Preprints
Filtering by Subject: Physical Sciences and Mathematics
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: 2020-04-13
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: 2020-04-13
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: 2020-04-13
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: 2020-04-13
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 [...]
Social as much as environmental: the drivers of tree biomass in smallholder forest landscape restoration programmes
Published: 2020-04-13
Subjects: Environmental Sciences, Life Sciences, Natural Resources and Conservation, Physical Sciences and Mathematics
A major challenge for forest landscape restoration initiatives is the lack of quantitative evidence on how social factors drive environmental outcomes. Here we conduct a transdisciplinary quantitative analysis of the environmental and social drivers of tree biomass accumulation across 639 smallholder farms restoring native tree species in Mexico, Uganda and Mozambique. We use environmental and [...]
Cascading Failure Phenomenon in the Multi-Stage Hydraulically Fractured Wells
Published: 2020-04-13
Subjects: Environmental Sciences, Oil, Gas, and Energy, Physical Sciences and Mathematics
The phenomenon of cascading fracture failure during flowback and initial production from a horizontal multistage hydraulically fractured well is introduced, described, and investigated. First, a simplified analytical model of production from such well is built. This model allows evaluating a range of systems parameters through which the cascading failure evolves and performing a sensitivity study [...]
Weak influence of paleoenvironmental conditions on the subsurface biosphere of lake Ohrid in the last 515 ka
Published: 2020-04-13
Subjects: Earth Sciences, Environmental Microbiology and Microbial Ecology Life Sciences, Environmental Sciences, Life Sciences, Microbiology, Other Earth Sciences, Paleobiology, Physical Sciences and Mathematics
Understanding the response of geo- and biosystems to past climatic disturbance is primordial to assess the short to long terms effects of current global change. Lacustrine sediments are commonly used to investigate the impact of climatic change on biogeochemical cycling. In these sediments, subsurface microbial communities play a primordial role in nutrient, organic matter and elemental cycling, [...]
Global heat uptake by inland waters
Published: 2020-04-12
Subjects: Earth Sciences, Environmental Sciences, Physical Sciences and Mathematics
Heat uptake is a key variable for understanding the Earth system response to greenhouse gas forcing. Despite the importance of this heat budget, heat uptake by inland waters has so far not been quanti?ed. Here we use a unique combination of global-scale lake models, global hydrological models and Earth system models to quantify global heat up take by natural lakes, reservoirs and rivers. The [...]
A new approach to inferring basal drag and ice rheology in ice streams, with applications to West Antarctic ice streams
Published: 2020-04-12
Subjects: Earth Sciences, Glaciology, Physical Sciences and Mathematics
Drag at the bed and along the lateral margins are the primary forces resisting flow in outlet glaciers. Simultaneously inferring these parame- ters is challenging since basal drag and ice viscosity are coupled in the momen- tum balance, which governs ice flow. Here, we test the ability of adjoint-based inverse methods to infer the slipperiness coefficient in a power-law sliding law and the [...]