Preprints
There are 4725 Preprints listed.
An initial assessment of community representation and diversity within UK geophysics
Published: 2021-05-17
Subjects: Education
The British Geophysical Association (BGA) is a Joint Association of the Geological Society of London (GSL) and the Royal Astronomical Society (RAS) that aims to promote the subject of geophysics, and to strengthen the relationship between geology and geophysics in the UK. As such, engagement with all members of the geophysics community is integral to our purpose, and we recognise that the Earth [...]
Determination of the spatial distribution of wetting in the pore networks of rocks
Published: 2021-05-17
Subjects: Engineering, Physical Sciences and Mathematics
The macroscopic movement of subsurface fluids involved in CO2 storage, groundwater, and petroleum engineering applications is controlled by interfacial forces in the pores of rocks, micrometre to millimetre in length scale. Recent advances in physics based models of these systems has arisen from approaches simulating flow through a digital representation of the complex pore structure. However, [...]
Nature and timing of anatectic event of the Hida Belt (Japan): Constraints from titanite geochemistry and U-Pb age of clinopyroxene-bearing leucogranite
Published: 2021-05-17
Subjects: Geochemistry, Geology
The Hida Belt, central Japan, is a continental fragment, which was once a part of the crustal basement of the East Asian continental margin. It consists mainly of Permo-Triassic granite-gneiss complexes with both syn-to-late-metamorphic migmatite or granite bodies. Clinopyroxene-bearing leucogranite, locally called as 'Inishi'-type migmatite, occurs characteristically in the migmatite zone [...]
Evaluating the benefits of alternative leak detection programs
Published: 2021-05-15
Subjects: Oil, Gas, and Energy
New technologies have the potential to reduce the cost of leak detection and repair (LDAR) for producers of all sizes through smart LDAR program design, the right combination of technologies, and by collaboration between producers within the same geographic area. This potential was examined in an extensive study by conducting multiple simulations using the Arolytics AROfemp model to evaluate the [...]
AMS and rock magnetism in the Caviahue-Copahue Volcanic Complex (Southern Andes): emission center, flow dynamics, and implications to the emplacement of non-welded PDCs
Published: 2021-05-14
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Volcanology
Pyroclastic deposits can cover significant areas and register major geological events. Despite their importance, understanding depositional dynamics of pyroclastic density currents (PDCs) and linking explosive deposits to their emission centers is still a challenge, especially in the case of non-welded, massive ignimbrites. Located in the Southern Andes, the Caviahue Copahue Volcanic Complex [...]
The carbon cycle of southeast Australia during 2019-2020: Drought, fires and subsequent recovery
Published: 2021-05-13
Subjects: Atmospheric Sciences, Environmental Monitoring, Environmental Sciences, Forest Sciences, Physical Sciences and Mathematics
2019 was the hottest and driest year on record for southeast Australia leading to bushfires of unprecedented extent. Ecosystem carbon losses due to drought and fire are believed to have been substantial, but have not been well quantified. Here, we utilize space-based measurements of trace gases (TROPOspheric Monitoring Instrument XCO, Orbiting Carbon Observatory 2 XCO2) and up-scaled GPP (FluxSat [...]
A High-Resolution Shear Velocity Model of the Crust and Uppermost Mantle beneath Westernmost Mediterranean including Radial Anisotropy
Published: 2021-05-13
Subjects: Earth Sciences
Using seismic data from 1186 stations deployed across the westernmost Mediterranean, I construct a high-resolution 3-D radially anisotropic model from a joint inversion of Rayleigh and Love wave dispersions, along with receiver functions. The Rayleigh and Love data are extracted from both ambient noise interferograms and earthquake waveforms, and a new three-station ambient noise interferometry [...]
A damage model for the frictional shear failure of brittle materials in compression
Published: 2021-05-13
Subjects: Applied Mathematics, Computational Engineering, Earth Sciences, Engineering, Geology, Materials Science and Engineering, Physical Sciences and Mathematics
Damage models have been successfully employed for many decades in the modelling of tensile failure, where the crack surfaces separate as a crack grows. The advantage of this approach is that crack trajectories can be computed simply and efficiently on a fixed finite element mesh without explicit tracking. The development of damage models for shear failure in compression, where the crack faces [...]
Field evidence for disequilibrium dynamics in preserved fluvial cross-strata: A record of discharge variability or morphodynamic hierarchy?
Published: 2021-05-13
Subjects: Earth Sciences
Bedforms preserved in the rock record can provide detailed information on the morphologies and hydrodynamics of ancient fluvial systems on Earth and other planets. Existing process–product relations for bedform preservation assume that fluvial cross strata reflect conditions under which bedforms were equilibrated with the prevailing flow, i.e., steady-state conditions. However, recent theoretical [...]
Geochemical signatures of rare earth elements and yttrium in the vicinity of an ion-adsorption type deposit: roles of source sediment control
Published: 2021-05-13
Subjects: Biogeochemistry, Geochemistry, Geology, Hydrology
The elevated concentrations of rare earth elements (REE) and yttrium (REE+Y) in acid mine drainage (AMD) constitute an opportunity for REE+Y recovery. However, the source and control of REE+Y signatures in AMD remains uncertain. Water, rock, sediment and sludge samples were collected from an ion-adsorption rare earth mining area to investigate REE+Y concentration and fractionation patterns in [...]
Distributed Acoustic Sensing for Near Surface Imaging from Submarine Telecommunication Cable: Case Study in the Trondheim Fjord
Published: 2021-05-13
Subjects: Geophysics and Seismology, Geotechnical Engineering, Signal Processing, Systems and Communications
Distributed acoustic sensing (DAS) transforms submarine telecommunication cables into densely sampled seismic receivers. To demonstrate DAS applications for seismic imaging, we use an optical cable on the seafloor in the Trondheim Fjord, Norway, to record seismic data generated by a controlled seismic source. The data are simultaneously recorded by a towed hydrophone array and the fiber optic [...]
Influence of variable decoupling between vertically separated fault populations on structural inheritance – The Laminaria High, NW Shelf of Australia
Published: 2021-05-13
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
When extension events are greatly separated in time, older faults may be buried and stratigraphically separated from newly developing faults at shallower depths. During rifting, the buried structures may reactivate and propagate upwards to be expressed within the shallow system. The degree of linkage between structural levels determines the influence that the deeper structures can exert over the [...]
Distributed chaos of the atmospheric tracers
Published: 2021-05-13
Subjects: Physical Sciences and Mathematics
It is shown, using results of numerical simulations, atmospheric experiments and observations with natural trace-gases (ozone, carbon dioxide etc.), that the spatio-temporal distributed chaos can provide good quantitative description of the statistical properties of the passive scalar tracers in the atmosphere from the atmospheric surface layer up to the stratosphere. Related properties of the [...]
Advancing floating macroplastic detection from space using hyperspectral imagery
Published: 2021-05-13
Subjects: Environmental Sciences, Hydrology, Other Environmental Sciences
Airborne and spaceborne remote sensing (RS) collecting hyperspectral imagery provides unprecedented opportunities for the detection and monitoring of floating riverine and marine plastic debris. However, a major challenge in the application of RS techniques is the lack of fundamental understanding of spectral signatures of water-borne plastic debris. Recent work has emphasised the case for [...]
Mapping methane point emissions with the PRISMA spaceborne imaging spectrometer
Published: 2021-05-13
Subjects: Environmental Sciences
The detection of methane emissions from fossil fuel production activities, such as oil and gas extraction and coal mining, has been identified as a key means for the reduction of greenhouse gas emissions to the atmosphere. Several types of optical satellite sensors have recently been shown to be instrumental for this task. Spaceborne imaging spectrometers belong to this group. These instruments [...]