Preprints
There are 6976 Preprints listed.
Thermal budgets of magma storage constrained by diffusion chronometry: the Cerro Galán ignimbrite
Published: 2021-12-02
Subjects: Physical Sciences and Mathematics
The long-term thermochemical conditions at which large bodies of silicic magma are stored in the crust is integral to our understanding of the timing, frequency, and intensity of volcanic eruptions, and provides important context for interpreting volcano monitoring data. Despite this, however, individual magmatic systems may exhibit a range of time-temperature paths, or thermal histories, that [...]
Developing an internally consistent methodology for K-feldspar MAAD TL thermochronology
Published: 2021-12-06
Subjects: Geology
Luminescence thermochronology and thermometry can quantify recent changes in rock exhumation rates and rock surface temperatures, but these methods require accurate determination of several kinetic parameters. For K-feldspar thermoluminescence (TL) glow curves, which comprise overlapping signals of different thermal stability, it is challenging to develop measurements that capture these parameter [...]
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 [...]
Corona structures driven by plume-lithosphere interactions and evidence for ongoing plume activity on Venus
Published: 2021-12-04
Subjects: Earth Sciences, Physical Sciences and Mathematics, Planetary Sciences
In the absence of global plate tectonics, mantle convection and plume-lithosphere interaction are the main drivers of surface deformation on Venus. Among documented tectonic structures, circular volcano-tectonic features known as coronae may be the clearest surface manifestations of mantle plumes and hold clues to the global Venusian tectonic regime. Yet, the exact processes underlying coronae [...]
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 [...]
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 [...]
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 [...]
High-magnitude stresses induced by mineral-hydration reactions
Published: 2021-12-05
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 [...]
Real Drivers of Climate Change?
Published: 2021-12-04
Subjects: Physical Sciences and Mathematics
As momentum gradually builds behind the strategy to address climate change through the global attainment of net zero emissions, recent science, post-dating this strategic implementation, throws doubt on the efficacy of such a strategy. Instead this science points to other potentially significant, if not primary, drivers of global warming largely overlooked by the established approach.
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 scalable framework for quantifying field-level agricultural carbon outcomes
Published: 2022-01-01
Subjects: Environmental Studies, Physical and Environmental Geography, Remote Sensing, Social and Behavioral Sciences
Agriculture contributes nearly a quarter of global greenhouse gas (GHG) emissions, which is motivating interest in certain farming practices that have the potential to reduce GHG emissions or sequester carbon in soil. The related GHG emission (including N2O and CH4) and changes in soil carbon stock are defined here as “agricultural carbon outcomes”. Accurate quantification of agricultural carbon [...]
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 [...]
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.