Preprints
There are 7981 Preprints listed.
Dehydration of Serpentinized Ultramafic Rocks as a Candidate Deep Crustal Source of Natural Hydrogen and Hydrocarbons: Experimental Evidence from the Lesser Caucasus
Published: 2026-10-29
Subjects: Earth Sciences, Geology, Geophysics and Seismology
Natural hydrogen generated by serpentinization — the hydration of ultramafic rocks, in which ferrous iron is oxidised and molecular hydrogen is liberated from water — has recently been shown to proceed at rates of only 0.1 to 0.5 tonnes H₂ yr⁻¹ km⁻³ of reactive rock, implying that economically significant accumulations would require 10³ to 10⁴ years to develop [1]. A complementary process [...]
Late Paleocene leaf macroflora from a destroyed outcrop of the Marcelina Formation, Paso Diablo Mine, Venezuela: a rescue record
Published: 2026-10-29
Subjects: Earth Sciences, Geology, Other Plant Sciences, Paleobiology, Paleontology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
In 2016, a production blast at a mining face of the Paso Diablo Mine (Guasare Basin, northwestern Venezuela) exposed a level rich in fossil leaves of the Marcelina Formation (late Paleocene), located between coal seams 4O and 4M. The material was removed as overburden by a mining shovel a few hours after it was documented. We present the first published record of leaf macroflora from this [...]
Post-processing Subglacial Physics Model with Per-site JEPA Specialist Models Enable Natural-language Glaciological Intelligence
Published: 2026-10-29
Subjects: Physical Sciences and Mathematics
Glaciers slide over their beds, and how fast they slide depends on the pressure of meltwater trapped beneath them. This subglacial environment is nearly impossible to observe directly and is one of the largest uncertainties in how fast glaciers lose ice and how much water they deliver to communities downstream. Ice-sheet models represent it with empirical rules that are hard to test, and although [...]
Role of Topo-Climatic Factors in Landslide Susceptibility Mapping: A Machine Learning Perspective
Published: 2026-10-29
Subjects: Engineering
With the rapid growth of machine learning (ML) applications in landslide susceptibility mapping (LSM), many studies have relied on large and diverse datasets to improve predictive performance. However, in data-scarce regions, model transferability becomes challenging, and not all input variables contribute meaningful information to landslide prediction, leading to the well-known problem of [...]
Satellite Quantification of Methane Emissions from Individual Countries in Southeast Asia: Roles of Dry and Wet Seasons
Published: 2026-10-29
Subjects: Physical Sciences and Mathematics
Southeast Asia is a global methane (CH4) hotspot, yet its emissions remain highly uncertain particularly regarding seasonal variability. Here we quantify methane emissions over ten Southeast Asian countries using TROPOMI satellite observations and analytical inversions at up to 0.25°×0.3125° resolution (~25km×25km), separately for the dry (October 2021-April 2022) and wet (May-September 2022) [...]
How Rural Is Rural? Agreement Between the FARS Rural/Urban Label and 2020 Census Urban Areas for U.S. Traffic Deaths, 2015–2024
Published: 2026-10-29
Subjects: Geographic Information Sciences, Spatial Science, Transportation Engineering
U.S. rural road safety statistics, including the National Highway Traffic Safety Administration’s annual rural/urban fatality reports, classify each fatal crash by the rural/urban variable (RUR_URB) in the Fatality Analysis Reporting System (FARS). Population research, in contrast, usually defines rural with the Census Bureau’s urban areas. We measure how well the two definitions agree for every [...]
Stock to crop? Quantifying agricultural expansion in northern Australia and examining its drivers
Published: 2026-10-29
Subjects: Physical Sciences and Mathematics
In recent decades, local, state, and federal governments have actively promoted irrigation and rainfed cropping expansion as a pathway to regional economic development for inland northern Australia (INA). This has created tension and competing narratives about development in the region. This study seeks to ground discussion in observed patterns of change by synthesising the cropping, horticulture [...]
Protracted Dyking of High-Viscosity Magma into Near-Solidus Rock at Casiri, Peru
Published: 2026-10-29
Subjects: Earth Sciences, Physical Sciences and Mathematics
Dykes are a key mechanism for material transport within volcanic arcs and typically propagate over days to months. We document an unusually slow dyking episode in the arc of southern Peru that lasted for 1.5 years. The dyke opened up to 0.5 m from 2-8 km depth and was coupled with inflation of an underlying arc-parallel magma reservoir. To reconcile the slow opening of such a thin dyke with [...]
Characterising Methane Concentration Variability at Coal Stockpiles in a Surface Coal Mine
Published: 2026-10-29
Subjects: Engineering, Physical Sciences and Mathematics
The spatiotemporal variability of atmospheric methane concentration at surface coal mines remains insufficiently characterised. The impact of local meteorology and mining activities on methane emission have not yet been fully evaluated. In this study, ground observations of the methane concentration along with meteorology were carried out around coal stockpiles (CSP) in an active surface coal [...]
Apatite inclusions in zircon reveal a crustal origin for HREE depletion in Archean granitoids
Published: 2026-10-29
Subjects: Physical Sciences and Mathematics
Reconstructing the geodynamic conditions of the Hadean and Archean is essential for understanding Earth’s evolution and the conditions that ultimately enabled life to emerge. Archean tonalite–trondhjemite–granodiorite (TTG) suites have been studied extensively because their evolved compositions provide clues to the processes that formed the early continental crust. Their trace-element signatures, [...]
Triple oxygen isotope equilibrium between calcite and water: new constraints over 8–200 °C and their metrological implications
Published: 2026-10-29
Subjects: Earth Sciences, Geochemistry, Physical Sciences and Mathematics
High-precision measurements of carbonate oxygen-17 compositions are increasingly used for studying paleo-environments, hydrology, diagenesis, or biomineralization processes. Calibrating triple oxygen isotope equilibrium fractionations between calcite and water as a function of temperature provides a critical baseline for many applications. Here we report new observations constraining these [...]
Structure Function Sampling Uncertainty: A Gaussian-Increment Reference Framework
Published: 2026-10-29
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology
Structure functions (SFs) are widely used to characterize scale-dependent variability in geophysical fields, but their sampling uncertainty is difficult to quantify because pairwise increments are generally dependent. Dependence arises from both shared observations and spatial covariance of the underlying field, so pair counts alone do not determine uncertainty. The sampling variance is governed [...]
Decompression, self-leveling, and wobble decay of bubble rings released by scuba divers
Published: 2026-10-29
Subjects: Dynamic Systems, Fluid Dynamics, Oceanography, Ordinary Differential Equations and Applied Dynamics
Scuba divers blow bubble rings, hollow vortex rings with a gas core that expands as the ring rises because the water pressure drops with every meter of ascent. Classical theory keeps the gas volume fixed and treats only level rings, and the one earlier estimate of the expansion, for a laboratory tank, found it small. Here the ring is modeled as a thin hollow vortex ring with a core that obeys [...]
Forward-testing mineral prospectivity models with discovery dates: Quebec graphite and nickel
Published: 2026-10-28
Subjects: Geology, Mining Engineering
Mineral prospectivity models are usually evaluated with spatial cross-validation, but known occurrences cluster around past exploration, so this may measure performance within the explored footprint rather than the ability to rank later discoveries. We trained seven prospectivity models on graphite and nickel occurrences known in Quebec, Canada, before 2000 and tested how they ranked cells with [...]
Drivers of The Daggers: Backstress-triggered fracture propagation on the Thwaites Eastern Ice Shelf, West Antarctica
Published: 2026-10-28
Subjects: Physical Sciences and Mathematics
The destabilization of ice shelves around Antarctica is not just a sea-level-rise priority, but an opportunity to observe and understand the mechanisms of ice-shelf failure. Recent studies show that ice shelves fail against their pinning points or ridges once sufficiently weakened by thinning and damage---a "backstress-triggered" failure mechanism that is not represented in ice-shelf collapse [...]