Preprints
Filtering by Subject: Physical Sciences and Mathematics
How do intra-basement fabrics influence normal fault growth? Insights from the Taranaki Basin, offshore New Zealand
Published: 2018-06-15
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
Pre-existing intra-basement structures can have a strong influence on the evolution of rift basins. Although 3D geometric relationships provide some insight into how intra-basement structures determine the broad geometry and spatial development (e.g. strike and dip) of rift-related faults, little is known about the impact of the former on the detailed kinematics (i.e. nucleation and tip [...]
A fossiliferous spherule-rich bed at the Cretaceous-Paleogene (K-Pg) boundary in Mississippi, USA: implications for the K-Pg mass extinction event in the MS Embayment and Eastern Gulf Coastal Plain
Published: 2018-06-14
Subjects: Astrophysics and Astronomy, Earth Sciences, Geochemistry, Geology, Paleobiology, Paleontology, Physical Sciences and Mathematics, Sedimentology
We describe an outcrop of the Cretaceous–Paleogene (K–Pg) boundary exposed due to construction near New Albany, Union County, Mississippi. It consists of the Owl Creek Formation and overlying Clayton Formation. The Owl Creek Formation is rich in the ammonites Discoscaphites iris and Eubaculites carinatus, which, along with biostratigraphically important dinoflagellate cysts and calcareous [...]
Introduction to Interferometry of Fiber Optic Strain Measurements
Published: 2018-06-14
Subjects: Applied Mathematics, Earth Sciences, Geophysics and Seismology, Other Applied Mathematics, Physical Sciences and Mathematics
Distributed acoustic sensing (DAS) measures the average axial strain (strain rate) along a subset of a fiber optic cable, as opposed to the particle displacement (velocity) at a particular small point sensor. In shifting from measuring a vector field to a tensor field, DAS changes the directional sensitivity of measurements of every type of seismic wave when compared to single component [...]
A strong role for the AMOC in partitioning global energy transport and shifting ITCZ position in response to latitudinally discrete solar forcing in the CESM1.2
Published: 2018-06-14
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
This preprint is a non peer reviewed version submitted to the Journal of Climate. This work has been accepted for publication with an updated title, A strong role for the AMOC in partitioning global energy transport and shifting ITCZ position in response to latitudinally discrete solar forcing in the CESM1.2. The accepted version is substantially different from the preprint version due to the [...]
Is the Earth Lazy? A review of work minimization in fault evolution
Published: 2018-06-13
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
The principle of work minimization has been used in various forms to account for the development of active fault systems within a wide range of tectonic settings. We review the successes, challenges and implications learned from previous applications of work minimization. Examination of the energy budget provides insight into the competing influences of different processes within fault systems [...]
Effects of shoal margin collapses on the morphodynamics of a sandy estuary
Published: 2018-06-12
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
Shoal margin collapses of several Mm3 have occurred in the Western Scheldt estuary, the Netherlands, on average five times a year over the last decades. While these collapses involve significant volumes of material, their effect on the channel‐shoal morphology is unknown. We hypothesize that collapses dynamicise the channel‐shoal interactions, which could impact the ecological functioning, flood [...]
A tutorial introduction to the Hamiltonian Monte Carlo solution of weakly nonlinear inverse problems
Published: 2018-06-11
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
We present an introduction to Hamiltonian Monte Carlo (HMC) sampling of high-dimensional model spaces with focus on linear and weakly nonlinear inverse problems. This includes the theoretical foundations, intuitive examples, as well as applications to linear and nonlinear, adjoint-based traveltime tomography. HMC rests on the construction of an artificial Hamiltonian system where a model is [...]
Secondary microplastics were prevalent in sediment in a freshwater UK urban river
Published: 2018-06-07
Subjects: Environmental Sciences, Physical Sciences and Mathematics
Plastic pollution has been documented in terrestrial and aquatic environments worldwide, with growing concern for ‘microplastics’ (MPs, <5 mm). Understanding of the sources, fate, and impact of MPs remains limited, particularly in freshwater environments. Furthermore, their small sizes and a lack of standardised methodology hinders monitoring and risk assessment of these emerging contaminants. [...]
New analogue materials for nonlinear lithosphere rheology, with an application to slab break-off
Published: 2018-06-07
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics, Tectonics and Structure
Stress-dependent nonlinear upper mantle rheology has a firm base in rock mechanical tests, where this nonlinearity results from dislocation creep of minerals. In the last few decades there has been some attention to nonlinear, power-law, materials for application in scaled analogue experiments for tectonic processes. However, studies describing the rheology of analogue materials with the same [...]
Steady state analysis of vegetation growth models with correlated white noises
Published: 2018-06-07
Subjects: Environmental Sciences, Other Environmental Sciences, Physical Sciences and Mathematics
Vegetation community plays a pivotal role in geomorphic processes. However, the growth of vegetation intrinsically depends on the effective shear stresses exerted by the flow of material (e.g. water or soil) along the slope. We comparatively assess the growth and decay of vegetation using linear and logistic growth model coupled with a runoff erosion model. The model parameters are calibrated [...]
Detrital Zircons from the Amazon river-to-fan system reveal base level controls on land-to-sea sediment transfer
Published: 2018-06-06
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Sedimentology
Large tropical sediment routing systems have relatively stable output fluxes over observable timescales. However, the functioning of sediment transfer in these systems across Pleistocene climate and sea-level fluctuations is not well documented. Here, we use new U-Pb detrital zircon (DZ) geochronology from the Pleistocene Amazon submarine fan (n=1,362 grains) to investigate provenance signatures [...]
Field evidence for the lateral emplacement of igneous dykes: Implications for 3D mechanical models and the plumbing beneath fissure eruptions.
Published: 2018-06-06
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure, Volcanology
Seismological and geodetic data from modern volcanic systems strongly suggest that magma is transported significant distance (tens of kilometres) in the subsurface away from central volcanic vents. Geological evidence for lateral emplacement preserved within exposed dykes includes aligned fabrics of vesicles and phenocrysts, striations on wall rocks and the anisotropy of magnetic susceptibility. [...]
Do Geology Field Courses Improve Penetrative Thinking?
Published: 2018-06-05
Subjects: Earth Sciences, Education, Geology, Physical Sciences and Mathematics
Spatial thinking skills are important for geoscientists, and field courses play an important role in using and developing those skills. This study examines the development of spatial perception and geoscience-specific penetrative thinking skills, as measured by paired pre- and post-tests using the water-level test and the Geologic Block Cross-sectioning Test, in a sophomore field mapping course. [...]
Insights into agricultural influences and weathering processes from major ion patters
Published: 2018-06-04
Subjects: Chemistry, Earth Sciences, Environmental Chemistry, Environmental Sciences, Geochemistry, Hydrology, Physical Sciences and Mathematics, Water Resource Management
Karst areas and their catchments pose a great challenge for protection because fast conduit flow results in low natural attenuation of anthropogenic contaminants. Studies of the hydrochemistry of karst sources and river solutes are an important tool for securing and managing water resources. A study of the geochemical downriver evolution of the Wiesent River and its tributaries, located in a [...]
Mars Global Simulant MGS-1: A Rocknest-based open standard for basaltic martian regolith simulants
Published: 2018-06-04
Subjects: Physical Sciences and Mathematics, Planetary Geology, Planetary Sciences
The composition and physical properties of martian regolith are dramatically better understood compared to just a decade ago, particularly through the use of X-ray diffraction by the Curiosity rover. Because there are no samples of this material on Earth, researchers and engineers rely on terrestrial simulants to test future hardware and address fundamental science and engineering questions. Even [...]