Preprints
Filtering by Subject: Physical Sciences and Mathematics
Flow directions of rivers are set by the mantle
Published: 2020-04-17
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Large rivers play crucial roles in determining loci of civilisation, natural resources and biodiversity. The positions of their mouths control nutrient and sediment supply to oceans. The paths that rivers take across the Earth’s surface varies considerably with scale. For example, at large scales big North American rivers (e.g. Mississippi, Colorado, Columbia) have simple flow paths that can be [...]
Lateral variations in lower crustal strength control the temporal evolution of mountain ranges: examples from south-east Tibet
Published: 2020-04-17
Subjects: Earth Sciences, Geochemistry, Geomorphology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Controversy surrounds the rheology of the continental lithosphere, and how it controls the evolution and behaviour of mountain ranges. In this study, we investigate the effect of lateral contrasts in the strength of the lower crust, such as those between cratonic continental interiors and weaker rocks in the adjacent deforming regions, on the evolution of topography. We combine numerical [...]
Evaluating UK natural hazards: the national risk assessment
Published: 2020-04-15
Subjects: Earth Sciences, Environmental Indicators and Impact Assessment, Environmental Sciences, Other Environmental Sciences, Physical Sciences and Mathematics
Despite its relatively temperate climate and stable geography, natural hazards present multiple risks to human activity in the UK. These range from small-scale local occurrences, such as landslides, through regional incidents, such as flooding, to major high impact, low probability events, such as space weather. The impacts of such hazards can be wide-ranging but may include disruption to [...]
Do atmospheric plastics act as fomites for novel viruses?
Published: 2020-04-15
Subjects: Atmospheric Sciences, Civil and Environmental Engineering, Engineering, Environmental Health and Protection, Environmental Sciences, Life Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Plastic particles are ubiquitous in various environmental compartments, the atmosphere being the least explored compartment in terms of plastic pollution. The way that atmospheric plastics affect the biological systems has not yet been explored when compared to aquatic ecosystems. There are many speculated human health impacts, one definite and direct impact of atmospheric plastics would be [...]
Forming a Mogi Doughnut in the years prior to and immediately before the the 2014 M8.1 Iquique, Northern Chile Earthquake
Published: 2020-04-15
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
Asperities are patches where the fault surfaces stick until they break in earthquakes. Locating asperities and understanding their causes in subduction zones is challenging because they are generally located offshore. We use seismicity, inter- and co-seismic slip, and the residual gravity field to map the asperity responsible for the 2014 M8.1 Iquique Chile earthquake. Until two weeks before the [...]
The tipping points and early-warning indicators for Pine Island Glacier, West Antarctica
Published: 2020-04-15
Subjects: Earth Sciences, Glaciology, Physical Sciences and Mathematics
Mass loss from the Antarctic Ice Sheet is the main source of uncertainty in projections of future sea-level rise, with important implications for coastal regions worldwide. Central to this is the marine ice sheet instability: once a critical threshold, or tipping point, is crossed, ice-internal dynamics can drive a self-amplifying retreat committing a glacier to irreversible, rapid and [...]
Recognizing fracture pattern signatures contributed by seismic loadings
Published: 2020-04-14
Subjects: Earth Sciences, Geology, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
The impacts of seismic loadings to fault zone rocks are still not well understood. While field and experimental studies have suggested several markers, such as pseudotachylytes and pulverized rocks, for indicating seismic loadings, the corresponding markers of other types or at larger scales are still lacking. Here by summarizing results of dynamic ruptures with off-fault damage, we recognize [...]
The enigma of the Albian Gap: spatial variability and the competition between salt expulsion and extension
Published: 2020-04-14
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Stratigraphy, Tectonics and Structure
The Albian Gap is a uniquely large (up to 65 km wide and >450 km long), enigmatic salt-related structure in the Santos Basin, offshore Brazil. It is located near the basin margin and trends NE (i.e. sub-parallel to the Brazilian coastline). The gap is characterized by a near-complete absence of Albian strata above depleted Aptian salt. Its most remarkable feature is an equivalently large, [...]
Interferometric Processing of ScanSAR Data Using Stripmap Processor: New Insights from Coregistration
Published: 2020-04-14
Subjects: Aerospace Engineering, Civil and Environmental Engineering, Computer Engineering, Earth Sciences, Electrical and Computer Engineering, Engineering, Geology, Geophysics and Seismology, Glaciology, Hydrology, Mining Engineering, Other Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure, Volcanology
Processing scanning synthetic aperture radar (ScanSAR) data using a stripmap processor, which is called full-aperture processing, has been the choice of many researchers. ScanSAR data are known to require very high azimuth coregistration precision which is usually achieved by a geometrical coregistration followed by a spectral diversity coregistration on the ScanSAR burst. However, for [...]
Equilibrium climate sensitivity controls uncertainty in regional climate change over the 21st century
Published: 2020-04-14
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Improved projections of local temperature change over the 21st century are essential for evaluating impacts and setting policy targets (Lehner and Stocker 2015, Senevirante et al 2016). Uncertainty in these projections is due to two approximately equal factors: uncertainty in greenhouse gas emissions, and uncertainty in the response of climate to those emissions (Hawkins and Sutton 2009). For the [...]
Interferometry with ALOS-2 full-aperture ScanSAR data
Published: 2020-04-14
Subjects: Aerospace Engineering, Civil and Environmental Engineering, Earth Sciences, Electrical and Computer Engineering, Engineering, Geology, Geophysics and Seismology, Glaciology, Mining Engineering, Other Engineering, Physical Sciences and Mathematics, Physics, Tectonics and Structure, Volcanology
Advanced Land Observing Satellite-2 (ALOS-2) is designed to routinely acquire both scanning synthetic aperture radar (ScanSAR) and stripmap data. In this paper, we present a special multiband bandpass filter (MBF) to remove azimuth nonoverlap spectra for the interferometric processing of ALOS-2 full-aperture ScanSAR product. As required by the MBF, we estimate the important ScanSAR system [...]
A mixed $RT_0 - P_0$ Raviart-Thomas finite element implementation of Darcy Equation in GNU Octave
Published: 2020-04-14
Subjects: Applied Mathematics, Bioresource and Agricultural Engineering, Chemical Engineering, Computational Engineering, Earth Sciences, Engineering, Environmental Sciences, Hydrology, Numerical Analysis and Computation, Partial Differential Equations, Physical Sciences and Mathematics, Water Resource Management
In this paper we shall describe mixed formulations -differential and variational- of Darcys flow equation, an important model of elliptic problem. We describe * Galerkin method with finite dimensional spaces; * Local matrices and assembling; * Raviart-Thomas $RT_0 - P_0$ elements; * Edge basis and local matrices for $RT_0 - P_0$ FEM; * Model problem with corresponding local matrices, right hand [...]
SymAE: an autoencoder with embedded physical symmetries for passive time-lapse monitoring
Published: 2020-04-13
Subjects: Applied Mathematics, Computer Sciences, Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
We introduce SymAE, an auto-encoder architecture that learns to separate multichannel passive-seismic datasets into qualitatively interpretable components: one component corresponds to path-specific effects associated with subsurface properties while the other component corresponds to the spectral signature of the passive sources. This information is represented by two latent codes produced by [...]
Enhanced secondary pollution offset reduction of primary emissions during COVID-19 lockdown in China
Published: 2020-04-13
Subjects: Atmospheric Sciences, Environmental Health and Protection, Environmental Monitoring, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
To control the spread of the 2019 novel coronavirus (COVID-19), China imposed nationwide restrictions on the movement of its population (lockdown) after the Chinese New Year of 2020, leading to large reductions in economic activities and associated emissions. Despite such large decreases in primary pollution, there were nonetheless several periods of heavy haze pollution in East China, raising [...]
Success at the farm-level in payments for ecosystem services: monetary incentives, participatory processes and institutional adaptation all matter
Published: 2020-04-13
Subjects: Earth Sciences, Environmental Sciences, Life Sciences, Natural Resources and Conservation, Physical Sciences and Mathematics
While payments for ecosystem services (PES) schemes are increasingly common, in most cases, their effectiveness has lagged behind initial expectations. A major debate exists around whether performance can be improved by prioritising project design features that align with the theoretical, economistic model of PES, or whether, where necessary, it is more important for projects to depart from this [...]