Preprints
Filtering by Subject: Earth Sciences
Influence of nodular structures on fracture development in fine-grained rocks: numerical simulations based on the discrete element method
Published: 2019-05-10
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
Discrete element experiments were performed to simulate fracturing processes in nodule-bearing, fine-grained rocks. Two models that contain a collection of bonded circular particles were subjected to uniaxial compression to yield shortening and fracturing of the particle assembly. Model I with soft nodules produced incremental amount of microfractures within nodules during the early stage of [...]
On the automatic and a priori design of unstructured mesh resolution for coastal ocean circulation models
Published: 2019-05-10
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Other Civil and Environmental Engineering, Other Earth Sciences, Physical Sciences and Mathematics
This study investigates the design of unstructured mesh resolution and its impact on the modeling of barotropic tides along the United States East Coast and Gulf Coast (ECGC). A discrete representation of a computational ocean domain (mesh design) is necessary due to finite computational resources and an incomplete knowledge of the physical system (e.g., shoreline and seabed topography). The [...]
Complex earthquake behavior on simple faults
Published: 2019-05-10
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
While power-law distributions in seismic moment and interevent times are ubiquitous in regional catalogs, the statistics of individual faults remains controversial. Continuum fault models typically produce characteristic earthquakes or a narrow range of sizes, leading to the view that the regional statistics originates from interaction of multiple faults. I present theoretical arguments and [...]
Revising Contemporary Heat Flux Estimates for the Lena River, Northern Eurasia
Published: 2019-05-10
Subjects: Earth Sciences, Hydrology, Physical Sciences and Mathematics
The Lena River heat flux affects the Laptev Sea hydrology. Published long-term estimates range from 14.0 to 15.7 EJ·a-1, based on data from Kyusyur, at the river outlet. A novel daily stream temperature (Tw) dataset was used to evaluate contemporary Lena R. heat flux, which is 16.4±2.7 EJ·a-1 (2002-2011), confirming upward trends in both Tw and water runoff. Our field data from Kyusyur, however, [...]
Growing primordial continental crust self-consistently in global mantle convection models
Published: 2019-05-10
Subjects: Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics
The majority of continental crust formed during the hotter Archean was composed of Tonalite-Trondhjemite-Granodiorite (TTG) rocks. In contrast to the present-day loci of crust formation around subduction zones and intra-plate tectonic settings, TTGs are formed when hydrated basalt melts at garnet-amphibolite, granulite or eclogite facies conditions. Generating continental crust requires a two [...]
A spatially resolved fluid-solid interaction model for dense granular packs/Soft-Sand.
Published: 2019-05-09
Subjects: Earth Sciences, Engineering, Materials Science and Engineering, Physical Sciences and Mathematics
Fluid flow through dense granular packs or soft sands can be described as a Darcy s flow for low injection rates, as the friction between grain-grain and grain-walls dominate the solid system behaviour. For high injection rates, fluid forces can generate grain displacement forming flow channels or ``fractures, which in turn modify local properties within the system, such as permeability and [...]
Fracturing and crystal plastic behaviour of garnet under seismic stress in the dry lower continental crust (Musgrave Ranges, Central Australia)
Published: 2019-05-08
Subjects: Earth Sciences, Physical Sciences and Mathematics
Garnet is a high strength mineral compared to other common minerals, such as quartz and feldspar, in the felsic crust. In felsic mylonites, garnet typically occurs as porphyroclasts that mostly evade intracrystalline deformation, except under relatively high temperature conditions. The microstructure of garnet in felsic lower-crustal rocks of the Musgrave Ranges (Central Australia) records both [...]
Analysis of Persistence in the Flood Timing and the Role of Catchment Wetness on Flood Generation in a Large River Basin in India
Published: 2019-05-08
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Engineering, Hydraulic Engineering, Hydrology, Physical Sciences and Mathematics, Statistics and Probability
This study contributes to the understanding of the timing of occurrence of floods and role of the catchment wetness in flood processes (i.e., magnitude and the timing of floods) over one of the largest tropical pluvial river basin system, Mahanadi, in India. Being located in the monsoon ‘core’ region (18° - 28° N latitude and 73° - 82° E longitude) and its proximity to Bay of Bengal, Mahanadi [...]
Trends of hydroclimatic intensity in Colombia
Published: 2019-05-08
Subjects: Applied Statistics, Civil and Environmental Engineering, Climate, Earth Sciences, Engineering, Environmental Engineering, Environmental Sciences, Hydrology, Life Sciences, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Risk Analysis, Statistics and Probability, Water Resource Management
Prediction of changes in precipitation in upcoming years and decades caused by global climate change associated with the greenhouse effect, deforestation and other anthropic perturbations is a practical and scientific problem of high complexity and huge consequences. To advance toward this challenge we look at the daily historical record of all available rain gauges in Colombia to estimate an [...]
Drainage rearrangement as a driver of geomorphological evolution during the Upper Pleistocene in a small tropical basin
Published: 2019-05-07
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
The development of river networks in contexts where intense tectonic activity converges with great lithological variability, such as the Ocoa River Basin in the south of the Dominican Republic, usually hosts excellent examples of drainage rearrangement. This mechanism is defined as a transfer of part or all of a rivers flow to another river. According to the process involved, drainage [...]
Global distribution of sediment-hosted metals controlled by craton edge stability
Published: 2019-05-07
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
Sustainable development and the transition to a clean-energy economy drives ever-increasing demand for base metals, significantly outstripping the discovery rate of new deposits and necessitating dramatic improvements in exploration success. Rifting of the continents has formed widespread sedimentary basins, some of which contain large quantities of copper, lead and zinc. Despite over a century [...]
Three Billion Year Secular Evolution of the Triple Oxygen Isotope Composition of Marine Chert
Published: 2019-05-07
Subjects: Earth Sciences, Geochemistry, Other Earth Sciences, Physical Sciences and Mathematics
The 18O/16O ratios of ancient marine minerals show a puzzling increase over geologic time. Long-term changes in temperature, seawater 18O/16O ratios, and post-depositional overprinting can all explain this trend, but few tracers can distinguish between these scenarios. Here, we report high-precision 18O/16O and 17O/16O ratios of cherts through 3.4 Ga of Earth′s history. We find that Phanerozoic [...]
Causation of Late Quaternary Rapid-increase Radiocarbon Anomalies
Published: 2019-05-07
Subjects: Astrophysics and Astronomy, Cosmochemistry, Earth Sciences, Physical Sciences and Mathematics
Brief (<100 y) rapid-increase anomalies in the Earth’s atmospheric 14C production have previously been attributed to either gamma photon radiation from supernovae or to cosmic ray particle radiation from exceptionally large solar flares. Analysis of distances and ages of nearby supernovae (SNe) remnant surveys, the probable gamma emissions, the predicted Earth-incident radiation, and the [...]
Identification and Characterization of a Buried Volcanic Field Using Seismic Reflection and Borehole Data
Published: 2019-05-06
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics
Buried volcanoes occur in great numbers within sedimentary basins globally. Knowledge of ancient buried volcanic systems has improved significantly over the past two decades. The in-depth understanding of these buried systems was mainly possible due to increasing availability of high-quality seismic reflection and sub-surface borehole data. This paper examines a cluster of Miocene volcanoes now [...]
Paleogeographic and Morphologic Reconstroction of a Buried Monogenetic Volcanic Field
Published: 2019-05-06
Subjects: Earth Sciences, Geology, Life Sciences, Physical Sciences and Mathematics
Technological advances of our modern society motivated an unprecedented necessity to find natural resources in the subsurface of our planet. The search for these valuable resources has revealed an unexpected number of ancient volcanoes buried and preserved within sedimentary basins globally. Continuous improvements in remote sensing techniques such as seismic reflection can provide a valid [...]