Preprints
Filtering by Subject: Physical Sciences and Mathematics
Damped Gravity Waves, Weak Temperature Gradients, and Tropical Deep Convection
Published: 2024-10-02
Subjects: Physical Sciences and Mathematics
The "damped gravity wave" (DGW) approximation occurs when convective momentum dissipation is balanced by the pressure gradient force of convectively forced gravity waves. While this balance has been used to parameterize large-scale lifting in limited-domain models of tropical deep convection, its applicability to observed phenomena has not been carefully examined. A scale analysis indicates that [...]
Effect of organic coatings on optical properties of black carbon aerosol: Insights from Mie theory based model simulations
Published: 2024-10-02
Subjects: Physical Sciences and Mathematics
Black carbon (BC), plays a crucial role in climate change due to its significant impact on radiative forcing. This study investigates the influence of organic carbon (OC) coatings on the optical properties of BC aerosols using Mie theory-based calculations. We have examined a range of core diameters and coating thicknesses to assess changes in both absorption and scattering cross-sections. The [...]
Imaging a buried terrane with district-scale ambient noise tomography and gravity modelling: insights for scale-reduction in mineral exploration
Published: 2024-10-02
Subjects: Earth Sciences, Physical Sciences and Mathematics
Mineral exploration proceeds by a process of scale-reduction. Decisions need to be made at all stages as the physical search space becomes progressively reduced from regional through to district, camp and tenement/deposit scale. While there are many regional scale datasets available to explorers through public geoscience agencies, one of the most difficult steps to make is from the regional-scale [...]
Seismicity-constrained fault detection and characterization with a multitask machine learning model
Published: 2024-09-28
Subjects: Physical Sciences and Mathematics
Geological fault detection and characterization from geophysical data have been one of the center challenges in geophysics and seismology as it holds the key to understanding subsurface dynamics ranging from borehole, reservoir, to regional scales. While paradigms of auto or semi-auto fault delineation either based on seismicity location analysis or on seismic migration image reflector [...]
Groundwater use to reduce natural hazard susceptibilities and inequities in the metacrisis
Published: 2024-09-27
Subjects: Earth Sciences, Environmental Sciences, Hydrology, Physical Sciences and Mathematics
Long-term thinking is broadly advocated for groundwater - the largest available freshwater resource that is essential for drinking water, irrigation and ecosystems around the world. Long-term thinking is crucial to support sustainability of this slowly renewed resource, but here we propose another crucial, novel and emerging approach for groundwater: short-term use over days and months during or [...]
Regional Source-type Discrimination Using Nonlinear Alignment Algorithms
Published: 2024-09-26
Subjects: Physical Sciences and Mathematics
The discrimination problem in seismology aims to accurately classify different underground source types based on local, regional and/or teleseismic observations of ground motion. Typical discriminant approaches are rooted in fundamental, physics-based differences in radiation pattern or wave excitation, which can be frequency dependent and may not make use of the full waveform. In this paper, we [...]
Normal fault interactions in seismic cycles and the impact of fault network geometry
Published: 2024-09-26
Subjects: Physical Sciences and Mathematics
Understanding the mechanisms behind the characteristics of earthquake cycles on normal faults is challenging due to their long recurrence times. Despite their moderate magnitude, normal faulting earthquakes can produce considerable damage. We investigate the effects of fault network geometry and spacing on the seismic cycle of a system of two normal faults modelled with rate-and-state friction [...]
VolFe: an open-source tool for calculating melt-vapor equilibria including silicate melt, carbon, hydrogen, sulfur, and noble gases
Published: 2024-09-25
Subjects: Physical Sciences and Mathematics
VolFe is an open-source flexible and adaptable thermodynamic framework in Python for calculating the equilibrium composition of melt and vapor. VolFe considers basaltic through rhyolitic melts including the volatiles carbon, hydrogen, sulfur, and noble gases. VolFe models both reduced and oxidised systems due to the range of melt and vapor species included. Hence, VolFe is applicable to [...]
How Should Multiple Temperature Time Series be Compared on Graphs?
Published: 2024-09-24
Subjects: Physical Sciences and Mathematics
How temperature biases in both climate models and observations are adjusted in order to make comparisons of climate change signals has been seldom discussed, yet the choice of adjustment method has a large impact on the resulting conclusions. When the primary interest is how global warming evolves through time, how the models’ diagnosed equilibrium climate sensitivities (ECS) correlate with [...]
Al Hawi, a 4-km-wide impact structure in northern Saudi Arabia
Published: 2024-09-24
Subjects: Astrophysics and Astronomy, Earth Sciences, Geology, Geomorphology, Other Earth Sciences, Physical Sciences and Mathematics, Physics, Planetary Geology, Planetary Sciences, The Sun and the Solar System
The northern region of Saudi Arabia hosts several impact craters and structures. This paper describes the discovery of a 4-km-wide complex impact structure located in the paleozoic sedimentary rocks of northern Saudi Arabia 210 kilometers north east of the city of Tabuk. The impact structure is composed of a central peak displaying intense folding and shock metamorphism surrounded by an inner [...]
Sunken micro continents of the North Atlantic: Is the sub-basaltic Faroe Islands basement similar to the basement of the Rockall Plateau?
Published: 2024-09-23
Subjects: Physical Sciences and Mathematics
Seafloor extension/stretching and associated rifting in the North Atlantic Area, which started in Early Paleogene times (From ~62 Ma), were rather complex affairs in their entireties. The pre-rift North Atlantic area was a patchwork of continental geological terrains being ‘wreckages’ from the closure of the ancient Iapetus Ocean. Current offshore areas in the North Atlantic known to harbour such [...]
Very high fire danger in UK in 2022 at least 6 times more likely due to human-caused climate change
Published: 2024-09-20
Subjects: Physical Sciences and Mathematics
The UK experienced an unprecedented heatwave in 2022, with temperatures reaching 40°C for the first time in recorded history. This extreme heat was accompanied by widespread fires across London and elsewhere in England, which destroyed houses and prompted evacuations. While attribution studies have identified a strong human fingerprint contributing to the heatwave, no studies have attributed the [...]
Atlantic will tear us apart: sand provenance correlation of Early Cretaceous aeolian strata from the conjugate margins of Africa and South America
Published: 2024-09-18
Subjects: Physical Sciences and Mathematics
The Twyfelfountein Formation in Namibia and the Botucatu Formation in East South America represent a single dune-field separated through rifting of Gondwana during the Cretaceous. The Early Cretaceous Botucatu desert was the last depositional system operating in the Gondwanan heartland prior to continental drift initiated by the Paraná-Etendeka large igneous province. The dry-aeolian dunes, [...]
Xdas: a Python Framework for Distributed Acoustic Sensing
Published: 2024-09-18
Subjects: Physical Sciences and Mathematics
Xdas is a Python library designed to manipulate Distributed Acoustic Sensing (DAS) data. It provides a unified abstraction for reading any DAS file format into a standardized Python object, streamlining data handling across different acquisition systems. To address the challenge of massive, multi-file datasets, Xdas aggregates data chunks into virtually contiguous arrays organized by instrument [...]
Comparative Analysis of Earthquake Detection Methods Using Deep Learning: Reproducibility and Uncertainty Assessment in EQTransformer
Published: 2024-09-18
Subjects: Physical Sciences and Mathematics
This study evaluates the performance and reliability of earthquake detection using the EQTransformer, a novel AI program that is widely used in seismological observatories and research for enhancing earthquake catalogs. We test the EQTransformer capabilities and uncertainties using seismic data from the Volcanological and Seismological Observatory of Costa Rica and compare two detection options: [...]