anomaly) allowed us to distinguish main rock types based on physical properties. This separation matches the lithology of the Niaqornarssuit complex, our study area in West Greenland.