Preprints
Filtering by Subject: Earth Sciences
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: 2020-07-23
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 [...]
Transgressive sills and lateral lava flows: On the visual observation of igneous sheets in rugged terrains and the optical illusion factor
Published: 2020-07-22
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
Abstract Transgressive sills are of common occurrences in rift-related offshore and onshore sedimentary settings worldwide and have been reported in onshore volcanic settings in e.g. flood basalt provinces as well. General geometries of individual sills and of entire sill complexes too are well documented from seismic images in many offshore sedimentary settings of exploration interest, but [...]
Visualizing the daily evolution and extent of snow drought
Published: 2020-07-22
Subjects: Earth Sciences, Environmental Sciences, Hydrology, Natural Resources Management and Policy, Physical Sciences and Mathematics
Snow droughts are commonly defined as below average snowpack at a point in time, typically 1 April in the western United States. This definition is valuable for interpreting the state of the snowpack for resource management but obscures the temporal evolution of snow drought. Borrowing from dynamical systems theory, we applied phase diagrams to visually examine the evolution of snowpack [...]
Estimating survival probability using the terrestrial extinction history for the search for extraterrestrial life
Published: 2020-07-22
Subjects: Astrophysics and Astronomy, Earth Sciences, Physical Sciences and Mathematics, Planetary Sciences
Several exoplanets have been discovered to date, and the next step is the search for extraterrestrial life. However, it is difficult to estimate the number of life-bearing exoplanets because our only template is based on life on Earth. In this paper, a new approach is introduced to estimate the probability that life on Earth has survived from birth to the present based on its terrestrial [...]
The Anthropozoic era revisited
Published: 2020-07-22
Subjects: Earth Sciences, Physical Sciences and Mathematics, Stratigraphy
This paper explains in some detail the poorly known proposal of Stoppani (1873) regarding the Anthropozoic era, whose beginning was defined by the first traces of human presence on Earth. This author set the stratigraphic bases for the definition of the “human era”, but the proposal had two main weaknesses: the dismissal of biological evolution and the lack of an absolute chronology. Further [...]
Contributions of paleoecology to Easter Island’s prehistory: a thorough review
Published: 2020-07-22
Subjects: Earth Sciences, Ecology and Evolutionary Biology, Environmental Sciences, Life Sciences, Physical Sciences and Mathematics, Plant Sciences, Sustainability
Easter Island (Rapa Nui) is well known for the enigmas surrounding its unique megalithic statues, the moai, and the prehistoric (i.e., pre-European contact) Rapanui society that built them. These enigmas include, among others, the time of the island’s settlement, the geographical origin of the first settlers, the technology associated with moai transportation and emplacement, the occurrence (or [...]
Observing traveling waves in glaciers with remote sensing: New flexible time series methods and application to Sermeq Kujalleq (Jakobshavn Isbræ), Greenland
Published: 2020-07-22
Subjects: Earth Sciences, Glaciology, Physical Sciences and Mathematics
The recent influx of remote sensing data provides new opportunities for quantifying spatiotemporal variations in glacier surface velocity and elevation fields. Here, we introduce a flexible time series reconstruction and decomposition technique for forming continuous, time-dependent surface velocity and elevation fields from discontinuous data and partitioning these time series into short- and [...]