Preprints
There are 6789 Preprints listed.
Modeling PDC cutter-rock interactions using finite discrete element method for geothermal drilling applications
Published: 2026-04-09
Subjects: Earth Sciences, Physical Sciences and Mathematics
Polycrystalline diamond compact (PDC) cutters are used in geothermal energy drilling operations as they are exceptionally effective due to their strength and resistance to abrasion. It is important to understand the effect of downhole conditions to accurately model rock-cutter-rock interactions, as well as wear on the bit and drilling efficiency. Cutting efficiency is determined through the [...]
Automated Detection of Slow Slip Events from InSAR: Application to the North Anatolian Fault
Published: 2026-04-09
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
The growing volume of InSAR time series offers new opportunities to systematically detect transient aseismic deformation, but identifying low-amplitude slow slip events (SSEs) remains challenging due to noise and limited temporal resolution. Here, we adapt the geodetic matched filter, originally developed for GNSS data, to InSAR displacement time series in the context of shallow strike-slip [...]
PharmGuard: A blockchain and LLM-integrated framework with provenance-aware anomaly scoring for securing pharmaceutical supply chains
Published: 2026-04-09
Subjects: Computer Engineering
Counterfeit and substandard medicines remain a major global health threat, underscoring the need for end-to-end traceability and proactive monitoring across pharmaceutical supply chains. This paper presents PharmGuard, a framework that combines a permissioned blockchain ledger (Hyperledger Fabric) for tamper-evident provenance with a large-language-model analytics layer for detecting anomalous [...]
Paleomagnetic data from the Qaidam Block quantify post-middle Triassic convergence preceding eastern Eurasian assembly
Published: 2026-04-09
Subjects: Geology
Amalgamation of East Asian blocks with Eurasia involved progressive closure of several oceanic basins preserved as sutures. Since the Permian, the North China Block has undergone ~2500 km of paleolatitudinal motion relative to Eurasia, forming Mongol–Okhotsk suture in the north. Surprisingly, no evidence in its western part has been found to coordinate this motion, which is essential for a triple [...]
Quantifying the Regional Dynamics and Redistribution of Physical Vulnerability in Least Developed Countries
Published: 2026-04-09
Subjects: Categorical Data Analysis, Civil Engineering, Environmental Indicators and Impact Assessment, Environmental Monitoring, Geographic Information Sciences, Other Computer Sciences, Physical and Environmental Geography, Remote Sensing, Spatial Science, Structural Engineering
In the margins of the accelerating development of digital technology worldwide are the Least Developed Countries (LDCs), which continually face an exacerbated risk crisis at the intersection of rapid rural-urban growth, persistent physical vulnerability, and intensifying climate hazards. Despite decades of international development commitments, the rate of built-up expansion across LDCs has [...]
Simulation of Groundwater Flow To Evaluate Hydrogeologic Controls on a PFAS Plume, Coakley Landfill Superfund Site, Rockingham County, New Hampshire
Published: 2026-04-09
Subjects: Earth Sciences, Environmental Health and Protection, Environmental Sciences, Geology, Hydrology, Physical Sciences and Mathematics, Water Resource Management
Per- and polyfluoroalkyl substances (PFAS), including perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), have been detected at combined concentrations above 2,000 nanograms per liter (ng/L) at groundwater seep locations near the Coakley Landfill Superfund site, in North Hampton, New Hampshire. The landfill was active from 1972 to 1985. An impermeable cap was placed on the [...]
Geochemical and granulometric fingerprints of 8,200-year Westerly variability recorded in inner-fjord lake sediments from Central Svalbard
Published: 2026-04-09
Subjects: Earth Sciences, Environmental Sciences, Physical Sciences and Mathematics
The Arctic is warming faster than any other region on Earth. As sea-ice diminishes, surface boundary conditions (roughness and air-sea coupling) change and open-water fetch increases, potentially strengthening the effective wind forcing on Arctic coasts. These changes can be recorded in lake sediments through the deposition of wind-blown grains and elements, offering insights into past wind and [...]
Natural organic matter coating changes the role of iron oxides in carbon preservation in marine sediments
Published: 2026-04-08
Subjects: Biogeochemistry
Preservation of organic carbon (OC) in marine and terrestrial depositional settings is enhanced by the association between OC and reactive iron oxides. However, microbially mediated iron reduction in anoxic marine sediments may lead to the reductive dissolution of iron oxides and consequently to the remobilization of iron-associated organic matter. The underlying mechanism remains poorly studied. [...]
Seasonal Shift in the Dominant Pathway Energizing Mesoscale Eddies in the California Current
Published: 2026-04-08
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Mesoscale eddies are the dominant reservoir of kinetic energy in the ocean, yet the mechanisms that generate and maintain them in eastern boundary current systems remain incompletely assessed. Here we use a 1-km resolution simulation of the California Current System (CCS) to diagnose and quantify the processes that supply kinetic energy to the mesoscale band. A pronounced seasonal transition is [...]
Introducing Microalgae Carbon Fixation and Sinking (MCFS): a new approach for controlled and scalable CDR
Published: 2026-04-08
Subjects: Biogeochemistry, Climate, Oceanography, Other Oceanography and Atmospheric Sciences and Meteorology
Achieving global climate targets requires scalable and durable carbon dioxide removal (CDR) technologies to tackle both historical and hard-to- abate emissions. We introduce Microalgae Carbon Fixation and Sinking (MCFS), a marine CDR methodology designed to enhance carbon fixation and export to the deep ocean through a controlled process. At the core of the MCFS approach is a tailored substrate: [...]
Balancing Food Production and Environmental Sustainability in Ethiopian Agriculture: A Systematic Review
Published: 2026-04-08
Subjects: Environmental Studies
Ethiopia faces the dual challenge of increasing food production for a rapidly growing population while preserving the natural resource base that sustains its agricultural systems. This systematic review synthesizes evidence from 130 peer-reviewed studies published between 2010 and 2025 to examine the relationship between agricultural productivity and environmental sustainability in Ethiopia. [...]
Changing the Chilly Climate: Observations on Gender Diversity and Inclusion at a Geoscience Conference in the Netherlands
Published: 2026-04-08
Subjects: Earth Sciences, Environmental Sciences, Higher Education, Social and Behavioral Sciences
The aim of this study was to observe audience participation in a conference where the planned structures (presenters, keynotes and chairs) had an equal gender balance. The collected data can give an indication of the effectiveness of diversity and inclusion initiatives beyond the planned structures of the conference itself. We observed behaviours of attendees of the annual Dutch Earth and [...]
Longitudinal stress induced by basal slippery patch
Published: 2026-04-07
Subjects: Physical Sciences and Mathematics
Supraglacial lake drainages create spatially finite regions of reduced basal friction, slippery patches, at the ice-bed interface that perturb local stresses in the overlying ice, potentially sufficiently to trigger cascading hydrofracture-driven lake drainage events. We derive analytical solutions for the perturbed stress response to such slippery patches using the shallow shelf approximation [...]
Closure of Constraints in the Earth System: Biogeochemical Cycles and Planetary-Scale Biological Organisation
Published: 2026-04-06
Subjects: Earth Sciences, Life Sciences, Systems Biology
The concept of closure of constraints has been developed as a characterization of the distinctive causal regime at work in biological systems. Its extension to ecological systems has been attempted but faces persistent difficulties regarding the individuation of ecosystems and the scope of functional ascription. Meanwhile, the question of the biological character of the Earth system (variously [...]
First Characterisation of P-band Scattering Mechanisms from Orbit in Lower Shire Valley, southern Malawi, using ESA Biomass Imagery
Published: 2026-04-06
Subjects: Earth Sciences, Terrestrial and Aquatic Ecology
The European Space Agency (ESA) Biomass mission provides the first spaceborne fully polarimetric P-band synthetic aperture radar (SAR) observations in orbit. Here, we report the first characterisation of P-band scattering mechanisms over the Lower Shire Valley (LSV) floodplain, southern Malawi. A single quad-polarimetric acquisition, collected at the onset of the rainy season in November 2025, [...]