Preprints
Filtering by Subject: Physical Sciences and Mathematics
The large-scale troughs on Asteroid 4 Vesta accommodate opening-mode displacement
Published: 2020-10-27
Subjects: Physical Sciences and Mathematics
The Dawn mission at Asteroid 4 Vesta revealed two sets of enormous linear structures. Both sets are troughs—linear, negative-relief landforms—with one spanning around two-thirds of the equator and the other set located in the northern hemisphere. Previous work evaluated the shapes of the troughs and interpreted them to be analogous to grabens, which are landforms caused by faulting; however, an [...]
Improving mechanical behaviour of collapsible soils by grouting active clay nanoparticles
Published: 2020-10-27
Subjects: Engineering, Physical Sciences and Mathematics
The primary geotechnical concern of collapsible soils such as loess is their hydromechanical instability. During (re)wetting, metastable aggregates disintegrate leading soil to collapse under the applied load or self-weight. In situ chemical stabilisation, such as grouting, is a favoured option to improve the mechanical behaviour of soils; however, the low permeability of loess limits the [...]
Characterizing seismic scattering in 3D heterogeneous Earth by a single parameter
Published: 2020-10-24
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
We derive a theoretical parameter for three seismic scattering regimes where seismic wavelengths are either much shorter, similar, or much longer than the correlation length of small-scale Earth heterogeneities. We focus our analysis on the power spectral density of the von Karman autocorrelation function, used to characterize the spatial heterogeneity of small-scale variations of elastic rock [...]
A data assimilation approach to last millennium temperature field reconstruction using a limited high-sensitivity proxy network
Published: 2020-10-23
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Paleoclimate field reconstructions using data assimilation commonly employ large proxy networks, which are often composed of records that have a complex range of sensitivities to the target climate field. This can introduce biases into reconstructions or decrease overall skill. Smaller networks of highly-sensitive proxies provide an alternative, but have not been extensively used for assimilation [...]
ROMY: A Multi-Component Ring Laser for Geodesy and Geophysics
Published: 2020-10-23
Subjects: Physical Sciences and Mathematics
Single-component ring lasers have provided high-resolution observations of Earth's rotation rate as well as local earthquake- or otherwise-induced rotational ground motions. Here we present the design, construction, and operational aspects of ROMY, a four-component, tetrahedral-shaped ring laser installed at the Geophysical Observatory Fürstenfeldbruck near Munich, Germany. Four equilateral, [...]
Controls on denudation along the East Australian continental margin
Published: 2020-10-22
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
We report a comprehensive inventory of Be-10-based basin-wide denudation rates (n=160) and Al-26/Be-10 ratios (n=67) from 48 drainage basins along a 3,000 km stretch of the East Australian passive continental margin. We provide data from both basins draining east of the continental divide (n=37) and discharging into the Tasman and Coral Seas, and from basins draining to the west as part of the [...]
Linking elastic and electrical properties of rocks using cross-property DEM
Published: 2020-10-22
Subjects: Earth Sciences, Engineering Science and Materials, Geophysics and Seismology, Materials Science and Engineering, Physical Sciences and Mathematics
Joint electrical-elastic rock physics modelling can be instrumental in lowering uncertainty in subsurface reservoir characterisation. Typical electrical-elastic cross-property models, however, are empirical or require an intermediate step of porosity estimation to link a rock's electrical and elastic moduli, which can be error-prone away from well controls. Another outstanding issue in [...]
Tuning sedimentation through surface charge and particle shape
Published: 2020-10-22
Subjects: Engineering, Physical Sciences and Mathematics
Mud forms the foundation of many coastal and tidal environments. Clay suspensions carried downstream from rivers encounter saline waters, which encourages aggregation and sedimentation by reducing electrostatic repulsion among particles. We perform experiments to examine the effects of surface charge on both the rate and style of sedimentation, using kaolinite particles as a model mud suspension [...]
Towards a new geological time scale: A template for improved rock-based subdivision of pre-Cryogenian time
Published: 2020-10-22
Subjects: Physical Sciences and Mathematics
Four first-order (Hadean, Archean, Proterozoic and Phanerozoic eon) and nine second-order (Paleoarchean, Mesoarchean, Neoarchean, Paleoproterozoic, Mesoproterozoic, Neoproterozoic, Paleozoic, Mesozoic and Cenozoic era) units continue to provide intuitive subdivision of geological time. Major transitions in Earth’s tectonic, biological and environmental history occurred at approximately 2.5-2.3, [...]
An explanation to the Nusselt-Rayleigh discrepancy in naturally convected porous media
Published: 2020-10-22
Subjects: Engineering, Physical Sciences and Mathematics
We model hydrothermal convection using a partial differential equation formed by Darcy velocity and temperature - the velocity formulation. Using the Elder problem as a benchmark, we found that the velocity formulation is a valid model of hydrothermal convection. By performing simulations with Rayleigh numbers in the non-oscillatory regime, we show that multiple quasi-steady-state solutions can [...]
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: 2020-10-21
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: 2020-10-21
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 [...]