bluuebunny/crossref_metadata_2025 huggingface dataset:
A recipe for continental fragment formation: big data analysis of rift models
Authors: Yu Alan , Gün Erkan , McCaffrey Ken , Heron Philip
Published: March 2024

Former plate boundaries (sutures) are usually considered to be future locations for continental breakup, but this is not always the case. For example, continental rifting can generate a crustal fragment, where a sliver of a plate diverges from its component part and remains attached to another plate. Despite the prevalence of continental fragments and accreted terranes in the geological record, the underlying tectonic processes leading to their formation remain poorly understood. Previous geodynamic models have indicated structural and rheological heterogeneities inherited from past tectonic events as a key mechanism driving the initiation of continental breakup. Most of these studies have primarily focused on the styles of rifted margins, but limited attention is given to the mechanism of continental fragment formation.In this study, we present a suite of over 100 different numerical models of inherited structures with the tectonic potential to generate a new continental fragment during continental extension. Our models show the first-order impact of structural inheritance on the evolution of rifting and continental fragmentation. Here, the size of the fragment is influenced by the extent and geometry of the inherited structures. By analyzing our models using novel data science techniques, we are able to quantify the impact of different initial conditions on generating a continental fragment. Our models provide a range of new physical constraints for the formation of continental fragments. Most importantly, they highlight the potential role of different forms of structural inheritance in controlling deformation within complex tectonic plate margins. Finally, we apply these findings to some real-world examples of continental fragments.
The Marble climate informatics platform: data discovery and data access
Authors: Chandan Deepak , Schwartz Misha , Easterbrook Steve
Published: March 2024

Advances in remote sensing and computing infrastructure, and demands of modern climate research are driving the production of new climate datasets at a breathtaking pace. It is increasingly felt by researchers, that the growing volume of climate datasets is challenging to store, analyze or generally "shepherd" through their analysis pipelines. Quite often, the ability to do this is limited to those with access to government or institutional facilities in wealthier nations, raising important questions around equitable access to climate data.The Data Analytics for Canadian Climate Services (DACCS) project has built a cloud based network of federated nodes, called Marble, that allows anyone seeking to extract insights from the large volumes of climate data to undertake their study without concerning themselves with the logistics of acquiring, cleaning and storing data. The aspiration for building this network is to provide a low-barrier entry not only to those working in core climate change research, but also to those involved in climate mitigation, resilience and adaptation work and to policy makers, non-profits, educators and students. Marble is one of the platforms selected to contribute to the 'Open Science Platform' component of the OGC’s OSPD initiative.The user-facing aspect of the platform is comprised of two components: (i) the Jupyter compute environment and (ii) the data server and catalogue. Here, we focus on the latter and present details of the infrastructure, developed on top of proven open-source software and standards (e.g. STAC), that allows for discovery and access of climate datasets stored anywhere on the network by anyone on the network. We will also discuss the publication capability of the platform that allows a user to host their own data on the network and make it quickly available to others.
On the key role of anthropogenic warming in triggering extreme convective events: the case of the destructive Mediterranean derecho in 2022
Authors: González-Alemán Juan Jesús , Insua-Costa Damian , Bazile Eric , González-Herrero Sergi , Miglietta Mario Marcello , Groenemeijer Pieter , Donat Markus G.
Published: March 2024

A derecho is a widespread, long-lived, straight-line windstorm that is associated with a fast-moving group of severe thunderstorms known as a mesoscale convective system.During 18 August 2022, a highly intense and organized convective storm, classified as a derecho, developed over the western Mediterranean Sea affecting Corsica, northern Italy and Austria, with wind gusts up to 62 m/s and giant hail (~11 cm). There were 12 fatalities and 106 people injured. This event received much attention in the media for its extraordinary impact and the rareness over the Mediterranean Sea. The derecho developed over an extreme marine heatwave that persisted during the whole summer. Therefore, the hypothesis of a relationship between the extreme atmospheric event and the extreme marine heatwave rapidly arose, and thus, a possible link with anthropogenic climate change.This convective event can be considered as extreme from the affected locations point of view (in terms of winds) but also is between one of the most powerful derechos ever recorded in the USA and Europe. Also, the event developed over an extreme marine heatwave that was mainly affecting the western Mediterranean Sea during summer 2022.Here, by performing model simulations with both the NCAR Model for Prediction Across Scales and the Météo-France nonhydrostatic operational AROME model and using an storyline approach, we find a relationship between the marine heatwave, the actual anthropogenic climate change conditions, and the development of this extremely rare and severe convective event. We also find a future worrying increase in intensity, size and duration of such an event with future climate change conditions.
A Fuzzy Cognitive Mapping approach to support WEFE NEXUS policies and decision-making
Authors: Sanchez-Revuelta Maite , A. Segovia-Cardozo Daniel , Schneider Xenia , Rodriguez-Sinobas Leonor
Published: March 2024

Water stress, together with rising energy prices, have become a major concern worldwide, especially for food production (the major water consumer) that leads to ecosystem degradation in arid and semiarid countries such as Spain. The Spanish irrigated area ​​ has been continuously expanding and modernizing in response to the food demant increase and to promote economic development and support the rural areas which are aspects generally considered on an individual basis, against the advice of the international community to achieve a balance in  Water, Energy, Food and Ecosystem (WEFE) Nexus. But also, it is crucial to consider stakeholders' perspectives, understand their experiences and opinions to work together and find more realistic and effective solutions. Participatory modeling, such as Fuzzy Cognitive Mapping (FCM), is frequently used, with satisfactory results, within the WEFE Nexus context to understand the perception of stakeholders for decision making.This work aims to analyze the perceptions of various stakeholders (researchers, policymakers, environmental groups, farmers' associations, food retailers, consumer organizations, water treatment companies, and water reuse experts) regarding interactions in variables related to the four sectors of the WEFE nexus in the Duero River basin. Understanding the perception of the stakeholders about these topics can help to improve policy, decision making and to enhance scientific research, innovation, and knowledge transfer in the fields related to the WEFE Nexus.To identify the concepts, three workshops were conducted with 14 participants from different sectors related to WEFE NEXUS areas.  The workshop accomplished  different activities with the purpose of highlighting the main ideas about WEFE in a participative way, that were reinforced in the following workshop, to make sure that we gather the real perception of the stakeholders without leaving any of them aside. As a result, 30 concepts have been identified, simplified and used to develop a FCM, in which stakeholders will identify relations between them, assigning weights to these relationships correlations based on their own perception. Then, the final FCM will be analyzed by Metal Modeler program, which will allow to understand interconnections among variables according to the stakeholders´ perception and study future scenarios obtained as a result of performed workshops. Scenario analysis allows to explore the intricate relationships that exist within a system, and to examine how changes in one variable can influence the dynamics of the entire system. Creating narrative pathways from plausible future developments helps decision-makers assess the potential impact of policies from the perspective of multidisciplinary stakeholders.
Phoebe Paints Rocks: Creative geologist and adventurer
Authors: Sleath Phoebe
Published: March 2024

When on PhD fieldwork on the Pembrokeshire coast in SW Wales in 2021, in my breaks I would paint the view of the rocks and sea with watercolours. I noticed that when painting I was making useful geological recordings and interpretations, which I included in my research. I bought a sketchbook and started to paint whenever I was outside, both on fieldwork and adventurers into the hills hiking and climbing. By allowing me to take the time to properly look at the changing landscape, painting became a process that increased my understanding of geology, the world, and my place within both.Through finding my creative voice as an artist, I also found my voice both as a scientist and a person. It became easier to communicate my research, helping with writing, discussions with colleagues and drawing figures. My research moved to explore the creative side of geology, the uncertainty in how we observe and interpret faults in mountain building areas, and the way geologists communicate their findings through drawings and illustrations. I am interested in connection and perspective of landscapes across time. As a qualified Mountain Leader I love sharing the outdoors with others, to share skills and stories.Sharing my work with others on social media has led to lots of opportunities including exhibitions and events with the Scottish Mountaineering Press, the Scottish Geology Trust, North East Open Studies, Fort William Mountain Festival and Artist-in-Residence for the Dundee Mountain Film Festival. I find people are interested in my connection to the landscape, my painting process and how they can connect better with the landscapes they love and want to protect.
Comparison of the sedimentary characteristics and diagenesis of modern carbonate deposits between tidal channels and mangrove marshes, Abu Dhabi, United Arab Emirates
Authors: Cao Tianyu , Alsuwaidi Mohammad , Morad Sadoon
Published: March 2024

As a typical modern low-angle carbonate ramp sedimentary system, the shallow-marine mangrove marsh and tidal channel environments adjacent to Abu Dhabi Island contain a wide variety of allochems and diverse early-diagenetic processes. Integrating data from cores, thin sections, cathodoluminescence (CL), and scanning electron microscopy (SEM) allows for quantifying the abundance of components and providing new insights into various diagenetic events. The sediments show various skeletal and non-skeletal carbonate components, as well as a minor amount of terrigenous siliciclastic minerals (quartz and feldspar) and organic matter. The low energy within protected intertidal systems accounts for the greater abundance of carbonate mud (average 76%) in marshes, compared to tidal channels (average 3%). The high energy of tidal currents resulted in more abundant peloids and bioclasts (including bivalves, gastropods, foraminifera, algae, corals, and bryozoans) in the tidal channels. In addition, siliciclastic grains are more abundant in marshes near dredged channels. The anthropogenic activities, such as channel excavation, may increase the input of Pleistocene aeolian deposits into the modern carbonate sediments around dredged channels. Aragonite and high-Mg calcite cements with diverse crystal morphologies are slightly more common in tidal channels than in marshes. This is attributed to relatively strong hydrodynamic conditions and permeable sandy sediments, which cause higher rates of marine porewater flow. The intensity and extent of micritization and microboring of the allochems are greater in tidal channels than in marshes. The micrite envelopes of aragonite-dominated fragments are non-luminescent, whereas the micrite envelopes of bioclasts dominated by high-Mg calcite exhibit dull orange luminescence. There are no discernible differences in the elemental composition between host bioclasts and their micrite envelopes. Dolomite cement in modern sediments, which is rarely found in previous studies, mainly occurs as scattered single rhombic crystals or aggregates in the deposits from tidal channels. Energy dispersive X-ray spectrometer (EDS) data shows that patchy dolomite cements are surrounded by high-Mg microcrystalline cements. Extracellular polymeric substances (EPS) and metabolic processes of organisms may facilitate dolomite precipitation. Besides, the relatively high evaporation rate leads to an increase in the Mg/Ca ratio in pore water, thereby promoting the formation of dolomite.
The influence of deep mantle thermal conductivity on the long-term thermal evolution of Earth's mantle and core
Authors: Tian Jiacheng , Tackley Paul
Published: March 2024

Constraining the heat flow across the core-mantle boundary (CMB) is crucial for understanding the thermal history of Earth’s mantle and the core. The primary mechanism governing heat transfer at the CMB is conduction, with lattice vibration (lattice thermal conductivity) commonly considered to be the dominant mechanism of thermal conduction in the lower mantle. However, there are large uncertainties in current estimates of lattice thermal conductivity of mantle material under CMB condition, due to the influence from mineral composition and the post-perovskite phase transition (e.g., Hsieh et al., 2018 PNAS; Ohta et al., 2017 EPSL). On the other hand, the role of radiative contribution (radiative thermal conductivity) remains less well understood. Several recent studies have attempted to measure the radiative thermal conductivity of bridgmanite and pyrolitic materials under lower mantle conditions, but the resulting experimental data have yielded divergent estimations for the radiative thermal conductivity of average mantle material at CMB conditions, ranging from 0.35 W/(m K) to 4.2 W/(m K) (Lobanov et al., 2020 EPSL; Murakami et al., 2022 EPSL). Adopting the highest estimate could result in an approximate 50% increase in the estimated bulk thermal conductivity compared to conventionally assumed values.  

To address the implications of these thermal conductivity uncertainties on mantle convection, we have incorporated variable thermal conductivities into a global thermochemical geodynamic model, StagYY. The simulations use a 2D spherical annulus geometry and extend over a 4.5 Gyr timespan. The geodynamic model includes parameterized core cooling, heat-producing elements partitioning, and crust formation, but it does not include an initial primordial reservoir at CMB. Preliminary findings from our study reveal that the relationship between thermal conductivity and CMB heat flux is not always straightforward. For models with stagnant-lid tectonics, higher thermal conductivity leads to higher CMB heat flux in the initial 1 Gyr and lower CMB heat flux at 4.5 Gyr. However, in models with mobile-lid tectonics, the CMB heat flux also increases with higher thermal conductivity in the first 1 Gyr, but CMB heat flux varies more and becomes unrelated to thermal conductivity at 4.5 Gyr. In summary, deep mantle thermal conductivity has little effect on the present-day CMB heat flux due to plate tectonics on Earth. Varying thermal conductivity mainly influences the amount of core cooling, particularly in early planetary evolution. 
On the contribution of ocean fronts to the anomalous scaling of the structure functions
Authors: Isern-Fontanet Jordi , Turiel Antonio , González-Haro Cristina , Gea Viktor G.
Published: March 2024

The upper ocean is crowded with fronts of different intensities and extensions,  which are known to play a major role in the dynamics of the oceanic upper layers and contribute to set some properties such as the spectral slopes of Sea Surface Temperatures (SST), among others. Here, we show that the upper layers of the ocean can be modeled by the multifractal theory of turbulence and, then, we use this theory to predict the link between the most intense fronts and the scaling properties of the structure functions. This prediction is, finally, verified with a wide range of observations and numerical simulations.In particular, we show that the behavior of thermal gradients at small enough scales can be characterized by singularity exponents. Then, we use the singularity exponents of thermal gradients as a measure of the intensity of thermal fronts; and the fractal dimension of the set of points with the same singularity exponent, known as the singularity spectrum, as a measure of their extension. This allows us to connect fronts with the structure functions of temperature using the multifractal formalism. Assuming that the turbulent cascade can be modeled with the log-Poisson model, we analytically shown that the anomalous scaling of the structure functions is a function of the intensity of the strongest front, i.e. the smallest singularity exponent. This prediction is verified using the SST provided by numerical simulations of an upwelling system; simulations of the global ocean; and satellite observations. Moreover, we show that the predicted relationship is also valid for other variables such as velocities.Our results not only provide insight on the functioning of the upper ocean, but also provide a guide to develop and adjust numerical models. Indeed, our results imply that numerical models have to correctly model, or parametrize, those processes generating the most intense fronts, in order to properly reproduce some of the statistics of ocean temperatures. 
The Role of Artificial Intelligence in Modeling and Predicting Ground Deformation Using Advanced InSAR Data
Authors: Khan Junaid , Rosi Ascanio , Meena Sansar raj , Floris Mario
Published: March 2024

Ground deformation, encompassing sudden and gradual shifts in the Earth's surface, poses significant global geohazard risks. These phenomena demand thorough investigation and monitoring and are influenced by a range of natural and anthropogenic factors such as mining, excessive groundwater extraction, seismic activities, structural loads, and subsurface geology. Our research is centered on the location in the Venetian-Friulian Plain (Veneto Region, NE Italy). This area is of interest because it represents a transitional zone where sedimentary deposits from both river systems (fluvial) and lagoon/coastal environments are found, marking the transition from the alluvial plain to the coastal plain. Ground displacement maps are generated using pre-event data from the Veneto Region Sentinel 1-PS data Service and the European Ground Motion Service (EGMS), allowing us to analyze the heightened susceptibility of areas undergoing deformation. Our approach integrates artificial intelligence techniques with InSAR-derived data to create comprehensive pre- and post-event multi-temporal deformation inventories and susceptibility maps. This fusion offers exceptional accuracy and timeliness in identifying, modeling, and predicting ground deformation events. Utilizing insights from InSAR data and AI techniques, we aim to project future trends and potential risks, contributing valuable insights to geohazard assessment and management within the study region.
Probabilistic Estimates of Fractional Snow Cover Area in Mountainous Terrain
Authors: Casson David R. , Wood Andrew W. , Tang Guoqiang , Rittger Karl , Clark Martyn
Published: March 2024

This study investigates probabilistic estimates of fractional Snow Cover Area (fSCA) in mountainous terrain, aiming to bridge the gap between mechanistic hydrological models and operational remote sensing measurements. To capture the spatial variability of snow cover, we generate high-resolution ensemble meteorological forcing datasets from in-situ measurements, employing locally weighted regression and random forest methods. We then discretize a physically-based hydrological model tailored for mountainous terrain, incorporating the dominant factors influencing snow cover. Subsequently, fluxes from an intermediate complexity snowpack model are utilized to simulate fSCA, which we evaluate against an operational data source. This research is a progressive step toward integrating ensemble data assimilation techniques, with the goal of improving hydrological forecast performance.
Precise Relative Navigation in Medium Earth Orbits with Global Navigation Satellite Systems and Intersatellite Links for Black Hole Imaging
Authors: Salas María , Fernández Jaime , van den IJssel Jose
Published: March 2024

The Event Horizon Telescope (EHT) is a ground-based array of Very Long Baseline Interferometry (VLBI) telescopes designed to image the event horizon of black holes. To overcome its limitations, this work explores a mission concept involving a two-satellite constellation of VLBI telescopes deployed in circular and polar Medium Earth Orbit (MEO) at more than 8000 km altitude.  The attainment of high-resolution black hole images requires extremely precise baseline determination at the few millimetre level. To address this challenge, each satellite within the constellation is equipped with two Global Navigation Satellite System (GNSS) receivers and an optical Intersatellite Link (ISL) for relative navigation. This work assesses the feasibility of achieving highly accurate relative positioning within the constellation, particularly considering the large intersatellite distances involved.The methodology employed in this simulation study encompasses several steps. Initially, the satellite orbits are estimated independently for each satellite using GNSS observations. Following this, the orbit of one of the satellites is held fixed as a reference, while the orbit of the other satellite is re-estimated by incorporating the ISL observations. To enhance the accuracy of the orbit estimation, integer GNSS ambiguity resolution is implemented in the precise orbit determination process. The simulated data incorporates an extensive set of realistic error sources, including thermal noise, instrumental delays, clock biases, errors in the GNSS ephemerides and clocks, uncertainties in the geopotential and solar radiation pressure models, and white noise in the ISL observations.The results highlight the importance of integer ambiguity resolution in meeting the stringent relative navigation requirements of the mission. The analysis also reveals that the ISL observations primarily improve the baseline estimation along the direction of the link itself. However, in the direction of the black hole, the impact of ISL observations is minimal, indicating that the ISL does not significantly contribute to meeting the specific relative navigation requirements. Furthermore, the study identifies that large intersatellite distances lead to degraded relative orbit accuracy due to fewer shared errors between the two satellites. The work will show the accuracy obtained with the simulations, the assumptions considered, and the next steps needed.
Detection of OH radicals in aqueous solution using terephthalate: Overestimation of the OH radical concentration due to photochemical hydroxylation of terephthalate
Authors: Werner Laura , Naumann Robert , Theis Alexander
Published: March 2024

OH radicals play a key role for the self-cleaning and oxidation capacity of the atmosphere. Therefore, the detection of OH radicals in water is of great interest for atmospheric research. Terephthalate is a commonly used reagent to detect OH radicals in the aqueous system, forming the fluorescent product 2-hydroxytherephthalate. This reaction is reported to be a selective and sensitive method that can detect OH radicals in the nanomolar range. By irradiating a solution of disodium terephthalate in ultrapure water with different wavelengths between 250 nm and 310 nm the influence of photochemical excitation on the formation of 2-hydroxyterephthalate was studied using fluorescence spectroscopy. First results indicate that in the aqueous system the fluorescent 2-hydroxyterephthalate is not only formed by OH radicals but also through a photochemical reaction upon direct excitation of terephthalate. This photochemically driven hydroxylation may lead to an overestimation of the actual OH radical concentration, which could have a significant effect on the measurement outcome, particularly when measuring at the edge of the detection limit. Therefore, it can be concluded that the excitation wavelength should be carefully considered when using terephthalate as a detection reagent for OH radicals in aqueous solutions.
Phytolith and microalgae records of Late Pleistocene and Holocene climate-driven landscape shifts in the Canary Islands
Authors: Castilla-Beltrán Alvaro , Martín Ramos María del Pilar , Davtian Nina , Fernández-Palacios Enrique , Criado Hernández Constantino , Nogué Sandra , Villanueva Joan , Fernández-Palacios José María , de Nascimento Lea
Published: March 2024

Rapid climatic changes at the end of glacial cycles have shaped landscapes and biodiversity globally, yet their influence on the landscapes of the islands of Macaronesia remains poorly understood. Here we discuss how three microfossil records from the islands of Tenerife, Gran Canaria and La Gomera can shed light on landscape transformations linked to climatic changes after the Late Glacial Maximum. Phytoliths as proxy data from vegetation change and microalgae (diatoms and chrysophytes) as proxies of hydrological dynamics are analysed alongside sedimentological and geochemical data to understand the multiple aspects of landscape change linked to climatic variability. Our data show the occurrence of significant vegetation changes linked to deglaciation, after 16,000 cal yr BP in Gran Canaria and Tenerife based on increases in palm (Phoenix canariensis) phytolith and shifts in grassland composition. Records from Tenerife and La Gomera show a decrease in palms and changes in microalgae communities after the end of the African Humid Period linked to the aridization of the Sahara (c. 5000 cal yr BP-present day). Multi-proxy and inter-island record comparison reveals significant variability dependent on mesoclimates and local vegetation dynamics, showing the complexity of understanding the influence of climatic changes in the landscapes of this archipelago. 
Intraplate magmatism, serpentinization and hydrothermal venting in the ultra-slow spreading setting of the Eurasia Basin, Arctic Ocean
Authors: Meza Juan Camilo , Faleide Jan Inge , Minakov Alexander , Gaina Carmen
Published: March 2024

The Eurasia Basin, one of two major oceanic basins of the Arctic Ocean, is composed of the Amundsen and Nansen basins, which were created due to the slow and ultra-slow seafloor spreading at the mid-oceanic Gakkel Ridge initiated during the Paleocene-Eocene transition (53-56 Ma). Since the beginning of the current millennia the Gakkel Ridge and the Eurasia Basin have been subject of marine geological and geophysical studies leading to the collection of diverse datasets including rock samples, seismic, and potential-field datasets. New marine seismic data has become available in the western Eurasia Basin in the very last years, including data acquired by the Norwegian Petroleum Directorate in the context of the UN Law of the Sea, together with seismic lines gathered by Norwegian research institutions and partners. During October-November 2022 the first High Arctic GoNorth marine expedition collected new seismic reflection and refraction, as well as gravity and magnetic datasets. It is considered that this polar region may hold important clues for the understanding of global processes such as passive margin formation, and the complex links between plate tectonics and climate. Volcanic additions have been suggested within the flanks of the Eurasia Basin during different stages in the Cenozoic. Existing hypotheses further postulate corridors of exhumed mantle formed across the western Eurasia Basin because of the magmatic segmentation imposed by the Gakkel Ridge. Consequently, the oceanic basement of this area should be prone to deformation, hydrothermal alteration and serpentinization. However, little is known about the relationships between such processes with the sedimentary units above, or whether such processes occur away from the ridge and to what extent.The new compilation of multi-channel seismic reflection profiles provides an image of the sedimentary structure and the upper crust, within the oceanic crust and the continent-ocean transition (COT) between northern Svalbard margin and Eurasia Basin. The preliminary analysis of these datasets indicates that the sediments and basement structures within the southwestern corner of the Eurasia Basin have been modified in a unique manner due to an underlying geothermal anomaly beneath the lithosphere. This is expressed as focused late Miocene (< 20 Ma) to recent sill intrusion events resulting in basement and sediment deformation, and intense hydrothermal and sediment evacuation features. We present unique examples of hydrothermal venting on seismic reflection data and discuss implications of the post-rift NE Atlantic and Arctic setting, including the role of breakup magmatism, post-breakup intraplate volcanism, and sheared/passive margin development during the Cenozoic.
Long-term changes and influencing factors of water quality in aquaculture dominated lakes unveiled by sediment records and time series remote sensing images
Authors: Chen Cheng , Chen Qiuwen
Published: March 2024

Hydraulic connectivity has great effects on water quality. Enclosure aquaculture can largely alter lake flow regime and thus deteriorate water quality. Understanding the dynamics and influencing factors of water quality in enclosure aquaculture lakes is of great significance to ecosystem restoration of degraded lakes. However, it remains challenging due to the lack of long time series data. In this study, the dynamics of water quality in aquaculture dominated lakes were captured through 210Pb and 137Cs dating based on sediment records. Meanwhile, the effects of landscape pattern within aquaculture lakes on water quality were revealed by long time series of remote sensing images. Results showed the 210Pb and 137Cs sediment dating could provide an effective way to obtain long-term series of lake water quality data in the unmonitored area. The contents of lake sediment nutrients showed an upward trend from 1960 to 2018. The transformation of lakes from agriculture dominated to aquaculture dominated had increased sediment nutrients level. The long-term changes of lake sediment nutrients could be well explained by the landscape pattern metrics within aquaculture lakes, with an average explain power of 87.6%. The configuration metrics at class level had the most contribution (73.6%) to the changes of lake sediment nutrients, followed by the composition metrics (48.8%) and the configuration metrics at landscape level (33.4%). This study can provide a promising method to understand water quality changes in lakes with no historical monitoring data available and is of great benefit to water quality management in aquaculture dominated lakes.
Evidences for Neoproterozoic fragments with Indian origin in Oman and northern Madagascar
Authors: Bauer Wilfried , Rasaona Imboarina T. , Jacobs Joachim , Collins Alan , Edwards Lesley Ellen , Callegari Ivan , Scharf Andreas
Published: March 2024

Newly obtained geochemical and geochronological data from the Saih Hatat Dome in northeastern Oman and the Betsiaka Group in northern Madagascar reveal compelling similarities in the Neoproterozoic geological evolution of these geographically distant regions. The Saih Hatat Dome serves as a tectonic window with a NW-SE extension of
Ecological Responses to Vapor Pressure Deficit, Heat, and Soil Moisture: A Species-Specific Perspective across Climatic Regions
Authors: Werner Christiane
Published: March 2024

The intensifying global warming scenario leads to a notable increase in atmospheric evaporative demand, presenting novel threats to plant and ecosystems. Thus, it is crucial to comprehend the intricate relationship among temperature, vapor pressure deficit (VPD), and ecosystem processes to effectively address the challenges presented by climate change. Plants have evolved a myriad of strategies to cope with heat, drought, and high VPD. Thus, the impact of these environmental stressors will strongly depend on species-specific adaptations and prevailing environmental conditions.This study delves into the intricate dynamics of ecological responses to vapor pressure deficit (VPD), heat, and soil moisture, with a focus on species-specific adaptations, and their consequential effects on carbon and water fluxes in diverse climatic regions. By examining dominant plant responses from field studies in semi-arid, temperate, and tropical forests, examples of species-specific adaptations to VPD, heat and drought and the ecological responses across various spatial and temporal scales will be presented. Utilizing field data, the role of soil moisture in modulating the impacts of VPD and heat on carbon and water fluxes will be explored, considering the seasonal dynamics that influence these interactions.The findings highlight the importance of species-specific adaptations in influencing ecosystem responses to environmental stressors, emphasizing the need for a nuanced understanding of these adaptations across different climatic zones. A comprehensive understanding of the interplay between VPD, heat, soil moisture, and species-specific adaptations will be important for improved ecosystem management and climate change mitigation strategies tailored to specific regions and vegetation types. 
 Long-term monitoring of seismic and volcanic activity using distributed fibre optic sensing: examples in Iceland (2015-2024) and Italy (2018-2024).
Authors: Jousset Philippe , Hersir Gylfi , Currenti Gilda , Wollin Christopher , Díaz-Meza Sergio , Allegra Martina , Maass Regina , Prestifilippo Michele , Gudnason Egill , Napoli Rosalba , Krawczyk Charlotte
Published: March 2024

Monitoring of seismic activity around volcanoes has been conventionally performed using data from continuous seismic and deformation networks, which give real-time information on the status of a volcano at any time. In case of a volcanic crisis, the number of earthquakes often increases with time and conventional networks are completed by deployment of additional sensors, which allow for a better hazard assessment, e.g., by lowering the detection threshold and improving earthquake locations. The deployment of such additional sensors is labour intensive and may be dangerous due to increased volcanic hazard.Existing fibre optic telecommunication cables can be used with distributed dynamic strain sensing interrogators to density and complement the monitoring network. It has been demonstrated that the usage of fibre optic sensing allows for a rapid response and the acquisition of crucial data describing a developing crisis (e.g., at Vulcano, Italy). However, fibre optic interrogators are rarely deployed as permanent interrogating systems, despite the capability of such systems for long-term monitoring as demonstrated during a 7 months continuous recording on the Reykjanes Peninsula, Iceland, in 2020. Instead, interrogators are usually deployed for limited time periods when the activity occurs, ideally before new activity starts. For example, we connected an iDAS interrogator on the telecommunication 16-km long cable running between the Reykjanes and Svartsengi (“Blue Lagoon”) geothermal power plants in 2015 for an initial test of 10 days, in 2020 for 7 months (GFZ rapid response to the seismic crisis and precursory activity to the 2021 and 2022 eruptions of Fagradalsfjall volcano), and in November 2023 (recording still on 10.01.2024) as a GFZ rapid response before the 18 december 2023 eruption.In this work, we investigate the possibility to use repetitive campaign-based measurements of dynamic strain sensing performed in the course of multiple years on the Reykjanes Peninsula (2015; 2020; 2023-2024) and at Etna volcano (2018; 2021; 2022; 2023-2024). Analysing earthquakes and ambient noise, we search for differences and similarities in the strain-rate response between the different and disjunct recording periods. We report preliminary results.
The Early Pliocene fish fauna of the Rharb Basin in NW Morocco based on otoliths - a reservoir for remigration into the Mediterranean
Authors: Schwarzhans Werner
Published: March 2024

The coquina along the Oued Beth south of Dar bel Hamri near Sidi Slimane is known for its fossil-richness, but the stratigraphic position has long been debated for Late Miocene or Early Pliocene age. A review of fossils and samples taken during field work in the mid-70ies supports an Early Pliocene age. Recently, I described the rich otolith-based fish fauna from these rocks, which are positioned in a funnel-shaped embayment close to the Strait of Gibraltar ideally situated as a reservoir for remigration of biota into the Mediterranean following the Messinian Salinity Crisis. The analysis of the fish fauna revealed that:1.- The diversification of the fish fauna is exceptionally high and dominated by otoliths from adult specimens, which probably indicates a high food supply at moderate depth on a middle to lower shelf position during the deposition of the coquina.2.- The otolith-based fish fauna from the Early Pliocene of the Rharb Basin shows a good resemblance not only to the coeval fauna of the Mediterranean, but also exhibits a notable proportion of putative endemic species and species related to today’s tropical West African fauna.3.- The faunal composition thus exhibits a unique character that is sufficiently different from known or deduced neighboring bioprovinces, and thus a “Maghrebian bioprovince” is proposed for the Early Pliocene NW African region.4.- The faunal comparison between Early Pliocene Mediterranean and NW African fish fauna reveals few candidates for allopatric speciation and in situ survival in the Mediterranean.
Glacial rock flour is a potential source for marine carbon dioxide removal by stimulating phytoplankton growth
Authors: Bendtsen Jørgen , Daugbjerg Niels , Vallentin Larsen Kristina , R. Vives Clara , Dyrberg Dahms Rasmus , Richardson Katherine , Thorleif Rosing Minik
Published: March 2024

Glacial rock flour (GRF) is a fine-grained silicate mineral formed below the Greenland Ice Sheet where the bedrock is abraded to a fine powder. GRF is transported by meltwater into fjords and coastal waters and its dissolution in seawater is part of the natural cycling of material between continents and the ocean. It is present in large sedimentary deposits along the coast of Greenland. However, due to the relatively small size distribution of GRF (d50 ~ 2-5 µm) it has a relatively long residence time in the coastal surface layers and significant amounts reach the open ocean as suspended particulate material. As a silicate-rich material, also containing substantial amounts of micronutrients (e.g., iron and manganese), dissolution of GRF has the potential to both increase alkalinity and support phytoplankton growth. Therefore, it may be considered a source for large-scale marine CO2 removal (mCDR). In this presentation we focus on its potential for supporting phytoplankton growth. We present results from incubation experiments in the field with natural phytoplankton communities and from climate-regulated laboratory experiments with a single-species phytoplankton culture. Field-incubations (6 days) with a subtropical phytoplankton community showed a significant increase in photosynthetic activity (Fv/Fm) in treatments with GRF. Similar field-experiments with natural communities from an Arctic fjord in Greenland, with a high natural background concentration of GRF, showed a modest or a neutral response to further addition of GRF. Long laboratory incubation experiments (3 weeks) with an Arctic green alga showed a significant increase in both growth rate and photosynthetic activity in treatments with GRF. The growth increased gradually with increasing concentrations of GRF until saturation was reached. This response was consistent with a simple model of trace-metal limited growth where micronutrients (e.g., iron) is biologically mobilized from GRF during the incubation period. These results show that substances in GRF, likely trace metals, can be biologically mobilized on timescales of days to weeks and thereby support growth of phytoplankton. Thus, GRF may be a source for large-scale mCDR due to its potential for increasing ocean productivity and strengthening the biological pump. 
Detecting multi-decadal changes in the Brewer-Dobson circulation from in situ trace gas measurements and idealized modeling
Authors: Ray Eric , Moore Fred , Hall Brad , Hintsa Eric , Dutton Geoff , Garny Hella
Published: March 2024

We utilize in situ stratospheric measurements of trace gases from two recent high altitude aircraft campaigns, DCOTTS and SABRE, to compare mean ages and long-lived trace gas relationships in the NH stratosphere to those from ER-2 campaigns in the 1990s.  The ER-2 campaign data from three decades ago have been a primary reference for in situ-based estimates of mean age in the lower stratosphere from 16-22 km altitude, but very few measurements have been made in this region since then.  We use an updated technique to consistently calculate mean ages from simultaneous in situ measurements of SF6, CO2, N2O and CH4, allowing us to compare mean ages and their relationship with N2O between the 1990s and 2020s.  The mesospheric loss of SF6 and subsequent old age biases are largely accounted for based on newly developed theory and modeling work.  We then use the idealized tropical leaky pipe model to explore stratospheric circulation and mixing changes that are consistent with the observations.
Thermo-hygric weathering of Carrara Gioia marble monitored with Nonlinear Resonant Ultrasound Spectroscopy
Authors: Chavazas Marie-Laure , Bromblet Philippe , Berthonneau Jérémie , Payan Cédric
Published: March 2024

Carrara marble is widely used, in buildings and sculptures, in ancient and recent works. Yet, it can develop deteriorations over time, such as bowing, cracks, expansion, reduction of mechanical strength, when it is exposed to environmental conditions. Previous studies have shown that these deteriorations can result from exposure to temperature variations, and that they can be enhanced by additional humidity variations. However, the mechanisms at stake at the microstructure level are still not well-understood.This work is therefore focused on the understanding of the degradation mechanisms induced on marble by temperature and humidity fluctuations. Laboratory experiments are carried out on Carrara marble samples first heated at different temperatures and then undergoing thermal, hygric, and thermo-hygric cycles. The temperature investigated during cycling belongs to the mild temperature range (40 – 105 °C) in order to simulate outdoor exposure conditions.The mechanical state of Carrara marble samples is non-destructively monitored during the cycles with Nonlinear Resonant Ultrasound Spectroscopy (NRUS), through the evolution of resonant frequency and of nonclassical nonlinearity. The first parameter is related to sample stiffness, and the latter is highly sensitive to any change occurring at the microstructure level (micro cracks, friction, capillary effects, etc.). Additionally, microstructural characterization (mercury intrusion porosimetry, optical microscope and SEM observations) is made on marble samples to link the evolution of the NRUS parameters to the changes occurring in marble microstructure.The impact of heating on marble is first studied for temperatures between 40 and 250 °C, and the progressive granular decohesion of the material is monitored with NRUS. Marble state is also characterized during adsorption-desorption cycles, which shows that relative humidity fluctuations alone do not induce permanent damage. Finally, the influence of thermal cycling at mild temperatures and the impact of combined temperature and relative humidity cycling are studied with NRUS.
Local Solid Earth Tides and Their potential use in assessing and forecasting the risk of seismic hazards
Authors: Vespe Francesco , Dousa Jan , Doglioni Carlo , Ficini Eleonora , Masci Olimpia , Nico Giovanni , Nosek Jakub , Vaclavovic Pavel , Sottili Gianluca , Zaccagnino Davide , Mendes Luis , Amarillo-Fernandez Francisco
Published: March 2024

This work presents some results achieved in the frame of TILDE project (Tidal Interplate Lithospheric Deformation of Earth). The main goal of TILDE project was the estimation of Local Solid Earth Tides (LSET); i.e. models which depends on the geographical position of the selected sites. The LSET models are built estimating Love and Shida numbers for each station and for each tidal constituents. The objectives were to investigate possible correlations between LSET and geological/geophysical events, such as tectonic plates movements, earthquakes and volcanic activities. GNSS data collected at 98 stations, split into global and regional networks have been used. The global network consists of 73 GNSS stations which have piled up a stack of data 20 years long. The regional networks consist of 25 stations, 7 located in New Zealand, 1 in Kamchatka, and 17 stations in Italy for which 3 year-long time series of data are available.The LSET models have been achieved using GNSS coordinates expressed both in geocentric XYZ and local NEU references, estimated in Precise Post Processing mode, with a sampling rate in turn of 1 day and 3 hours.  Different GNSS solutions have been generated according the objectives of the project. The first one is the background solution in which the full IERS2010 tides model has been applied. The second solution is obtained by switching off the tides model. The third one is the solution in which only the Long-Periodic Tides (LPT) has been switched off. This last solution has been applied in order to lower the level of flickering of GNSS time series when Love and Shida numbers of LPT had to be estimated.This analysis showed that there is a correlation between the latitude measured from the tectonic equator and Love numbers. This confirms the theory that moon tides contribute to trigger tectonic movements.An interesting result, relevant for the assessment and potential precursiveness of the risk of seismic hazards, was the correlation found between the variation in time of Love numbers of diurnal (K1) and semi-diurnal (M2) tides and the occurrence of earthquakes nearby GNSS sites.  At this purpose we selected GNSS global stations which were at a distance