Preprints
Filtering by Subject: Earth Sciences
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 [...]
The seismic wavefield as seen by Distributed Acoustic Sensing (DAS) arrays: local, regional and teleseismic sources
Published: 2021-10-21
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 [...]
The role of mass-transport complexes (MTCs) in the initiation and evolution of submarine canyons
Published: 2021-10-20
Subjects: Earth Sciences, Sedimentology
The offshore area of the Otway Basin (SE Australia) is dominated by a multibranched canyon system where mass-transport complexes (MTCs) are widely distributed. Our study integrates high-resolution multibeam and seismic data to investigate the importance of MTCs in dictating the evolution of canyons. Our study interprets three regionally distributed MTCs that fail retrogressively and affect almost [...]
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 [...]
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 [...]
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 [...]
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 [...]
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 [...]
The sulfur solubility minimum and maximum in silicate melt
Published: 2021-10-09
Subjects: Earth Sciences, Physical Sciences and Mathematics
The behaviour of sulfur in magmas is complex because it dissolves as both sulfide (S2-) and sulfate (S6+) in silicate melt. An interesting aspect in the behaviour of sulfur is the solubility minima (SSmin) and maxima (SSmax) with varying oxygen fugacity (fO2). We use a simple ternary model (silicate–S2–O2) to explore the varying fO2 paths where these phenomena occur. Both SSmin and SSmax occur [...]
Grain shape effects in bed load sediment transport
Published: 2021-10-08
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics, Planetary Geomorphology
Bed load sediment transport, in which wind or water flowing over a bed of sediment causes grains to roll or hop along the bed, is a critically important mechanism in contexts ranging from river restoration to planetary exploration. Despite its widespread occurrence, predictions of bed load sediment flux are notoriously imprecise. Many studies have focused on grain size variability as a source of [...]
Impact of climate change on volcanic processes: current understanding and future challenges
Published: 2021-10-08
Subjects: Earth Sciences, Physical Sciences and Mathematics
The impacts of volcanic eruptions on climate are increasingly well understood, but the mirror question of how climate changes affect volcanic systems and processes, which we term “climate-volcano impacts”, remains understudied. Accelerating research on this topic is critical in view of rapid climate change driven by anthropogenic activities. Over the last two decades, we have improved our [...]
A Review of Open Educational Resources in the Geosciences: Guidelines and Criteria
Published: 2021-10-07
Subjects: Earth Sciences, Science and Mathematics Education
Open Educational Resources (OER) offer a link between new trends in learning and instruction, and the promise of transparency and inclusion offered by open science practices. Open textbooks, virtual field and laboratory experiences, interactive computational environments, and openly licensed media are among the many types of OER in use today. Adoption of subject-specific OER has the potential to [...]