Preprints
There are 6976 Preprints listed.
Comparison of permeability predictions on cemented sandstones with physics-based and machine learning approaches
Published: 2020-02-06
Subjects: Chemical Engineering, Earth Sciences, Engineering, Hydrology, Multivariate Analysis, Petroleum Engineering, Physical Sciences and Mathematics, Statistics and Probability
Permeability prediction has been an important problem since the time of Darcy. Most approaches to solve this problem have used either idealized physical models or empirical relations. In recent years, machine learning (ML) has led to more accurate and robust, but less interpretable empirical models. Using 211 core samples collected from 12 wells in the Garn Sandstone from the North Sea, this [...]
Machine learning for digital soil mapping: applications, challenges and suggested solutions
Published: 2020-02-06
Subjects: Agriculture, Life Sciences, Other Life Sciences
The uptake of machine learning (ML) algorithms in digital soil mapping (DSM) is transforming the way soil scientists produce their maps. Machine learning is currently applied to mapping soil properties or classes much in the same way as other unrelated fields of science. Mapping of soil, however, has unique aspects which require adaptations of the ML algorithms. These features are for example, [...]
Novel insights from Fe-isotopes into the lithological heterogeneity of Ocean Island Basalts and plume-influenced MORBs
Published: 2020-02-02
Subjects: Earth Sciences, Geochemistry, Physical Sciences and Mathematics, Volcanology
The extent of lithological heterogeneity in the Earth’s convecting mantle is highly debated. Whilst the presence of pyroxenite in the mantle source regions of Ocean Island Basalts (OIBs) has traditionally been constrained using the minor-element chemistry of olivine phenocrysts, recent studies have shown that the Ni and Mn contents of primitive olivines are influenced by the conditions of mantle [...]
Drivers of Local Ocean Heat Content Variability in ECCOv4
Published: 2020-02-06
Subjects: Climate, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Variation in upper ocean heat content is a critical factor in understanding global climate variability. By using temperature anomaly budgets in a physically consistent ocean state estimate we describe the balance between atmospheric forcing and ocean transport mechanisms for different depth horizons and at varying temporal and spatial resolutions. The processes controlling local variations in [...]
Centrifugal and symmetric instability during Ekman adjustment of the bottom boundary layer
Published: 2020-02-04
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Flow along isobaths of a sloping lower boundary generates an across-isobath Ekman transport in the bottom boundary layer. When this Ekman transport is down the slope it causes convective mixing --- much like a downfront wind in the surface boundary layer --- destroying stratification and potential vorticity. In this manuscript we show how this can lead to the development of a forced centrifugal [...]
A new model for fault growth during syn-kinematic deposition
Published: 2020-02-04
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
Constraining the mechanisms of fault growth is essential for understanding extensional tectonics. In these dynamic systems the propagation of existing faults through recent syn-kinematic depositions is a poorly understood yet critical process. To understand how underlying structures influence faulting, we examine fault growth in a 10 kyr magmatically-resurfaced region of the Krafla fissure swarm, [...]
High-resolution surface velocities and strain for Anatolia from Sentinel-1 InSAR and GNSS data
Published: 2020-02-04
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
Measurements of present-day surface deformation are essential for the assessment of long-term seismic hazard. The European Space Agencys Sentinel-1 satellites enable global, high-resolution observation of crustal motion from Interferometric Synthetic Aperture Radar (InSAR). We have developed new automated InSAR processing systems that exploit the first ~5 years of Sentinel-1 data to measure [...]
Comprehensive review of the annual haze episode in Northern Thailand
Published: 2023-12-09
Subjects: Environmental Sciences, Environmental Studies, Oceanography and Atmospheric Sciences and Meteorology, Public Health
The mountainous part of northern Thailand is subject to an intense haze episode occurring almost every year between January and May. In the last couple of decades, this atmospheric phenomenon has been extensively covered in the media and is now a main concern for the population living in this area. In this review, we synthesized the information available from hundreds of publications on air [...]
Developing a coral proxy system model to compare coral and climate model estimates of changes in paleo-ENSO variability
Published: 2020-02-04
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Coral records of surface-ocean conditions extend our knowledge of interannual El Niño-Southern Oscillation (ENSO) variability into the pre-instrumental period. That said, the wide range of natural variability within the climate system as well as multiple sources of uncertainties inherent to the coral archive produce challenges for the paleoclimate community to detect forced changes in ENSO using [...]
‘Scallywag Bunkers’: Geophysical Investigations of WW2 Auxiliary Unit Operational Bases (OBs) in the UK
Published: 2020-02-05
Subjects: Earth Sciences, Education, Geography, Other Earth Sciences, Other Physical Sciences and Mathematics, Physical Sciences and Mathematics, Social and Behavioral Sciences
In 1940, with the fall of France imminent, Britain prepared for invasion. After Dunkirk, with most armour and transport lost, a defence ‘stop line’ (GHQ Line) was prepared. Local Defence Volunteers (later Home Guard) were raised to buy time for the Home Army to deploy. Secret ‘Auxiliary Units’ were also formed, tasked with ‘Scallywagging’ – guerrilla activities ––in the invading army’s rear. 4-8 [...]
Base Level Changes based on Basin Filling Modelling: a Case Study from the Paleocene Lishui Sag, East China Sea Basin
Published: 2020-02-04
Subjects: Earth Sciences, Physical Sciences and Mathematics, Sedimentology
Estimation of base level changes in geological records is an important topic for petroleum geologists. Taking the Paleocene Upper Lingfeng Member of Lishui Sag as an example, this paper conducted a base level reconstruction based on Basin Filling Modelling (BFM). The reconstruction was processed on the ground of a previously interpreted seismic stratigraphic framework with several assumptions and [...]
A Shallow Water Model for Convective Self-Aggregation
Published: 2020-02-02
Subjects: Atmospheric Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Convective self-aggregation is proposed to be fundamental to the development of tropical cyclones and the Madden-Julian Oscillation, both of which are long-term mysteries in tropical meteorology. Therefore, understanding self-aggregation is key to deciphering how convection works in the tropical atmosphere. Here we present a 1D shallow water model that simulates the dynamics of the planetary [...]
On the potential of linked-basin tidal power plants: an operational and coastal modelling assessment
Published: 2020-02-02
Subjects: Civil and Environmental Engineering, Computational Engineering, Engineering, Environmental Engineering, Hydraulic Engineering, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Single-basin tidal range power plants have the advantage of predictable energy outputs, but feature non-generation periods in every tidal cycle. Linked-basin tidal power systems can reduce this variability and consistently generate power. However, as a concept the latter are under-studied with limited information on their performance relative to single-basin designs. In addressing this, we [...]
Entangled external and internal controls on submarine fan evolution: an experimental perspective
Published: 2020-02-02
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Submarine fans are formed by sediment-laden flows shed from continental margins into ocean basins. Their morphology represents the interplay of external controls such as tectonics, climate, and sea-level with internal processes including channel migration and lobe compensation. However, the nature of this interaction is poorly understood. We used physical modelling to represent the evolution of a [...]
The what, how and why of human coprolite analysis in archaeology
Published: 2020-02-06
Subjects: Earth Sciences, Environmental Sciences, Environmental Studies, Life Sciences, Other Earth Sciences, Physical Sciences and Mathematics, Social and Behavioral Sciences
Coprolites are a highly informative but still underutilized proxy for understanding past environments, palaeodiets, and ancient human health. Here we provide a critical review of the history and current state of research in human coprolite analysis encompassing, macroscopic, microscopic, and biomolecular approaches. We present new data from a number of key sites which demonstrates how new [...]