Preprints
There are 6976 Preprints listed.
Remote sensing large-wood storage downstream of reservoirs during and after dam removal: Elwha River, Washington, USA
Published: 2024-08-09
Subjects: Physical Sciences and Mathematics
Large wood is an integral part of many rivers, often defining river-corridor morphology and habitat, but its occurrence, magnitude, and evolution in a river system are much less well understood than the sedimentary and hydraulic components, and due to methodological limitations, have seldom previously been mapped in substantial detail. We present a new method for this, representing a substantial [...]
Expanded constraints on chemical weathering reactions and carbon cycling beneath the Antarctic Ice Sheet
Published: 2024-08-11
Subjects: Physical Sciences and Mathematics
Ice sheets may influence the global carbon cycle by releasing chemical weathering products and carbon from basal environments. However, limited data describing subglacial biogeochemical cycles beneath Antarctic and Greenland ice leaves open fundamental questions regarding the feedbacks between climate, ice sheets, and the carbon cycle. Most notably: does subglacial chemical weathering beneath ice [...]
Critical Review of the Article: "Evidence of Dark Oxygen Production at the Abyssal Seafloor" by Sweetman et al. in Nat. Geosci. 1–3 (2024)
Published: 2024-08-12
Subjects: Geochemistry
This review examines the findings and methodologies presented in Sweetman et al. (2024) (hereafter referred to as ‘the paper’). The paper presents findings contrasting those of all previous comparable work and has stirred international debate pertaining to deep-sea minerals. We identify significant issues in data collection, validation, and interpretation including unvalidated data collection [...]
Influence of temperature on the residual shear strength of landslide soil: role of the clay fraction
Published: 2024-08-13
Subjects: Geology, Geotechnical Engineering
The occurrence and fate of landslides are, among other factors, controlled by the shear strength of the materials involved and by how this strength changes during the landslide process. Temperature affects the strength of pure clays according to their mineralogy, stress history, and hydro-mechanical boundary conditions. However, natural soils often consist of heterogeneous mixtures of various [...]
Comparative Analysis of SVM and CNN for Hyperspectral Image Classification
Published: 2024-08-13
Subjects: Computer Engineering, Computer Sciences, Other Computer Sciences, Physical Sciences and Mathematics
This paper presents a comparative analysis of tra- ditional machine learning methods and Convolutional Neural Networks (CNNs) for hyperspectral image classification. Utilizing the Indian Pines dataset, we explore the efficacy of Principal Component Analysis (PCA) combined with a Support Vector Machine (SVM) classifier against a deep learning approach involving CNNs. Our methodology includes [...]
Influence of wind speed on canopy Normalized Difference Vegetation Index (NDVI) measurements for forest ecosystem
Published: 2024-08-13
Subjects: Forest Sciences
Wind speed can affect the observation of canopy vegetation index. When the wind blows, plants will swing, and the spatial structure of the canopy will change. This change may affect the vegetation index measurements. Normalized Difference Vegetation Index (NDVI) from satellite remote sensing was chosen as the index to explore the influence of wind on canopy measurements for forest ecosystems. Our [...]
A methodologically robust densification function for snow on multiyear Arctic sea ice
Published: 2024-08-13
Subjects: Earth Sciences, Environmental Sciences, Physical Sciences and Mathematics
Partial ruptures governed by the complex interplay between geodetic slip deficit, rigidity, and pore fluid pressure in 3D Cascadia dynamic rupture simulations
Published: 2024-08-15
Subjects: Geophysics and Seismology
Physics-based simulations are crucial to assessing the seismic hazard in the Cascadia subduction zone (CSZ), requiring assumptions about fault stress and material properties. Geodetic slip deficit models (SDMs) may inform the initial stresses governing megathrust earthquake dynamics. We present a unified workflow linking SDMs to 3D dynamic rupture simulations, and 22 rupture scenarios to unravel [...]
The influence of wildfire smoke on ambient chemical species concentrations in the contiguous US
Published: 2024-08-15
Subjects: Environmental Sciences, Physical Sciences and Mathematics
Wildfires are a significant contributor to ambient air pollution and pose a growing public health threat in many parts of the world. Increased wildfire activity over the past few decades has exacerbated smoke exposure across the US, yet our understanding of how wildfire influences specific chemicals and their resulting concentration in smoke remains incomplete. We combine 15 years of daily [...]
3-DOF Simulation of Hypothetical Crew Vehicle Launch into Low Mars Orbit
Published: 2024-08-15
Subjects: Aerospace Engineering, Engineering, Navigation, Guidance, Control and Dynamics
A major challenge in space exploration has been the return of a vehicle from the surface of Mars to Earth. This problem has proven to be quite difficult, with current plans to return small rock samples turning out to be too expensive and time consuming[1]. If humans are ever to explore the surface of the red planet, a practical way to launch a crew from the surface of Mars into an orbit from [...]
Reduced contribution of sulfur to the mass extinction associated with the Chicxulub impact event
Published: 2024-08-15
Subjects: Planetary Sciences
The Chicxulub asteroid impact event at the Cretaceous-Paleogene (K-Pg) boundary ~66 Myr ago is widely considered responsible for the mass extinction event leading to the demise of the non-avian dinosaurs. Short-term cooling due to massive release of climate-active agents is hypothesized to have been crucial, with S-bearing gases originating from the target rock vaporization considered a main [...]
Spatial Variability of Water Temperature within the White River Basin, Mount Rainier National Park, Washington
Published: 2024-08-16
Subjects: Life Sciences, Physical Sciences and Mathematics
Water temperature is a primary control on the occurrence and distribution of cold-water species. Rivers draining Mount Rainier in western Washington, including the White River along its northern flank, support several cold-water fish populations, but the spatial distribution of water temperatures, particularly during late-summer base flow between August and September, and the climatic, [...]
The Effect of Rayleigh-Love Coupling in an Anisotropic Medium
Published: 2024-08-17
Subjects: Physical Sciences and Mathematics
For a weakly anisotropic medium, Rayleigh and Love wave phase speeds at angular frequency $\omega$ and propagation azimuth $\psi$ are given approximately by $V(\omega,\psi) = A_0 + A_{2c} \cos 2 \psi + A_{2s} \sin 2 \psi + A_{4c} \cos 4 \psi + A_{4s} \sin 4 \psi$. Earlier theories of the propagation of surface waves in anisotropic media based on non-degenerate perturbation theory predict that the [...]
An Integrated Framework for Actionable Flood Warnings on Road Structures Using High Resolution Satellite Imagery
Published: 2024-08-17
Subjects: Civil and Environmental Engineering, Environmental Monitoring, Hydrology
Floods rank among the most devastating natural hazards globally. Unlike many other natural calamities, floods typically occur in densely populated regions, resulting in immediate and long-term adverse impacts on communities, including fatalities, injuries, health risks, and significant economic and environmental losses annually. Traditional flood models, while useful, are constrained by [...]
Complex and confined laboratory ruptures explain scaling of the critical slip distance for earthquake faulting
Published: 2024-08-23
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Earthquake sequences in nature are complex, exhibiting a range of magnitudes and slip behaviors. In contrast, earthquake-like instabilities generated on frictional faults in the laboratory and in continuum numerical models are usually quasi-periodic with a smaller range of magnitudes and durations. The discrepancy, especially apparent for cm-sized samples used in lab friction experiments, has [...]