bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploration and Application of High-Precision Inclined Photography Technology in Digital Collection of Geological Outcrops
Authors: Lin Zongqi , Wang Bingqian , Wu Yuqing , Zhou Wenfeng , Peng Xueli , Xu Yuhao , Wang Chenyu , Wang Cai
Published: March 2024

With the ongoing evolution of unmanned aerial vehicle (UAV) technology in geology, particularly the emergence of oblique photogrammetry, a novel approach for creating high-precision 3D models of geological outcrops has been introduced. This technique offers a more abundant and detailed perspective compared to traditional orthophotography. To guarantee optimal data collection, an extensive preliminary survey of the surrounding area of the geological outcrop was conducted using satellite imagery. We selected the DJI Mavic 3 drone, equipped with a 4/3 CMOS sensor and boasting an effective resolution of 20 million pixels. The incorporation of a Hasselblad lens significantly enhances the image quality. During the photography process, we meticulously controlled critical parameters such as the overlap rate of images, flight altitude, and the angle of photography. The overlap rate was typically maintained between 60-70%, necessitating systematic photography from macroscopic to microscopic levels and the continual adjustment of the drone camera's tilt to capture intricate details of the outcrop from various angles, enabling the construction of a more detailed and comprehensive 3D model.Our project has digitally captured and modeled over 120 notable geological outcrops across 12 countries, including China, the United Arab Emirates, Italy, France, Germany, Spain, and Namibia, etc. We have amassed over 240,000 drone photos for 3D modeling, in excess of 7,000 panoramic shots, and more than 800 video segments featuring international experts discussing outcrops, culminating in 8000GB of data. The essence of our work is rooted in precise UAV oblique photography, and through extensive experimentation, we've established a systematic approach, achieving centimeter-level resolution.Looking to the future, our goal is to further the digitalization of classical geological outcrops, field practice bases, and world geoparks. The data and models we produce are invaluable for geological research and education, offering a more vivid and intuitive understanding of complex geological phenomena to both the academic community and the public.
Balancing food system greenhouse gas emissions reduction and food security in China
Authors: Zhao Hao , Zhang Haotian , Havlik Petr , Chang Jinfeng
Published: March 2024

China's increasing food consumption, particularly for animal products, presents a substantial challenge to mitigating greenhouse gas (GHG) emissions, not only within China but also extending to its trading partners. In this study, we employ the well-established food system integrated assessment model (GLOBIOM-China) to comprehensively investigate GHG emissions within the context of China's future food consumption. Our study indicates that in the baseline scenario (BAU), GHG emissions from China's food consumption side are projected to be 965 million tonnes of CO2 equivalent (Mt CO2 eq) by 2060, similar to the current level. Domestically, ruminant production accounts for a substantial 44% of total consumption-based emissions. Meanwhile, livestock-related methane emissions take prominence in terms of different gas categories, comprising a significant 45%. Virtual GHG emissions import is expected to decrease due to the deceleration of land use change, while the GHG emissions attributable to livestock product imports are projected to incrementally rise, eventually constituting 17.2% of the total food consumption-based emissions. Striving for food self-sufficiency (SS scenario) offers a pathway to diminishing China's food system GHG emissions and virtually imported emissions by 6% and 43%, respectively. However, this scenario presents an increase of domestic emissions by 2% and simultaneously poses challenges to domestic land use and other related indicators. Maintaining basic food self-sufficiency, and reducing calorie intake from animal sources and improving production practices contribute to a 216 Mt CO2eq reduction of total GHG emissions. This approach not only holds promise for emission reduction but also brings broader benefits such as decreased agricultural commodity prices (by -28%), reduced nitrogen fertilizer uses (by -13%), diminished agricultural land requirement (by -10%), and only 2% decline in per capita calorie intake. Our study reconciles GHG mitigation strategies and food security within China's food system, thereby contributing significantly to global sustainable development.
On the triggering mechanism of fault-slip bursts during deep underground excavation
Authors: Pan Wenbo , Zhang Zixin , Wang Shuaifeng , Zhao Chenxi , Lei Qinghua
Published: March 2024

To meet the target of net-zero emissions by 2050, six times more mineral inputs are required in 2040 than today. However, with the depletion of mineral resources in the shallow subsurface, mining at great depth is inevitable. Furthermore, the rapid development of urban systems, transport networks, and hydropower plants also impose an increased demand of deep underground excavation. These deep mining or tunneling activities are, however, confronted with the risk of induced earthquakes and rockbursts. For example, during the Gotthard Base Tunnel construction at great depths of up to 2.5 km in the Swiss Alps, extensive regional earthquakes with magnitudes reaching up to Mw 2.4 were recorded. Accompanying some of these earthquake events, intense rockbursts occurred at the Faido Multifunction Station. So far, it remains poorly understood the triggering mechanisms of these rockburst events and their relationship with the induced earthquakes. Here, we develop a novel three-dimensional coupled seimo-mechanical model which can capture the rupture of a seismogenic fault zone, the redistribution of stress field, the propagation of seismic waves, and the occurrence of coseismic rockbursts in a tunnel located a few hundred meters away from the hypocenter (i.e., in the near-field of the earthquake fault). We investigate the competing roles of static and dynamic triggering in generating these fault-slip burst events and find that static stress changes play a much more dominant role than dynamic waves. The results and insights derived from our research have important implications for understanding and predicting catastrophic rockbursts during deep underground excavation for various geoenergy or geoengineering applications, ranging from critical mineral extraction and nuclear waste disposal to underground energy storage and civil infrastructure development.
Joint effects of storage-runoff limitation amplify global stress in water availability
Authors: Li Xueying , Peng Jian
Published: March 2024

Nearly 80% of the global population faces severe water stress, yet changes in global water availability are not well quantified. Two essential factors for identifying water stress and promoting sustainable development include runoff, a flux variable reflecting water use, and freshwater storage, representing the potentially maximum water resources. Despite their importance, integrated analysis of changes in runoff/storage and their impacts on society remains in its infancy at the global scale. By leveraging the strengths of remote sensing techniques, advanced land surface models, and reanalysis data, here we quantified global changes in total water storage (TWS) and runoff over the past two decades. In addition, we proposed new indices to evaluate the relative vulnerability in water availability normalized at the global scale. The results show that 80% of global areas experienced declines in TWS and/or runoff for the past two decades, and 39% of areas suffered from water loss in both storage and runoff. The joint effects of storage-runoff limitation amplified vulnerability in water availability, reflected by not only a larger spatial domain but also higher severity relative to individual stress caused by either TWS or runoff changes. The most vulnerable regions in water availability were found across the north and central South America, south Asia, and Europe. Specific threats include the loss of solid water storage, groundwater extraction for irrigation, and climate-induced extreme heat and drought over the past two decades. Our findings provide valuable insights not only for understanding hydrologic responses to a changing climate and fast-developing society, but also for developing adaptive strategies for water-stressed hotspots.
Employing ancient oral traditions in Central Java to warn of volcano–earthquake interaction
Authors: Troll Valentin , Deegan Frances M. , Seraphine Nadhirah
Published: March 2024

Merapi volcano in Central Java, Indonesia, is one of the most hazardous volcanoes in Southeast Asia, yet humans have inhabited the area around Merapi since ancient times. Responses to official hazard warnings are not always taken up by all community members, and some groups actively resist  engaging in protection measures initiated by official authorities. A relatively new strategy to raise hazard awareness and to improve communication with interest groups involves cultural communication tools, such as the use of local wisdom and ancient oral traditions. The local legends around Merapi volcano describe the interaction of the spirit kings that reside within Merapi volcano and the Queen of the South Sea, who resides in the Indian Ocean near Parangtritis, some 50 km SSE of the volcano. The royal palace in Yogyakarta is located half-way between Merapi volcano and Parangtritis beach and is believed to balance these opposing forces. In 2006 and 2010, Merapi erupted explosively and on both occasions, earthquakes shook the region and caused the eruptions to grow more intense. Notably, the 2006 earthquakes clustered along the Opak River fault system to the south of the volcano that reaches the sea at Parangtritis beach, the fabled residence of the Queen of the South Sea. We argue that local legends developed to rationalise the dynamic interaction between the volcano and the frequent regional earthquakes through the rich oral traditions and ceremonies in the districts around Merapi. These legends can thus be thought of as comprising an ancient hazard catalogue with respect to local eruptive behaviour and seismic phenomena. This realisation is now finding increasing use in communicating volcanic hazard knowledge to diverse local resident and interest groups, including local primary schools, showing considerable (and measurable) effects on hazard awareness and hazard preparedness (1). The use of cultural communication tools can thus help to further reduce casualties in times of future volcanic crisis.
Piecewise-ICP: Efficient Registration of 4D Point Clouds for Geodetic Monitoring
Authors: Yang Yihui , Czerwonka-Schröder Daniel , Holst Christoph
Published: March 2024

The permanent terrestrial laser scanning (PLS) system has opened the possibilities for efficient data acquisition with high-temporal and spatial resolution, thus allowing for improved capture and analyses of complex geomorphological changes on the Earth's surface. Accurate georeferencing of generated four-dimensional point clouds (4DPC) from PLS is the prerequisite of the following change analysis. Due to the massive data volume and potential changes between scans, however, efficient, robust, and automatic georeferencing of 4DPC remains challenging, especially in scenarios lacking signalized and reliable targets. This georeferencing procedure can be typically realized by designating a reference epoch and registering all other scans to this epoch. Addressing the challenges in targetless registration of topographic 4DPC, we propose a simple and efficient registration method called Piecewise-ICP, which first segments point clouds into piecewise patches and aligns them in a piecewise manner.Assuming the stable areas on monitored surfaces are locally planar, supervoxel-based segmentation is employed to generate small planes from adjacent point clouds. These planes are then refined and classified by comparing defined correspondence distances to a monotonically decreasing distance threshold, thus progressively eliminating unstable planes in an efficient iterative process as well as preventing local minimization in the ICP process. Finally, point-to-plane ICP is performed on the centroids of the remaining stable planes. We introduce the level of detection in change analysis to determine the minimum distance threshold, which mitigates the influence of outliers and deformed areas on registration accuracy. Besides, the spatial distribution of empirical registration uncertainties on registered point clouds is derived based on the variance-covariance propagation law.Our registration method is demonstrated on two datasets: (1) Synthetic point cloud time series with defined changes and transformation parameters, and (2) a 4DPC dataset from a PLS system installed in the Vals Valley (Tyrol, Austria) for monitoring a rockfall. The experimental results show that the proposed algorithm exhibits higher registration accuracy compared to the existing robust ICP variants. The real-time capability of Piecewise-ICP is significantly improved owing to the centroid-based point-to-plane ICP and the efficient iteration process.
The age of buried carbon changes the greenhouse gas budget of a dam
Authors: Tittel Jörg , Rosenlöcher Yvonne , Dadi Tallent , Lechtenfeld Oliver J. , Simon Carsten
Published: March 2024

Dams are a globally relevant source of greenhouse gases (GHG), which impair their function as a source of green energy. High burial rates of organic carbon (OC) in dam sediments may partly or fully offset the emissions. We argue that only the burial of carbon fixed in the timespan of dam operation changes the GHG balance. Here, we took sediment cores from a temperate dam. We analyzed radiocarbon age and OC molecular composition by laser desorption ionization mass spectrometry in the bulk OC and in four extract fractions. The bulk samples included modern OC, fixed after 1950. However, the extracted OC was of different ages (modern to 1900 years BP). Compounds with H/O ratios >2.5 predominated in 14C-old fractions, while compounds with ratios
A Comparative study of water fluids of coastal and island mud volcanoes: Acase study of the South Caspian Basin
Authors: Bayramova Aygun
Published: March 2024

On a global scale, the South Caspian is a basin where mud volcanoes aremost densely distributed. Numerous active volcanoes are registered here, both onland and in the adjacent sea basin (Caspian Sea), which, as a result of their dailyactivity, discharge water fluids to the Earth's surface.In this work, using samples taken from coastal and island mud volcanoes, acomparative study of the chemical compositions of the fluids expelled from thesalse and gryphon-type emissions, as well as their origin, including thecontribution of various stratigraphic units to the water formation processes.According to our results, the contribution of the condensed waters of theCaspian Sea was greater in the formation of Na-Cl type waters of mud volcanoesin the South Caspian Basin. In addition, the origin of volcanic waters also formedas a result of the contribution of shallow ‘low-mineralized’ pore fluids and deep-seated ‘high-mineralized’ brines correlates well with the depths (1-5.5 km) of theProductive Series strata.
Palynofloral change across Oceanic Anoxic Event 2 in the Iberian Basin, Spain
Authors: Heimhofer Ulrich , Barroso-Barcenilla Fernando , Berrocal-Casero Mélani , Li Suping , Müller Katharina , Wheeler Alexander
Published: March 2024

The Cenomanian–Turonian Oceanic Anoxic Event (OAE2; ~94.5 million years ago) represents an episode of global-scale marine anoxia and biotic turnover, which corresponds to one of the warmest time intervals in the Phanerozoic. Despite its global significance, information on the dynamics of continental ecosystems during this greenhouse episode is scarce. Here we present a terrestrial palynological record combined with chemostratigraphic data from an expanded marine OAE2 section from the Iberian Basin, Central Spain. Carbon isotope records of carbonate and organic carbon from two nearby sections show the characteristic positive CIE (carbon isotope excursion) associated with OAE2 and, together with ammonite finds, facilitate the construction of a stratigraphically well-constrained composite record. The spore-pollen assemblage is dominated by non-saccate gymnosperm (Classopollis, Araucariacites, Inaperturopollenites) and angiosperm pollen (mainly representatives of the Normapolles group incl. Atlantopollis and Complexiopollis), with pteridophyte spores being quantitatively less abundant. With stratigraphic height, the spore-pollen assemblage shows distinct changes in frequency distribution including a distinct rise in the angiosperm pollen Atlantopollis within an interval assigned to the Plenus Cold Event. In contrast, a pronounced increase in Classopollis reaching >50% of the total palynoflora parallels the 2nd peak of the CIE and is followed by an abrupt decline. These palynofloral changes indicate changing proportions of arborescent conifer forests and more open, non-arborescent, angiosperm-rich vegetation. Despite the exceptional warmth associated with OAE2, the continental hinterland bordering the Iberian seaway did support a diverse vegetation, adapted to persist under elevated temperatures. Fluctuations in spore-pollen frequency distribution are considered to reflect significant climatic changes over the course of OAE2 controlled ultimately by the interplay of large-scale magmatic activity and enhanced organic carbon burial.
Electromagnetic monitoring of active volcanic zones: Monitoring of Phase Tensor parameters from Mount St Helens and Stromboli volcanoes
Authors: Karcioglu Gokhan , Hill Graham , Moorkamp Max , Avram Yann , Hogg Colin , Gahr Sophia , Maetschke Katharina , Schultz Adam , Bowles-Martinez Esteban , Peacock Jared , Chen Chaojian , Cimarelli Corrado , Caricchi Luca , Ogawa Yasuo , Kiyan Duygu
Published: March 2024

The main goal of volcano monitoring is to understand processes occurring within the magmatic system from there geophysical response signatures that informs on the eruptive behavior of the system. Traditional volcano monitoring approaches have relied primarily on changes in seismicity, and geodetic response which depend on active changes such as magma migration.The magnetotelluric method, informs the physical property electrical conductivity, which within a magmatic context is sensitive to the presence of fluids, temperature, and melt fraction. High quality magnetotelluric measurements allow identification of conductivity variations related to the physical changes in magmatic systems, making it possible to determine temporal changes in magma content and temperature. Thus, magnetotellurics may be a valuable additional monitoring tool able to detect static phase changes of the magmatic fluids within the system, contributing to our understanding of the dynamics occurring within magmatic systems absent of and/or preceding magma movement within the system.Mount St Helens as perhaps the most studied volcanic system including a dense 3D MT data set collected during the 2004-2008 dome building eruption provides the opportunity to investigate the difference within the magmatic system in different eruptive states (i.e. eruptive 2004-2008 and current quiescence). This is been achieved by a complete repeat of the initial survey (67 sounding locations) collected in 2005-06 and establishment of 4 ‘continuous’ telemetered systems. Given the current non-eruptive state of Mount St Helens a second system has been selected, Stromboli, currently in an eruptive cycle for installation of 4 continuous telemetered MT systems. Stromboli volcano, maintains a persistent eruptive activity, with near daily minor explosions typically punctuated by 1-2 larger events a year.Initial evaluation of the streamed measurements has been completed using Phase Tensor parameters, which are immune to galvanic distortions, which can occur from seasonal near-surface conductivity changes (e.g. variations in soil moisture content). The Phase Tensor represents conductivity gradients in the subsurface, and Phase Tensor differences between two measurement times hence reflects the changes in conductivity structure in time. The temporal application of magnetotellurics provides a mechanism to determine short-term and long-term conductivity changes within the magmatic system representative of physical changes within the system, correlatable to active eruptive behavior, properties of the system during periods of quiescence and eruptive phases.
Combining local earthquake tomography and petrological models to constrain wavespeeds in the subducting Nazca Plate
Authors: Hassan Nazia , Henry Sally , Sippl Christian
Published: March 2024

Intermediate-depth seismicity in Northern Chile shows a pattern which is distinct from a conventional double seismic zone (DSZ) setting. While two distinct seismicity planes are present in the updip part of the slab, there is a sharp transition to a highly seismogenic cluster of 25–30 km thickness at ∼80-90 km depth, extinguishing the gap between the two seismicity planes. As seismic velocities can be used to constrain mineralogy and fluid content, characterizing seismic wavespeeds of this subduction zone segment using local earthquake tomography can provide important constraints on the mineralogical processes that produce the seismicity pattern seen here.We used the catalog of Sippl et al. (2018), which contains arrival time data from permanent stations of IPOC (Integrated Plate Boundary Observatory Chile), complemented by several temporary deployments spanning shorter time sequences. The catalog contains more than 100,000 earthquakes and 1,200,404 P- and 688,904 S-phase picks for the years 2007 to 2014. In order to use the best available picks for tomography, we limit our analysis to events that have more than 14 P-arrivals as well as more than 7 S-arrivals, leading to a total of 8883 events with 213,908 P- and 99466 S-arrivals.Parallelly, we also attempt to obtain an estimate of the possible mineral compositions at the depths and P-T conditions relevant to our study in the DSZ setting. For this, we assume a simple model where the upper plane of the DSZ is considered to be evolving from MORB-like composition and the lower plane of the DSZ from depleted-mantle composition. These global average compositions are then fed into Perple X (Connolly & Kerrick, 1987) as starting compositions and pseudosections of possible mineral assemblages are constructed for P-T conditions significant to this study. We calculate the theoretical Vp and Vp/Vs values for those P-T conditions using the same software.We present 3D models of P- and S-wavespeeds from the Northern Chile forearc between about 20.4° S and 22.5° S, as well as images of ray coverage, relocated seismicity, and synthetic resolution tests. Tomography models for different choices of grid spacing and damping-smoothing parameters are compiled and compared to derive the optimal settings for the inversion. The seismic velocity distribution obtained through tomography is compared with the aforementioned theoretical wavespeeds to narrow down the range of possible reactions occurring at depth.
Unveiling the Covert Linkage Between Geomagnetic Dynamics and Climate in the Northern South China Sea Over the Last 30 ka
Authors: Wu Shuang , Yang Xiaoqiang
Published: March 2024

The hidden link between the geomagnetic field and climate is gradually being noted for its unexpected consistency. However, the unclear linking mechanisms and questions regarding whether geomagnetic reconstructions entirely exclude climatic influences have sparked controversy surrounding this relationship. Here, we analyze a high-resolution geomagnetic paleosecular variation record since 30 ka in the northern South China Sea and find a good correlation between its climate-independent inclination record with the regional temperature and precipitation.The studied core, SCS-5, was obtained from the northern South China Sea (21.21°N, 118.04°E) at a water depth of 1600 m, twenty AMS 14C ages were used to establish the age framework since ~30 ka, with an overall sedimentation rate exceeding 30cm/kyr. Detailed rock magnetic and environmental magnetic analysis determined that the sedimentary environment of the core is stable and homogeneous. Reliable characteristic remanent magnetization directions are established, with all the maximum angular deviations less than 3. The inclination has fluctuated considerably over the last 30 ka period, but is more moderate during 20-10 ka. Reconstructed paleointensity shows an overall upward trend except for a slight decrease during 15-12 ka, with several significant shallowing of the inclination corresponding to the low values of the field intensity, which may be related to the role of geomagnetic reverse flux patches.Comparing the local precipitation δ18Osw local record of the core and the paleotemperature record from South China, we observe that as the geomagnetic field strength decreases with shallower inclination, regional precipitation increases significantly, while the land temperature decreases. We hypothesize that the decline in geomagnetic strength may have regulated the regional hydroclimate through the mediation of cosmic rays, aerosols, and cloud cover. The weakening field could have induced increased cloudiness, leading to a parasol effect and greater precipitation. Additionally, the correlation between rainfall and the geomagnetic field is evident throughout the Late Pleistocene-Holocene, whereas the relationship between temperature and the geomagnetic field is more pronounced in the Holocene. It suggests that the forcing mechanism of the geomagnetic field on climate change is complex and nonlinear, which may differ in glacial and interglacial periods due to low-latitude processes or other forcing mechanisms.
Using sediment facies & ground penetrating radar profiles to investigate the internal architecture and genesis of De Geer moraines
Authors: Rivers Gwyneth , Storrar Robert , Mäkinen Joni , Ojala Antti , Holmes Naomi , Holmroos Camilla
Published: March 2024

De Geer moraines (DGMs) have the potential to generate very high-resolution spatial and temporal ice margin reconstructions (~annual in contrast to 100-500 years, the current state-of-the-art). Existing studies suggest that DGMs likely form annually in a sub-aqueous, ice-marginal environment whereby basal sediments are advected and deposited at the grounding-line during seasonal advances. However, there have also been suggestions of a crevasse-fill origin that challenges this temporal regularity. Whilst the spatiotemporal properties of DGMs are disputed, the balance of evidence suggests an ice-marginal depositional environment with annual/seasonal regularities. Understanding the processes related to DGM formation is therefore critical, as it underpins the ability to use DGM to delineate ice-marginal retreat at unprecedented (potentially annual) resolutions.A recent large-scale 3D morphometry study of DGMs and Crevasse-Squeeze Ridges (CSRs) was undertaken to constrain landform metrics and explore their formation processes. The results revealed statistically significant differences across all morphometrics between the sampled DGMs and CSRs. DGMs were found to be lower-relief, narrower, slightly more asymmetrical, and more sinuous than the studied CSRs. The morphometrics of DGMs support an ice marginal depositional environment. Furthermore, tendencies for cross-sectional asymmetry suggest a unidirectional push movement involved during formation. These inferences, however, must be supported with geophysical and/or sedimentological investigations.Here we present the results of a field study using sedimentological and geophysical (Ground Penetrating Radar) techniques to investigate the internal architecture of DGMs in southwest Finland. Sedimentological data was acquired from two excavated exposures and 55 GPR profiles were obtained from four different locations across SW Finland. Radar facies were identified and corroborated with the lithofacies units as observed in the ca. 30 m long trench excavations. Typically, these facies comprise of stacked thrusted planes of laminated clay and diamicton on proximal slopes, sheared diamicton on surfaces indicative of proglacial pushing/overriding, and gravity-driven flow deposits on distal slopes. At places, glaciotectonic structures such as dipping, faults and folds were also identified.The results may be used to complement the existing morphometry study, constraining the main processes involved in DGM formation and validating the use of DGMs as ice marginal indicators. This can ultimately be used as a foundation to explore the climatic significance of DGM ridges, thus meriting further work to constrain the spatial and temporal properties of DGMs during deglaciation.
Reactive macronutrient ratios as predictors for nitrate cycling in stream ecosystems
Authors: Große Anika , Perujo Nuria , Reisinger Alexander J , Fink Patrick , Borchardt Dietrich , Graeber Daniel
Published: March 2024

Human activities have significantly altered macronutrient concentrations in surface waters, impacting both ecological functions and water quality. Typically, research assesses this alteration and its effects from a single macronutrient perspective. Alternatively, we propose that macronutrient perspectives need to be integrated via a stoichiometric framework via carbon (C) : nitrogen (N) : phosphorus (P) ratios. These ratios may help to assess and improve natural attenuation at ecosystem and catchment level. From the C:N:P perspective, agricultural practices have resulted in a stoichiometric N surplus in temperate stream ecosystems, an issue of which German streams are a prime example.  In contrast, Florida's streams are characterized by a P surplus relative to N and C due to high geological background P supply.  Our study encompasses five streams in Germany and Florida, covering a wide range of C:N:P ratios, each characterized by distinct catchment characteristics. Here, we ask whether C:N:P ratios are the main driver of microbial nitrate-N uptake, irrespective of other differences between the two regions. Through streamside mesocosm and microcosm laboratory experiments employing an isotope tracer approach, we compared nitrate uptake. Additionally, we manipulated C:N:P ratios to assess the short-term effects on nitrate uptake and measured retention in the streamside mesocosm experiment. Enhancing our understanding of the interconnectedness of biogeochemical cycles enables the development of management recommendations for stoichiometric restoration in highly impacted stream ecosystems. This research contributes valuable insights towards sustainable practices and the preservation of aquatic ecosystems facing nutrient-related challenges and water security.
Integrated Assessment of Climate Change and Land Use Impact on Runoff Dynamics in the Jhelum Basin
Authors: Islam Shahid Ul , Chakma Sumedha
Published: March 2024

This study addresses the significant factors contributing to warming during the 20th century, namely Greenhouse Gases (GHG) and Land Use (LU), emphasizing the need for localized hydrological impact assessments. Recognizing the limitations of Global Climate Models (GCMs) in predicting local-scale phenomena, the research employs a downscaling approach for hydrological impact studies. Observed datasets and downscaled GCM data are utilized to analyze temperature, precipitation, and potential evapotranspiration (PET) trends. The study integrates downscaled GCM data from the Coupled Model Inter-comparison Project 6 (CMIP6) to project future climate scenarios under Representative Concentration Pathways (RCPs) 4.5 and 8.5. Runoff data from three stations within the Jhelum Basin is collected and analyzed over various time scales, providing a comprehensive understanding of historical and future hydrological trends. Future climate projections are corrected using the Daily Bias Correction (DBC) method). The study then employs the Soil & Water Assessment Tool (SWAT) model, given its suitability for hydrological studies with limited data availability. SWAT is calibrated and validated using SWAT CUP, incorporating observed river discharge. The impact assessment on runoff considers different climate change and land use change scenarios. Future Land Use and Land Cover (LULC) predictions are made for 2025 to 2100, and the model is rerun to analyze the combined impact of changing climate and LULC on runoff. The study aims to achieve a robust understanding of future water resource dynamics for runoff generation; the integrated assessment of climate and land use impact on the hydrological dynamics of the Jhelum Basin uncovers substantial shifts in runoff patterns. The combination of changing climate conditions and evolving Land Use/Land Cover (LULC) scenarios reveals intricate interactions, influencing the basin's hydrological response. Future projections highlight the nuanced interplay between climate scenarios and LULC changes, offering valuable insights into the complex dynamics of water resource management. These results provide essential information for policymakers and decision-makers, guiding the formulation of adaptive strategies to address the evolving challenges in runoff generation within the Jhelum Basin. The research explores runoff responses to LULC and climate change through scenario-based setups. By quantitatively analyzing the effects on runoff and peak discharge across different periods, the study provides valuable insights for policymakers and decision-makers in water resources. This integrated assessment contributes to a more informed and sustainable approach to water resource management in the Jhelum Basin amidst changing climatic and land use conditions.
Visualising magma plumbing systems in 4D
Authors: Magee Craig
Published: March 2024

Significant advances have been made in using a wide variety of geophysical techniques to track melt migration, image the structure of active and ancient magma plumbing systems, and constrain emplacement mechanics. In particular, integrating traditional petrological and geochemical results with such geophysical data and modelling has afforded exciting insights into the development of entire magmatic systems. However, divisions between the scales and physical settings over which these methods are applied remain. To characterise these differences and promote the benefits of further combining geophysical, petrological, and geochemical datasets, I discuss how geophysical techniques can be utilised to provide structural context and place physical constraint to the chemical evolution of magma plumbing systems. I am no expert in many geophysical techniques and thus lean on the work of many others, showcasing the importance of collaboration to pushing the boundaries of our science. Here, I will examine on what we can do with some geophysical and geodetic techniques, whilst importantly highlighting what we cannot do with them, and discuss how their application can help us solve some of the key questions within our field. Overall, I hope to show that approaching problems concerning magma plumbing systems from an integrated petrological, geochemical, and geophysical perspective, brought together with various modelling methods, will yield important scientific advances and provide exciting future opportunities for the entire volcanological community.
Spanning the Arc: Margin Geometry and Topography Control Upper Plate Deformation in the Central Andean Subduction Zone
Authors: Schurr Bernd , Dielforder Armin , Lehmann Lukas , Faccenna Claudio
Published: March 2024

Subduction zone forearcs deform transiently and permanently due to the frictional coupling with the converging lower plate. Transient stresses are mostly the elastic response to the seismic cycle. Permanent deformation is evidenced by forearc topography, upper plate faulting, and earthquakes; its relation to the megathrust seismic cycle is debated. Here we study upper plate seismicity, interplate earthquake slip vectors, and the GNSS strain field in the northern Chile subduction zone to deduce the stress field and to separate elastic and permanent strain. We find that seismicity is distributed unevenly and that high seismicity rates concur both with a break in the forearc topography and tectonics of the Coastal Cordillera and the onset of a change in subduction obliqueness. Earthquakes in the South American crust under the sea and the Coastal Cordillera show a remarkably homogenous north-south, i.e., trench-parallel, compressional stress field. The trench-parallel compression above the plate coupling zone, almost perpendicular to plate convergence direction, may be explained by strain resulting from a change in subduction obliqueness due to the concave shape of the plate margin, which we demonstrate by investigating inter-plate earthquake slip vectors. From these, we derive a strain rate estimate (-5×10e-8 /a) and compare it to one derived from upper plate earthquakes (-8×10e-9 /a). We argue that the dominance of trench-parallel compressive stresses over trench-perpendicular ones is due to canceling of the latter by tensional gravitational stresses due to the topographic gradient between the Andes and the Nazca trench. Based on the distribution of the type of faulting we investigate the trench-perpendicular stress field with a force-balance model. The observed deep strike-slip earthquakes, expression of trench-perpendicular tension, require the deepest extent of the megathrust to be very weak.
Estimation of the potential value of given sea segments for certain time periods
Authors: Cziraki Kamilla , Timár Gábor
Published: March 2024

Since Gauss (1828), the theoretical shape of the Earth has been defined as a distinct potential surface of the gravity field that best fits the sea level at rest. The gravity field is described as a sum of spherical function series whose coefficients are calculated from satellite and in situ gravity measurements. Sea levels have been measured in harbours since the 18th century using mareographs, and are now often supplemented by data from nearby GNSS stations.In our work, we developed a program to determine the potential value for a given height from mareograph data. This allows us to use the data available from the stations to determine what this value was in an earlier period as well. Furthermore, if more than one dataset is available for a particular sea segment, the average value for that sea over a certain period can be given.We tested the method in the Japanese Sea, where we had data from 9 stations. These were averaged every 5 years and the resulting data were used to calculate the potential values, as well as the average value for the sea segment for the latest period 2016-2020. In the future, we plan to use this method to perform such calculations for more sites, which would also provide information on the effects of tectonics and global sea level change.Gauss, C. F. (1828) Bestimmung des Breitenunterschiedes zwischen den Sternwarten von Göttingen und Altona. Vandenhoeck und Ruprecht, Göttingen, 84 p.Supported by the ÚNKP-23-1 New National Excellence Program of the Ministry for Culture and Innovation from the source of the National Research, Development and Innovation Fund.
Irreversible glacier change and trough water for centuries after overshooting the Paris Agreement temperature goal
Authors: Schuster Lilian , Maussion Fabien , Schmitt Patrick , Rounce David R. , Ultee Lizz , Lacroix Fabrice , Frölicher Thomas
Published: March 2024

Mountain glaciers significantly impact sea level rise and water availability during droughts. Models project continued glacier mass loss in the 21st century due to past and future rising temperatures. Our study delves into the repercussions of overshooting the 1.5°C Paris Agreement target and returning to it afterwards. For the first time, we explore the effects of these peak-and-decline overshoot scenarios on glacier volume and runoff using the Open Global Glacier Model (OGGM) framework. We apply novel climate simulations from 2000 to 2500  conducted with a  comprehensive  Earth System Model. These simulations either stabilise at global warming levels of 1.2°C (current warming), 1.5°C and 3°C, or temporally overshoot 1.5°C peaking at 3°C before declining and stabilising at 1.5°C after 2300. Although some glacier regions regrow within a century after the overshoot, the slow global glacier response results in irreversible ice loss over centuries. In 2500, overshooting the 1.5°C scenario temporarily by a peak at 3°C results in 10% more global glacier loss than directly stabilising at 1.5°C. While glacier runoff may temporarily increase in some basins in the coming decades, all basins will see a reduced contribution of glacier runoff to streamflow by the end of the 22nd century under global stabilisation scenarios at 2°C or higher. In regions where glaciers regrow within the simulation period to reach a new equilibrium after a temporal temperature overshoot, glacier runoff contribution reduces temporally further than if temperature stabilises ("trough water"). The consequences of this newly documented "trough water" will depend on local conditions such as the local temperature overshoot magnitude, volume response time, future precipitation shifts, and melt versus precipitation seasonality. This study lays the first conceptual groundwork for overshoot scenarios on glaciers and introduces the potential of trough water risks. Additional Earth System Model realisations are needed for a detailed regional analysis and adaptation planning.
Wastewater discharges and urban land cover dominate urban hydrology signals across England and Wales 
Authors: Coxon Gemma , McMillan Hilary , Bloomfield John P , Bolotin Lauren , Dean Joshua F , Kelleher Christa , Slater Louise , Zheng Yanchen
Published: March 2024

Urbanisation is a critical driver of changes in streamflow. These changes are not uniform across catchments due to the diverse changes to water sources, storage, and pathways in urban river systems from impervious areas, abstractions, sewage networks, and sewage treatment plans. While land cover data are typically used to explain urbanisation, water management practices are poorly quantified. Consequently, urbanisation impacts are often difficult to detect and quantify, and the relative impact of these factors is currently poorly understood.Here, we assess urban impacts on streamflow dynamics for a large-sample of catchments across England and Wales using data characterising water management practices and land cover. We quantify urban impacts on a wide range of streamflow dynamics (flow magnitudes, variability, frequency and duration) using random forest models. We demonstrate that wastewater discharges from sewage treatment plants and urban land cover dominate urban hydrology signals across England and Wales and have different impacts on streamflow dynamics. Wastewater discharges increase low flows and reduce flashiness in urban catchments, while urban land cover increases flashiness and frequency of medium and high flow events. We demonstrate the need to move beyond land cover metrics and include other features of urban river systems in large-sample hydrological analyses to quantify current and future drivers of urban streamflow.
Water modulate the Fe-Mg partitioning in Earth’s deep lower mantle
Authors: Hu Qingyang
Published: March 2024

Minor amount of water may alter the chemical properties of minerals. In this talk, we review the role of water as an oxidant and explore the chemistry between water and mineral at Earth’s deep lower mantle. We consider the addition of pyrite-type (Mg,Fe)O2, which is stable at depth of 1800 through the reaction between water and ferropericlase. Among the major lower mantle components, we find that this pyrite-type phase holds the strongest affinity to ferrous Fe. This is consistent with quenched experiments in which we observed amorphous bands enriched with Fe and an excessive amount of O, possibly derived from the decompression-induced amorphization of high-pressure samples. Our results support the existence of Fe-rich and dense pyrite-type (Mg,Fe)O2 near the core mantle boundary. It features high density due to its Fe concentration. At the meantime, the pyrite-type phase is known to exhibit low seismic velocity. The formation of this phase suggests some seismic heterogeneities, for example the LLSVP, may have originated from the chemistry between water and surrounding minerals.
Building local capacity for air quality monitoring devices in Africa: Lessons from Nigeria
Authors: Joseph Dada , Babatunde Rabiu
Published: March 2024

The lack of industrial capacity has led to the importation of low-cost sensors to monitor air pollution in data sparse regions of Africa.  However, there are several challenges with this approach.  Most of the devices are not suitable for the climate of Africa, the “low cost” is still prohibitive in many regions of Nigeria, some of these low-cost sensors provide our data to third parties, and repairs can take a long time if possible.  To this end, the United Nations African Regional Centre initiated a campaign for the local development of low-cost air monitoring devices.  This provides the flexibility of building for our environment, designed to meet our peculiar situation especially in terms of power and internet, and ease of repair or replacement of parts.  In the last six months, several of these devices have been built to monitor particulate matter and gaseous pollutants including carbon monoxide and ozone. Our designs were found to be of comparable performance with imported low-cost sensors.   The design team will share details of design, solutions to power and internet issues, and other lessons learned.
The Polarized Submillimeter Ice-Cloud Radiometer (PolSIR): Observing the diurnal cycle of ice clouds in the tropics and sub-tropics
Authors: Bennartz Ralf , Wu Dong ,   PolSIR Science Team
Published: March 2024

The Polarized Submillimeter Ice-Cloud Radiometer (PolSIR): Observing the diurnal cycle of ice clouds in the tropics and sub-tropicsIn May 2023 NASA has selected PolSIR as the latest addition to its Earth Venture Instrument class missions. PolSIR addresses key research priorities related to uncertainties in our current understanding in high clouds and cloud feedbacks as formulated in NASA’s latest Decadal Survey and in the latest Intergovernmental Panel on Climate Change (IPCC) Assessment. In this context, PolSIR will address the following objectives:Constrain the seasonally influenced diurnal cycle amplitude, form, and timing of the ice water path (IWP) and particle diameter in tropical and sub-tropical ice clouds
Determine the diurnal variability of ice clouds in the convective outflow areas and understand relation to deep convection
Determine the relationship between shortwave and longwave radiative fluxes and the diurnal variability of ice clouds
Enable improvement of climate models by providing novel observations of the diurnal cycle of ice clouds, ultimately leading to improved climate modeling skills and increased fidelity of climate forecasts in support of critical decision-making.
The PolSIR mission consists of two 12U CubeSats, each equipped with a cross-track scanning polarized submillimeter radiometer in the spectral range of 325–680 GHz. The two PolSIR satellites fly in separate, 52-degree inclination, non-sun-synchronous orbits, taking science measurements between ±35 degrees latitude enabling monthly sampling of the diurnal cycle of ice clouds and their microphysical properties in the tropics and sub-tropics. PolSIR’s observation concept provides significant benefits over the Program of Record (PoR) as well as synergies with future missions which will either be in sun-synchronous orbits, thus not sampling the diurnal cycle, or lack the observation frequencies needed to fully observe ice water path (IWP).