Preprints
There are 6346 Preprints listed.
Environmental Flows Assessments in the face of uncertainty: supporting the adaptive management of environmental flows
Published: 2021-12-06
Subjects: Civil and Environmental Engineering, Other Life Sciences
Adaptive management has become the preferred approach for managing environmental flows globally, and successful implementation recognizes multiple dimensions of variability and complexity in socio-ecological systems. This paper outlines an environmental flow assessment methodology that explicitly addresses the uncertainty and change inherent in adaptively managing multiple values for management [...]
Evaluating essential features of proppant transport at engineering scales combining field measurements with machine learning algorithms
Published: 2021-12-06
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Sciences, Geology, Hydraulic Engineering, Oil, Gas, and Energy, Sustainability
The characterization of the proppant transport at a field-engineering scale is still challenging due to the lack of direct subsurface measurements. Features that control the proppant transport may link the experimental and numerical observations to the practical operations at a field scale. To improve the numerical and laboratory simulations, we propose a machine-learning-based workflow to [...]
Integrated framework for rapid climate stress testing on a monthly timestep
Published: 2021-12-06
Subjects: Civil and Environmental Engineering
“Bottom-up” methods are increasingly used to assess the vulnerability of water systems to climate change. Central to these methods is the climate “stress test”, where the system is subjected to various climatic changes to test for unacceptable outcomes. We present a framework for climate stress testing on a monthly timestep, suitable for systems whose dominant dynamic is seasonal or longer (eg. [...]
Spatio-temporal clustering of seismicity enabled by off-fault plasticity
Published: 2021-12-06
Subjects: Applied Mechanics, Civil and Environmental Engineering, Dynamics and Dynamical Systems, Earth Sciences, Engineering, Engineering Mechanics, Engineering Science and Materials, Geophysics and Seismology, Mechanical Engineering, Mechanics of Materials, Other Mechanical Engineering, Physical Sciences and Mathematics, Tribology
While significant progress has been made in understanding earthquake source processes in linear elastic domains, the effect of more realistic rheologies including plasticity is poorly understood. Here, we simulate sequence of earthquake and aseismic slip of a 2D antiplane rate-and-state fault embedded in a full-space elastic-plastic bulk. We show that off-fault plasticity may lead to partial [...]
Sequences of seismic and aseismic slip on bimaterial faults show dominant rupture asymmetry and potential for elevated seismic hazard
Published: 2021-12-06
Subjects: Physical Sciences and Mathematics
We perform numerical simulations of sequences of earthquake and aseismic slip on planar rate and state faults separating dissimilar material within the 2-D plane strain approximation. We resolve all stages of the earthquake cycle from aseismic slip to fast ruptures while incorporating full inertia effects during seismic event propagation. We show that bimaterial coupling results in favorable [...]
Soil Excavation pH level Modification
Published: 2021-12-06
Subjects: Engineering
Territories are becoming new areas for conservationist replanting and forestation. Excavators are capable of producing entrainment s for new reservations. There lacks knowledge of soil conditions and methods of measurement of fertility of the developments. This research improves knowledge on the subject of excavations. To decide on territories which can be a best fit for excavations.
Timing of oil expulsion from source rocks and a revitalization of the pre-1970 model
Published: 2021-12-06
Subjects: Earth Sciences, Physical Sciences and Mathematics
New data from North Sea Upper Jurassic source rock samples show no decline in the total amount of organic matter (TOC) within the oil expulsion window between 120 and 150°C which is a key prediction by today’s model for oil expulsion. However, today’s model for oil expulsion is not consistent with either subsurface source rock TOC data or chemical attributes of shallow oils. Instead, these data [...]
Methane Fluxes of Vegetated Areas in Natural Freshwater Ecosystems: Assessments and Global Significance
Published: 2021-12-05
Subjects: Biogeochemistry, Earth Sciences, Environmental Sciences, Other Environmental Sciences
Freshwater ecosystems, including wetlands, lakes, and running waters, are estimated to contribute roughly 40% to global emissions of methane (CH4), a highly potent greenhouse gas. The emission of CH4 to the atmosphere entails the diffusive, ebullitive, and plant-mediated pathway. The latter, in particular, has been largely understudied and is neither well understood nor quantified. We have [...]
A copula-based assessment of renewable energy droughts across Europe
Published: 2021-12-05
Subjects: Multivariate Analysis, Oil, Gas, and Energy, Other Earth Sciences
Meeting carbon-reduction targets will require thorough consideration of climate variability and climate change due to the increasing share of climate-sensitive renewable energy sources (RES). One of the main concerns arises from situations of low renewable production and high demand, which can hinder the power system. We analysed energy droughts, defined as periods of low energy production (wind [...]
Supraglacial debris thickness and supply rate in High-Mountain Asia
Published: 2021-12-05
Subjects: Physical Sciences and Mathematics
Supraglacial debris strongly modulates glacier melt rates and can be decisive for ice dynamics and mountain hydrology. It is ubiquitous in High-Mountain Asia (HMA), yet because its thickness and supply rate from local topography are poorly known, our ability to forecast regional glacier change and streamflow is limited. Here we resolved the spatial distribution of supraglacial debris thickness [...]
Evidences of horizontal urban heat advection in London using 6 years of data from a citizen weather station network
Published: 2021-12-05
Subjects: Climate, Environmental Monitoring, Environmental Sciences, Meteorology, Physical and Environmental Geography
Recent advances in citizen weather station (CWS) networks, with data accessible via crowd-sourcing, provide relevant climatic information to urban scientists and decision makers. In particular, CWS can provide long-term measurements of urban heat and valuable information on spatio-temporal heterogeneity related to horizontal heat advection. In this study, we make the first compilation of a [...]
High-magnitude stresses induced by mineral-hydration reactions
Published: 2021-12-04
Subjects: Physical Sciences and Mathematics
Fluid-rock interactions play a critical role in Earth’s lithosphere and in engineered subsurface systems. In the absence of chemical mass transport, mineral-hydration reactions will be accompanied by a solid-volume increase that may induce differential stresses and associated reaction-induced deformation processes, such as dilatant fracturing to increase fluid permeability. However, the [...]
Thresholds in road network functioning on US Atlantic and Gulf barrier islands
Published: 2021-12-04
Subjects: Analysis, Geomorphology, Nature and Society Relations, Sustainability
Barrier islands predominate the Atlantic and Gulf coastlines of the USA, where development exceeds national trends. Forward-looking models of barrier island dynamics often include feedbacks with management practices – particularly those aimed at mitigating damage to buildings from natural hazards – and how real estate markets may be linked to barrier island dynamics. However, models thus far do [...]
Variable dynamic styles of primordial heterogeneity preservation in the Earth’s lower mantle
Published: 2021-12-04
Subjects: Physical Sciences and Mathematics
The evolution of the system Earth is critically influenced by the long-term dynamics, composition and structure of the mantle. While cosmochemical and geochemical constraints indicate that the lower mantle hosts an ancient primordial reservoir that may be enriched in SiO2 with respect to the upper mantle, geophysical observations and models point to efficient mass transfer and convective mixing [...]
Coupled dynamics and evolution of primordial and recycled heterogeneity in Earth’s lower mantle
Published: 2021-12-04
Subjects: Earth Sciences, Planetary Sciences
The nature of compositional heterogeneity in Earth’s lower mantle remains a long-standing puzzle that can inform about the long-term thermochemical evolution and dynamics of our planet. Here, we use global-scale 2D models of thermo- chemical mantle convection to investigate the coupled evolution and mixing of (intrinsically-dense) recycled and (intrinsically- strong) primordial heterogeneity in [...]