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The original version of this Article contained errors. The fourth sentence of the first paragraph in the section titled “Halving the proportionof untreated wastewater (SDG6.3)” incorrectly read “The largest expansions required before 2030 are in China (40 million m3), the USA (16 million m3) and India (15 million m3), with these three countries alone accounting for ~45% of the required expansions.” The correct version states ‘billion m3 yr-1’ in place of ‘million m3’. In addition, the first sentence of the caption for Figure 2 incorrectly read “a Expansions in wastewater treatment capacity (106 m3) required by 2030 to achieve SDG6.3 for the top 30 countries”. The correct version states “(109 m3 yr-1)” in place of “(106 m3)”. These errors have been corrected in both the PDF and HTML versions of the Article.

The movement of large, slow-moving, deep-seated landslides is regulated principally by changes in pore-water pressure in the slope. In urban areas, drastic reorganization of the surface and subsurface hydrology—for example, associated with roads, housings or storm drainage—may alter the subsurface hydrology and ultimately the slope stability. Yet our understanding of the influence of slope urbanization on the dynamics of landslides remains elusive. Here we combined satellite and (historical) aerial images to quantify how 70 years of hillslope urbanization changed the seasonal, annual and multi-decadal dynamics of a large, slow-moving landslide located in the tropical environment of the city of Bukavu, Democratic Republic of the Congo. Analysis of week-to-week landslide motion over the past 4.5 years reveals that it is closely tied to pore-water pressure changes, pointing to interacting influences from climate, weathering, tectonics and urban development on the landslide dynamics. Over decadal timescales, we find that the sprawl of urbanized areas led to the acceleration of a large section of the landslide, which was probably driven by self-reinforcing feedbacks involving slope movement, rerouting of surface water flows and pipe ruptures. As hillslopes in many tropical cities are being urbanized at an accelerating pace, better understanding how anthropogenic activity influences surface processes will be vital to effective risk planning and mitigation.

The end-Triassic biodiversity crisis was one of the most severe mass extinctions in the history of animal life. However, the extent to which the loss of taxonomic diversity was coupled with a reduction in organismal abundance remains to be quantified. Further, the temporal relationship between organismal abundance and local marine redox conditions is lacking in carbonate sections. To address these questions, we measured skeletal grain abundance in shallow-marine limestones by point counting 293 thin sections from four stratigraphic sections across the Triassic/Jurassic boundary in the Lombardy Basin and Apennine Platform of western Tethys. Skeletal abundance decreased abruptly across the Triassic/Jurassic boundary in all stratigraphic sections. The abundance of skeletal organisms remained low throughout the lower-middle Hettangian strata and began to rebound during the late Hettangian and early Sinemurian. A two-way ANOVA indicates that sample age (p

We present the first 3D triangulation of Transient Luminous Events (TLEs) over Africa. The 6 TLEs were simultaneously observed in the middle atmosphere from Sutherland and Carnarvon in South Africa, separated by 192 km, during the 2019 sprites campaign. These two distinctive locations have low radio interference and are free from light pollution. The lightning times, locations, peak current, and polarities, which initiated the observed TLEs, were obtained from the South African Lightning Detection Network and Earth Networks Total Lightning Networks. We investigate the TLEs' altitude and horizontal displacement from their parent lightning strokes. TLEs appear approximately 12.5 to 49.3 km away from their parent lightning strokes. We found that TLE altitudes range from 29 to 92.6 km. The lightning electric field and peak current may be related to the displacement of TLEs and the TLEs' horizontal spread.

Funding: The work was funded by a NERC Large Grant to S.L.L. (‘CongoPeat’, NE/R016860/1), a NERC Doctoral Training Partnership award to B.C. (‘SPHERES DTP’, NE/L002574/1) and a Greenpeace Fund award to S.L.L. JAXA, NASA, METI, USGS, ESA, OSFAC and WWF are acknowledged for collecting and/or processing remote-sensing data. The world’s largest tropical peatland complex is found in the central Congo Basin. However, there is a lack of in situ measurements to understand the peatland’s distribution and the amount of carbon stored in it. So far, peat in this region has been sampled only in largely rain-fed interfluvial basins in the north of the Republic of the Congo. Here we present the first extensive field surveys of peat in the Democratic Republic of the Congo, which covers two-thirds of the estimated peatland area, including from previously undocumented river-influenced settings. We use field data from both countries to compute the first spatial models of peat thickness (mean 1.7 ± 0.9 m; maximum 5.6 m) and peat carbon density (mean 1,712 ± 634 MgC ha−1; maximum 3,970 MgC ha−1) for the central Congo Basin. We show that the peatland complex covers 167,600 km2, 36% of the world’s tropical peatland area, and that 29.0 PgC is stored below ground in peat across the region (95% confidence interval, 26.3–32.2 PgC). Our measurement-based constraints give high confidence of globally significant peat carbon stocks in the central Congo Basin, totalling approximately 28% of the world’s tropical peat carbon. Only 8% of this peat carbon lies within nationally protected areas, suggesting its vulnerability to future land-use change. Postprint Postprint

Within urban centres, underground spaces such as storage areas, transportation corridors, basement car parks, public facilities, retail & office as well as private spaces (e.g., residential basements), present priority risk areas during flood events with respect to timely evacuation. However, often the location, geometry and volume of these underground spaces is not well known. Furthermore, these underground spaces are commonly not considered in flood prediction models for urban centres. At the same time, communicating flood risks and enhancing emergency preparedness poses further challenges. Thus emergency planners need engaging communication tools to increase community resilience and preparedness to flooding events. Low-cost Mobile Laser Scanning (MLS) and Airborne Laser Scanning (ALS) technologies as well as other remote sensing applications and street view imagery data are becoming increasingly available and affordable, providing high-resolution data for the urban environment. The presented project focusses on gaining better knowledge of the location and internal geometry of underground spaces in urban centres by using low-cost MLS data. The presented project is developing efficient database approaches to handle the large data sets and to integrate the information into flood prediction models. These models provide refined information on urban flood levels and flooding rates into the underground spaces, which in turn may be used as part of risk communication tools using low-cost virtual reality applications which provide an immersive experience of flood risk with the aim to better engage communities in emergency preparedness. The comparison of rapid low-cost high-resolution terrestrial MLS with ALS data for an urban case study site in Belfast (Northern Ireland) highlights the advantages of the rapid low-cost MLS approaches and their use for the detection and surveying of urban underground spaces and the integration of these identified priority flood risks into urban flood models. Incorporating the identified underground spaces provides more realistic inundation scenarios and enhanced information with regard to accessible evacuation routes to inform flood risk mitigation plans.

Introduction: The East Iran orogen has experienced multiple buckling phases resulting in the formation of strike-slip fault splays. The geometric and kinematic characteristics of these splays are influenced by folding mechanisms. This study focuses on investigating the structural characteristics and tectonic evolution model of the Khousf splay, located in the northern terminus of the Nehbandan right-lateral strike-slip fault system.Methods: Field visits and geometrical properties from map views were used to analyze the structural features of the Khousf splay. The splay was found to consist of a multi-plunging anticline and syncline, referred to as the Khousf anticline and Khousf syncline, respectively. Flexural slip was identified as a significant mechanism for the formation of these structures. Structural evidence, including parasitic folds, active folds, and strike-slip duplexes, suggested that flexural slip occurred on discrete movement horizons among the rock units.Results: Analysis of the parasitic folds in the cores and limbs of the Khousf anticline and syncline revealed M, W, Z, and S shapes, with complex slicken-line patterns observed on faults parallel to the beds at the limbs. The analysis results indicated strain partitioning and inclined left- and right-lateral transpressional zones. Shortening estimates obtained from profiles in the Shekarab inclined transpressional zone were approximately 33%, 65%, and 68% for NE-SW, N-S, and NW-SE profiles, respectively. In the Arc area, which is the core of the anticline, shortening estimates from NE-SW and N-S profiles ranged from 14% to 10%. Structural analysis of the folds in this area revealed broad, close, semi-elliptical, and parabolic shapes, suggesting that secondary folds with NW-SE axis directions have been superimposed on the first-generation folds with E-W axis directions in the Khousf refolded splay.Discussion: The findings of this study highlight the structural characteristics and tectonic evolution model of the Khousf splay in the northern terminus of the Nehbandan right-lateral strike-slip fault system. The results suggest that flexural slip played a crucial role in the formation of the multi-plunging anticline and syncline in the Khousf splay. The presence of parasitic folds and complex slicken-line patterns on faults indicate the complexity of deformation processes. The observed strain partitioning and inclined transpressional zones suggest a complex tectonic history in the study area. The superimposition of secondary folds with different axis directions on first-generation folds adds further complexity to the structural evolution of the Khousf refolded splay. Overall, this study provides new insights into the structural characteristics and tectonic evolution of the Khousf splay in the East Iran orogen.

The Kuroshio Current in the North Pacific displays path changes on an interannual-to-decadal time scale. In an idealized barotropic quasi-geostrophic model of the double-gyre wind-driven circulation under stochastic wind-stress forcing, such variability can occur due to transitions between different equilibrium states. The high-dimensionality of the problem makes it challenging to determine the probability of these transitions under the influence of stochastic noise. Here we present a new method to estimate these transition probabilities, using a Dynamical Orthogonal (DO) field approach. In the DO approach, the solution of the stochastic partial differential equations system is decomposed using a Karhunen–Loève expansion and separate problems arise for the ensemble mean state and the so-called time-dependent DO modes. The original method is first reformulated in a matrix approach which has much broader application potential to various (geophysical) problems. Using this matrix-DO approach, we are able to determine transition probabilities in the double-gyre problem and to identify transition paths between the different states. This analysis also leads to the understanding which conditions are most favorable for transition.

Tang, V., & Painho, M. (2023). Exploring the relationships between perceived neighborhood boundaries and street network orientation. Transactions in GIS, 27(3), 877-899. https://doi.org/10.1111/tgis.13058 --- Funding: The authors acknowledge the funding from the Portuguese national funding agency for science, research, and technology (Fundação para a Ciência e a Tecnologia—FCT) through the CityMe project (EXPL/GES-URB/1429/2021; https://cityme.novaims.unl.pt/). The neighborhood is a core unit of analysis in urban research, planning, and policy-making. However, perceptual and historical processes oftentimes result in neighborhoods that are not tied to sub-urban jurisdictions. For instance, historic neighborhoods might lack official spatial definitions, hampering neighborhood-based tasks in local offices. In this case, urban practitioners can benefit from readily available spatial proxies, such as the local street network. In this study, we conducted an exploratory analysis that combines neighborhood mapping and street network modeling. By retrieving participants' sketched boundaries and quantifying spatial orientations of sketched polygons and local network patterns, we were able to measure and compare the relationships between the urban fabric and the perceived extents of two historic neighborhoods in Lisbon, Portugal. The results provided insights for enhancing existing definitions of non-official neighborhoods, outlining new urban districts as well as for discussions about the role of the urban form in shaping people's perceptions. publishersversion published

Model output from climate projections often requires bias-adjustment to compensate for systematic model errors. A bias-adjustment method for extreme precipitation intensity is proposed that preserves the scaling equation for different accumulation levels from hourly to daily, using intensity-duration-frequency (IDF) modeling. A validation is performed within a pseudo-reality setting, based on hourly precipitation from 28 regional climate model projections of the EURO-CORDEX ensemble over Belgium. The scaling-based adjustment methods improve upon previous methods, an optimal method is identified, and, analytical quantile mapping methods must be avoided due to three identified problems. The ensemble mean of the adjusted extreme precipitation intensity obeys the above-mentioned scale-invariance property, which is consistent with observed extreme intensities. We thus show that IDF modeling provides added value in the context of bias-adjustment, and, that the particular IDF model proposed balances well between accuracy and the preservation of desired properties such as scale invariance and consistency among rainfall durations.

In recent decades, the vegetation on many coastal dunes has expanded spatially, which is attributed, among other things, to global-scale climate change. The intersite variability in this dune greening has not yet been substantially investigated, nor is it known whether it is consistent with intersite variability in climate change. Therefore, the objectives of this work were firstly to quantify and analyse the change in vegetation cover from multitemporal NDVI time series at a large number (186) of dune fields worldwide, calculated from Landsat satellite imagery available between 1984 and 2021 and secondly, to correlate the identified trends with trends in the main climate variables influencing vegetation growth (temperature, precipitation and wind speed). We show that greening is strongest in cool temperate climates (35° to 66.5° north/south latitudes) and that the rate of greening is accelerating at many sites. We find no dependence between the rate of greening and the local temporal change in temperature, precipitation and/or wind speed. Based on existing literature, sand supply and anthropogenic activities are discussed as possible reasons for the absence of a clear global relationship between variability in dune greening and climate change.

Caves containing perennial ice deposits make up a little-known, but emerging part of the cryosphere under increasing scrutiny from the scientific community. M-17, a sag-type ice cave opening at 1879 m asl in the Tolminski Migovec massif of the Julian Alps (NW Slovenia) contains a perennial underground ice deposit whose paleoclimate sensitivity is poorly understood and whose longevity under current climate change is at risk. The past mass balance of this cave is constrained using wood macro-remains embedded in ice. Accelerator mass spectrometry radiocarbon dating of 18 wood samples embedded in ice provides the largest currently available dataset for a subterranean ice deposit in the southern European Alps. The reconstructed chronostratigraphy reveals three main phases of likely positive ice balance around 900–1100 AD, 1200–1300 AD, and 1700–1800 AD, as well as a period of negative mass balance around 1300–1400 AD. The onset of cave glaciation is deemed to have occurred no later than about 900 AD, with evidence of overall positive ice mass balance during multi-decadal periods characterized by cooler-than-average summers and wetter-than-average springs. Conversely, negative mass balance is recorded during a period warmer-than-average summers and dry springs. The cave has experienced ice mass loss since its discovery in the 1980s.

Funding Information: This open-access publication was funded by the University of Freiburg. Funding Information: Financial support. The project is supported by the Wassernetzwerk Baden-Württemberg (Water Research Network of the State Baden-Württemberg), which is funded by the Ministerium für Wissenschaft, Forschung und Kunst Baden-Württemberg (Ministry of Science, Research and the Arts of the State Baden-Württemberg) (grant no. AZ. 7532.21/2.1.6) and Maa-ja vesitekniikan tuki ry foundation. Doris E. Wendt acknowledges her support as part of the NERC-funded Groundwater Drought Initiative (NE/R004994/1). Lucy J. Barker was supported by the Natural Environment Research Council (NE/R016429/1) as part of the UK-SCAPE programme delivering National Capability. The contributions of Mirek Trnka, Lenka Bartošová, and Jaak Jaagus have been supported by SustES – Adaptation strategies for sustainable ecosystem services and food security under adverse environmental conditions (CZ.02.1.01/0.0/0.0/16_019/0000797). Publisher Copyright: © 2022 Veit Blauhut et al. Drought events and their impacts vary spatially and temporally due to diverse pedo-climatic and hydrologic conditions, as well as variations in exposure and vulnerability, such as demographics and response actions. While hazard severity and frequency of past drought events have been studied in detail, little is known about the effect of drought management strategies on the actual impacts and how the hazard is perceived by relevant stakeholders. In a continental study, we characterised and assessed the impacts and the perceptions of two recent drought events (2018 and 2019) in Europe and examined the relationship between management strategies and drought perception, hazard, and impact. The study was based on a pan-European survey involving national representatives from 28 countries and relevant stakeholders responding to a standard questionnaire. The survey focused on collecting information on stakeholders' perceptions of drought, impacts on water resources and beyond, water availability, and current drought management strategies on national and regional scales. The survey results were compared with the actual drought hazard information registered by the European Drought Observatory (EDO) for 2018 and 2019. The results highlighted high diversity in drought perception across different countries and in values of the implemented drought management strategies to alleviate impacts by increasing national and sub-national awareness and resilience. The study identifies an urgent need to further reduce drought impacts by constructing and implementing a European macro-level drought governance approach, such as a directive, which would strengthen national drought management and mitigate damage to human and natural assets.

Despite the growing interest among researchers, satellite-based prediction of soil salinity remains highly uncertain. The improvements in prediction accuracy reported in previous studies are usually limited to a single area. We performed a meta-analysis of regional satellite-based soil salinity predictions combined with in situ soil sampling and machine learning. Based on R² and root-mean-square error (RMSE) collected, we evaluated the effects of various features on the model accuracy and established a Bayesian network to evaluate the joint causal effect of multifeatures. Most significant differences were found in soil sampling schemes and characteristics of the study area, including the mean and variability (averaged R² of 0.75 for soil sample sets with lower salinity variation and 0.62 for others) of the salinity, climate type (R² of 0.64 in arid areas and 0.74 in others), soil texture (R² of 0.66 in sandy areas and 0.57 in others), and the interval between sampling date and satellite data acquisition date (R² of 0.53 under the condition of over 15 days and 0.65 in others). Generally, using different satellite data has limited effects on model performance among which Sentinel-2 performed better (R² = 0.72) than Landsat (R² = 0.66). The sampling of subsamples for each sample should focus on their subpixel-scale spatial heterogeneity across satellite data rather than the number of subsamples. It is also necessary to select appropriate vegetation and salinity indices for different satellite data under different vegetation conditions. Among algorithms, random forests (R² = 0.70) and support vector machines (R² = 0.71) performed best.

Earthquake site response is an essential part of seismic hazard assessment, especially in densely populated areas. The shallow geology of the Netherlands consists of a very heterogeneous soft sediment cover, which has a strong effect on the amplitude of ground shaking. Even though the Netherlands is a low- to moderate-seismicity area, the seismic risk cannot be neglected, in particular, because shallow induced earthquakes occur. The aim of this study is to establish a nationwide site-response zonation by combining 3D lithostratigraphic models and earthquake and ambient vibration recordings. As a first step, we constrain the parameters (velocity contrast and shear-wave velocity) that are indicative of ground motion amplification in the Groningen area. For this, we compare ambient vibration and earthquake recordings using the horizontal-to-vertical spectral ratio (HVSR) method, borehole empirical transfer functions (ETFs), and amplification factors (AFs). This enables us to define an empirical relationship between the amplification measured from earthquakes by using the ETF and AF and the amplification estimated from ambient vibrations by using the HVSR. With this, we show that the HVSR can be used as a first proxy for site response. Subsequently, HVSR curves throughout the Netherlands are estimated. The HVSR amplitude characteristics largely coincide with the in situ lithostratigraphic sequences and the presence of a strong velocity contrast in the near surface. Next, sediment profiles representing the Dutch shallow subsurface are categorised into five classes, where each class represents a level of expected amplification. The mean amplification for each class, and its variability, is quantified using 66 sites with measured earthquake amplification (ETF and AF) and 115 sites with HVSR curves. The site-response (amplification) zonation map for the Netherlands is designed by transforming geological 3D grid cell models into the five classes, and an AF is assigned to most of the classes. This site-response assessment, presented on a nationwide scale, is important for a first identification of regions with increased seismic hazard potential, for example at locations with mining or geothermal energy activities.

Earth’s climate experienced a major reorganization across the mid-Pleistocene transition (MPT) from 1.25 to 0.6 million years ago (Ma), when the dominant climate periodicity transitioned from 41-thousand years (kyr) to around 100-kyr. The MPT occurred without a concomitant shift in the orbital forcing rhythm, so it is related to internal climate dynamics rather than external astronomical forcing. Here, we investigate Asian climate dynamics associated with two extreme glacial loess coarsening events at the onset and middle of the MPT by combining new and existing grain size and magnetic susceptibility records from the Chinese Loess Plateau (CLP) spanning the last 1.6 Ma. We find that the two extreme glacial events were marked by a combination of intensified and expanded Asian aridity, winter monsoon strengthening, and distinct coarsening of loess layers L15 and L9-1 across the CLP. These two glacial intensifications coincided with notable Northern Hemisphere glacial ice sheet expansion at 1.25 and 0.9 Ma when the 100-kyr initiated and intensified. By integrating observations, land-sea correlations, and model simulations, we propose that these anomalously dry and windy Asian glacials were probably driven by an amplified terrestrial climate response to the coincident Northern Hemisphere ice sheet expansion. The shift from a 41-kyr to 100-kyr orbital periodicity across the MPT also occurred in our monsoon records, which reflect Northern Hemisphere ice sheet control on orbital-scale Asian climate variability, not just on extreme glacial Asian climate events at 1.25 and 0.9 Ma. Our study supports a close relationship between Asia-interior and global climate changes., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Marine carbon cycle processes are important for taking up atmospheric CO2 thereby reducing climate change. Net primary and export production are important pathways of carbon from the surface to the deep ocean where it is stored for millennia. Climate change can interact with marine ecosystems via changes in the ocean stratification and ocean circulation. In this study we use results from the Community Earth System Model version 2 (CESM2) to assess the effect of a changing climate on biological production and phytoplankton composition in the high latitude North Atlantic Ocean. We find a shift in phytoplankton type dominance from diatoms to small phytoplankton which reduces net primary and export productivity. Using a conceptual carbon-cycle model forced with CESM2 results, we give a rough estimate of a positive phytoplankton composition-atmospheric CO2 feedback of approximately 60 GtCO2/°C warming in the North Atlantic which lowers the 1.5° and 2.0°C warming safe carbon budgets.

A new meteorological dataset derived from records of Antarctic automatic weather stations (here called the AntAWS dataset) at 3 h, daily and monthly resolutions including quality control information is presented here. This dataset integrates the measurements of air temperature, air pressure, relative humidity, and wind speed and direction from 267 Antarctic AWSs obtained from 1980 to 2021. The AWS spatial distribution remains heterogeneous, with the majority of instruments located in near-coastal areas and only a few inland on the East Antarctic Plateau. Among these 267 AWSs, 63 have been operating for more than 20 years and 27 of them in excess of more than 30 years. Of the five meteorological parameters, the measurements of air temperature have the best continuity and the highest data integrity. The overarching aim of this comprehensive compilation of AWS observations is to make these data easily and widely accessible for efficient use in local, regional and continental studies; it may be accessed at https://doi.org/10.48567/key7-ch19 (Wang et al., 2022). This dataset is invaluable for improved characterization of the surface climatology across the Antarctic continent, to improve our understanding of Antarctic surface snow–atmosphere interactions including precipitation events associated with atmospheric rivers and to evaluate regional climate models or meteorological reanalysis products.

Geodetic observations after large subduction earthquakes reflect multiple postseismic processes, including megathrust relocking. The timing of relocking and the observational constraints on it are unclear. Relocking was inferred to explain some observed landward motion that occurs within months. It was also considered unable to explain other, greater landward motion, including that off the coast of Japan beginning weeks after the 2011 Tohoku earthquake, attributed to postseismic relaxation. We use generic, 3D numerical models to show that relocking, particularly of the shallow interface, is needed for postseismic relaxation to produce landward motion on the tip of the overriding plate. We argue that this finding is consistent with previous simulations that implicitly relock the megathrust where afterslip is not included. We conclude that the Tohoku megathrust relocked within less than 2 months of the earthquake. This suggests that the shallow megathrust probably behaves as a true, unstably sliding asperity.

Tidal flats are among the ecologically richest areas of the world where sediment composition (e.g. median grain size and silt content) and the macrozoobenthic presence play an important role in the health of the ecosystem. Regular monitoring of environmental and ecological variables is essential for sustainable management of the area. While monitoring based on field sampling is very time-consuming, the predictive performance of these variables using satellite images is low due to the spectral homogeneity over these regions. We tested a novel approach that uses features from a variational autoencoder (VAE) model to enhance the predictive performance of remote sensing images for environmental and ecological variables of tidal flats. The model was trained using the Sentinel-2 spectral bands to reproduce the input images, and during this process, the VAE model represents important information on the tidal flats within its layer structure. The information in the layers of the trained model was extracted to form features with identical spatial coverage to the spectral bands. The features and the spectral bands together form the input to random forest models to predict field observations of the sediment characteristics such as median grain size and silt content, as well as the macrozoobenthic biomass and species richness. The maximum prediction accuracy of feature-based maps was close to 62% for the sediment characteristics and 37% for benthic fauna indices. The encoded features improved the prediction accuracy of the random forest regressor model by 15% points on average in comparison to using just the spectral bands. Our method enhances the predictive performance of remote sensing, in particular the spatiotemporal dynamics in median grain size and silt content of the sediment thereby contributing to better-informed management of coastal ecosystems.

Funding Information: This work was financially supported by FCT (National Foundation of Science and Technology) within the Research Unit CTS—Centre of Technology and Systems, UIDB/00066/2020 and through Project foRESTER (PCIF/SSI/0102/2017, http://www.forester.pt, accessed on 19 October 2022) and project PEST (UIDB/00066/2020). Publisher Copyright: © 2023 by the authors. To effectively manage the terrestrial firefighting fleet in a forest fire scenario, namely, to optimize its displacement in the field, it is crucial to have a well-structured and accurate mapping of rural roads. The landscape’s complexity, mainly due to severe shadows cast by the wild vegetation and trees, makes it challenging to extract rural roads based on processing aerial or satellite images, leading to heterogeneous results. This article proposes a method to improve the automatic detection of rural roads and the extraction of their centerlines from aerial images. This method has two main stages: (i) the use of a deep learning model (DeepLabV3+) for predicting rural road segments; (ii) an optimization strategy to improve the connections between predicted rural road segments, followed by a morphological approach to extract the rural road centerlines using thinning algorithms, such as those proposed by Zhang–Suen and Guo–Hall. After completing these two stages, the proposed method automatically detected and extracted rural road centerlines from complex rural environments. This is useful for developing real-time mapping applications. publishersversion published

Radiocarbon (14C) concentrations in the oceans are different from those in the atmosphere. Understanding these ocean-atmospheric 14C differences is important both to estimate the calendar ages of samples which obtained their 14C in the marine environment, and to investigate the carbon cycle. The Marine20 radiocarbon age calibration curve is created to address these dual aims by providing a global-scale surface ocean record of radiocarbon from 55,000–0 cal yr BP that accounts for the smoothed response of the ocean to variations in atmospheric 14C production rates and factors out the effect of known changes in global-scale palaeoclimatic variables. The curve also serves as a baseline to study regional oceanic 14C variation. Marine20 offers substantial improvements over the previous Marine13 curve. In response to community questions, we provide a short intuitive guide, intended for the lay-reader, on the construction and use of the Marine20 calibration curve. We describe the choices behind the making of Marine20, as well as the similarities and differences compared with the earlier Marine calibration curves. We also describe how to use the Marine20 curve for calibration and how to estimate ΔR—the localized variation in the oceanic 14C levels due to regional factors which are not incorporated in the global-scale Marine20 curve. To aid understanding, illustrative worked examples are provided.

Rocha, J., Duarte, A., Fabres, S., Quintela, A., & Serpa, D. (2023). Influence of DEM Resolution on the Hydrological Responses of a Terraced Catchment: An Exploratory Modelling Approach. Remote Sensing, 15(1), 1-18. [169]. https://doi.org/10.3390/rs15010169 Funding Information: The author (Dalila Serpo) would like to acknowledge the financial support of CESAM ZUIDP/50017/2020+UIDB/50017/2020+LA/P/0094/2020) by FCT/MCTES, through national funds. Dalila Serpa was funded by national funds (OE) through FCT, I.P., in the scope of the framework contract foreseen in the numbers 4, 5, and 6 of article 23 of the Decree-Law 57/2016, of 29 August, changed by Law 57/2017, of 19 July. Publisher Copyright: © 2022 by the authors. Terracing is widely used as an effective soil and water conservation practice in sloped terrains. Physically based hydrological models are useful tools for understanding the hydrological response of terraced catchments. These models typically require a DEM as input data, whose resolution is likely to influence the model accuracy. The main objective of the present work was to investigate how DEM resolution affects the accuracy of terrain representations and consequently the performance of SWAT hydrological model in simulating streamflow for a terraced eucalypt-dominated catchment (Portugal). Catchment´s hydrological responses were analyzed based on two contrasting topographic scenarios: terraces and no terrace, to evaluate the influence of terraces. To this end, different SWAT models were set up using multi-resolution DEMs (10 m, 1 m, 0.5 m, 0.25 m and 0.10 m) based on photogrammetric techniques and LiDAR data. LiDAR-derived DEMs (terraces scenario) improved topographic surface and watershed representation, consequently increasing the model performance, stage hydrographs and flow-duration curves accuracy. When comparing the contrasting topographic scenarios, SWAT simulations without terraces (10 m and 1 m DEMs) produced a more dynamic and rapid hydrological response. In this scenario, the streamflow was 28% to 36% higher than SWAT simulations accounting for the terraces, which corroborates the effectiveness of terraces as a water conservation practice. publishersversion published

Tropical mountainous regions are often identified as landslide hotspots with growing population pressure. Anthropogenic factors are assumed to play a role in the occurrence of landslides in these densely populated regions, yet the relative importance of these human-induced factors remains poorly documented. In this work, we aim to explore the impact of forest cover dynamics, roads and mining activities on the characteristics and causes of landslides in the rift flank west of Lake Kivu in the Democratic Republic of the Congo (DR Congo). To do so, we compile a comprehensive multi-temporal inventory of 2730 landslides. The landslides are of different types and are grouped into five categories that are adapted to study the impact of human activities on slope stability: old (pre-1950s) and recent (post-1950s) deep-seated landslides, shallow landslides, landslides associated with mining and landslides associated with road construction. We analyse the landslides according to this classification protocol via frequency–area statistics, frequency ratio distribution and logistic regression susceptibility assessment. We find that natural factors contributing to the cause of recent and old deep-seated landslides were either different or changed over time. Under similar topographic conditions, shallow landslides are more frequent, but of a smaller size, in areas where deforestation has occurred since the 1950s. We attribute this size reduction to the decrease in regolith cohesion due to forest loss, which allows for a smaller minimum critical area for landsliding. In areas that were already deforested in the 1950s, shallow landslides are less frequent, larger and occur on less steep slopes. This suggests a combined role between regolith availability and soil management practices that influence erosion and water infiltration. Mining activities increase the odds of landsliding. Landslides associated with mining and roads are larger than shallow landslides but smaller than the recent deep-seated instabilities, and they are controlled by environmental factors that are not present under natural conditions. Our analysis demonstrates the role of human activities on the occurrence of landslides in the Lake Kivu region. Overall, it highlights the need to consider this context when studying hillslope instability characteristics and distribution patterns in regions under anthropogenic pressure. Our work also highlights the importance of using landslide classification criteria adapted to the context of the Anthropocene.

Large Oligocene Antarctic ice sheets co-existed with warm proximal waters offshore Wilkes Land. Here we provide a broader Southern Ocean perspective to such warmth by reconstructing the strength and variability of the Oligocene Australian-Antarctic latitudinal sea surface temperature gradient. Our Oligocene TEX86-based sea surface temperature record from offshore southern Australia shows temperate (20–29 °C) conditions throughout, despite northward tectonic drift. A persistent sea surface temperature gradient (~5–10 °C) exists between Australia and Antarctica, which increases during glacial intervals. The sea surface temperature gradient increases from ~26 Ma, due to Antarctic-proximal cooling. Meanwhile, benthic foraminiferal oxygen isotope decline indicates ice loss/deep-sea warming. These contrasting patterns are difficult to explain by greenhouse gas forcing alone. Timing of the sea surface temperature cooling coincides with deepening of Drake Passage and matches results of ocean model experiments that demonstrate that Drake Passage opening cools Antarctic proximal waters. We conclude that Drake Passage deepening cooled Antarctic coasts which enhanced thermal isolation of Antarctica.

While the Intergovernmental Panel on Climate Change (IPCC) physical science reports usually assess a handful of future scenarios, the Working Group III contribution on climate mitigation to the IPCC's Sixth Assessment Report (AR6 WGIII) assesses hundreds to thousands of future emissions scenarios. A key task in WGIII is to assess the global mean temperature outcomes of these scenarios in a consistent manner, given the challenge that the emissions scenarios from different integrated assessment models (IAMs) come with different sectoral and gas-to-gas coverage and cannot all be assessed consistently by complex Earth system models. In this work, we describe the “climate-assessment” workflow and its methods, including infilling of missing emissions and emissions harmonisation as applied to 1202 mitigation scenarios in AR6 WGIII. We evaluate the global mean temperature projections and effective radiative forcing (ERF) characteristics of climate emulators FaIRv1.6.2 and MAGICCv7.5.3 and use the CICERO simple climate model (CICERO-SCM) for sensitivity analysis. We discuss the implied overshoot severity of the mitigation pathways using overshoot degree years and look at emissions and temperature characteristics of scenarios compatible with one possible interpretation of the Paris Agreement. We find that the lowest class of emissions scenarios that limit global warming to “1.5 ∘C (with a probability of greater than 50 %) with no or limited overshoot” includes 97 scenarios for MAGICCv7.5.3 and 203 for FaIRv1.6.2. For the MAGICCv7.5.3 results, “limited overshoot” typically implies exceedance of median temperature projections of up to about 0.1 ∘C for up to a few decades before returning to below 1.5 ∘C by or before the year 2100. For more than half of the scenarios in this category that comply with three criteria for being “Paris-compatible”, including net-zero or net-negative greenhouse gas (GHG) emissions, median temperatures decline by about 0.3–0.4 ∘C after peaking at 1.5–1.6 ∘C in 2035–2055. We compare the methods applied in AR6 with the methods used for SR1.5 and discuss their implications. This article also introduces a “climate-assessment” Python package which allows for fully reproducing the IPCC AR6 WGIII temperature assessment. This work provides a community tool for assessing the temperature outcomes of emissions pathways and provides a basis for further work such as extending the workflow to include downscaling of climate characteristics to a regional level and calculating impacts.

The temperature at Earth’s core-mantle boundary (CMB) is a key parameter to understand the dynamics of our planet’s interior. However, it remains poorly known, with current estimate ranging from about 3000 K to 4500 K and more. Here, we introduce a new approach based on joint measurements of seismic shear-wave velocity,VS, and quality factor,QS, in the lowermost mantle. Lateral changes in bothVSandQSabove the CMB provide constraints on lateral temperature anomalies with respect to a reference temperature,Tref, defined as the average temperature in the layer immediately above the CMB. The request that, at a given location, temperature anomalies inferred independently fromVSandQSshould be equal gives a constraint onTref. CorrectingTreffor radial adiabatic and super-adiabatic increases in temperature gives an estimate of the CMB temperature,TCMB. This approach further relies on the fact thatVS-anomalies are affected by the distribution of post-perovskite (pPv) phase. As a result, the inferredTrefis linked to the temperatureTpPvat which the transition from bridgmanite to pPv occurs close to the CMB. A preliminary application toVSandQSmeasured beneath Central America and the Northern Pacific suggest that forTpPv= 3500 K,TCMBlies in the range 3,470–3880 K with a 95% likelihood. Additional measurements in various regions, together with a better knowledge ofTpPv, are however needed to determine a precise value ofTCMBwith our method.

Tonini, A., Painho, M., & Castelli, M. (2022). Estimation of Human Body Height Using Consumer-Level UAVs. Remote Sensing, 14(23), 1-21. [6176]. https://doi.org/10.3390/rs14236176 ----- This study was supported by grant DSAIPA/DS/0113/2019 from FCT (Fundação para a Ciência e a Tecnologia), Portugal. This work was also supported by national funds through FCT (Fundação para a Ciência e a Tecnologia), under the project—UIDB/04152/2020—Centro de Investigação em Gestão de Informação (MagIC)/NOVA IMS. Consumer-level UAVs are often employed for surveillance, especially in urban areas. Within this context, human recognition via estimation of biometric traits, like body height, is of pivotal relevance. Previous studies confirmed that the pinhole model could be used for this purpose, but only if the accurate distance between the aerial camera and the target is known. Unfortunately, low positional accuracy of the drones and the difficulties of retrieving the coordinates of a moving target like a human may prevent reaching the required level of accuracy. This paper proposes a novel solution that may overcome this issue. It foresees calculating the relative altitude of the drone from the target by knowing only the ground distance between two points visible in the image. This relative altitude can be then used to calculate the target-to-camera distance without using the coordinates of the drone or the target. The procedure was verified with real data collected with a quadcopter, first considering a controlled environment with a wooden pole of known height and then a person in a more realistic scenario. The verification confirmed that a high level of accuracy can be reached, even with regular market drones. publishersversion published

The International Union of Geological Sciences Executive Committee (IUGS EC) voted on 13 October 2021 to ratify a proposal for the Neogene subseries/subepochs to have formal status. They are now incorporated into a six-tiered chronostratigraphic hierarchy within the International Chronostratigraphic Chart (ICC). The Lower/Early Miocene Subseries/Subepoch comprises the Aquitanian and Burdigalian stages/ages, the Middle Miocene Subseries/Subepoch comprises the Langhian and Serravallian stages/ages, the Upper/Late Miocene Subseries/Subepoch comprises the Tortonian and Messinian stages/ages, the Lower/Early Pliocene Subseries/Subepoch comprises the Zanclean Stage/Age and the Upper/Late Pliocene Subseries/Subepoch comprises the Piacenzian Stage/Age. This ratification is an important move towards both a common language in the wider Earth Sciences community and a step forward in the unification of Cenozoic chronostratigraphy, with Neogene and Quaternary subseries/subepochs now formalized.

Greening of the planet has increased global surface water availability, but vegetation changes can have diverse local and remote impacts across different regions.

The Pleistocene Series/Epoch of the Quaternary System/Period has been divided unofficially into three subseries/subepochs since at least the 1870s. On 30th January, 2020, the Executive Committee of the International Union of Geological Sciences ratified two proposals approved by the International Commission on Stratigraphy formalizing: 1) the Lower Pleistocene Subseries, comprising the Gelasian Stage and the superjacent Calabrian Stage, with a base defined by the GSSP for the Gelasian Stage, the Pleistocene Series, and the Quaternary System, and currently dated at 2.58 Ma; and 2) the term Upper Pleistocene, at the rank of subseries, with a base currently undefined but provisionally dated at ~129 ka. Defining the Upper Pleistocene Subseries and its corresponding stage with a GSSP is in progress. The Middle Pleistocene Subseries is defined by the recently ratified GSSP for the Chibanian Stage currently dated at 0.774 Ma. These ratifications complete the official division of the Pleistocene into three subseries/subepochs, in uniformity with the similarly subdivided Holocene Series/Epoch.

A Global Navigation Satellite System (GNSS) receiver usually needs a sufficient number of full pseudorange measurements to obtain a position solution. However, it is time-consuming to acquire full pseudorange information from only the satellite broadcast signals due to the navigation data features of GNSS. In order to realize fast positioning during a cold or warm start in a GNSS receiver, the existing approaches require an initial estimation of position and time or require a number of computational steps to recover the full pseudorange information from fractional pseudoranges and then compute the position solution. The BeiDou Navigation Satellite System (BDS) has a unique constellation distribution and a fast navigation data rate for geostationary earth orbit (GEO) satellites. Taking advantage of these features, we propose a fast positioning technique for BDS receivers. It simultaneously processes the full and fractional pseudorange measurements from the BDS GEOs and non-GEOs, respectively, which is faster than processing all full measurements. This method resolves the position solution and recovers the full pseudoranges for non-GEOs simultaneously within 1 s theoretically and does not need an estimate of the initial position. Simulation and real data experiments confirm that the proposed technique completes fast positioning without a priori position and time estimation, and the positioning accuracy is identical with the conventional single-point positioning approach using full pseudorange measurements from all available satellites.

Funding Information: This study was funded by the Agencia Estatal de Investigación (Ministerio de Ciencia e Innovación/ http://dx.doi.org/10.13039/501100011033 ) of the Government of Spain (grant number PID2019-108705-GB-I00 ), the Spanish Ministerio de Economía y Competitividad-FEDER (grant number CGL2012-35662 ), and the Regional Government of Aragón (grant number E32_20R ; research group Geotransfer: Investigación Geológica para la Ciencia y la Sociedad). We are very grateful to Luis Alcalá, Luis Mampel and Eduardo Espilez for their help with the location of the paleontological sites. We would like to thank Prof. Miguel Garcés, Sevket Sen, Imre Magyar and an anonymous reviewer for their useful comments and suggestions, which helped us improve the manuscript. Publisher Copyright: © 2022 The Authors The northern sector of the Teruel Basin (Spain) houses a dense and continuous record of late Neogene mammal fossil sites, as well as numerous biostratigraphic and magnetostratigraphic information making it a reference basin to define and refine the European mammal biostratigraphy from the Vallesian to the Villafranchian. The Neogene mammal chronology is in ongoing revision, and distinct correlations between basins and Europe provinces have been proposed based on their relative ages. New calibration methods based on numerical modelling have allowed the absolute ages of the paleontological sites to be refined. Nevertheless, some discrepancies arise, evidencing that anchoring between absolute ages and mammal fossil record would benefit from a stronger stratigraphical framework. This work provides such a robust 3D stratigraphic framework of the whole basin that, together with magnetostratigraphy, allows establishing an accurate chronostratigraphic model and hence a precise chronology of sedimentary units and mammal sites. The absolute age of MN zones, or mammal stages, in the Teruel Basin has been revised on the basis of a detailed and confident stratigraphic correlation, and updated to the most recent Geomagnetic Polarity Time Scale. In particular, new accurate ages have been proposed for the boundaries MN 9/10 to MN 16/17 from data exclusively located in the Teruel Basin, with a precision generally of 0.1–0.2 Ma. publishersversion published

In the past decade, drones have become available and affordable for civil applications, including mapping and monitoring the Earth with geophysical sensors. In 2017 and 2019, the feasibility of executing frequency domain electromagnetic (FDEM) surveys using an off-the-shelf drone was investigated at Deltares Institute. This paper reports firstly the preparatory tests executed to determine the optimal instrumental configuration, flight path, data processing and inversion schemes and secondly the three field validation tests executed to demonstrate the feasibility of the drone-borne electromagnetic survey in real-scale applications. At several test sites, the optimal configuration of the drone and electromagnetic instruments, such as the mounting device and distance of the electromagnetic (EM) sensor with respect to the drone, the flight altitude, the coil separation and frequency of the EM source, efficiency and safety, and the assemblage of instrument and drone data were investigated. This has resulted in a robust method to acquire accurate and repeatable in-phase, quadrature and apparent resistivity data, and a workflow for data correction, processing and inversion scheme was developed. During those tests, three EM instruments were tested. The drone-borne electromagnetic (DR-EM) system has the ability and efficacy to fly over inaccessible areas and surface water. Compared to helicopter-borne electromagnetic surveys, the spatial resolution is much higher, which allows very detailed 3D mapping of subsurface targets, and the survey costs are relatively low. Repeated drone-borne electromagnetic (DR-EM) surveys allow low-cost monitoring of local changes in water saturation and salinity.

This work was supported by the Scottish Blue Carbon Forum. Additional, sample collection was supported by the Biotechnology and Biological Sciences Research Council (BBSRC) and the manuscript submitted to Global Biogeochemical Cycles Natural Environment Research Council (NERC) (BB/M026620/01). NERC also supported the analysis within this project through the NERC Life Science Mass Spectrometry Facility (CEH_L_098_11_2015 and CEH_L-155-05-2018). The sediments within fjords are critical components of the mid- to high-latitude coastal carbon (C) cycle, trapping and storing more organic carbon (OC) per unit area than other marine sedimentary environments. Located at the land-ocean transition, fjord sediments receive OC from both marine and terrestrial environments; globally, it has been estimated that 55% to 62% of the OC held within modern fjord sediments originates from terrestrial environments. However, the mid-latitude fjords of the Northern Hemisphere have largely been omitted from these global compilations. Here we investigate the mechanism driving the distribution of OC originating from different sources within the sediments of 38 Scottish fjords. From an array of fjord characteristics, the tidal range and outer sill depth were identified as the main drivers governing the proportions of marine and terrestrial OC in the sediments. Utilizing this relationship, we estimate that on average 52 ± 10% of the OC held within the sediments of all Scotland’s fjords is terrestrial in origin. These findings show that the Scottish fjords hold equivalent quantities of terrestrial OC as other global fjord systems. However, the analysis also highlights that the sediments within 29 % of Scottish fjords are dominated by marine derived OC, which is driven by local fjord geomorphology and oceanography. Publisher PDF

Hydrocarbons in subsurface nanoporous media, such as shale, are promising energy resources to compensate for the shortage of conventional reservoirs. Pore-network modeling serves as a valuable tool for simulating microscale fluid transport and elucidating flow physics in porous media. However, traditional pore-network models have failed to capture features of spatial structure and fluid flow in unconventional shale rock. This work presents a critical review of pore-network modeling of single-phase and two-phase flow in shale rock. Pore-network modeling advances of shale are reviewed based on three major parts: network morphology and geometries, flow principles in nanocapillaries, and pore-network computational algorithms. First, based on key geological features of shale rock, we analyze network topology, multiscale network, pore geometries, and network representativeness of shale pore-network models. Then, we discuss four important aspects that may influence flow principles of fluids in nanocapillaries: gas and liquid slippage, sorption and diffusion behavior, hydrocarbon thermodynamics, and the presence of water. Finally, we present pore-network modeling methods used for flow simulations in shale rock, including quasi-static and dynamic algorithms. We hope that this review could shed light on fundamentals of pore-network modeling of shale rock.

It is difficult to quantify the amount of groundwater inflow on the Tibetan Plateau (TP), yet it can be critically important for sustaining lake water balance. Here we show that most endorheic lakes on the western TP exhibited considerable water level increase during the ice-covered period, which contrasts with lakes in other regions of the TP. An analysis of lake water balance attributes this water surplus to significant groundwater inflow, which is estimated to be about 59%–66% of total inflow into lakes. The groundwater inflow occurred after the 2000s, which is consistent with the rapid lake expansion and significant increase in precipitation. We suggest that the groundwater inflow is mainly related to large-scale active faults in the limestone bedrock and sufficient meltwater from high elevations. Our results imply that groundwater may be deeply involved in the water cycle and modify the seasonal and inter-annual lake variations on the western TP.

Clumped isotope thermometry can independently constrain the formation temperatures of carbonates, but a lack of precisely temperature-controlled calibration samples limits its application on aragonites. To address this issue, we present clumped isotope compositions of aragonitic bivalve shells grown under highly controlled temperatures (1–18°C), which we combine with clumped isotope data from natural and synthetic aragonites from a wide range of temperatures (1–850°C). We observe no discernible offset in clumped isotope values between aragonitic foraminifera, mollusks, and abiogenic aragonites or between aragonites and calcites, eliminating the need for a mineral-specific calibration or acid fractionation factor. However, due to non-linear behavior of the clumped isotope thermometer, including high-temperature (>100°C) datapoints in linear clumped isotope calibrations causes them to underestimate temperatures of cold (1–18°C) carbonates by 2.7 ± 2.0°C (95% confidence level). Therefore, clumped isotope-based paleoclimate reconstructions should be calibrated using samples with well constrained formation temperatures close to those of the samples.

The quality of global water resources is increasingly strained by socio-economic developments and climate change, threatening both human livelihoods and ecosystem health. With inadequately managed wastewater being a key driver of deterioration, Sustainable Development Goal (SDG) 6.3 was established to halve the proportion of untreated wastewater discharged to the environment by 2030. Yet, the impact of achieving SDG6.3 on global ambient water quality is unknown. Addressing this knowledge gap, we develop a high-resolution surface water quality model for salinity as indicated by total dissolved solids, organic pollution as indicated by biological oxygen demand and pathogen pollution as indicated by fecal coliform. Our model includes a novel spatially-explicit approach to incorporate wastewater treatment practices, a key determinant of in-stream pollution. We show that achieving SDG6.3 reduces water pollution, but is still insufficient to improve ambient water quality to below key concentration thresholds in several world regions. Particularly in the developing world, reductions in pollutant loadings are locally effective but transmission of pollution from upstream areas still leads to water quality issues downstream. Our results highlight the need to go beyond the SDG-target for wastewater treatment in order to achieve the overarching goal of clean water for all.

When continents collide, the arrival of positively buoyant continental crust slows down subduction. This collision often leads to the detachment of earlier subducted oceanic lithosphere, which changes the subsequent dynamics of the orogenic system. Recent studies of continental collision infer that the remaining slab may drive convergence through slab roll-back even after detachment. Here we use two-dimensional visco-elasto-plastic thermo-mechanical models to explore the conditions for post-collisional slab steepening versus shallowing by quantifying the dynamics of continental collision for a wide range of parameters. We monitor the evolution of horizontal mantle drag beneath the overriding plate and vertical slab pull to show that these forces have similar magnitudes and interact continuously with each other. We do not observe slab rollback or steepening after slab detachment within our investigated parameter space. Instead, we observe a two-stage elastic and viscous slab rebound process lasting tens of millions of years, which is associated with slab unbending and eduction that together generate orogenic widening and trench shift towards the foreland. Our parametric studies show that the initial length of the oceanic plate and the stratified lithospheric rheology exert a key control on the orogenic evolution. When correlated with previous studies our results suggest that post-detachment slab rollback may only be possible when minor amounts of continental crust subduct. Among the wide variety of natural scenarios, our modelling applies best to the evolution of the Central European Alps. Furthermore, the mantle drag force may play a more important role in continental dynamics than previously thought. Finally, our study illustrates that dynamic analysis is a useful quantitative framework that also intuitively explains observed model kinematics.

When continents collide, the arrival of positively buoyant continental crust slows down subduction. This collision often leads to the detachment of earlier subducted oceanic lithosphere, which changes the subsequent dynamics of the orogenic system. Recent studies of continental collision infer that the remaining slab may drive convergence through slab roll-back even after detachment. Here we use two-dimensional visco-elasto-plastic thermo-mechanical models to explore the conditions for post-collisional slab steepening versus shallowing by quantifying the dynamics of continental collision for a wide range of parameters. We monitor the evolution of horizontal mantle drag beneath the overriding plate and vertical slab pull to show that these forces have similar magnitudes and interact continuously with each other. We do not observe slab rollback or steepening after slab detachment within our investigated parameter space. Instead, we observe a two-stage elastic and viscous slab rebound process lasting tens of millions of years, which is associated with slab unbending and eduction that together generate orogenic widening and trench shift towards the foreland. Our parametric studies show that the initial length of the oceanic plate and the stratified lithospheric rheology exert a key control on the orogenic evolution. When correlated with previous studies our results suggest that post-detachment slab rollback may only be possible when minor amounts of continental crust subduct. Among the wide variety of natural scenarios, our modelling applies best to the evolution of the Central European Alps. Furthermore, the mantle drag force may play a more important role in continental dynamics than previously thought. Finally, our study illustrates that dynamic analysis is a useful quantitative framework that also intuitively explains observed model kinematics.

This study introduces a technique for four-dimensional pore pressure monitoring using passive image interferometry. Surface-wave velocity changes as a function of frequency are directly linked to depth variations of pore pressure changes through sensitivity kernels. We demonstrate that these kernels can be used to invert time-lapse seismic velocity changes, retrieved with passive image interferometry, for hydrological pore pressure variations as a function of time, depth and region. This new approach is applied in the Groningen region of the Netherlands. We show good recovery of pore pressure variations in the upper 200 m of the subsurface from passive seismic velocity observations. This depth range is primarily limited by the reliable frequency range of the seismic data.

Recent climate change mitigation strategies rely on the reduction of methane (CH4) emissions. Carbon and hydrogen isotope ratio (δ13CCH4 and δ2HCH4) measurements can be used to distinguish sources and thus to understand the CH4 budget better. The CH4 emission estimates by models are sensitive to the isotopic signatures assigned to each source category, so it is important to provide representative estimates of the different CH4 source isotopic signatures worldwide. We present new measurements of isotope signatures of various, mainly anthropogenic, CH4 sources in Europe, which represent a substantial contribution to the global dataset of source isotopic measurements from the literature, especially for δ2HCH4. They improve the definition of δ13CCH4 from waste sources, and demonstrate the use of δ2HCH4 for fossil fuel source attribution. We combined our new measurements with the last published database of CH4 isotopic signatures and with additional literature, and present a new global database. We found that microbial sources are generally well characterised. The large variability in fossil fuel isotopic compositions requires particular care in the choice of weighting criteria for the calculation of a representative global value. The global dataset could be further improved by measurements from African, South American, and Asian countries, and more measurements from pyrogenic sources. We improved the source characterisation of CH4 emissions using stable isotopes and associated uncertainty, to be used in top-down studies. We emphasise that an appropriate use of the database requires the analysis of specific parameters in relation to source type and the region of interest. The final version of the European CH4 isotope database coupled with a global inventory of fossil and non-fossil δ13CCH4 and δ2HCH4 source signature measurements is available at https://doi.org/10.24416/UU01-YP43IN (Menoud et al., 2022a).

The Triassic–Jurassic transition, which is here broadly defined as extending from the Late Triassic through the Early Jurassic (~237 Ma to 174 Ma), was an important interval in Earth history. The end-Triassic mass extinction (ETME), at ~201 Ma, ranks among the ‘Big Five’ Phanerozoic mass extinctions. It largely completed the shift from the ‘Paleozoic Evolutionary Fauna’ to the ‘Modern Evolutionary Fauna’ that had been initiated by the end-Permian mass extinction, and may have contributed to the ‘Mesozoic Marine Revolution’ and rise of dinosaurs to dominance in terrestrial environments. In addition, the Triassic–Jurassic transition encompasses a second-order mass extinction during the early Toarcian oceanic anoxic event (T-OAE), at ~181 Ma. The ETME was triggered by Central Atlantic Magmatic Province (CAMP) magmatism, and the T-OAE by Karoo-Ferrar Large Igneous Province (KFLIP) magmatism, both associated with the stepwise disintegration of the Pangean supercontinent. These events led to major changes in continental and marine habitats, including climatic warming, ocean acidification, and widespread watermass anoxia, that produced a cascade of lethal environmental stresses. This article undertakes a review of the ETME and T-OAE mass extinctions, the large igneous province eruptions that triggered those biotic events, and the web of environmental changes that linked them together.

In this paper we discuss recent developments in documenting the spread of millet across the Eurasian steppes. We emphasize that, despite a recent proposal that millet consumption in southern Siberia can be attributed to the Early Bronze Age (i.e., the late third to early second millennium BC), at present there are no direct data for southern Siberia indicating the consumption of millet prior to the Late Bronze Age, from the 14th century BC. We also present in full the combined stable isotope and 14C datasets from the Minusinsk Basin to support this conclusion.

This paper aims at expanding the scope of the dominantly pragmatic, local scale-oriented smart village scholarship towards a perspective that recognizes that smart village development is a multiscalar political process. To show the necessity of this move, the shaping of smart village policies and practices in Hungary is examined through a qualitative lens. As the authors argue, path-dependent structural obstacles and interscalar relations undermine the prospects of smart village building in the sense of bottom-up integrated rural development, and there is a risk of a bias towards technological innovation. This exploratory article, using Hungary as a case study, argues that smart village scholarship should draw on the results of critical smart city scholarship to acquire in-depth understanding of current debates regarding potential smart village developments.

Layer-bound, low-displacement normal faults, arranged into a broadly polygonal pattern, are common in many sedimentary basins. Despite having constrained their gross geometry, we have a relatively poor understanding of the processes controlling the nucleation and growth (i.e., the kinematics) of polygonal fault systems. In this study we use high-resolution 3-D seismic reflection and borehole data from the northern North Sea to undertake a detailed kinematic analysis of faults forming part of a seismically well-imaged polygonal fault system hosted within the up to 1,000 m thick, Early Palaeocene-to-Middle Miocene mudstones of the Hordaland Group. Growth strata and displacement-depth profiles indicate faulting commenced during the Eocene to early Oligocene, with reactivation possibly occurring in the late Oligocene to middle Miocene. Mapping the position of displacement maxima on 137 polygonal faults suggests that the majority (64%) nucleated in the lower 500 m of the Hordaland Group. The uniform distribution of polygonal fault strikes in the area indicates that nucleation and growth were not driven by gravity or far-field tectonic extension as has previously been suggested. Instead, fault growth was likely facilitated by low coefficients of residual friction on existing slip surfaces, and probably involved significant layer-parallel contraction (strains of 0.01–0.19) of the host strata. To summarize, our kinematic analysis provides new insights into the spatial and temporal evolution of polygonal fault systems.

The Braiding Index (BI), defined as the average count of intercepted channels per cross-section, is a widely used metric for characterizing multi-thread river systems. However, it does not account for the diversity of channels (e.g., in terms of water discharge) within different cross-sections, omitting important information related to system complexity. Here we present a modification of BI, the Entropic Braiding Index (eBI), which augments the information content in BI by using Shannon Entropy to encode the diversity of channels in each cross section. eBI is interpreted as the number of “effective channels” per cross-section, allowing a direct comparison with the traditional BI. We demonstrate the potential of the ratio BI/eBI to quantify channel disparity, differentiate types of multi-thread systems (braided vs. anastomosed), and assess the effect of discharge variability, such as seasonal flooding, on river cross-section stability.

The Braiding Index (BI), defined as the average count of intercepted channels per cross-section, is a widely used metric for characterizing multi-thread river systems. However, it does not account for the diversity of channels (e.g., in terms of water discharge) within different cross-sections, omitting important information related to system complexity. Here we present a modification of BI, the Entropic Braiding Index (eBI), which augments the information content in BI by using Shannon Entropy to encode the diversity of channels in each cross section. eBI is interpreted as the number of “effective channels” per cross-section, allowing a direct comparison with the traditional BI. We demonstrate the potential of the ratio BI/eBI to quantify channel disparity, differentiate types of multi-thread systems (braided vs. anastomosed), and assess the effect of discharge variability, such as seasonal flooding, on river cross-section stability.