Preprints
Filtering by Subject: Earth Sciences
Monitoring seasonal variations in seismic velocity and groundwater levels in Harvey, Western Australia using borehole ambient seismic noise interferometry
Published: 2020-01-30
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
In order to explore the relationships between environmental subsurface changes and seismic velocities, we use nearly four years (2015-2018) of continuous ambient seismic noise data recorded in a multi-level borehole sensor array to measure relative seismic velocity changes at the SW Hub CO2 Geosequestration Site in Harvey, Western Australia using seismic noise interferometry. We find a direct [...]
Sensitivity Analysis of a Conceptual, Lumped Model Using VARS-TOOL Applied to Western Ghats Catchments of India
Published: 2020-01-30
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Engineering, Environmental Sciences, Hydrology, Other Civil and Environmental Engineering, Physical Sciences and Mathematics, Water Resource Management
The present work considers the application of Variogram Analysis of Response Surfaces Toolbox (VARS-TOOL) to identify the sensitive parameters of a rainfall-runoff model in the Netravati river basin of Karnataka, India using the global sensitivity analysis method. The statistical bootstrapping method is used to obtain the confidence intervals around each of the sensitivity indices. The VARS-TOOL [...]
Avalonia, get bent! Paleomagnetism from SW Iberia confirms the Greater Cantabrian Orocline
Published: 2020-01-28
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
The amalgamation of Pangea formed the contorted Variscan-Alleghanian orogen, suturing Gondwana and Laurussia during the Carboniferous. From all swirls of this orogen, a double curve stands out in Iberia, the coupled Cantabrian Orocline and Central Iberian Curve. The Cantabrian Orocline formed subsequent to Variscan orogeny (ca. 315-295 Ma). The mechanisms of formation for this orocline are [...]
High Attenuation Recycled Materials as landfill liners (the HARM project) – A new concept for improved landfill liner design
Published: 2020-01-28
Subjects: Bioresource and Agricultural Engineering, Civil and Environmental Engineering, Earth Sciences, Education, Engineering, Engineering Science and Materials, Environmental Public Health, Environmental Sciences, Geochemistry, Geotechnical Engineering, Hydrology, Medicine and Health Sciences, Physical Sciences and Mathematics, Public Health, Soil Science
A new approach in landfill liner design which combines hydraulic containment of leachate with contaminant attenuation to improve the performance of these environmental control systems at landfills is described. The idea is to re-use readily available industrial waste residues (construction and biomass waste) as additives for natural clay liners, wherein the additives have specific properties [...]
Event-based contact angle measurements inside porous media using time-resolved micro-computed tomography
Published: 2020-01-28
Subjects: Earth Sciences, Fluid Dynamics, Hydrology, Physical Sciences and Mathematics, Physics
Hypothesis Capillary-dominated multiphase flow in porous materials is strongly affected by the pore walls’ wettability. Recent micro-computed tomography (mCT) studies found unexpectedly wide contact angle distributions measured on static fluid distributions inside the pores. We hypothesize that analysis on time-resolved mCT data of fluid invasion events may be more directly relevant to the fluid [...]
Suspended-sediment induced stratification inferred from concentration and velocity profile measurements in the lower Yellow River, China
Published: 2020-01-27
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics, Sedimentology
Despite a multitude of models predicting sediment transport dynamics in an open-channel flow, the interaction between fluid and sediment, so to produce self-organized vertical density stratification, has not been robustly investigated and as such is poorly understood. This two-phase phenomenon develops in channels that possess low channel-bed slope and high sediment concentration. As the Yellow [...]
Post-critical SsPmp and its Applications to Virtual Deep Seismic Sounding (VDSS)–3: Back-projection Imaging of the Crust-Mantle Boundary in a Heterogeneous Lithosphere
Published: 2020-01-25
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Virtual Deep Seismic Sounding (VDSS) uses the arrival time of post-critical SsPmp relative to the direct S wave to infer Moho depth at the Pmp reflection point. Due to the large offset between the virtual source and the receiver, SsPmp is more sensitive to lateral variations of structures than near-vertical phases such as Ps that is used to construct conventional P receiver functions. However, [...]
Rainsplash Erosion for Natural Slopes and Rainfall Conditions
Published: 2020-01-24
Subjects: Earth Sciences, Environmental Sciences, Geomorphology, Physical Sciences and Mathematics
Rainsplash is significant for interrill erosion since it facilitates the movement of loosened soil frangments. Because it is a technically dicult process to measure, many studies focus on experimental simulation under controlled conditions both in field and laboratory. Raindrop erosion studies have produced models to predict the erosivity due to raindrop impact on varying ground surfaces, with a [...]
Dynamics of displacement in mixed-wet porous media
Published: 2020-01-22
Subjects: Earth Sciences, Engineering, Fluid Dynamics, Physical Sciences and Mathematics, Physics
We identify a distinct two-phase flow invasion pattern in a mixed-wet porous medium. Time-resolved high-resolution synchrotron X--ray imaging is used to study the invasion of water through a small rock sample filled with oil, characterized by a wide non-uniform distribution of local contact angles both above and below $90^{\circ}$. The water advances in a connected front, but throats are not [...]
Dilation of subglacial sediment governs incipient surge motion in glaciers with deformable beds
Published: 2020-01-22
Subjects: Earth Sciences, Glaciology, Physical Sciences and Mathematics
Glacier surges are quasi-periodic episodes of rapid ice flow that arise from increases in slip-rate at the ice-bed interface. The mechanisms that trigger and sustain surges are not well-understood. Here, we develop a new model of incipient surge motion for glaciers underlain by sediments to explore how surges may arise from slip instabilities within a thin layer of saturated, deforming subglacial [...]
Pleistocene - Holocene volcanism at the Karkar geothermal prospect, Armenia
Published: 2020-01-22
Subjects: Earth Sciences, Geochemistry, Geology, Other Earth Sciences, Physical Sciences and Mathematics, Volcanology
Quaternary volcanic centres north of the Bitlis-Zagros suture in Turkey, Iran and the Caucasus represent both volcanic hazards and potential or actual geothermal energy resources. Such challenges and opportunities cannot be fully quantified without understanding these volcanoes’ petrogenesis, geochronology and magmatic, tectonic or other eruption triggers. In this preliminary study, we discuss [...]
Seismic source tracking with six degree-of-freedom ground motion observations
Published: 2020-01-17
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Back azimuth (BAz) information can be determined from combined measurements of rotations and translations at a single site. Such six degree-of-freedom (6-DoF) measurements are reasonably stable in delivering similar information compared to a small-scale array of three-component seismometers. Here we investigate whether a 6-DoF approach is applicable to tracking seismic sources. While common [...]
The architecture of an intrusion in magmatic mush
Published: 2020-01-17
Subjects: Earth Sciences, Physical Sciences and Mathematics, Volcanology
Magmatic reservoirs located in the upper crust have been shown to result from the repeated intrusions of new magmas, and spend much of the time as a crystal-rich mush. The geometry of the intrusion of new magmas may greatly affect the thermal and compositional evolution of the reservoir. Despite advances in our understanding of the physical processes that may occur in a magmatic reservoir, the [...]
Abyssal Circulation Driven By Near-Boundary Mixing: Water Mass Transformations and Interior Stratification
Published: 2020-01-13
Subjects: Earth Sciences, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The emerging view of the abyssal circulation is that it is associated with bottom enhanced mixing, which results in downwelling in the stratified ocean interior and upwelling in a bottom boundary layer along the insulating and sloping seafloor. In the limit of slowly-varying vertical stratification and topography, however, boundary layer theory predicts that these up- and down-slope flows largely [...]
Discriminating stacked distributary channel from palaeovalley fill sand bodies in foreland basin settings
Published: 2020-01-10
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Stratigraphy
Stacked fluvial distributary channel deposits and palaeovalley fills can form major, multi-storey sand bodies with similar thicknesses, and with lateral extents often greater than a single exposure. Consequently, they can be difficult to tell apart from one another using outcrop data. This study addresses this problem by quantitatively analysing the architecture of five stacked fluvial [...]