Preprints
There are 7329 Preprints listed.
Detecting illegal water abstractions using Earth Observation and artificial intelligence: challenges, research gaps, and future directions
Published: 2026-07-28
Subjects: Artificial Intelligence and Robotics, Environmental Monitoring, Hydrology, Natural Resources Management and Policy, Remote Sensing, Water Resource Management
Water scarcity and unsustainable withdrawals are major environmental challenges, particularly in semi-arid and Mediterranean regions where agriculture places strong pressure on limited hydrological resources. Illegal or unreported water abstractions intensify these pressures by undermining ecosystem stability, policy compliance, and long-term water security. Although Earth Observation (EO) and [...]
Thermal migration and climatic de-territorialisation of North American professional sports leagues, 1950–2025
Published: 2026-07-28
Subjects: Geographic Information Sciences, Nature and Society Relations, Physical and Environmental Geography
Over the past seven decades, the four major North American professional sports leagues (NHL, MLB, NBA, NFL) have expanded and relocated across the continent, shifting their collective geography towards the Sun Belt. We quantify the climatic consequences of this movement by combining the complete franchise location history of the four leagues from 1950 to 2025 with ERA5-Land reanalysis data and [...]
SCI-OBS: Detection and Classification of People on the Beach and in the Surf Zone
Published: 2026-07-28
Subjects: Environmental Monitoring, Natural Resources Management and Policy, Oceanography, Remote Sensing
Understanding how many people use beaches and surf zones is vital for safety, tourism, and coastal management. Traditional manual headcounts are time-consuming and inconsistent, while existing automated systems often fail in complex conditions due to glare, waves obstructing the view, and the small apparent size of distant subjects. We present SCI-OBS, an automated multi-class detector deployed [...]
Using tectonic block modeling to quantify the impact of potentially–active faults on seismic hazard and risk in western Canada
Published: 2026-07-28
Subjects: Tectonics and Structure
In order to understand the impact of large, potentially active faults on seismic hazard and risk in western Canada, faults in the region are characterized using a geodetic-geologic block model. The results are then integrated into Canada's existing national seismic hazard and risk models. To do this, potentially active faults are mapped to build a block model around them; then, several thousand [...]
Trigger or driver? Tracing the role of climate variability since the Little Ice Age in the abandonment of mountain villages in the Eastern Pyrenees: evidence from historical documents
Published: 2026-07-28
Subjects: Environmental Studies
In recent decades, rural depopulation has emerged as a widespread phenomenon across much of Europe, driven by shared underlying processes but shaped by region-specific dynamics. Understanding how climate variability interacts with socioeconomic dynamics to drive long-term settlement abandonment is critical in the context of current global change. High-mountain regions are particularly sensitive [...]
Effective Microbial Kinetics under Pore-Scale Transport Limitation: A Biofilm Effectiveness-Factor Theory
Published: 2026-07-27
Subjects: Biogeochemistry, Earth Sciences, Physical Sciences and Mathematics
Reactive-transport models of porous media usually evaluate microbial reactions with Monod kinetics and rate constants measured on well-mixed laboratory cultures, in which every cell is exposed to the same substrate concentration. In natural sediments and aquifers this assumption fails at the pore scale, because the cells are not suspended but reside in biofilms and aggregates attached to the [...]
Connectivity effects on fluid age and residence time distributions in two- and three-dimensional pore networks
Published: 2026-07-27
Subjects: Biogeochemistry, Earth Sciences, Hydrology, Physical Sciences and Mathematics
Pore-scale simulations are often run on a single plane cut from a three-dimensional image, because resolving the whole pore space is expensive. This study asks what that shortcut costs. What is at stake is the distribution of fluid ages, and above all its long tail, because that tail is what slow reactions respond to. We computed the distribution directly from the flow field, by labeling the [...]
Rapid SRO aluminosilicate formation in a narrow pH interval fractionates silicon isotopes
Published: 2026-07-27
Subjects: Earth Sciences, Geochemistry, Soil Science
Short-range ordered (SRO) hydrous aluminosilicates (HAS) are among the earliest secondary phases formed during incongruent silicate weathering, yet the timescales and silicon isotope (δ30Si) fractionation associated with their initial formation remains poorly constrained. We use stepwise room temperature NaOH titration to resolve pH buffering, Si–Al removal, and dissolved δ30Si evolution in two [...]
Reconstructing age and reactivity distributions from the moments carried by central-moment transport models
Published: 2026-07-26
Subjects: Biogeochemistry, Earth Sciences, Hydrology, Physical Sciences and Mathematics
A central-moment transport model follows a property that varies across a population, such as the age of water parcels or the decay rate of organic-matter particles. Instead of storing the whole distribution of that property, it keeps only a few summary numbers, the moments, and moves those through the model. But the distribution itself is usually what a scientist wants, so it has to be rebuilt [...]
Southeast African mangroves: an exceptionally young paleobotanical record
Published: 2026-07-26
Subjects: Paleobiology, Paleontology
Mangroves are pantropical intertidal forests that maintain coastal biodiversity, provide a wide range of ecological services and represent the most efficient blue-carbon ecosystems for mitigating global warming. A recent global initiative aims to reconstruct the historical biogeography of mangroves using comprehensive paleobotanical datasets from biogeographically coherent regions. This approach [...]
Open at the interface, closed at the core: neutrality claims in AI‑enabled geoscience infrastructure focusing on Africa – The case of Deep‑Time Digital Earth and GeoGPT
Published: 2026-07-25
Subjects: Earth Sciences, Geology
Geological data has become strategic infrastructure for resource assessment, investment negotiation, and economic sovereignty. Remotely hosted big data and Artificial Intelligence (AI) platforms are increasingly promoted for geoscience in the Global South, particularly Africa. Whether such platforms are genuinely geopolitically unaligned, and how this can be verified, has direct implications for [...]
Microseismic Detection in Borehole DAS as a Spatial Localization Problem: Cross-System Validation at the 2024 Utah FORGE Stimulation
Published: 2026-07-25
Subjects: Geophysics and Seismology, Physical Sciences and Mathematics
Distributed acoustic sensing (DAS) turns borehole fibers into dense seismic arrays, but converting terabytes of continuous strain-rate data into reliable real-time detections remains a bottleneck for induced-seismicity monitoring. We argue that the limiting question for DAS microseismic monitoring has been posed incorrectly. Existing detectors ask whether an event is present in a record; on a [...]
Reliability-Constrained Statistical Analysis of NASA CNEOS Fireball Events: Implications for Bolide Population Studies
Published: 2026-07-24
Subjects: Applied Statistics, Geophysics and Seismology, Other Planetary Sciences, Statistical Models
The NASA Center for Near-Earth Object Studies (CNEOS) Fireball Database is one of the most widely used resources for investigating global bolide populations. However, variations in event reliability, detection thresholds, and observational coverage introduce potential selection biases that may influence inferred population statistics. While the database has been extensively employed in studies of [...]
Machine-learning-based classification of shear-band particles in a discrete-element reverse-fault model
Published: 2026-07-24
Subjects: Earth Sciences, Engineering
Discrete element method (DEM) simulations provide time-resolved particle-scale information on particle motion, contact forces, rotation, and local deformation. However, these outputs are high-dimensional, making it difficult to directly interpret which particle-level descriptors characterize localized deformation. This study develops a machine-learning workflow for classifying shear-band [...]
Reconstructing Satellite-Era Southern Ocean Temperature and Salinity Trends within Observational Uncertainty
Published: 2026-07-24
Subjects: Physical Sciences and Mathematics
Southern Ocean (SO) sea surface temperatures (SSTs) have exhibited large-scale cooling over the satellite era (1979-present). Several potential drivers of this cooling have been proposed -- including changes in winds, freshwater fluxes, and natural variability -- but their relative contributions have been challenging to identify because climate models largely fail to simulate the observed trend. [...]