Preprints
Filtering by Subject: Physical Sciences and Mathematics
Simulation of multiply scattered elastic waves with 3D wave-equation and radiative transfer equation for displacements and their gradients
Published: 2025-04-19
Subjects: Physical Sciences and Mathematics
In this study, we investigate the behavior of seismic waves in a highly scattering medium using numerical simulations of the full wavefield, based on Spectral Element Method solutions of the wave equation. The simulated 3D elastic medium was designed with Von Kármán-correlated heterogeneity, providing a realistic representation of the complexities present in natural seismic environments. We [...]
Infrared Backradiation under low humidity conditions: An Evaluation of Greenhouse Gas Impact
Published: 2025-04-19
Subjects: Engineering, Physical Sciences and Mathematics
This study examines the impact of greenhouse gases (GHG) on infrared back radiation (IRBR) in extreme desert and midlatitude winter conditions. Employing MODTRAN simulations, pyrgeometer measurements and energy balance fit models, we assess the impacts of CO₂, Argon (Ar), N2O and R-134a. Results indicate that increasing CO₂ concentrations yield a very limited additional IRBR effect, whereas [...]
Oxic conditions in shallow marine settings during the Permian-Triassic Mass Extinction
Published: 2025-04-17
Subjects: Physical Sciences and Mathematics
The concept that ultra-shallow marine anoxia was a major cause of the Permian-Triassic mass extinction was partly based on sections from the Dolomites (Italy). We test this hypothesis by re-examining the Dolomites record, utilizing an updated redox sensitive trace metal (V, U and Mo) approach, combined with Fe speciation and Th/U ratios, and paleontological observations. Redox sensitive trace [...]
Assessing legacy nitrogen in groundwater using numerical models of the Long Island aquifer system, New York
Published: 2025-04-15
Subjects: Earth Sciences, Environmental Sciences, Hydrology, Physical Sciences and Mathematics, Water Resource Management
Nitrogen transported along groundwater flow paths in coastal aquifers can contribute substantially to nitrogen loading into surface water receptors, particularly in hydrologic systems dominated by groundwater discharge. Nitrogen entrained in the aquifer is a function of land use and associated nitrogen sources at the time of groundwater recharge, which may differ considerably from present-day [...]
Missing well logs prediction method based on K-nearest neighbors regression
Published: 2025-04-14
Subjects: Engineering, Physical Sciences and Mathematics
In petroleum exploration, well logs are crucial for reservoir characterization. However, missing well logs frequently occur due to tool failures or economic constraints, which can impede accurate subsurface modeling. This research presents a method for predicting missing well logs using the K-Nearest Neighbors (KNN) regression algorithm, trained on data from the University of Kansas. The study [...]
Targeting bias in algorithm optimization improves reconstructions of surface ocean pCO2
Published: 2025-04-11
Subjects: Physical Sciences and Mathematics
In order to fully understand current and future climate impacts from rising carbon emissions, it is crucial to accurately quantify the air-sea CO2 flux and the ocean carbon sink in space and time. Air-sea flux estimates from observation-based data products used in the Global Carbon Budget show a large spread, and suggest a stronger carbon sink than global ocean biogeochemistry models (GOBMs) in [...]
Tidal flexure reveals effective elasticity in grounding zones on the Ross Ice Shelf
Published: 2025-04-11
Subjects: Earth Sciences, Glaciology, Physical Sciences and Mathematics
The grounding zones of Antarctic ice shelves are among the continent’s most dynamic regions, where floating ice shelves buttress grounded upstream ice and tidal forcing drives cyclic flexure at the ice-ocean-bed interface. We use ICESat-2 altimetry and airborne ice-penetrating radar to constrain the effective Young’s modulus E* of ice in the flexure zone at three sites on the Ross Ice Shelf. By [...]
Differential Impacts of Marine Heatwaves and Coldwaves on Air-Sea CO2 Flux Across Global Oceans
Published: 2025-04-10
Subjects: Engineering, Physical Sciences and Mathematics
The contrasting impacts of marine heatwaves (MHWs) and marine cold waves (MCWs) on the ocean carbon cycle remain insufficiently understood. Based on observational and reanalysis data from 1990 to 2019, this study investigates the global-scale responses of air-sea CO2 fluxes (FCO2) to MHWs and MCWs. Results reveal that MHWs and MCWs exert opposing influences on FCO2, with the magnitude of [...]
How the Magnetic North Pole and Energetic Particle Precipitation Control Earth's Climate
Published: 2025-04-09
Subjects: Physical Sciences and Mathematics
The hypothesis that the position of the magnetic North Pole (Dip Pole) (latitude) ought to be very highly correlated with global temperature change on Earth has been tested and shown to be correct. The probability of such a correlation happening by chance is close to zero. Moreover, this has likely been the dominant climate driver for the last 2000 years. A Granger causality test shows Pole Shift [...]
Deep source regions for Patagonia backarc volcanism imaged by finite frequency body wave tomography
Published: 2025-04-09
Subjects: Earth Sciences, Geochemistry, Geology, Geophysics and Seismology, Glaciology, Physical Sciences and Mathematics, Tectonics and Structure, Volcanology
The subduction of Chile Ridge beneath South America beginning 12-16 Myr ago opened a gap in the subducting slab beneath southern Patagonia, which migrated northward and is located today at 46oS. Geodynamic processes associated with the slab window are poorly understood. Here we apply finite-frequency P and S body wave tomography to seismic data from several temporary arrays as well as regional [...]
Assessing Future Ice Shelf Collapse Vulnerability in the ISMIP6 Ensemble
Published: 2025-04-08
Subjects: Earth Sciences, Glaciology, Physical Sciences and Mathematics
Understanding the possibility of future ice shelf collapses similar to the Larsen B is critical for improving sea-level-rise projections due to the restraint on upstream flow that ice shelves provide. Prior research has provided a criterion for assessing the vulnerability of ice shelf to hydrofracture. We apply these calculations to the model ensemble results from the Ice Sheet Modeling [...]
An Event-Based Framework for Estimating Annual Methane Emissions and Managing Emissions Data from Upstream Oil and Gas Facilities
Published: 2025-04-05
Subjects: Engineering, Physical Sciences and Mathematics
Accurate reporting of annual site-level methane emissions is increasingly required under emerging regulatory and voluntary frameworks in the oil and gas (O&G) sector. In this study, we present an event-based framework for estimating annual methane emissions from upstream O&G facilities. The framework applies the Emission Event Data Model (EEDM) to spatiotemporally aggregate multi-scale [...]
A New Fault Model for the 1933 Long Beach Earthquake, Long Beach Area, Southern California
Published: 2025-04-05
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics
Newly identified thrust faults and their corresponding thrust sheets, combined with recent micro-earthquake epicenters, better explain anomalous rupture data observed during the 1933 Long Beach Earthquake than previous models based exclusively on Newport-Inglewood Fault Zone strike-slip faulting. A high-quality 45 km2 3D seismic dataset was recorded in 2017, centered along the Seal Beach [...]
Geoscientific Input Feature Selection for CNN-driven Mineral Prospectivity Mapping
Published: 2025-04-05
Subjects: Physical Sciences and Mathematics
In recent years, machine learning techniques such as convolutional neural networks have been used for mineral prospectivity mapping. Since a diverse range of geoscientific data are often available for training, it is computationally challenging to select a subset of features that optimizes model performance. Our study aims to demonstrate the effect of optimal input feature selection on [...]
Chaotic variability of the magnetic field at Earth's surface driven by ionospheric and space plasmas
Published: 2025-04-05
Subjects: Physical Sciences and Mathematics
It is shown that the universal chaotic/turbulent processes in space (solar wind and magnetosphere) and in ionospheric plasmas drive the chaotic temporal variability and determine the level of randomness of the magnetic field at Earth's surface in the temporal range from a few hours to a few years. The results of observations provided by the spacecraft and satellite missions, and the global [...]