Preprints
Filtering by Subject: Physical Sciences and Mathematics
Sedimentological and stratigraphic criteria to distinguish between basin-floor and slope mudstones: Implications for the delivery of mud to deep-water environments
Published: 2020-10-22
Subjects: Physical Sciences and Mathematics
Deep-water mudstones overlying basin-floor and slope sandstone-prone deposits are widely interpreted as hemipelagic drapes deposited during extended periods of sand starvation. However, the processes of mud transport and deposition, and the resulting facies and sedimentary architecture of mudstones in different deep-water environments, remain poorly understood. This study documents the [...]
Assessing streamflow sensitivity to precipitation variability in karst-influenced catchments with unclosed water balance
Published: 2020-10-22
Subjects: Physical Sciences and Mathematics
Karst hydrological models are widely used for simulating groundwater dynamics at the aquifer scale. However, modeling streamflow of a topographic catchment that is partially covered by karst is rarely reported. This is due to difficulties of properly considering the strong differences of karstic and non-karstic hydrodynamics and the widespread occurrence of unclosed water balances in karstic [...]
The International Sedimentary Geosciences Congress (ISGC) 2021 – An Opportunity to Shape the Future of Sedimentary Geosciences
Published: 2020-10-22
Subjects: Physical Sciences and Mathematics
The 1st International Sedimentary Geosciences Congress (ISGC) was conceived a few years ago as a unique opportunity for the broad sedimentary geosciences community to come together in a time of transformations. The aim of the congress is to allow the community to express, plan and implement what we all know are necessary changes to progress into the new decades with new motivations, ideas and [...]
Pangeo Benchmarking Analysis: Object Storage vs. POSIX File System
Published: 2020-10-21
Subjects: Computer Sciences, Earth Sciences, Physical Sciences and Mathematics
Pangeo is a community of scientists and software developers collaborating to enable Big Data Geoscience analysis interactively in the public cloud and on high-performance computing (HPC) systems. At the core of the Pangeo software stack is (1) Xarray, which adds labels to metadata such as dimensions, coordinates and attributes for raw array-oriented data, (2) Dask, which provides parallel [...]
Relative humidity gradients as a key constraint on terrestrial water and energy fluxes
Published: 2020-10-21
Subjects: Earth Sciences, Physical Sciences and Mathematics
Earth’s climate and water cycle are highly dependent on the latent heat flux (LE) associated with terrestrial evapotranspiration. While the widely-used Penman-Monteith LE model is useful to explore vegetative controls on LE, land-atmosphere interactions are difficult to interpret due to the complex role of biological controls on underlying physical processes. Here, we present a novel LE model [...]
The importance of the study of igneous rocks and compositions to constrain the martian planetary evolution
Published: 2020-10-21
Subjects: Physical Sciences and Mathematics
This white paper summarizes the scientific importance of studying igneous compositions in meteorites, surface samples, and through orbital analyses to better constrain the geology of Mars as a whole and better understand the geological processes that have shaped Mars in the past and present. In support of martian igneous studies, we strongly advocate for the following in the upcoming [...]
Dynamical analysis of a reduced model for the North Atlantic Oscillation
Published: 2020-10-21
Subjects: Applied Mathematics, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The dynamics of the North Atlantic Oscillation (NAO) are analyzed through a data-driven model obtained from atmospheric reanalysis data. We apply a regularized vector autoregressive clustering technique to identify recurrent and persistent states of atmospheric circulation patterns in the North Atlantic sector (110W-0E, 20N-90N). In order to analyze the dynamics associated with the resulting [...]
Downhole distributed acoustic sensing reveals the wave field structure of the coastal microseisms
Published: 2020-10-21
Subjects: Engineering, Physical Sciences and Mathematics
Ocean-generated seismic waves are omnipresent in passive seismic records around the world and present both a challenge for earthquakes observations and an input signal for interferometric methods for characterisation of the Earth's interior. Understanding of these waves requires the knowledge of the depth-dependence of the oceanic noise at the transition into continent. To this end, we examine 80 [...]
High-Pressure Deformation of Iron–Nickel–Silicon Alloys and Implications for Earth’s Inner Core
Published: 2020-10-21
Subjects: Earth Sciences, Geophysics and Seismology, Mineral Physics, Physical Sciences and Mathematics
Earth’s inner core exhibits strong seismic anisotropy, often attributed to the alignment of hexagonal close-packed iron (hcp-Fe) alloy crystallites with the Earth’s poles. How this alignment developed depends on material properties of the alloy and is important to our understanding of the core’s crystallization history and active geodynamical forcing. Previous studies suggested that hcp-Fe is [...]
Dynamics of core-mantle separation: influence of viscosity contrast and metal/silicate partition coefficients on the chemical equilibrium
Published: 2020-10-21
Subjects: Earth Sciences, Geochemistry, Geophysics and Seismology, Physical Sciences and Mathematics
The composition of the Earth's core and mantle is set by the chemical equilibrium between metals and silicates during core/mantle segregation. The metallic core separated from the mantle by gravitational descent in the form of diapirs in a magma ocean, and therefore the dynamics of the diapir's downward movement has an influence on the chemical equilibrium. In this study, we characterize the [...]
3-D seismic interpretation with deep learning: a brief introduction
Published: 2020-10-21
Subjects: Physical Sciences and Mathematics
Understanding the internal structure of our planet is a fundamental goal of the Earth Sciences. As direct observations are restricted to surface outcrops and borehole cores, we rely on geophysical data to study the Earth’s interior. Especially, seismic reflection data showing acoustic images of the subsurface, provide us with critical insights into sedimentary, tectonic and magmatic systems. The [...]
Inverse analysis to reconstruct hydraulic conditions of non-steady turbidity currents: Application to an ancient turbidite of the Kiyosumi Formation of the Awa Group, Boso Peninsula, central Japan
Published: 2020-10-21
Subjects: Earth Sciences, Physical Sciences and Mathematics, Sedimentology
This study proposes a new method of inverse analysis from ancient turbidites to the non-steady turbidity currents with consideration of multiple grain-size classes. The forward model employed in this study is based on the shallow water equation, and the initial condition of flows are assumed to be the lock-exchange type condition. To obtain a solution of the inverse problem, this study employed [...]
Uncertainties in Projected Rainfall over Brazil: The Role of Climate Model, Bias Correction and Emission Scenario
Published: 2020-09-02
Subjects: Earth Sciences, Hydrology, Physical Sciences and Mathematics
The aim of this study is to answer four main questions: How well the Eta regional climate model simulates past precipitation over Brazil? What is the impact of bias correction on the reduction of model’s biases? What is the contribution of climate models, bias correction and emission scenarios to the total uncertainty of projected precipitation? And finally, what is the projected change in [...]
A continental-scale assessment of density, size, distribution, and historical trends of Australian farm dams
Published: 2020-09-02
Subjects: Environmental Monitoring, Environmental Sciences, Natural Resources and Conservation, Natural Resources Management and Policy, Physical Sciences and Mathematics, Water Resource Management
Australia is the second driest continent on Earth and freshwater is, therefore, a critical policy concern. Farm dams are ubiquitous and drive AU$17.7 billion of agricultural value, yet there has never been a formal census of Australian dams. In this study, we present a continental-scale assessment on density, distribution, and historical trends of farm dams in each State and Territory of [...]
What does the NDVI really tell us about crops? Insight from proximal spectral field sensors
Published: 2020-09-01
Subjects: Environmental Monitoring, Environmental Sciences, Other Physical Sciences and Mathematics, Physical Sciences and Mathematics
The use of remote sensing in agriculture is expanding due to innovation in sensors and platforms. Drones, high resolution instruments on CubeSats, and robot mounted proximal phenotyping sensors all feature in this drive. Common threads include a focus on high spatial and spectral resolution coupled with the use of machine learning methods for relating observations to crop parameters. As the [...]