Preprints
Filtering by Subject: Physical Sciences and Mathematics
Late Eocene-early Oligocene paleoenvironmental changes recorded at Lühe, Yunnan, southwestern China
Published: 2021-10-23
Subjects: Physical Sciences and Mathematics
During the late Eocene to the early Oligocene, marine records document a globally congruent record of declining carbon dioxide concentrations, Antarctic icesheet growth, and associated reorganisation of the global climate system. In contrast, the few existing terrestrial records demonstrate high heterogeneity of environmental change and are difficult to reconcile with those of the oceanic realm. [...]
Sharp-based, mixed carbonate-siliciclastic shallow-marine deposits (upper Miocene, Betic Cordillera, Spain): the record of ancient transgressive shelf ridges?
Published: 2021-10-23
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Isolated sharp-based sedimentary bodies in shelf settings can develop via the reworking of regressive deposits during transgressions. An example of these are shelf ridges, formed under a wide range of processes, and widely studied due to their high reservoir potential. However, there is still a lack of examples in mixed (carbonate-siliciclastic) successions. This study presents an outcrop example [...]
Constraints on the ice composition of carbonaceous chondrites from their magnetic mineralogy
Published: 2021-10-22
Subjects: Earth Sciences, Geochemistry, Physical Sciences and Mathematics, Planetary Sciences
Carbonaceous chondrites experienced varying degrees of aqueous alteration on their parent asteroids, which influenced their mineralogies, textures, and bulk chemical and isotopic compositions. Although this alteration was a crucial event in the history of these meteorites, their various alteration pathways are not well understood. One phase that formed during this alteration was magnetite, and [...]
Fe5S2 identified as a host for sulfur in Earth and planetary cores
Published: 2021-10-22
Subjects: Physical Sciences and Mathematics
Cosmochemical considerations suggest that sulfur is a candidate light alloying element in rocky planetary cores, such that the high pressure-temperature (P-T) Fe-S phase relations likely play a key role in planetary core crystallization thermodynamics. The iron-saturated Fe-S phase relations were investigated to 200 GPa and 3250 K using combined powder and single-crystal X-ray diffraction [...]
The seismic wavefield as seen by Distributed Acoustic Sensing (DAS) arrays: local, regional and teleseismic sources
Published: 2021-10-20
Subjects: Earth Sciences, Physical Sciences and Mathematics
Distributed acoustic sensing (DAS) exploiting fibre optic cables provides a means for high-density sampling of the seismic wavefield. The scattered returns from multiple laser pulses provide local averages of strain rate over a finite gauge length, and the nature of the signal depends on the orientation of the cable with respect to the passing seismic waves. The properties of the wavefield in [...]
Linking technical geothermal potential from borehole heat exchangers and heating demand scenarios on a regional scale
Published: 2021-10-20
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Sciences, Natural Resources Management and Policy, Other Earth Sciences, Physical Sciences and Mathematics
Extracting shallow geothermal energy using borehole heat exchangers (BHEs) can help decarbonising the residential heating sector. To assist urban planers and policy makers in developing carbon-neutral heating plans the regional technical shallow geothermal potential must be analysed. Here, we propose a methodology to estimate the technical geothermal potential of BHE fields on a regional scale [...]
Ocean model response to stochastically perturbed momentum fluxes
Published: 2021-10-20
Subjects: Physical Sciences and Mathematics
In climate model configurations, standard approaches to the representation of unresolved, or subgrid scales, via deterministic closure schemes are being challenged by stochastic approaches inspired by statistical dynamical theory. Despite gaining popularity, studies of various stochastic subgrid scale parameterizations applied to atmospheric climate and weather prediction systems have revealed 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 [...]
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 [...]
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 [...]