Preprints
Filtering by Subject: Geophysics and Seismology
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 [...]
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 [...]
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 [...]
The Tarim Mega Impact Event: A Permian (~290 Ma) Mega-Impact Triggering Global Magmatism, the Artinskian Warming Event, and the Central Asian Arc-LIP Belt
Published: 2026-07-20
Subjects: Geochemistry, Geographic Information Sciences, Geomorphology, Geophysics and Seismology, Sedimentology, Stratigraphy, Tectonics and Structure, Volcanology
We propose that an oblique mega-impact by a ferronickel asteroid (~180×100×90 km, 22 km/s, incidence angle 24°) that occurred at ~290 Ma in the present-day Tarim Basin can, through the "thin-target penetration" mechanism, attempt to unify within a single physical framework: (1) the Tarim Large Igneous Province (TLIP) flood basalts; (2) the Pamir–Iran–Turkey arcuate mafic–ultramafic magmatic belt; [...]
Azimuthal Anisotropy and Lateral Velocity Gradient Beneath Australia From Teleseismic P-wave Polarization Anomalies
Published: 2026-07-18
Subjects: Geophysics and Seismology
Teleseismic P-wave polarization anomalies provide useful constraints on lateral heterogeneity and anisotropic structure beneath seismic stations, but their application to continental-scale structures has remained limited. Here, we analyze long-period teleseismic P-wave polarization anomalies recorded at permanent and temporary seismic stations across Australia. We apply a harmonic analysis to the [...]
Mechanical Association between Pressure Wave Propagation Time and Constitutive Parameter Damage in Porous Media: Theoretical Derivation and Sensitivity Analysis
Published: 2026-07-16
Subjects: Engineering Mechanics, Geology, Geophysics and Seismology, Geotechnical Engineering, Hydraulic Engineering, Hydrology, Physics, Soil Science
The propagation time of pressure waves in porous media carries critical information about the constitutive parameters of the medium. This study rigorously derives the mechanical relationship between the lag time of pressure wave and the hydraulic parameters of porous media based on the diffusion wave equation. The lag time is shown to be a direct functional of the hydraulic conductivity and [...]
Storm-source geometry biases mantle transition-zone water estimates from a century-scale geomagnetic archive
Published: 2026-07-12
Subjects: Geophysics and Seismology, Tectonics and Structure
Electromagnetic estimates of water in the mantle transition zone depend on the assumed geometry of storm-time source fields. We audit the effect of that assumption using paired processing chains that differ only by inclusion of a degree-3 zonal source term, together with pre-specified admission gates. The experiment is applied to three separately processed, partially overlapping observatory [...]
A Reproducible Framework for the Compressibility of Truncated Spherical-harmonic Planetary Potential-field Models
Published: 2026-07-09
Subjects: Geophysics and Seismology, Numerical Analysis and Computation, Numerical Analysis and Scientific Computing, Planetary Geophysics and Seismology
For a planetary potential field whose degree-variance spectrum decays as a convergent power law σ²_ℓ ∼ ℓ^−α (α > 1), a single measured exponent simultaneously fixes three classically distinct rates: the truncation-error decay rate, the Sobolev smoothness index, and the Kolmogorov n-width rate. Spherical-harmonic degree truncation is the standard yet inherently lossy way to compress such [...]
The Rise of Diamond Open Access Journals in Earth Sciences: Past Developments, Present Tensions, and Future Pathways
Published: 2026-07-08
Subjects: Biogeochemistry, Cosmochemistry, Earth Sciences, Geochemistry, Geology, Geomorphology, Geophysics and Seismology, Library and Information Science, Paleontology, Planetary Sciences, Sedimentology, Tectonics and Structure, Volcanology
Over roughly the last decade, a visible, community-led Diamond Open Access (OA) ecosystem has emerged in the Earth sciences, not as a departure from tradition, but as the latest expression of a long-standing culture of open, society-supported scholarly communication. While free-to-read, fee-free publishing initiatives have deep roots in the field, predating the Diamond terminology by decades and [...]
Machine learning versus ETAS for earthquake forecasting in the Sea of Marmara: a leakage-audited negative result and a closed-form scoring artifact
Published: 2026-07-06
Subjects: Geophysics and Seismology, Physical Sciences and Mathematics
We ask whether machine learning adds 30-day earthquake-forecasting value beyond modern ETAS in the Sea of Marmara, a locked seismic gap beneath Istanbul, once leakage and scoring artifacts are controlled. On a homogenized KOERI catalog, feature causality is machine-checkable, and comparisons follow a pre-specified rule: paired block-bootstrap intervals on likelihood and ranking must agree. The [...]
When does array moveout help borehole phase picking? A leave-one-site-out, confound-free benchmark of array versus per-trace deep learning
Published: 2026-07-06
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Deep-learning phase pickers are increasingly deployed on borehole microseismic arrays, yet two questions central to operational monitoring remain poorly quantified: how well such models generalize to a site they were not trained on, and whether the cross-station moveout that an array provides actually improves that generalization. We give the first confound-free answer using the AMBER benchmark [...]
A hidden component of magnetic storms makes Earth's mantle transition zone look drier than it is
Published: 2026-07-04
Subjects: Geophysics and Seismology
Electromagnetic sounding provides a primary geophysical constraint on water in Earth's mantle transition zone, yet conductivity models disagree by up to an order of magnitude. We identify a source-side systematic invisible to internal consistency checks: omitting the degree-3 zonal (P₃⁰) storm-field component biases transition-zone conductivity by 0.1–0.35 decades, a tenth to a quarter of that [...]
ARGUS: A 17-ms End-to-End Deep Learning Pipeline for Real-Time Seismic Source Characterization and Ground Motion Prediction in Sparse-Network EGS/CCS Environments
Published: 2026-06-30
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
We present ARGUS (Automated Real-time Geophysical Understanding System), an end-to-end deep-learning pipeline that jointly estimates hypocenter location, centroid moment tensor (CMT), and peak ground acceleration (PGA) distribution from sparse seismic networks, targeting induced-seismicity monitoring in enhanced geothermal systems (EGS) and carbon capture and storage (CCS). From as few as four to [...]