Preprints
There are 6976 Preprints listed.
Subduction-driven mantle flow beneath and around the Philippine Sea Plate from seismic anisotropy
Published: 2025-12-09
Subjects: Physical Sciences and Mathematics
Shear-wave splitting illuminates mantle flow and subduction zone dynamics but is typically inferred near stations or earthquakes, limiting studies in sparsely instrumented regions away from earthquakes. Where stations or earthquakes are present, fast splitting directions are often parallel to the nearest trench, which has yet to be fully understood and reconciled with geodynamic flow predictions. [...]
A proposal for a horizontal vector approach in 3D electrical resistivity tomography and its associated geometric factor
Published: 2026-04-22
Subjects: Physical Sciences and Mathematics
Electrical resistivity tomography (ERT) is commonly implemented with collinear electrode arrays that measure only electric-field components along the survey line, neglecting horizontal variations in other directions. While this limitation is acceptable in 2D ERT, it can be significant in 3D settings with complex geometry and strong resistivity contrasts. To address this issue, we propose an [...]
Scale-dependent controls on forest carbon uptake across hydroclimatic extremes
Published: 2026-04-29
Subjects: Climate, Environmental Monitoring, Forest Sciences, Sustainability
Conifer forests span some of the most climatically contrasting environments on Earth, from energy-limited Boreal systems to water-limited semi-arid ecosystems. Whether their carbon uptake is governed by universal drivers or by site-specific boundary conditions remains unresolved. Using more than two decades of eddy-covariance and multi-depth soil moisture measurements from two climatic [...]
Erosion-driven changes in soil cation exchange capacity quantified using barium isotopes
Published: 2026-04-22
Subjects: Biogeochemistry, Earth Sciences, Geochemistry, Geomorphology, Physical Sciences and Mathematics, Soil Science
Human activities have perturbed the balance between rates of soil erosion and formation, driving declines in soil quality. However, quantifying these soil imbalances remains challenging, especially at large scales. Here we present a novel isotope mass balance approach that can be used to quantify river catchment wide rates of change in cation exchange capacity (CEC), a key soil quality metric, in [...]
Mesozoic ocean plate stratigraphy reveals a Franciscan plate separating Farallon and North America
Published: 2026-04-22
Subjects: Physical Sciences and Mathematics
Ocean plate stratigraphy preserved in the Franciscan Complex recorded the Mesozoic plate tectonic evolution of the North American Cordillera and eastern Pacific basin. New and published ocean floor and accretion ages for Jurassic–Cretaceous oceanic crust, derived from detrital zircons and radiolarians, indicate that eastward younging ocean floor existed between the Farallon and North American [...]
Living on the Edge: Unequal Rise of Global Population Exposure on Steep Terrain
Published: 2026-04-30
Subjects: Environmental Sciences, Sustainability
The global population living on steep terrain is rising, so is their landslide risk. However, hotspots and driving mechanisms of increasing exposure remain poorly understood. We assess changes in global gridded population and settlement characteristics on steep terrain (≥ 10◦ hillslope inclination) aggregated over topographic catchments (mean area ∼10,000 km2) for 1975–2025. We find that about [...]
Paleoarchean seawater and seafloor hydrothermal processes: insights from 3.5 to 3.3 Ga carbonate geochemistry
Published: 2026-04-13
Subjects: Life Sciences, Physical Sciences and Mathematics
Carbonates (3.5 to 3.3 Ga) in the East Pilbara Terrane (EPT), Western Australia, including interstitial carbonate between pillow basalts, fracture-filling calcite, sedimentary carbonates and carbonate associated with stromatolites, provide valuable geochemical archives for reconstructing Early Earth environments. This study highlights three key findings: (1) Fracture-filling calcite D-2-W from [...]
Geospatial Machine Learning for Predicting Flash Flood Response at Ungauged Appalachian Watersheds: Terrain, Soil, and Land Cover Controls
Published: 2026-04-14
Subjects: Physical Sciences and Mathematics
Flash floods remain among the deadliest weather hazards in the United States, yet the majority of flood-prone watersheds in the Appalachian region lack streamflow monitoring. Predicting flood response characteristics at these ungauged sites requires understanding which landscape properties control hydrologic behavior. This study evaluates whether geospatial basin descriptors derived from [...]
Anthropogenic acceleration of the leaky nitrogen cycle across the global land-river continuum
Published: 2026-04-13
Subjects: Life Sciences
Lateral nitrogen transfer (LNT) along the land-river continuum plays a critical role in regulating global nitrogen (N) cycling and its feedbacks to climate, yet it remains poorly represented in land surface models. Here, we incorporate LNT into a global land surface model within an Earth System Model framework, enabling a process-based quantification of N transport, transformation, and associated [...]
Settling and Rising Dynamics of River Litter
Published: 2026-04-22
Subjects: Engineering, Life Sciences, Physical Sciences and Mathematics
Global assessments of river litter transport, accumulation, and export to the oceans remain constrained because the particle-scale hydrodynamic variables governing litter movement are currently unknown. We resolve this by explaining the vertical dynamics of full-scale river litter in quiescent water through multi-camera, three-dimensional trajectory reconstructions of over a thousand litter items [...]
Airborne imaging spectrometer measurements of methane releases under turbulent conditions
Published: 2026-04-24
Subjects: Earth Sciences, Environmental Sciences, Other Earth Sciences, Physical Sciences and Mathematics, Physics
Methane plume detection and quantification from airborne and spaceborne platforms offers a promising approach for monitoring localized greenhouse gas emissions. Its performance must be demonstrated under realistic but controlled conditions. An airborne demonstrator of a compact shortwave infrared imaging spectrometer developed for the AIRMO Earth observation mission was therefore evaluated during [...]
Increasing Floods and Intensifying Droughts: The Future of Hydrological Extremes in a Warming Climate
Published: 2026-04-13
Subjects: Hydrology, Water Resource Management
Understanding how climate change alters the frequency and severity of hydrological extremes is critical for anticipating regional vulnerabilities and guiding adaptation. In this study, we analyze changes in the magnitude, intensity, and duration of extreme streamflow events, both floods and droughts, under RCP4.5 and RCP8.5 scenarios using the FutureStreams dataset. This dataset, driven by [...]
Green Hydrogen: The Future Prospect for Nepal's Energy Sector
Published: 2026-05-17
Subjects: Engineering
Nepal possesses an immense technically and economically feasible renewable energy potential of 45,000 MW, yet its current energy consumption remains heavily dominated by traditional sources and imported carbon-based fuels, driving a massive national trade deficit. This study investigates whether green hydrogen, produced using surplus hydroelectricity, serves as a viable prospective pathway toward [...]
Closing the Duration Gap in RVT: The Energetic Duration
Published: 2026-04-29
Subjects: Civil and Environmental Engineering, Engineering
Duration is a fundamental descriptor of earthquake ground motion, yet it remains ill-defined across engineering seismology, with numerous threshold-based measures adopted for specific applications. This ambiguity has allowed duration to function as a calibration parameter in analyses such as random vibration theory (RVT), where it is often adjusted to match observed response spectra. This paper [...]
First-principles theory for Earth's tropical-midlatitude climate boundary
Published: 2026-04-22
Subjects: Physical Sciences and Mathematics
In Earth's climate, the boundary between the tropics and midlatitudes is a key determinant of temperature and precipitation characteristics, influencing human societies through daily weather, atmospheric chemistry, carbon cycling, and vegetation distribution. The physical origin of these climate zones has been investigated through idealized simulations, observations, and state-of-the-art climate [...]