Preprints
There are 7324 Preprints listed.
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. [...]
The effect of seismic radiation patterns on the interpretation of SKS splitting: evidence from Phase 2 of the WA Array
Published: 2026-07-24
Subjects: Geophysics and Seismology
Coherent anisotropic fabrics trending E--W to NE--SW across Western Australia have been revealed by shear-wave splitting of the SKS and PKS (XKS) phases across the WA Array. This large temporary array of 130 stations with 40 km spacing shows that this seismic anisotropy is pervasive; yet individual stations, including permanent ones, produce relatively few results. We investigate the effect of [...]
PSI monitoring of fault zones at the Starobin potash deposit based on Sentinel-1 data
Published: 2026-07-24
Subjects: Engineering
The Starobin potash salt deposit has been mined for over forty years with annual extraction measured in millions of tons. In the vicinity of tectonic fault junction zones, this creates a risk of local technogenic earthquakes caused by fault activation. Local geodetic monitoring within mining allotments is of limited utility for assessing large-scale tectonic deformations, since intense local [...]
Authorship and contribution recognition in infrastructure-scale Earth science collaborations
Published: 2026-07-24
Subjects: Earth Sciences, Physical Sciences and Mathematics
Community-driven collaborative initiatives across palaeoclimate, oceanography, and Earth system science have transformed how scientific knowledge is generated, integrated, and interpreted. Proxy synthesis efforts, climate model intercomparison projects, and scientific drilling programmes increasingly function as collaborative scientific infrastructures sustained by distributed intellectual labour [...]
Feedback-Controlled Linear Actuator System to Simulate Laboratory Analogs of Landslides
Published: 2026-07-24
Subjects: Civil Engineering, Earth Sciences, Engineering, Geomorphology, Geophysics and Seismology, Geotechnical Engineering, Physical Sciences and Mathematics, Physics, Statistical, Nonlinear, and Soft Matter Physics
This study describes a scientific apparatus that induces granular flow by tilting an acrylic sample container under user-prescribed constant angular velocity and acceleration profiles. The system consists of a transparent sample container mounted within a motorized frame driven by a linear actuator that we control using pulse-width modulation with feed-forward compensation. Additional components [...]
Fabric and strain analyses support a unified framework for sediment deposition, relaxation, and glass formation
Published: 2026-07-24
Subjects: Earth Sciences, Geophysics and Seismology, Physics, Sedimentology, Statistical, Nonlinear, and Soft Matter Physics
The kinetic energy of particles at deposition Ek is a distinguishing feature of all near-surface environments, varying due to particle mass and local stress field within the fluid that transports the particles. Once deposited, a granular fabric emerges that exerts control on the subsequent relaxation processes, including on whether, when, and how granular sediments catastrophically fail. Despite [...]