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Global warming has caused widespread surface lowering of mountain glaciers. By comparing two firn cores collected in 2018 and 2020 from Corbassière glacier in Switzerland, we demonstrate how vulnerable these precious archives of past environmental conditions have become. Within two years, the soluble impurity records were destroyed by melting. The glacier is now irrevocably lost as an archive for reconstructing major atmospheric aerosol components. Information on past environmental conditions stored within high-altitude glaciers is being lost due to accelerated melting associated with climate change, according to ice core analysis from a Swiss glacier.

This paper describes instrumentation and procedures developed to measure H2 and Ne in polar ice core samples. Gases are extracted from ice core samples by melting under vacuum. Measurements are conducted by gas chromatographic separation with detection by a pulsed helium ionization detector (He-PDD). The analytical system was developed for field analysis of ice core samples immediately after drilling. This minimizes the potential for exchange of these highly permeable gases between the ice core and the modern atmosphere. The design, operation, and performance of the instrument are discussed using data from the initial deployment to Summit, Greenland. The results demonstrate the feasibility of ice core analysis of H2 and Ne with precision of 8.6 % and 10.2 % (1σ) respectively.

Background and aims The quantification of plant roots from soil represents a pivotal step in many studies in plant ecology and soil science. However, the substantial time investment required for this process often represents a considerable impediment to research progress. The objective of this study is to evaluate and propose a time-saving method to minimize the time required for collecting roots without compromising data integrity compared to traditional approaches. Methods The proposed Sub-sample Approach (SA) requires collecting fine roots from a sub-sample and subsequently leading calculations to estimate total root traits (mass, length, and length distribution among diameters) within the sampled soil core. A comparative analysis was carried out on root harvesting time between meticulous sample cleaning (Conventional Approach, CA) and SA. Moreover, these methods were assessed across different sites including grassland, oak forest, and olive orchard. Results The analysis conducted across many sites resulted in high heterogeneity of processing time when employing the CA (ranging from 2.6 to 27.6 h per sample). Conversely, the adoption of SA reduced processing time and resulted in less variation between samples (ranging from 37 to 112 min per sample). Remarkably, root trait data obtained using SA showed similarity to those obtained through the CA. Conclusion The SA offers a remarkable advantage over the CA by significantly reducing the time needed for root collection from soil core samples. Moreover, SA exhibits lower variability among different collection sites, while maintaining consistency in qualitative and quantitative data compared to the CA.

In 2015, a continuous 15.4 m snow/firn core was recovered from central South Georgia Island at ∼850 m a.s.l. All firn core samples were analyzed for major (Al, Ca, Mg, Na, K, Ti and Fe) and trace element concentrations (Sr, Cd, Cs, Ba, La, Ce, Pr, Pb, Bi, U, As, Li, S, V, Cr, Mn, Co, Cu and Zn) and stable water isotopes. The chemical and isotopic signal is well preserved in the top 6.2 m of the core. Below this depth, down to the bottom of the core, signal dampening is observed in the majority of the elemental species making it difficult to distinguish a seasonal signal. Thirteen elements (As, Bi, Ca, Cd, Cu, K, Li, Mg, Na, Pb, S, Sr and Zn) have crustal enrichment factor values higher than 10 suggesting sources in addition to those found naturally in the crust. While this study shows that 850 m a.s.l. is not high enough to preserve a record including recent years, higher-elevation (>1250 m a.s.l.) glaciers may be likely candidates for ice core drilling to recover better-preserved, continuous, recent to past glaciochemical records.

Ice crystals are mechanically and dielectrically anisotropic. They progressively align under cumulative deformation, forming an ice-crystal-orientation fabric that, in turn, impacts ice deformation. However, almost all the observations of ice fabric are from ice core analysis, and its influence on the ice flow is unclear. Here, we present a non-linear inverse approach to process co- and cross-polarized phase-sensitive radar data. We estimate the continuous depth profile of georeferenced ice fabric orientation along with the reflection ratio and horizontal anisotropy of the ice column. Our method approximates the complete second-order orientation tensor and all the ice fabric eigenvalues. As a result, we infer the vertical ice fabric anisotropy, which is an essential factor to better understand ice deformation using anisotropic ice flow models. The approach is validated at two Antarctic ice core sites (EPICA (European Project for Ice Coring in Antarctica) Dome C and EPICA Dronning Maud Land) in contrasting flow regimes. Spatial variability in ice fabric characteristics in the dome-to-flank transition near Dome C is quantified with 20 more sites located along with a 36 km long cross-section. Local horizontal anisotropy increases under the dome summit and decreases away from the dome summit. We suggest that this is a consequence of the non-linear rheology of ice, also known as the Raymond effect. On larger spatial scales, horizontal anisotropy increases with increasing distance from the dome. At most of the sites, the main driver of ice fabric evolution is vertical compression, yet our data show that the horizontal distribution of the ice fabric is consistent with the present horizontal flow. This method uses polarimetric-radar data, which are suitable for profiling radar applications and are able to constrain ice fabric distribution on a spatial scale comparable to ice flow observations and models.

Wetlands, critical yet vulnerable ecosystems worldwide, are increasingly threatened by contamination from anthropogenic activities. This study investigates the spatial and vertical distribution of 17 major and trace elements in sediment cores from the Anzali International Wetland, a Ramsar site in Iran under pressure from urbanization, agriculture, and industry. Cores were sliced at 2-cm intervals and analyzed via ICP-MS to reconstruct historical trends and evaluate spatiotemporal distributions, sources, and ecological risks using geoaccumulation index (I geo ), enrichment factor (EF), and pollution load index (PLI). Multivariate analyses (PCA, HCA) identified lithogenic (Al, Fe), carbonate-associated (Ca, Sr), and anthropogenic (Cd, Pb, Zn) elemental groupings. Severe Cd contamination (I geo > 5; EF > 40) was found at site 1, linked to industrial/agricultural discharges, while sites 2 and 3 showed moderate heavy metal enrichment. Cd, Cr, and Ni exceeded sediment quality guidelines, indicating significant ecological risk. Vertical profiles revealed contamination peaks at 24–26 cm (Site 1) and 50–62 cm (Site 2), correlating with historical pollutant influx. Sediment texture and organic matter influenced metal binding. PLI confirmed significant pollution (PLI > 3) across all sites, with Cd posing the highest risk. This study underscores the critical role of integrated sediment core analysis in reconstructing pollution history and informing targeted management strategies to protect and restore vulnerable aquatic ecosystems globally.

This study evaluates the novel machine learning based reduction of cross-sections and energy grid of continuous-energy nuclear data for one year full core Monte Carlo criticality and burn-up analysis using OpenMC. The approach modifies OpenMC’s ENDF/B-VII.1 Hierarchical Data Format, version 5 (HDF5) nuclear data files, retaining 10% to 50% of nuclear data for 23 nuclides while preserving thresholds and resonances. EPR and VVER-1000 full core models benchmark reduced nuclear data library against the original (windowed multipole disabled), to quantify performance and fidelity. Wall time decreased by 17.81% in EPR and 42.5% in VVER-1000. Peak memory (MaxRSS) decreased by 4.4% in EPR and increased by 5.0% in VVER-1000. The maximum absolute difference in for VVER-1000 remains within 96.79 pcm at all times. VVER-1000 end of cycle reaction rates relative differences found for U-235 0.0017%, U-238 0.0605%, Xe-135 0.0128%, Sm-149 0.03%. Inventories EOC relative difference were 0.0039% U-235, 0.0003% U-238, 0.0135% Xe-135, 0.0341% Sm-149. The EOC relative difference for the Plutonium vector has been analyzed. Results prove that the developed reduction method accelerates full core analysis, reduces MaxRSS while maintaining fidelity in neutronics studies.

We construct a high‐resolution shear‐wave velocity (VS) model for the uppermost 100 m using ambient noise tomography near the West Antarctic Ice Sheet Divide camp. This is achieved via joint inversion of Rayleigh wave phase velocity and H/V ratio, whose signal‐to‐noise ratios are boosted by three‐station interferometry and phase‐matched filtering, respectively. The VS shows a steep increase (0.04–0.9 km/s) in the top 5 m, with sharp interfaces at ∼8–12 m, followed by a gradual increase (1.2–1.8 km/s) between 10 and 45 m depth, and to 2 km/s at ∼65 m. The compressional‐wave velocity and empirically‐obtained density profile compares well with the results from Herglotz–Wiechert inversion of diving waves in active‐source shot experiments and ice core analysis. Our approach offers a tool to characterize high‐resolution properties of the firn and shallow ice column, which helps to infer the physical properties of deeper ice sheets, thereby contributes to improved understanding of Earth's cryosphere. Plain Language Summary Accurately determining the physical properties of Antarctic ice sheets enhances our understanding of climate change impacts on the Earth's cryosphere and improves sea level rise predictions. The uppermost ∼100 m of ice sheets are often covered by firn, an intermediate material between fresh granular snow and glacier ice. Firn acts as a buffer between the atmosphere and deep ice, playing a critical role in the mass balance, flow, and dynamics of the ice sheet. In this study, we use advanced techniques to measure seismic velocities of the top ∼100 m of the ice sheet and thus characterize the properties of the firn layer. Using a week‐long record of seismic ambient noise, we obtain velocity models that reveal the detailed structure of the firn layer, including rapid velocity increases over depth that indicate rapid changes in compaction and slight lateral velocity variations. These models were validated through favorable comparisons to conventional analyses and ice core records, and can be used to estimate other important ice properties (e.g., density) via empirical relationships. Our approach could easily be up‐scaled to long‐term monitoring of larger areas, to help inform predictive models of ice sheet dynamics. Key Points We denoise fundamental‐mode Rayleigh waves extracted from ambient noise recorded in West Antarctic via three‐station interferometry We improve the quality of Rayleigh wave H/V ratio measurements with phase‐matched filtering The high‐resolution Vs model obtained by jointly inverting phase velocities and H/V ratios reveals high‐resolution firn structures

Direct pore scale simulations of two-fluid flow on digital rock images provide a promising tool to understand the role of surface wetting phenomena on flow and transport in geologic reservoirs. We present computational protocols that mimic conventional special core analysis laboratory (SCAL) experiments, which are implemented within the open source LBPM software package. Protocols are described to simulate unsteady displacement, steady-state flow at fixed saturation, and to mimic centrifuge experiments. These methods can be used to infer relative permeability and capillary curves, and otherwise understand two-fluid flow behavior based on first principles. Morphological tools are applied to assess image resolution, establish initial conditions, and instantiate surface wetting maps based on the distribution of fluids. Internal analysis tools are described that measure essential aspects of two-fluid flow, including fluid connectivity and surface measures, which are used to track transient aspects of the flow behavior as they occur during simulation. Computationally efficient workflows are developed by combining these components with a two-fluid lattice Boltzmann model to define hybrid methods that can accelerate computations by using morphological tools to incrementally evolve the pore-scale fluid distribution. We show that the described methods can be applied to recover expected trends due to the surface wetting properties based on flow simulation in Benntheimer sandstone.

This study presents an integrated formation evaluation of the Middle Miocene syn-rift sandstones of the Hammam Faraun Member from the southern Gulf of Suez. Core data, XRD, wireline logs, and gas chromatography data have been utilized to assess the reservoir characteristics. Three lithofacies are identified from the cored intervals: (i) fine to medium-grained massive sandstone (F-1), (ii) low-angle cross-bedded fine-grained sandstone (F-2); and (iii) coarse to very coarse-grained massive sandstone (F-3). The dominantly massive nature of the sand units with sharp erosive base and bottom rip-up clasts strongly indicates a high energy channel or fan deposit. XRD analysis reveals quartz and feldspar to be the dominant constituents of this calcareous arkose. Montmorillonite and kaolinite are the major clay phases, along with minor illite. Routine core analysis of a total of 168 core plugs indicates meso- to megaporous sandstones with porosity up to 28% and Kh up to 1171 mD. Permeability anisotropy analysis exhibits the dominance of primary depositional fabric and isotropic pores. Wireline log analysis yielded shale volume < 0.2 v/v, porosity ~ 0.18–0.24 v/v, and water saturation ~ 0.33–0.49 v/v. Various gas ratios (wetness, balance, character, and oil indicator ratio) estimated from the chromatograph data indicate the presence of liquid hydrocarbons within the studied reservoirs. The study concludes excellent reservoir properties in the Hammam Faraun clastic intervals of the Esh El Mellaha area.HighlightsHammam Faraun reservoirs consist of meso-megaporous calcareous arkose.Massive sands with sharp erosive base and bottom rip-up clasts indicates a high energy tidal deposit.Wireline logs indicate poor shale volume and considerable hydrocarbon saturation.Gas chromatography data confirms the presence of liquid hydrocarbon.