Preprints
Filtering by Subject: Earth Sciences
Seismic diffraction imaging to better characterise mass-transport complexes: examples from the Gulf of Cadiz, south west Iberian Margin
Published: 2020-08-03
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Mass‐transport complexes (MTCs) are often characterised by small‐scale, discontinuous internal structure, such as slide blocks, rough interfaces, faults and truncated strata. Seismic images may not properly resolve such structure because seismic reflections are fundamentally limited in lateral resolution by the source bandwidth. The relatively weak seismic diffractions, instead, encode [...]
Serious Gaming for Water Resources Planning and Hazard Mitigation
Published: 2020-08-03
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Education, Environmental Engineering, Environmental Sciences, Hydrology, Physical Sciences and Mathematics, Sustainability, Water Resource Management
Hydrological hazards lead to a broad range of socio-economic and environmental risks. The development of a resilient community and risk reduction heavily rely on the adoption of holistic watershed master planning whereby the adaptation options consider the risk associated with individual or multiple hydrological hazards occurring simultaneously at a specific location. Such planning approaches [...]
An imbalancing act: the dynamic response of the Kaskawulsh Glacier to a changing mass budget
Published: 2020-08-03
Subjects: Earth Sciences, Glaciology, Physical Sciences and Mathematics
The Kaskawulsh Glacier is an iconic outlet draining the icefields of the St. Elias Mountains in Yukon, Canada. We determine and attempt to interpret its catchment-wide mass budget since 2007. Using SPOT5/6/7 data we estimate a 2007-2018 geodetic balance of $-$0.46 $\pm$ 0.17 m w.e. a$^{-1}$. By comparing computed balance fluxes with observed ice fluxes at nine flux gates we examine the [...]
Notes on Seismic Source Models in Elastostatics
Published: 2020-07-31
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Seismic source models in elastostatics lay the foundations for the popular earthquake deformation formula derived in Okada (1992), which forms key components for many studies in earthquake displacement simulations, earthquake source inversions and ground-motion predictions. However,despite of their importance, we found that the assumptions and proofs of some important theorems about the topic are [...]
Inferring Interseismic Coupling along the Lesser Antilles Arc: a Bayesian Approach
Published: 2020-07-31
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The Lesser Antilles subduction zone is a challenging region when it comes to unraveling its seismogenic behavior. Over the last century, the subduction megathrust has been seismically quiet, with no large thrust event recorded, which raises the question whether this subduction zone is able to produce large interplate earthquakes or not. However, two historical earthquakes in the 19th century, a M [...]
The formation and implications of giant blocks and fluid escape structures in submarine lateral spreads
Published: 2020-07-30
Subjects: Earth Sciences, Geology, Medicine and Health Sciences, Physical Sciences and Mathematics, Sedimentology
Lateral spread (or ‘spreading’) and submarine creep are processes that occur near the headwalls of both terrestrial landslides and submarine mass-transport complexes (MTCs). Both submarine creep and spread deposits may contain giant (km-scale) coherent blocks, but their transport processes remain poorly constrained. Here we use 2D and 3D seismic reflection data to determine the geometry, scale, [...]
Robust Q estimation using surface seismic data
Published: 2020-07-30
Subjects: Applied Mathematics, Computational Engineering, Earth Sciences, Engineering, Geophysics and Seismology, Numerical Analysis and Computation, Physical Sciences and Mathematics
Direct wave arrivals are the most robust signals to determine velocity and consequently they have been used for almost a century in hydrocarbon exploration. The reason is simple as the arrivaltime is explicitly available and provide a direct measurement of the average velocity of the sub-surface ray-path. These signals have not been extensively used to estimate attenuation or Q. One reason may [...]
Basement-Controlled Deformation of Sedimentary Sequences, Anadarko Shelf, Oklahoma
Published: 2020-07-30
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
Structures rooted in the crystalline basement frequently control the deformation of the host bedrock and the overlying sedimentary sequences. Here, we elucidate the structure of the c. 2‐km deep Precambrian granitic basement in the Anadarko Shelf, Oklahoma, and how the propagation of basement faults deformed the sedimentary cover. Although the basin is foreland in origin, the gently dipping shelf [...]
Crop residues are a key feedstock to bioeconomy but available methods for their estimation are highly uncertain
Published: 2020-07-29
Subjects: Agriculture, Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Sciences, Life Sciences, Natural Resource Economics, Natural Resources and Conservation, Other Earth Sciences, Other Environmental Sciences, Physical Sciences and Mathematics, Sustainability
Crop residues are acknowledged as a key biomass resource to feed tomorrow’s sustainable bioeconomy. Yet, the quantification of these residues at large geographical scales is primarily reliant upon generic statistical estimations based on empirical functions linking the residues production to the primary crop yield. These useful yet unquestioned functions are developed either using direct evidence [...]
From XRF and hyperspectral analyses to an automatic way to detect flood events on sediment cores
Published: 2020-07-29
Subjects: Earth Sciences, Physical Sciences and Mathematics, Sedimentology
Long-term changes in flood activity have often been reconstructed to understand their relationships to climate changes. This requires to identify flood layers according to certain characteristics (e.g. texture, geochemical composition, grain-size) and then to count them using naked-eye observation. This method is, however, time-consuming, and intrinsically characterized by a low resolution that [...]
Explaining the dependence of M-site diffusion in forsterite on silica activity: a Density Functional Theory approach
Published: 2020-07-29
Subjects: Earth Sciences, Mineral Physics, Physical Sciences and Mathematics
Experimentally silica activity (aSiO2) has been shown to have an effect on Mg diffusion in forsterite but without any obvious mechanism. We calculated the effects of aSiO2 and aluminium content (the main contaminant in the experimental studies), and their co-effect, on Mg diffusion in forsterite, using thermodynamic minimisations of defect formation energies (calculated using Density Functional [...]
The Volcanic & Magmatic Studies Group Equality, Diversity and Inclusion Report 2020
Published: 2020-07-24
Subjects: Earth Sciences, Education, Physical Sciences and Mathematics, Volcanology
The Volcanic and Magmatic Studies Group (VMSG) takes equality, diversity and inclusion (EDI) seriously and we recognise that the under-representation and/or unconscious marginalisation of any group impacts on our ability to fulfill our mission to serve the volcanology, petrology and geochemistry community. The following report summarises the findings from both the 2016-2020 VMSG annual meetings [...]
Volcanic and Magmatic Studies Group Members Survey 2020
Published: 2020-07-24
Subjects: Earth Sciences, Physical Sciences and Mathematics, Volcanology
The Volcanic & Magmatic Studies Group (VMSG) is a joint Special Interest Group of the Geological Society of London and Mineralogical Society. In January 2020 we conducted an online questionnaire to establish if (and how) VMSG fulfils its mission to serve the volcanology, petrology and geochemistry community. The survey was distributed via the VMSG mailing list, publicised at the VMSG annual [...]
Small-scale capillary heterogeneity linked to rapid plume migration during CO2 storage
Published: 2020-07-24
Subjects: Earth Sciences, Physical Sciences and Mathematics
Unpredicted, rapid plume elongation has been observed at subsurface CO2 storage projects worldwide, exemplified by the Sleipner project. We show that conventionally ignored centimetre-metre scale heterogeneity in capillary pressure characteristics can manifest as rapid field-scale, decametre-kilometre, plume migration. We analyse the effect in the Goldeneye Field, UK, a proposed storage site with [...]
Comparison of U-Pb detrital zircon signatures across sediment routing system segments: insights from the late Pleistocene Mississippi River and Deep-sea fan
Published: 2020-07-22
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
The Pleistocene Mississippi sediment routing system has experienced significant drainage reorganizations in response to Northern Hemisphere glaciation. Geologically recent (<25 ka) and large (~90 km) river avulsions have occurred in the Mississippi’s lower alluvial valley, yet whether these punctuated autogenic phenomena influenced down system records of sedimentary provenance is unknown. We [...]