bluuebunny/crossref_metadata_2025 huggingface dataset:
Mercury contamination in a former mining plant of NW Tuscany (central Italy)  
Authors: Barbara Nisi , Meloni Federica , Cabassi Jacopo , Vaselli Orlando
Published: March 2024

Mine dumps are man-made geological formations characterized by unique chemical, particle-size, bacterial, and physical and mechanical features, representing deposits or cumuli of crushed, grounded and roasted material. Processing plants of metallic poli-sulfide ore deposits have contributed to pollute soils and surface and ground waters in many areas worldwide. The southern sector of the Apuan Alps (northern Tuscany, Italy) hosts a number of small pyrite ± barite ± iron-oxide orebodies that have been exploited since at least the Middle Age, whose activity ceased at the end of the 20th century. The most important mining areas were those distributed along a 10 km-long NE-SW strip in high Hg contents the southern portion of the Apuan Alps. In this framework, the Rezzaio treatment plant (Valdicastello Carducci, Pietrasanta), dismissed since 1991, was the site where ore bodies hosted within the metamorphic rocks of the Apuane Unit, mainly from Monte Arsiccio, Pollone and Buca della Vena mines were treated. The materials extracted from these mines were barite and iron oxides (both hematite and magnetite) used as weighting agents as drilling mud during petroleum drilling wells. Abandoned mining tunnels and dumps and plants for mineral treatment are still present in the area, posing a series of environmental threats. Our study focused on assessing the impact due to mercury contamination released by the treatment plant of Rezzaio by the past-mining activity. The aims of this study were to (1) determine the concentration of Gaseous Elemental Mercury (GEM or Hg0) in air and interstitial soil inside and outside the plant, including the working areas and the edifices where the workers were operating (e.g., offices, laboratory, rock storage); (2) assess the total amount of Hg in the top- and sub-soils, mostly developed on a small mining dump and (3) quantify the release of Hg by soil leaching tests by Milli-Q water. According to WHO and the Italian Legislative Decrees, the GEM values in air and outside the plant and in the plant edifices and mining structure are below the Recommended Exposure Limit. The spatial distribution of Hg indicates that up to 88 mg/kg were recorded in the top- and sub-soils, the highest contents being found on the small mining dump that is partly the bank of a creek. However, in most cases the concentration of Hg leachate were < 1µg/L, suggesting that mercury is likely trapped within crystalline silicate structures recalcitrant to chemical weathering. These results suggest that despite the high contents, mercury is not apparently playing a critical role as a contaminant in the Rezzaio area, being hosted in relatively insoluble minerals.
The modulation of plant nutrition and soil properties by mycorrhizal fungi and their preferences for the soil texture they encounter
Authors: Jacob Eva , Camenzind Tessa , Bitterlich Michael
Published: March 2024

Arbuscular mycorrhizal fungi (AMF) affect both plant nutrition and soil physical properties, including soil water retention and hydraulic conductivity. However, much less is known about the preferences of AMF for proliferation into soils of different (physical) natures, i.e. soil textures. To investigate this, we designed a pot trial with tomato in which AMF had access to root-free soil patches of different textures. We hypothesized that AMF would prefer fine-textured soils over coarse-textured soils because a finer textured soil is comparatively moist (which most fungi prefer) and contains a greater share of low-weight particles (less growth resistance) than a coarse-textured soil.We inoculated tomato plants with the fungus Rhizopagus irregularis grown in 4L pots filled with a quartz sand: loam mixture (1:1 w/w). The loam is a calcareous alluvial loam obtained from the C-horizon with a pH of 7.5, low in organic matter (0.05% Corg), 42.72% sand, 44.22% silt, 13.06% clay and is highly P-fixing. The self-propagated fungal inoculum used was based on this loamy soil and, therefore, inoculation did not compromise the soil texture of the potting mix. Each pot received three ingrowth cores covered in root-excluding nylon mesh (37 µm) containing either pure quartz sand (grain size 0.3 – 1.0 mm), pure loam soil or a 1:1 mixture of the two (as in the main pot). To cause variance in soil hyphae development, we applied two treatments. On the one hand, half of the pots contained the tomato cultivar 76R and the other half its related rmc mutant, which is known to show reduced mycorrhizal colonization. On the other hand, we subjected half of the pots to two weeks of terminal drought to slow down plant and fungal growth, while the other half of the pots were kept under ample moisture. After harvest, we measured root colonization and plant nutrient uptake to verify the viability of the mycorrhizal symbioses. From the ingrowth cores, we extracted AMF hyphae and determined their length. As traits known to be affected by functional hyphae and plant activity as well as soil desiccation, we also measured aggregate stability indices in soils from the ingrowth cores.According to our expectations, we found that the 76R tomatoes, which were able to develop a viable symbiosis, had higher tissue P and N mass fractions in their dry matter than the rmc tomatoes.  Against our expectations, the 76R plants were more sensitive to drought when exposed to it and had significantly lower biomass than the rmc plants and the 76R plants maintained under ample moisture. Furthermore, we illustrate our findings on hyphal length density and aggregation and discuss them with regard to the preferences of AMF to populate the soils with different textures. We answer whether our hypothesis must be confirmed or denied and deduce some potential ecological consequences of our findings.
Deploying Pangeo on HPC: our experience with the Remote Sensing Deployment Analysis environmenT on SURF infrastructure
Authors: Nattino Francesco , Grootes Meiert W. , Chandramouli Pranav , Ku Ou , Alidoost Fakhereh , Dzigan Yifat
Published: March 2024

The Pangeo software stack includes powerful tools that have the potential to revolutionize the way in which research on big (geo)data is conducted. A few of the aspects that make them very attractive to researchers are the ease of use of the Jupyter web-based interface, the level of integration of the tools with the Dask distributed computing library, and the possibility to seamlessly move from local deployments to large-scale infrastructures. 

The Pangeo community and project Pythia are playing a key role in providing training resources and examples that showcase what is possible with these tools. These are essential to guide interested researchers with clear end goals but also to provide inspiration for new applications. 

However, configuring and setting up a Pangeo-like deployment is not always straightforward. Scientists whose primary focus is domain-specific often do not have the time to spend solving issues that are mostly ICT in nature. In this contribution, we share our experience in providing support to researchers in running use cases backed by deployments based on Jupyter and Dask at the SURF supercomputing center in the Netherlands, in what we call the Remote Sensing Deployment Analysis environmenT (RS-DAT) project. 

Despite the popularity of cloud-based deployments, which are justified by the enormous data availability at various public cloud providers, we discuss the role that HPC infrastructure still plays for researchers, due to the ease of access via merit-based allocation grants and the requirements of integration with pre-existing workflows. We present the solution that we have identified to seamlessly access datasets from the SURF dCache massive storage system, we stress how installation and deployment scripts can facilitate adoption and re-use, and we finally highlight how technical research-support staff such as Research Software Engineers can be key in bridging researchers and HPC centers. 
Fault orientation in earthquake seismic precursors: insights from the laboratory
Authors: Giorgetti Carolina , Brantut Nicolas
Published: March 2024

Faults in the brittle crust lie at any orientation to the far-field stress. However, laboratory experiments designed to investigate earthquake physics commonly simulate favorably oriented faults, potentially overlooking the complexity of natural fault behavior. Here, we assess the role of stress field orientation in fault reactivation and earthquake precursors by conducting triaxial saw-cut experiments with laboratory faults oriented at different angles to the maximum principal stress, ranging from 30° to 70°. The samples were instrumented with strain gauges and piezo-electric sensors. Laboratory well-oriented faults describe a rather simple system in which the elastic energy is stored via the deformation of the surrounding host rock during the inter-seismic period and released via on-fault slip during the co-seismic phase with associated precursor acoustic activity. Consistent with previous laboratory data, an abrupt increase in the on-fault acoustic emission rate occurs shortly before the laboratory earthquake. A more complex picture emerges when deforming laboratory misoriented faults. Particularly, acoustic emissions and strain gauge data indicate that when the fault is misoriented, off-fault permanent deformation occurs well before fault reactivation. The stress state in the host rock surrounding the fault is indeed far beyond the one required for the onset of inelastic deformation. In this case, acoustic activity distributed in the rock volume during the pre-seismic phase is associated with permanent deformation in the critically stressed host rock and is not a direct precursor to the following laboratory earthquake. Unlike well-oriented faults, laboratory mis-oriented faults lack detectable seismic precursors. The laboratory-observed increase in acoustic activity prior to, but not precursor of, mis-oriented fault reactivation impacts our understanding of earthquake precursors in natural faults.
High-resolution design rainfall estimation from climate model data
Authors: Müller-Thomy Hannes , Ebers Niklas , Schröter Kai
Published: March 2024

For urban hydrology, rainfall time series and especially design values with high temporal resolution are crucial. Since most climate scenarios offer daily resolution only, statistical downscaling in time seems a promising and computational effective solution. In the presented method, rainfall is first disaggregated to continuous 5min time series, and subsequently design values are derived from these time series.The micro-canonical cascade model (MRC) is chosen as downscaling method since it conserves the daily rainfall amounts exactly, so the resulting 5 min time series are coherent with the daily time series used as starting point. Rainfall extreme values are often linked to temperature (especially convective events, which are crucial for e.g. urban hydrology or insurance companies). Therefore, a temperature-dependent MRC is introduced in this study. Temperature-dependency is tested for minimum temperature, mean temperature and maximum temperature, which all allow a physical interpretation of rainfall extreme values and provide deeper insights into their future changes.For this study 45 locations across Germany are selected. To ensure spatial coherence with the climate model data (~∆l=5 km*5 km), the YW dataset (radar-gauge-merged data) from the German Weather Service (DWD) with originally ∆l=1km*1 km and ∆t=5 min was aggregated in space and used for the estimation of the MRC parameters. The DWD core ensemble with six combinations of global and regional climate models is applied for the climate change analysis, for both, RCP4.5 and RCP8.5 scenario.For the temperature-dependency, class widths of 5 K are chosen to include a representative number of time steps in each class. No significant influence on continuous rainfall characteristics as wet spell amount, average intensity, wet and dry spell duration can be identified. To analyze the impact on rainfall extreme values peak-over-threshold series and 99.9 %-quantile q99.9 are studied. While the reference model without temperature-dependency leads to higher overestimations for ∆t=5 min for ϑ18 °C, the temperature-dependency reduces the deviations over the whole range to a median overestimation of 1 mm/5 min (range of observations: 4 mm/5 min
A “Rolling Hinge” Model of the Incremental Oceanward Development of the S-type Reflector Horizontal Detachment at Magma-Poor Rifted Margins
Authors: Kusznir Nick , Gomez-Romeu Julia
Published: March 2024

Recent 3D seismic reflection imaging has provided new insights into lithosphere extensional deformation processes in the hyper-extended domain of magma-poor rifted margins where extensional faults penetrate through the thinned continental crust into the topmost mantle. Seismic analysis shows that high-angle extensional faults sole out into a sub-horizontal reflector (the S-type reflector) in the top-most mantle. This reflector is interpreted as a horizontal detachment and has been shown to develop progressively oceanward with the in-sequence extensional faulting above.We examine the evolution of fault geometries during extensional faulting in the hyper-extended domain. We show that the predictions of a recursive flexural rolling-hinge model  of planar faulting of thinned continental crust soling out into a horizontal detachment in the top-most mantle are consistent with the seismic interpretations. Our modelling shows that initially high-angle extensional faults are isostatically rotated to low-angle by oceanward in-sequence faulting and that their deeper segments form a continuous sub-horizontal structure in the top-most mantle corresponding to the S-type reflector imaged by seismic data.Both 3D seismic interpretation and our modelling indicate that the sub-horizontal detachment imaged as the S-type reflector, and forming an apparent regional detachment, is not active simultaneously over its whole length in the dip-direction but that it developed oceanward incrementally together with the in-sequence high-angle extensional faulting above.
Optimizing Kilometer-Scale Climate Modeling: Refining Cloud Microphysics Using Machine Learning and Satellite Correlation
Authors: Eichholz Hannah Marie , Kretzschmar Jan , Umlauft Josefine , Quaas Johannes
Published: March 2024

The modeling of the Earth Climate System has undergone outstanding advances to the point of resolving atmospheric and oceanic processes on kilometer-scale, thanks to the development of high-performance computing systems. In the preparation phase of the global kilometre-resolution coupled ICON climate model, there's a critical need to fine-tune cloud microphysical parameters. Our approach involves investigating the optimal calibration of these parameters using machine learning techniques.Our initial focus involves calibrating the autoconversion scaling parameter by correlating it with satellite-derived top-of-atmosphere and bottom-of-atmosphere radiation fluxes. This calibration process entails conducting limited area simulations specifically within the North Atlantic and South Pacific region using ICON. Through these simulations, various adjustments to cloud microphysical parameters are made, aiming to assess their potential impacts on radiation flux output.
Climate services for finance, lessons learned and feedback for the public sector
Authors: Reveley Graham , Brennan James , Woodhouse Sally , Ramsamy Laura , Leach Nicholas , Sullivan Patricia , Davies Jonathan , Stables Joe
Published: March 2024

Driven by regulations to understand and attempt to mitigate risk from climate change there is an increase in demand for climate risk data from the financial sector. This has led to the generation of 3rd party data providers, such as Climate X, who aim to bridge the gap between academic research and the requirements of the financial sector. This requires a multi-disciplinary team bringing together hazard, remote sensing, and climate scientists which allows us to combine open-source earth observations and climate model data with in-house hazard modelling to generate metrics and losses that are useful and useable for our clients.In this talk we will cover the key requirements of our clients: asset-level and global intelligence, multi-hazard and loss information and multiple scenarios. We will outline how we address these, and how academic researchers can engage with the private sector to make their work as relevant as possible.
Assessment of the Indian Meteorological Ensemble Dataset (IMED) Performance in Identifying Cloudburst Events over the Northwest Himalayas (NWH) 
Authors: Peringiyil Anagha , Saharia Manabendra , Op Sreejith
Published: March 2024

Cloudbursts over the NWH have become more common in recent years. The uncertainty caused by the sparse density of the station network over NWH encouraged us to employ the developed dataset, Indian Meteorological Ensemble Dataset (IMED), which explicitly accounts for topographical complexity and uncertainties in precipitation estimations. In the NWH, where monitoring stations are sparse, and cloudbursts are hard to discern, this study examines IMED's efficiency in identifying cloudburst events. We aim to use the mean, 70th percentile, 80th percentile, and 99th percentile values from 30 ensembles of IMED data every day with a resolution of 0.25 degrees.  We evaluated 18 events in the NWH between 2014 and 2016, which were documented in different paper publications. Furthermore, we compare the cloudburst identification ability of the CHIRPS dataset to that of the IMED datasets. A pixel-wise analysis shows that IMED performs better than the CHIRPS dataset in this event detection. With the mean value of IMED, it can capture five events, whereas four events are captured by the CHIRPS dataset. With the 70 percentile, 80 percentile, and 99th percentile, IMED can capture more events. This study concludes that IMED performs better than CHIRPS in identifying cloud burst events over the NWH region.
Modelling reference evapotranspiration of green walls (ET0vert)
Authors: Hoffmann Karin A. , Saad Rabea , Kluge Björn , Nehls Thomas
Published: March 2024

Green walls, facade greenery, living walls – vertical building greening as part of urban green infrastructure are measures for climate sensitive urban design, for water management and microclimate regulation. Strategic integration of green walls into local water and energy cycles requires prediction of evapotranspiration, considering the individual design, plant species, and building characteristics. Available models address horizontal surfaces but disregard vertical particularities and urban conditions, e.g., reduced direct radiation, spatial patterns of radiation on the wall due to building orientation and shading obstacles, and very heterogeneous wind fields that are influenced by rough surfaces, canyons, and adjacent wind barriers. We present a verticalization model, ET0vert, for the reference crop evapotranspiration ET0 (FAO) based on a sensitivity analysis. It comprises the adaptation of solar radiation and wind to the individual situations in front of a wall or facade. The accuracies of the model predictions are evaluated for (i) remote climate station data (horizontal reference plane), (ii) interpolated climate data (both horizontal and vertical reference plane) and (iii) on-site measured climate data (vertical reference plane, both not height-adapted and height-adapted) as input. We validate the model with data for a one-month reference period (25/07/2014 – 29/08/2014) from a weighable lysimeter with Fallopia baldschuanica greening of a 12 m high wall in Berlin, Germany.Regarding individual meteorological input parameters, we found high relevance of both vapor pressure deficit (VPD) and solar radiation (RS) for the study area. Using VPD and RS, respectively, a linear model could explain 90 % and 85 % of daily ET0 variances. No such relationship could be detected for wind speed, but for maximum and minimum wind speed.Compared to remote horizontal input data, verticalization of input data (RS and wind) reduced overestimations of ET from about 90 % to 14 % and 27 % for the daily and hourly resolution, respectively. If onsite climate data is available, deviations are reduced to 9 % and 5 % for the daily and hourly resolution. Height-adaptation of input data resulted in further improvements of the prediction accuracies (1 % and 2 % deviation for hourly and daily resolution).We conclude that simply using remote horizontal climate data for calculating ET of green walls is not advisable. Instead, any input data, onsite measured or remote climate station data, should be verticalized and preferably height-adapted. The verticalized model predicts the hourly and daily evapotranspiration of green walls necessary for e.g., irrigation planning, building energy simulations or local climate modeling.For more information: https://doi.org/10.5194/hess-2023-22
Stress, strain and crustal flow patterns in a corner collision: insights from coupled 3D numerical models
Authors: van Agtmaal Luuk , Balazs Attila , May Dave , Gerya Taras
Published: March 2024

Large and fast collisional systems such as the Eastern Tibetan-Himalayan orogenic system can have distinct corner structures. Away from the corners, plate convergence is accommodated primarily by convergence-parallel processes such as (continental) subduction, crustal thickening and buckling. Around the corners, oblique and convergence-perpendicular processes become more important, such as strike-slip, transpressional and transtensional faults. The strike of the subduction front itself can also vary in space, as tomographic images show for the case of the Indian slab beneath Tibet and Burma. At the corners themselves, a peculiar syntaxis structure may form which is characterised by effective strain localisation and high rates of exhumation and erosion. However, our understanding of the temporal evolution of orogenic syntaxis formation is still elusive. Here, we use high-resolution, three-dimensional thermomechanical models to investigate principal stress orientations, strain rate patterns and upper versus lower crustal flow patterns within a continental corner collision setting loosely resembling the Eastern Tibetan-Himalayan orogenic system. We use a 1000 x 200 x 1000 (x * y * z) model domain with a permeable lower boundary and a 2 km grid resolution in each dimension. Each grid cell has 8 markers. The models are carried out using I3ELVIS (Gerya and Yuen, 2007) coupled to the surface process model FDSPM (Munch et al., 2022). Our numerical experiments highlight that i) significant lateral variability occurs despite prescribing orthogonal kinematic boundary conditions; ii) a high variability of stress states and deformation styles occur within the modelled orogen and plateau; iii) Lower crust beneath the plateau escapes later than upper crust, but around 3-4 times faster. Lastly, we examine the sensitivity of the model evolution to different degrees of strain weakening, intracrustal layering, and the diffusion coefficient of the surface process model.Gerya, T. V., & Yuen, D. A. (2007). Robust characteristics method for modelling multiphase visco-elasto-plastic thermo-mechanical problems. Physics of the Earth and Planetary Interiors, 163(1), 83–105. https://doi.org/10.1016/j.pepi.2007.04.015Munch, J., Ueda, K., Schnydrig, S., May, D. A., & Gerya, T. V. (2022). Contrasting influence of sediments vs surface processes on retreating subduction zones dynamics. Tectonophysics, 836, 229410. https://doi.org/10.1016/j.tecto.2022.2294
An active detachment fault ahead the Aden propagating oceanic rift in Afar: consequences on breaking-up processes
Authors: Geoffroy Laurent , Bernard Le Gall , François Chauvet , Mohamed Daoud , Mohamed Jalludin , Marion Jaud , Antoine Caminiti
Published: March 2024

The rift to drift stage in continental breakup systems remains enigmatic, especially when stretching and thinning are associated with significant mantle melting. Here we present the first on-site evidence in the Afar Depression of a segmented detachment fault of Quaternary age, the Doubié detachment, ahead of the proto-oceanic Asal segment, itself located at the tip of the propagating Aden oceanic rift system that separates Arabia from the Somali plate. The active Doubié Fault post-dates the last emplacement of flood basalts in the region and largely controls the development of a major hanging-wall crustal flexure, south of the Danakil block. On the fresh scarp, 36Cl datings show that this fault accommodated about 60% of the plate separation during the Holocene. We suggest that a similar detachment-fault, partly invaded by felsic magma at a late stage, was active before the onset of the Ghoubbet-Asal proto-oceanic segment. We highlight the strong implications of those findings on the dynamics of the latest stages of continental extension ahead propagating ultraslow oceanic spreading systems.
Antarctic extreme seasons under 20th and 21st century climate change
Authors: Bracegirdle Tom , Caton Harrison Thomas , Holmes Caroline , Lu Hua , Martineau Patrick , Phillips Tony
Published: March 2024

Extreme seasons (climate extremes) are of particular relevance to impacts, as they can produce accumulated effects on, for example, surface melt of ice shelves and penguin breeding. There is a gap in knowledge on how extreme seasons may change over Antarctica and the Southern Ocean under future climate forcing scenarios, with Antarctica not included in the IPCC AR6 WG1 Chapter 11 on extremes. In this presentation, available large ensemble datasets in the Coupled Model Intercomparison Phase 6 (CMIP6) archive were used to provide the first multi-variate overview of the evolution of extreme seasons over Antarctica and the Southern Ocean during the 20th and 21st centuries, with projections following medium-to-high radiative forcing scenarios (SSP2-4.5 and SSP3-7.0 forcing experiments). The variables assessed were near-surface temperature, surface precipitation rate and near-surface westerly wind. The results show significant differences between simulated changes in background mean climate and changes in low (10th percentile) and high (90th percentile) extreme seasons. Regional winter warming is most pronounced for cold extremes, particularly over or near to areas of climatological 20th century sea ice cover. In summer there are more pronounced increases in high extremes in precipitation and westerly wind during the ozone hole formation period (late 20th century) affecting coastal regions and in particular the Antarctic Peninsula. At sub-polar latitudes (between 50 and 60 degrees South) there is an approximately 20% reduction in the range of summer season wind extremes. Potential mechanisms/processes responsible for these differences will be discussed.
Critical evaluation and development of thermodynamic models for ionization of H2O, HCl and NaCl at high temperatures and pressures
Authors: Salomone Federica , Dolejš David
Published: March 2024

Ionization of water and speciation of aqueous electrolytes exerts important control on chemical composition, acid-base interaction, and fluid-mineral equilibria in hydrothermal systems. Several competing approaches are available to describe H2O, HCl and NaCl speciation under hydrothermal conditions: (i) electrostatic models using the Born theory (Tanger and Helgeson 1988; Shock et al. 1992, Djamali and Cobble 2009), (ii) semi-empirical correlations with H2O density (Marshall and Franck 1981, Mesmer et al. 1988, Holland and Powell 1998); (iii) hydration models (Pitzer 1982; Tanger and Pitzer 1989) and (iv) diverse theoretical models (e.g., Akinfiev and Diamond 2003, Lvov et al. 2018). Available models were compared to experimental data (n = 606) covering temperature from 0 to 800 °C and pressure of 1 to 8000 bar, with several measurements up to 1000 °C and 133 kbar. Various approaches consistently and accurately reproduce the experimental H2O ionization up to 400 °C and above 300 bar. By contrast, at higher temperatures or lower pressures the models substantially diverge and reveal conceptual deficiencies. For HCl dissociation, the electrostatic, density and virial models are accurate to 400 °C and 1500 bar, at higher temperatures remain consistent but rapidly inaccurate and at higher pressures they diverge. This critical evaluation identifies density models as most promising for formulating new equation of state for ionic species. Here we combine individual thermodynamic contributions representing intrinsic species properties, mechanical and electrostatic solute-solvent interaction during hydration, and standard-state conversion term. We use the experimental datasets for H2O, HCl and NaCl ionization to evaluate the performance and accuracy of optional functional forms for heat capacity, hydration compression and its coupling to the standard-state conversion term. Our preliminary results indicate that intrinsic enthalpy, entropy and volume coupled with heat capacity linearly dependent on temperature, compression and standard-state conversion terms, without involvement of electrostatic contribution or chemical hydration afford the most accurate description of thermodynamic properties of ionic species. This model provides basis for accurate prediction and modeling of mineral-fluid and melt-fluid equilibria in upper-crustal magmatic and hydrothermal systems.ReferencesAkinfiev N.N., Diamond L.W. (2003) Geochim. Cosmochim. Acta 67, 613-627.Djamali E., Cobble J.W. (2009) J. Phys. Chem. 113, 2398-2403.Lvov S.N. et al. (2018) J. Molecul. Liq. 270, 62-73.Marshall W.L., Franck E.U. (1981) J. Phys. Chem. Ref. Data 10, 295–304.Pitzer K.S. (1982) J. Phys. Chem. 86, 4704-4708.Shock E.L. et al. (1992) J.  Chem. Soc. Faraday Trans. 88, 803-826.Tanger IV J.C., Helgeson H.C. (1988) Am. J. Sci. 288, 19-98.Tanger IV J.C., Pitzer K.S. (1989) J. Phys. Chem. 93, 4941-4951.
Insights into the 36 Years of Seismic Activity at Vulcano Island, Italy, preceding the Volcanic Unrest in 202
Authors: Falsaperla Susanna , Barreca Giovanni , Cocina Ornella , Spampinato Salvatore
Published: March 2024

Numerous episodes of volcanic unrest have taken place at Vulcano island (Italy) since its last Vulcanian eruption occurred 133 years ago. Decades-long seismic monitoring has documented some of them. We have collected and examined all available seismic data recorded since 1985, most of which were in analog format and/or dispersed in old repositories. We were able to compile catalogs where three different types of seismic events are considered according to their location and magnitude: events in the Fossa Crater, in the Lipari-Vulcano complex, and earthquakes with M>2.5. The primary goal of this data collection was to identify the main features of seismic activity on and around the island in the 36 years preceding the last volcano unrest, which began in mid-September 2021 with a high occurrence frequency of Very Long Period (VLP) events. Our review of the past seismic activity allows us to contextualize the newly recorded anomalous variations. Furthermore, we sought the connection with the structural framework of the region.The duration of the episodes of volcanic unrest in 1985 and 1988 was relatively short (lasting just a few months) when compared to the recent one, which ended in December 2023. The source of the seismic events during those past unrests was mainly close to the reference station (now IVCR) with hypocenters mostly beneath the island at shallow crustal depths (up to 5 km below sea level). Their magnitude remained low (
On the role of plastic flow in THM simulations capturing glacial cycle effects on German nuclear waste repositories in clay rock
Authors: Silbermann Christian , Zill Florian , Meisel Tobias , Kern Dominik , Nagel Thomas , Kolditz Olaf
Published: March 2024

To properly assess the present and future conditions of potential nuclear waste repository sites, understanding their evolution in the past is mandatory. Here, glaciation cycles strongly affect the long-term thermo-hydro-mechanical (THM) evolution of the geosystem.
The AREHS project studies the effects of time-dependent boundary conditions on the long-term evolution of large-scale hydrogeological systems. The focus is on numerical modeling using the open-source multi-field finite element code OpenGeoSys with THM couplings. The impact of the glacial THM loading is taken into account using appropriate time-dependent THM boundary conditions. The generic geological model for a clay host rock formation includes almost only sedimentary rock layers. Within the scales of the physical problem, it can be assumed that the plastic flow behavior of the different sedimentary rocks shares qualitative features. Therefore, the same generic material model is used for all layers: The elasto-plastic modified Cam clay (MCC) model can describe qualitatively a range of relevant effects (dilatancy, contractancy, consolidation, normal and overconsolidation effects, etc.) with a manageable number of material parameters. The chosen approach is considered sufficient to demonstrate the effect of inelastic deformations. Comparing the results to the elastic reference case, the role of plastic flow in the context of such a long-term simulation is elaborated. Special emphasis is put on the specification of a suitable initial state: To this end, an initial simulation is carried out, where plastic flow can occur under the gravitational load. The fields for temperature, pore water pressure and effective stress are then transferred as initial values for the glacial cycle. Additional internal variables of the material model are automatically adopted. This means that the thermodynamic state is transferred in full. The simulation results are analyzed with respect to potential safety-critical parameters, such as maximum temperature, hydraulic pressure, subsidence, equivalent effective stress and strain.
Exploring the role of aggregation in ice-nucleating macromolecules of Betula pendula pollen
Authors: Reyzek Florian , Bothen Nadine , Schwidetzky Ralph , Seifried Teresa , Bieber Paul , Pöschl Ulrich , Meister Konrad , Bonn Mischa , Fröhlich-Nowoisky Janine , Grothe Hinrich
Published: March 2024

A wide range of aerosols, including dust, soot, and biological particles, can serve as ice nuclei, initiating the freezing of supercooled cloud droplets. This process significantly impacts cloud characteristics, and consequently, weather and climate. Among biological ice nuclei, some exhibit exceptionally high nucleation temperatures. While Ice Nucleating Macromolecules (INMs) found on pollen are typically not among the most active ice nuclei, they are abundant, as evidenced by their presence throughout the tissues of trees. Notably, recent studies have shown that certain tree-based INMs, such as those from Betula pendula, demonstrate ice nucleation activity above -10°C. These findings suggest that INMs emitted from the biosphere could play a more significant role in atmospheric processes than previously understood.Our research delves into the properties of Betula pendula INMs through comprehensive ice-nucleation assays. We explore the stability of these INMs and the factors influencing their ice nucleation activity. Our approach integrates experimental data with size measurements and chemical analyses to better comprehend the underlying mechanisms.Our findings reveal that Betula pendula INMs comprise three distinct classes active at -6°C, -15°C, and -18°C, each present in varying concentrations. We observed that freeze-drying and freeze-thaw cycles markedly alter their ice nucleation capacity. Additionally, heat treatments and chemical analysis suggest that these INM classes may be size-varying aggregates, with larger aggregates being more efficient at nucleating ice. This hypothesis aligns with previous studies on fungal and bacterial ice nucleators. Our research highlights the significance of birch INMs in atmospheric ice nucleation, not only because of their prevalence but also due to their occasional but notable high nucleation temperatures.
Invasive Prosopis trees in the hyperarid environment of the Dead Sea region
Authors: Grünzweig José , Levinzon Alon , Gelfand Ilya
Published: March 2024

Invasive species cause enormous damage to ecosystems and are considered one of the main biotic factors contributing to the loss of global biodiversity. One of the most common exoctic plants in drylands is of the genus Prosopis, which has invaded natural ecosystems in many parts of the world. Despite the increasing presence of Prosopis spp. in natural areas, our knowledge of their function and impact in hyperarid regions is sparse. The goals of this study were to assess the state of the distribution of Prosopis trees in the hyperarid environment of the Dead Sea area, to characterize the habitats in which they established themselves, and the ways of dispersal in the area. Moreover, the study aimed to compare the functioning of invasive Prosopis and local trees, and to assess the impact that Prosopis has on native species. An extensive field survey showed that the seed sources of the invasive individuals are those Prosopis trees that were planted in populated areas. A combination of seed source availability, adaptation to a variety of substrates, and efficient dispersal vectors allowed this nitrogen fixer to invade natural hyperarid environments. Prosopis was shown to be more resistant to strong radiation, intense heat and high evaporative demand and showed a higher level of anisohydricity compared to the native Acacia tortilis. Higher nitrogen-to-phosphorus (N:P) ratios in Prosopis than in Acacia leaves indicated that Prosopis can accumulate higher amounts of N per unit of P than Acacia, which may be advantageous under these dry conditions where P availability is considered to be low. In addition, Prosopis exerted a negative impact on native Ziziphus spina-christi trees, the latter of which had a significantly lower water potential when growing in the vicinity of Prosopis trees than when growing near conspecific trees. The results of this research suggest that Prosopis may become a significant invasive species in the hyperarid environment of the Dead Sea region. A further rise in heat and drought as expected under climate change could increase the competitiveness of Prosopis spp. relative to the native tree species in the region, thus decimating their populations. To reduce the threat stemming from this invasive species, it is recommended to halt the spreading of Prosopis trees by eliminating the existing seed sources and banning livestock, a very potent dispersal vector.
Regional Flood Frequency Analysis Utilizing LH-moment based framework for Godavari River Basin
Authors: Singh Amit , Chavan Sagar
Published: March 2024

Regional flood frequency analysis (RFFA) helps in estimating the design flood at ungauged locations within a hydrologically homogeneous region. LH moment is a statistical method often used in hydrology for estimating distribution parameter. The LH moment are the linear combination of higher probability weighted moment. It offers an alternative to traditional moments and is particularly useful when dealing with skewed distributions. The Godavari River, one of the major river systems in India, experiences varying hydro climatic conditions across the basin. This study presents a comprehensive regional flood frequency analysis (RFFA) conducted in the Godavari River basin employing LH moment as a robust statistical tool. The present study incorporates the formation of region using region of Influence approach (ROI) approach. In this study, five probability distributions namely generalized extreme value (GEV), generalized logistic (GLO), Pearson Type III (PE3), Generalized Normal (GNO) and generalized Pareto (GPA) are considered for performing RFFA for estimating ungauged flood quantiles corresponding to various return periods (e.g., 50, 100, and, 200 years) in the Godavari River basin. The discordancy measure and heterogeneity measure in LH-Moment framework are considered for screening of peak flow data and checking the heterogeneity of the region formed using ROI. The suitability of GEV, GLO, PE3, GNO, and GPA distribution is judged through the LH-moment ratio diagram and the Z-statistic criteria. The performance of LH-moment based RFFA is evaluated through Leave-One-Out Cross Validation (LOOCV). Results indicate that the LH-moment based RFFA yields more reliable estimates of flood quantiles.
Paleostress inversion of fault slip data: what is the problem?
Authors: Pascal Christophe
Published: March 2024

Paleostress inversion methods based on fault slip data (i.e. “fault slip inversion methods” or FSIMs) were formalised fifty years ago to become, shortly after, classical tools in structural geology and tectonics. The great popularity quickly gained by the methods was as remarkable as the enduring scepticism they prompted in the geological community. FSIMs belong to the rather narrow collection of methods, which allow for bridging traditional field observations and measurements (of fault planes and their respective slickenlines in the present case) to the stress tensor, a complex mathematical object. The latter statement highlights the originality of the approach and, perhaps, the roots of FSIM scepticism: stress are “observed” (or derived from observation of the nature) and not “measured” with the help of physical instrumentation, as it is traditionally done.FSIMs are thus methods that involve mathematical processing of field data after adequate encoding of these. They rely primarily on the so-called “Wallace-Bott hypothesis”, which assumes parallelism between the measured fault stria and the computed maximum resolved shear stress, and on additional background conditions. The purpose of the present contribution is to discuss the limits of FSIMs in the light of their theoretical background and of realistic geological situations. The discussion will mostly focus on key-issues (e.g. is the stress restored by FSIMs in agreement with the formal definition of mechanical stress?) and will try to propose some future research tracks.
Addressing the closure problem using supervised Machine Learning
Authors: Köhne Sophia , Laperre Brecht , Amaya Jorge , Jamal Sara , Lautenbach Simon , Grauer Rainer , Lapenta Giovanni , Innocenti Maria Elena
Published: March 2024

When deriving fluid equations from the Vlasov equation for collisionless plasmas, one runs into the so-called closure problem: each equation for the temporal evolution of one particle moment (density, current, pressure, heat flux, …) includes terms depending on the next order moment. Therefore, when choosing to truncate the description at the nth order, one must approximate the terms related to the (n+1)th order moment included in the evolution equation for the nth order moment. The order at which the hierarchy is closed and the assumption behind the approximations used determine how accurately a fluid description can reproduce kinetic processes.In this work, we aim at reconstructing specific particle moments from kinetic simulations, using as input the electric and magnetic field and the lower moments. We use fully kinetic Particle In Cell simulations, where all physical information is available, as the ground truth. The approach we present here uses supervised machine learning to enable a neural network to learn how to reconstruct higher moments from lower moments and fields.Starting from the work of Laperre et al., 2022 we built a framework which makes it possible to train feedforward multilayer perceptrons on kinetic simulations to learn to predict the higher moments of the Vlasov equation from the lower moments, which would also be available in fluid simulations. We train on simulations of magnetic reconnection in a double Harris current sheet with varying background guide field obtained with the semi-implicit Particle-in-Cell code iPiC3D (Markidis et al, 2010). We test the influence of data preprocessing techniques, of (hyper-)parameter variations and of different architectures of the neural networks on the quality of the predictions that are produced. Furthermore, we investigate which metrics are most useful to evaluate the quality of the outcome.
Rethinking the resilience of salt marshes to land subsidence and sea-level rise: The RESTORE project approach
Authors: Da Lio Cristina , Cosma Marta , Donnici Sandra , Ferronato Massimiliano , Mazzia Annamaria , Teatini Pietro , Tosi Luigi , Zoccarato Claudia
Published: March 2024

Coastal transitional environments (CTE) are among the most productive ecosystems in the world, supporting various natural functions and providing important ecosystem services to human societies. Because of their low elevation, CTE are expected to be severely threatened by the accelerated sea-level rise (SLR) and their resilience will depend on the capability to keep pace with SLR. Recent field studies and modelling analyses suggests that Holocene events in terms of sedimentation rates and distribution of lithology could significantly influence the evolution and resilience of CTE with expected climate changes. Using the Venice Lagoon (Italy) as a case study, the RESTORE (i.e. REconstruct subsurface heterogeneities and quantify sediment needs TO improve the REsilience of Venice saltmarshes) project proposes a new multidisciplinary approach that combines geological conceptualizations, numerical modelling and vulnerability assessment to quantify the amount of sediment that CTE need to keep pace with the relative SLR. Specific attention is paid to the type of deposits and shallow subsurface architecture that play a key role in the process of land subsidence and autocompaction, i.e., the natural compaction caused by sediment self-weight. Specifically, the RESTORE workflow includes developing a detailed 3D reconstruction of the Holocene stratigraphic architecture and associated geomechanical properties, developing a numerical model that can simulate the evolution of elevations and natural subsidence over the Holocene, and developing a vulnerability assessment able to highlight the areas of the lagoon most threatened by SLR. Expected results include the evaluation of quantitative data on the sediments needed to keep pace with IPCC projected sea-level rise and the production of  vulnerability maps of tidal morphologies to different sea-level rise scenarios to assist policymakers in developing restoration, conservation, and mitigation plans.