Preprints
There are 6229 Preprints listed.
Inverse modeling of satellite observations shows that the wet tropics drive the 2010-2022 methane increase
Published: 2024-01-04
Subjects: Atmospheric Sciences, Climate
Atmospheric methane concentrations rose rapidly over the past decade and surged in 2020-2022 but the causes are unclear. We find from inverse analysis of GOSAT satellite observations that global methane emissions increased from 500 to 550 Tg a-1 from 2010 to 2019 and surged to 570-590 Tg a-1 in 2020-2022. Concentrations of tropospheric OH (the main methane sink) show no long-term trend over [...]
Redox Geochemistry of the Late Cambrian SPICE Event in Durness Group, UK
Published: 2024-01-04
Subjects: Earth Sciences, Geochemistry, Geology
The Late Cambrian Steptoean Positive Carbon Isotope Excursion (SPICE) event occurring at approximately 497 Ma and lasting for about 2-4 Myr is emblematic of a global-scale oceanic anoxia, coinciding with the trilobite mass extinction. It is significant in the biotic evolution spanning the Late Cambrian to Ordovician. Nevertheless, the driving mechanism behind the SPICE event is contentious, and [...]
Near-source effects on DAS recording: implications for tap tests
Published: 2024-01-04
Subjects: Earth Sciences
In the immediate vicinity of a source there are strong gradients in the seismic wavefield that are tamed and modified in DAS recording due to combined effects of gauge-length averaging and local stacking on the local strain field. Close to a source broadside propagation effects are significant and produce a characteristic impact on the local DAS channels. In the presence of topography, of surface [...]
A shake and a surge: Assessing the possibility of an earthquake-triggered eruption at Steamboat Geyser
Published: 2024-01-03
Subjects: Earth Sciences, Physical Sciences and Mathematics, Volcanology
When and why earthquakes trigger volcano and geyser eruptions remains unclear. In September 2022, Steamboat Geyser in Yellowstone, USA erupted 8.25 hours after a local M3.9 earthquake—an improbable coincidence based on the geyser’s eruption intervals. We leverage monitoring data from the surrounding geyser basin to determine if the earthquake triggered this eruption. We calculate a peak ground [...]
Microbial indicators and detection of Cu-sulfide ore mineralization
Published: 2024-01-02
Subjects: Biogeochemistry, Earth Sciences, Geochemistry, Geology, Other Earth Sciences, Physical Sciences and Mathematics, Soil Science
Rapid electrification of society is placing unprecedented demand on critical mineral and metal resources. New strategies and technologies are thus needed to promote mineral discovery in regions where deposits are likely buried deep under soil and glacial till. We show that microbial communities from different soil types change in composition in response to amendment with copper. We also show [...]
New U-Pb zircon data and patterns of collision magmatism in the Northern Highlands of Scotland
Published: 2023-12-29
Subjects: Physical Sciences and Mathematics
The Northern Highlands Terrane of the Scottish Caledonides contain a record of Palaeozoic collision magmatism which overlaps with Baltica – Laurentia convergence and the Scandian Orogeny. Here, there remain gaps in our understanding of the relationship between collision dynamics and the spatial-temporal distribution of Caledonian intrusions. In this study, the Strontian and Helmsdale plutons and [...]
A Systematic Review of Machine Learning Algorithms in Groundwater Level Simulations and Forecasting
Published: 2023-12-29
Subjects: Education, Physical Sciences and Mathematics
Over two billion individuals worldwide rely on subterranean water as their primary reservoir of clean water. Ensuring the sustainable management of this heavily burdened resource necessitates a comprehensive quantitative evaluation of groundwater reserves. This becomes even more critical as water resources face escalating demands resulting from socioeconomic growth, population expansion, and the [...]
A Comprehensive Flood Risk Assessment for Railroad Network: Case Study for Iowa
Published: 2023-12-29
Subjects: Environmental Engineering, Risk Analysis
Climate-induced disasters, particularly floods, pose a substantial risk to human well-being. These risks encompass economic losses, infrastructural damage, disruption of daily life, and potential loss of life. This study focuses on understanding flood risks to critical infrastructure, emphasizing the resilience and reliability of essential services during such disasters. In the United States, the [...]
The Severe Storm Index: Gauging our progress in the “War-Effort” against climate change
Published: 2023-12-27
Subjects: Oceanography and Atmospheric Sciences and Meteorology
While it is difficult, if not impossible, for most humans to conceptualize CO2 levels or ocean temperatures, we are very aware of the growing number of storms and their increase in severity. Indeed, according to the National Weather Service, the number of severe storms has increased in the United States from 1 – 3/decade in the 1950s through the 1980s, to 8/decade in the 1990s, 30/decade in the [...]
Deep-Water Fan Hierarchy: Assumptions, Evidence, and Numerical Modelling Analysis
Published: 2023-12-26
Subjects: Physical Sciences and Mathematics
Submarine fan strata are commonly described and interpreted assuming a nested, hierarchical organisation of elements, from beds, to lobe elements, lobes and lobe complexes. However, describing outcrop and subsurface strata following a particular conceptual method or model is never evidence in itself that the model or method accurately reflects the true nature of the strata. To develop better [...]
Geochronology and geodynamics of collision magmatism in the Southern Uplands-Down-Longford Terrane in Scotland and Ireland
Published: 2023-12-24
Subjects: Physical Sciences and Mathematics
The relationship between igneous activity and the geodynamics of subduction and collision is uncertain in northern Britain and Ireland, which lay on the Laurentian margin during accretion of Baltica and peri-Gondwanan terranes during the Palaeozoic Caledonian - Acadian orogenies. There is uncertainty over the relevance and timing of Iapetus slab breakoff beneath the Laurentian margin, and modest [...]
Diverse Carbonates in Exoplanet Oceans Promote the Carbon Cycle
Published: 2023-12-22
Subjects: Astrophysics and Astronomy, Planetary Geochemistry, Planetary Sciences
Carbonate precipitation in oceans is essential for the carbonate-silicate cycle (inorganic carbon cycle) to maintain temperate climates. By considering the thermodynamics of carbonate chemistry, we demonstrate that the ocean pH decreases by approximately 0.5 for a factor of 10 increase in the atmospheric carbon dioxide content. The upper and lower limits of ocean pH are within 1-4 of each other, [...]
Dye tracing of upward brine migration in snow
Published: 2023-12-22
Subjects: Earth Sciences
The presence of salt in the snow overlying seasonal sea ice has profound thermodynamic and electromagnetic effects. However, the way that it arrives and is distributed within the marine snowpack remains poorly understood and modelled. We describe two experiments tracing upward brine movement in snow: one laboratory experiment at Rothera research station, West Antarctica, and a field experiment in [...]
Open-source approach for reproducible substrate mapping using semantic segmentation on recreation-grade side scan sonar datasets
Published: 2023-12-21
Subjects: Analysis, Artificial Intelligence and Robotics, Databases and Information Systems, Environmental Monitoring, Hydrology, Natural Resources and Conservation, Numerical Analysis and Computation, Numerical Analysis and Scientific Computing, Programming Languages and Compilers, Software Engineering, Terrestrial and Aquatic Ecology, Water Resource Management
Knowledge of the variation and distribution of substrates at large spatial extents in aquatic systems, particularly rivers, is severely lacking, impeding species conservation and ecosystem restoration efforts. Air and space-borne remote sensing important for terrestrial and atmospheric measurements are limited in benthic environments due to river stage, turbidity, and canopy cover, requiring [...]
On sea ice emission modeling for MOSAiC's L-band radiometric measurements
Published: 2023-12-21
Subjects: Engineering, Physical Sciences and Mathematics
The retrieval of sea ice thickness using L-band passive remote sensing requires robust models for emission from sea ice. In this work, measurements obtained from surface-based radiometers during the MOSAiC expedition are assessed with the Burke, Wilheit and SMRT radiative transfer models. These models encompass distinct methodologies: radiative transfer with/without wave coherence effects, and [...]