Preprints
There are 5932 Preprints listed.
The relative contributions of weathering and aeolian inputs to postglacial formation of Mediterranean alpine loess
Published: 2021-10-19
Subjects: Earth Sciences
Between the southern margin of the European loess belt and Sahara Desert, thin and irregularly distributed loess deposits occur in Mediterranean mountains. During the most recent deglaciation, along the Pleistocene-Holocene boundary, the deposition of glacial, periglacial and outwash sediments, was the main local source of Mediterranean alpine loess, whereas proximal alluvial planes comprised a [...]
Improving the reliability of Fe- and S-XANES measurements in silicate glasses: Correcting beam damage and identifying Fe-oxide nanolites in hydrous and anhydrous melt inclusions
Published: 2021-10-19
Subjects: Geochemistry, Geology, Mineral Physics, Physical Sciences and Mathematics, Volcanology
The redox state of silicate melts influences crystallization, element partitioning, and degassing behavior. Synchrotron-based micro-X-ray absorption near edge structure (μXANES) spectroscopy has emerged as a powerful tool for determining redox conditions through the direct measurement of speciation of multivalent elements such as iron and sulfur in silicate glasses. In particular, the high [...]
Evolution of seafloor pockmarks along the Northern Orange Basin, Offshore South Africa: Interplay between fluid flow and bottom current activities
Published: 2021-10-19
Subjects: Physical Sciences and Mathematics
Pockmarks are pervasive geomorphologic features identified along continental margins resulting from fluid expulsion on the seafloor. However, the understanding of the underlying geological mechanism/control in relation to their evolution, distribution, and morphology is limited, especially along data-starved continental margins such as the Northern Orange Basin. Analysis of a high-quality 3D [...]
Multi-temporal relative landslide risk analysis for sustainable development of rapidly growing cities
Published: 2021-10-19
Subjects: Earth Sciences, Environmental Sciences, Geomorphology, Physical Sciences and Mathematics
In the last decades, developing countries have experienced an increase in impact of natural disasters due to both the ongoing climate change and the sustained expansion of urban areas. Intrinsic vulnerability of settlements due to poverty and poor governance, as well as the lack of tools for urban occupation planning and mitigation protocols, have made such impact particularly severe. Cuenca [...]
Seiching period from experiment and numerical simulation
Published: 2021-10-19
Subjects: Hydrology
Seiching is a common phenomenon in nature where a large body of water exhibits periodic behavior. First, we set up water oscillations in a tank and measure its oscillation period. Then we use OpenFOAM to simulate the oscillation behavior of the water waves in a 3D mesh with the same dimensions as the tank used in the experiment. Applying the Fourier transformation on the velocities calculated [...]
Superpixel segmentations for thin sections: evaluation of methods to enable the generation of machine learning training data sets
Published: 2021-10-16
Subjects: Earth Sciences, Physical Sciences and Mathematics
Training data is the backbone of developing either Machine Learning (ML) models or specific deep learning algorithms. The paucity of well-labeled training image data has significantly impeded the applications of ML-based approaches, especially the development of novel Deep Learning (DL) methods like Convolutional Neural Networks (CNNs) in mineral thin section images identification. However, image [...]
Human-in-the-Loop Segmentation of Earth Surface Imagery
Published: 2021-10-16
Subjects: Engineering, Physical Sciences and Mathematics
Segmentation, or the classification of pixels (grid cells) in imagery, is ubiquitously applied in the natural sciences. Manual methods are often prohibitively time-consuming, especially those images consisting of small objects and/or significant spatial heterogeneity of colors or textures. Labeling complicated regions of transition that in Earth surface imagery are represented by collections of [...]
Thermochronologic constraints on the origin of the Great Unconformity
Published: 2021-10-16
Subjects: Earth Sciences, Physical Sciences and Mathematics
The origin of the phenomenon known as the Great Unconformity has been a fundamental yet unresolved problem in the geosciences for over a century. Recent hypotheses advocate either global continental exhumation of more than 3–4 km during Cryogenian (717–635 Ma) snowball Earth glaciations, or alternatively, diachronous episodic exhumation throughout the Neoproterozoic (1000–540 Ma) due to plate [...]
U-Pb zircon ages, mapping, and biostratigraphy of the Payette Formation and Idaho Group north of the western Snake River Plain: implications for hydrocarbon system correlation
Published: 2021-10-15
Subjects: Physical Sciences and Mathematics
The sedimentary deposits north of the western Snake River Plain host Idaho’s first and only producing oil and gas field. They consist of the mid-Miocene Payette Formation, the mid-late Miocene Chalk Hills Formation, and the Pliocene to early Pleistocene Glenns Ferry Formation. Using new geochronology, palynomorph biostratigraphy, and geologic mapping, we connect up-dip surface features to [...]
Consistent Controls on Trace Metal Micronutrient Speciation in Wetland Soils and Stream Sediments
Published: 2021-10-15
Subjects: Biogeochemistry, Geochemistry, Soil Science
Trace metal are essential for microbially-mediated biogeochemical processes occurring in anoxic wetland soils and stream bed sediments, but low availability of these elements may inhibit anaerobic element cycling and transformations. Solid-phase speciation is likely a critical control on trace metal availability but has seen limited study in anoxic systems having concentrations similar to [...]
Tidal marsh resilience to sea level rise controlled by vertical accretion and landward migration under nature-based human adaptation scenarios
Published: 2021-10-15
Subjects: Biodiversity, Ecology and Evolutionary Biology, Environmental Studies, Geography, Life Sciences, Marine Biology, Plant Sciences
Tidal marshes are not only lost to human disturbance but also face the threat of sea level rise (SLR). However, current earth system models used to estimate future changes in wetland extent omit wetland’s real responses to SLR without field observations. We synthesised global data on sediment accretion rate (SAR) and surface elevation change (SEC) for tidal marshes and developed a mathematical [...]
Volcanic hazard exacerbated by future global warming–driven increase in heavy rainfall.
Published: 2021-10-15
Subjects: Climate, Physical Sciences and Mathematics, Volcanology
Heavy rainfall drives a range of eruptive and noneruptive volcanic hazards; over the Holocene, the incidence of many such hazards has increased due to rapid climate change. Here we show that extreme heavy rainfall is projected to increase with continued global warming throughout the 21st century in most subaerial volcanic regions, dramatically increasing the potential for rainfall-induced [...]
Kathmandu Basin as a local modulator of seismic waves: 2D modelling of nonlinear site response under obliquely incident waves
Published: 2021-10-15
Subjects: Civil Engineering, Earth Sciences, Geophysics and Seismology, Geotechnical Engineering
The 2015 Mw 7.8 Gorkha, Nepal earthquake is the largest event to have struck the capital city of Kathmandu in recent times. One of its surprising features was the frequency content of the recorded ground motion, exhibiting a notable amplification at low frequencies (< 2 Hz) and a contrasting depletion at higher frequencies. The latter has been partially attributed to the damper behaviour of the [...]
Decline of sea-ice in the Greenland Sea intensifies extreme precipitation over Svalbard
Published: 2021-10-14
Subjects: Physical Sciences and Mathematics
Extreme precipitation over the Svalbard Archipelago in the Arctic can have severe consequences for the ecosystem and society. In recent years several extreme precipitation events have been observed at Ny Ålesund, a weather station in the north-western part of the Svalbard Archipelago. The most recent observed events in the years 2012, 2016, and 2018 were the highest events in the entire [...]
Volcanologists - Who are we and where are we going?
Published: 2021-10-14
Subjects: Earth Sciences, Geography, Human Geography, Physical Sciences and Mathematics, Social and Behavioral Sciences, Volcanology
Equity, diversity and inclusivity (EDI) are principles all scientific groups and organisations should strive to achieve as they secure working conditions, policies and practices that not only promote high-quality scientific output but also well-being in their communities. In this article, we reflect on the progress of EDI in volcanology by presenting data related to memberships of international [...]