Preprints
Filtering by Subject: Earth Sciences
Investigation on the Impacts of COVID-19 Lockdown and Influence Factors on Air Quality in Greater Bangkok, Thailand
Published: 2020-11-06
Subjects: Earth Sciences, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology
With the outbreak of the COVID-19 pandemic around the world, many countries announced lockdown measures, including Thailand. Several scientific studies have reported on improvements in air quality due to the impact of these COVID-19 lockdowns. This study aims to investigate the effects of the COVID-19 lockdown and its driving influence factors on air pollution in Greater Bangkok, Thailand using [...]
Thickness of the Saudi Arabian Crust
Published: 2020-11-05
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
We analyzed P-wave receiver functions from seismic stations covering most of Saudi Arabia to map the thickness of the crust across the Arabian plate. We present an update of crustal-thickness estimates and fill in data gaps for the western shield and the rifted margin at the Red Sea, as well as the eastern Arabian platform. Our application of a conventional H-k stacking algorithm included [...]
Preservation and re-exposure of late Palaeozoic glacial rock surfaces through cyclical burial and exhumation: apatite fission track evidence from the Fleurieu Peninsula, southeastern Australia
Published: 2020-11-05
Subjects: Earth Sciences, Physical Sciences and Mathematics
The antiquity of the Australian landscape has long been the subject of debate, with some studies inferring extraordinary longevity (>10^8 Myr) for some subaerial landforms dating back to the early Palaeozoic. A number of late Palaeozoic glacial erosion surfaces in the Fleurieu Peninsula, southeastern Australia, provide an opportunity to test the notion of long-term subaerial emergence, and thus [...]
Segment tip geometry of sheet intrusions, II: Field observations of tip geometries and a model for evolving emplacement mechanisms
Published: 2020-11-03
Subjects: Earth Sciences, Geology, Volcanology
Igneous sheet intrusions are segmented across several orders of magnitude, with segment tip geometry commonly considered indicative of the propagation mechanism (brittle or non-brittle). Proposed propagation mechanisms are inferred to represent host rock mechanical properties during initial magma emplacement; typically, these models do not account for segment sets that show a range of tip [...]
IBM PAIRS: Scalable big geospatial-temporal data and analytics as-a-service
Published: 2020-11-02
Subjects: Earth Sciences, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology
The rapid growth of geospatial-temporal data from sources like satellites, drones, weather modeling, IoT sensors etc., accumulating at a pace of PetaBytes to ExaBytes annually, opens unprecedented opportunities for both science and industrial applications. However, the sheer size and complexity of such data presents significant challenges for conventional geospatial information systems (GIS) [...]
Influence of ductile substrates and layer thickness on the spacing and topology of layer bound fault systems
Published: 2020-11-02
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Sedimentology, Tectonics and Structure
Polygonal fault systems are extraordinary features of many fine grained sedimentary succession and have been described from a significant number of deepwater sedimentary basins over the last two decades. Their formation represents an important mechanism by which fine grained sediments compact often resulting in a variety of complex patterns for which several controlling factors have been [...]
The miscibility of Calcium Silicate Perovskite and Bridgmanite: A single phase perovskite in hot, iron-rich regions
Published: 2020-11-02
Subjects: Earth Sciences, Mineral Physics, Physical Sciences and Mathematics
Calcium silicate perovskite and bridgmanite are two phases believed to coexist throughout the lower mantle, which at some temperature, at least theoretically, dissolve into each other to form a single perovskite solid solution (CaxMg1-xSiO3). This may have large seismic and geochemical implications due to the changes in density, elasticity and element partition coefficients between single and [...]
Extreme curvature of shallow magma pathways controlled by competing stresses
Published: 2020-10-30
Subjects: Earth Sciences, Physics
Eruptions at shield volcanoes often occur from radially aligned linear fissures fed by blade-like magma-filled cracks (dykes). The fissures of the 2018 Sierra Negra eruption were scattered on the flank of the volcano. Space-borne radar interferometric data (InSAR) revealed that, unexpectedly, part of the eruption was fed by a 15 km long, tortuous and flat-lying crack (sill). Here we develop a [...]
Rayleigh wave H/V ratio measurement from ambient noise cross-correlations, and its sensitivity to Vp: a numerical study
Published: 2020-10-30
Subjects: Earth Sciences, Geophysics and Seismology
The promise of passive seismology has increasingly been realized in recent years. Given the expense in installing and maintaining seismic station networks, it is important to extract as much information from the measurements as possible. In this context, the ellipticity or H/V amplitude ratio of Rayleigh waves can prove to be a valuable observable in ambient noise seismology due to its [...]
Megathrust Modeling Workshop Report
Published: 2020-10-29
Subjects: Earth Sciences
The Planning for a Modeling Collaboratory for Subduction Zone Science (MCS) Research Coordination Network (RCN) is one of three RCNs funded by the National Science Foundation (NSF) following the 2016 Subduction Zone Observatory (SZO) workshop. The MCS RCN aims to facilitate the development of the integrative earthquake and volcano modeling component of SZ4D, the MCS, and explore how computational [...]
Studying the initiation of volcanic eruptions: Time for a petrological perspective.
Published: 2020-10-28
Subjects: Earth Sciences, Volcanology
Volcano monitoring is essential for mitigating the risks associated with volcanic activity. As monitoring becomes more sophisticated and widespread, there is a growing need for understanding the relationship between different monitoring records and magmatic processes occurring at depth. This is particularly relevant to the processes that initiate eruptions after the extended periods of repose and [...]
Assimilation of GNSS Reflectometry Delay-Doppler Maps into Global Ocean Surface Wind Analyses
Published: 2020-10-26
Subjects: Earth Sciences
Direct remote sensing observations (e.g. radar backscatter, radiometer brightness temperature, or radio occultation bending angle) are often more effective for use in data assimilation (DA) than the corresponding geophysical retrievals (e.g. ocean surface winds, soil moisture, or atmospheric water vapor). In the particular case of Global Navigation Satellite System Reflectometry (GNSS-R), the [...]
Salt-magma interactions influence intrusion distribution and salt tectonics in the Santos Basin, offshore Brazil
Published: 2020-10-25
Subjects: Earth Sciences, Geology, Tectonics and Structure, Volcanology
Many sedimentary basins host thick evaporite (salt) deposits. Some of these basins also host extensive igneous intrusion networks. It thus seems inevitable that, in some locations, magma will interact with salt. Yet how interaction between these materials may influence salt tectonics or magma emplacement, particularly at the basin-scale, remains poorly understood. We use 3D seismic reflection [...]
Modeling transpiration with sun-induced chlorophyll fluorescence via water use efficiency and stomatal conductance
Published: 2020-10-25
Subjects: Earth Sciences, Hydrology
Successfully applied in the carbon research area, sun-induced chlorophyll fluorescence (SIF) has raised the interest of researchers from the water research domain. However, the mechanism between SIF emitted by plants and transpiration (T) has not been fully explored. To improve the understanding of the relationship between SIF and T, we developed two SIF-T models, the WUE model and the [...]
Microbial lipid signatures in Arctic deltaic sediments - insights into methane cycling and climate variability
Published: 2020-10-24
Subjects: Earth Sciences
Glycerol Dialkyl Glycerol Tetraethers (GDGTs) are ubiquitous biomolecules whose structural diversity or isotopic composition is increasingly used to reconstruct environmental changes such as air temperatures or pCO2. Isoprenoid GDGTs, in particular GDGT-0, are biosynthesized by a large range of Archaea. To assess the potential of GDGT-0 as a tracer of past methane cycle variations, three sediment [...]