Preprints
There are 6204 Preprints listed.
Geochronology of Taung and other southern African australopiths
Published: 2025-10-05
Subjects: Physical Sciences and Mathematics
One century after the Taung juvenile’s discovery, its age and that of many other southern African australopiths remains unknown. This lack of accurate geochronological constraints leaves important questions unanswered, including the temporal relationship between the South African fossil sites and their well dated eastern African counterparts. Previous age estimates for the Taung fossil range from [...]
Transformer Assisted U-Net for Marine Litter Detection on Sentinel-2 Imagery
Published: 2025-10-05
Subjects: Environmental Monitoring
The contamination of marine environments with man-made litter is a growing nation-wide concern. Satellite imagery combined with deep learning–based detection models has emerged as a robust and cost-effective solution for large-scale marine litter monitoring. In this article, we present a novel deep learning-based scheme to detect marine litter using Sentinel-2 imagery based on the Deep UNet [...]
A Field Study on Background Radiation Variability with Elevation in Eastern Nepal
Published: 2025-10-03
Subjects: Earth Sciences, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Physics
This research investigates how environmental radioactivity varies with altitude in the diverse landscapes of Eastern Nepal. Employing two calibrated Geiger–Müller (GM) counters, background radiation was recorded as counts per minute (cpm) across selected sites in the districts of Dhankuta, Panchthar, Taplejung, and Ilam. Data were geo- referenced using GPS to correlate radiation levels with [...]
Ecosystem extent mapping in a global monitoring context
Published: 2025-10-03
Subjects: Environmental Indicators and Impact Assessment, Geographic Information Sciences, Natural Resources and Conservation, Natural Resources Management and Policy, Other Ecology and Evolutionary Biology, Remote Sensing, Spatial Science, Sustainability
The vital role of ecosystems in maintaining biosphere stability is now recognised globally. Updates in policy frameworks on biodiversity and environmental decline include information on ecosystem extent (EE) as a core assessment indicator, e.g., the Global Biodiversity Framework indicator A2 ‘Extent of natural ecosystems’. The recently proposed System of Environmental-Economic Accounting – [...]
Accessible Climate and Impact Model Output for Studying the Human and Environmental Impacts of Nuclear Conflict
Published: 2025-10-03
Subjects: Agriculture, Earth Sciences, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology
Nuclear winter refers to the suite of physical and biological consequences that may follow nuclear conflict, particularly the cooling and darkening of Earth’s surface due to black carbon soot in the upper atmosphere. While the associated changes in temperature, precipitation, and food system productivity have been the subject of climate modeling for decades, the outputs of models used to project [...]
Unified Granular Intrusion Dynamics for Planetary Materials
Published: 2025-10-02
Subjects: Physical Sciences and Mathematics
Granular friction μ is a sensitive and poorly understood function of packing fraction ϕ. Every granular material has a distinct critical volume fraction ϕc that delineates two mechanical deformation modes – compaction for ϕ < ϕc, and dilation for ϕ > ϕc. Here we examine the relation(s) between friction and packing fraction, using quasi-static penetration tests in materials ranging from [...]
Worldwide inference of national methane emissions by inversion of satellite observations with UNFCCC prior estimates
Published: 2025-10-01
Subjects: Atmospheric Sciences, Environmental Engineering
Meeting climate policy goals to reduce methane emissions under the Paris Agreement and the Global Methane Pledge requires nations to set targets and quantify reductions. Individual countries report emissions by sector to the United Nations Framework Convention on Climate Change (UNFCCC) but there are large uncertainties. Here we optimize 2023 national emissions at up to 25 km grid resolution for [...]
Rapid increase of climate extremes across northern Amazonia
Published: 2025-10-01
Subjects: Environmental Sciences, Physical Sciences and Mathematics
Amazonia’s exceptional biodiversity, cultural significance, and ecosystem services make it pivotal to global and regional sustainability. However, the region is increasingly threatened by climate extremes, which exacerbate the effects of land use change (Barlow et al., 2018) and bring about abrupt changes in social and ecological condition (Bennett et al., 2023; Berenguer et al., 2021; Campanharo [...]
Estimating Stability Constants and Entropy for Reactions Between Aqueous Metal Ions and Monovalent Oxygen-Bearing Ligands: Applications to Hydrothermal Metal–Organic Acid Systems
Published: 2025-10-01
Subjects: Life Sciences, Medicine and Health Sciences, Physical Sciences and Mathematics
Linear free energy relations were obtained from existing experimental data and used to estimate stability constants for over 16,000 metal complexes with monovalent oxygen-bearing ligands comprising 75 metal species and 220 ligands. Similar relationships for metal-ligand entropy of association were also obtained which facilitate computation of stability constants from 0 to 125°C for over 6000 [...]
Climate Change Projections for the Central Peruvian Coast (2006–2100) Using CMIP5 Models: Agricultural Impacts and Implications for the Growth of Chenopodium quinoa Willd in Arid Zones
Published: 2025-10-01
Subjects: Agriculture
We evaluated climatic data for the central coastal region of Peru (Lima) as simulated by the climate models used in the Coupled Model Intercomparison Project Phase 5 (CMIP5). The models were: MIROC-ESM, CSIRO Mk 3.6, CNRM-CM5, GFDL-CM3, IPSL-CM5A-MR, and MPI-ESM-LR, with respective spatial resolutions of 2.81° × 1.77°, 1.875° × 1.86°, 1.4° × 1.40°, 2.5° × 2.0°, 2.5° × 1.27°, and 1.875° × 1.875°. [...]
Biomineralisation for Sustainable Ecotoxic Metal Immobilisation via Enzyme Induced Carbonate Precipitation
Published: 2025-10-01
Subjects: Engineering, Physical Sciences and Mathematics
Heavy metal contamination of water presents a critical global challenge driven by the persistence and toxicity of elements such as arsenic, cadmium and lead. Conventional remediation strategies, such as Enzyme-Induced Carbonate Precipitation (EICP), typically rely on commercial urease and a multi-step extraction process, which increases energy demand, generates ammonium byproducts, and requires [...]
From Complex SDG Systems to Network Models: an Ontology-Based Eight-Step Framework
Published: 2025-10-01
Subjects: Earth Sciences, Environmental Studies, Sustainability
With only 18% of Sustainable Development Goals (SDGs) on track for 2030, systems-based approaches to understanding their interdependencies are essential. Network science can reveal leverage points and guide prioritisation, yet it is often applied without sufficient domain integration, obscuring rather than clarifying sustainability dynamics. We present an eight-step framework for evaluating [...]
Trees and Life, Heat and Death: Integrating Temperature and Green Spaces with Social Determinants of Health in Hamilton, Ontario, Canada.
Published: 2025-10-01
Subjects: Medicine and Health Sciences, Physical Sciences and Mathematics
Objectives Climate change has wide-reaching implications for planetary and human health; one of its rising impacts is deaths related to extreme heat. This study attempts to integrate remotely sensed measures of temperature and greenness into the methodology of Code Red, a study examining the relationship between health and a variety of social determinants in Hamilton, Ontario, Canada, initially [...]
Mechanisms of Lithospheric Dripping in Earth’s Convecting Mantle: Implications for Tectonic Switching
Published: 2025-10-01
Subjects: Earth Sciences, Tectonics and Structure
Gravity-driven dripping is a key recycling process of lithospheric materials into the underlying mantle reservoir. Here, we use 2D computational fluid dynamic (CFD) thermo-chemical simulations to unveil how such dripping process occurs by modulating the thermal convection in Earth’s mantle. Our simulations incorporate the following variables: lithospheric buoyancy contrasts (B), metamorphic [...]
Development of a Coupled Hydro-Economic Model to Support Groundwater Irrigation Decisions
Published: 2025-09-30
Subjects: Physical Sciences and Mathematics
Groundwater sustains global agriculture but faces significant pressure from overexploitation, threatening long-term water security. Achieving a balance between agricultural productivity and sustainable groundwater use requires decision-support tools that are both practical and robust. This study develops an accessible farm-level hydro-economic model that integrates groundwater dynamics with [...]