Preprints
There are 7999 Preprints listed.
Shear-wave Anisotropy in the Earth’s Inner Core
Published: 2021-09-17
Subjects: Earth Sciences, Geophysics and Seismology, Mineral Physics, Physical Sciences and Mathematics
Earth’s inner core anisotropy is widely used to infer the deep Earth's evolution and present dynamics. Many compressional-wave anisotropy models have been proposed based on seismological observations. In contrast, inner-core shear-wave (J-wave) anisotropy – on a par with the compressional-wave anisotropy – has been elusive. Here we present a new class of the J-wave anisotropy observations [...]
Changes in deep groundwater flow patterns related to oil and gas
Published: 2021-09-17
Subjects: Engineering, Physical Sciences and Mathematics
Large volumes of saline formation water are both produced from and injected into sedimentary basins as a by-product of oil and gas production. Despite this, the location of production and injection wells has not been studied in detail at the regional scale and the effects on deep groundwater flow patterns (i.e. below the base of groundwater protection) possibly driving fluid flow towards shallow [...]
Upper Plate Structure and Tsunamigenic Faults near the Kodiak Islands, Alaska
Published: 2021-09-17
Subjects: Physical Sciences and Mathematics
The Kodiak Islands lie near the southern terminus of the 1964 Great Alaska earthquake rupture area and within the Kodiak subduction zone segment. Both local and trans-Pacific tsunamis were generated during this devastating megathrust event, but the local tsunami source region and the causative faults are poorly understood. We provide an updated view of the tsunami and earthquake hazard for the [...]
Classification of Multi-temporal Images using Machine Learning
Published: 2021-10-05
Subjects: Remote Sensing
In past, there has been a lot of research related to the image-based technique in remote sensing from which object-based classification is giving great results among all the techniques. This paper presents a new approach where we have mixed both OBIA (Object-Based Image Analysis) & supervised classification. And with this novel approach, our team aims to do classification as well as analysis for [...]
The evolution of triple junctions: from failure to success
Published: 2021-09-20
Subjects: Physical Sciences and Mathematics
Divergent triple junctions are stable plate margins where three spreading ridges meet. Although it is accepted that this configuration is inherited from an earlier phase of continental rifting, how post-breakup triple junctions emerge from the separation of two plates remains unclear. By documenting the strain rate history recorded in the three rift-arms of several modern and ancient triple [...]
Missing or Underrated Super-emitters of Nitrogen Oxides in China Exposed from Space
Published: 2021-09-21
Subjects: Environmental Monitoring, Environmental Sciences, Physical Sciences and Mathematics
Nitrogen oxides (NOx ≡ NO + NO2) play a central role in air pollution. Super-emitters present unique opportunities for emission mitigation in China and beyond. They comprise intensive industrial facilities (e.g., power or chemical plants), less than 1 × 1 km2 with high NOx plumes, dominating localized concentrations within a limited geographical scope. However, identification of super-emitters [...]
Imaging an Underwater Basin and its Resonance Modes using Optical Fiber Distributed Acoustic Sensing
Published: 2021-09-22
Subjects: Earth Sciences, Geophysics and Seismology
Distributed acoustic sensing is an ideal tool for ambient noise tomography owing to the dense spatial measurements and the ability to continuously record in harsh environments, such as underwater. We demonstrate the ability to image a complex underwater basin using ambient noise recorded on a fiber deployed offshore Greece. A two-dimensional shear-wave velocity model was derived by analyzing [...]
Dam Break Simulation with HEC-RAS and OpenFOAM
Published: 2021-09-22
Subjects: Earth Sciences, Hydrology, Physical Sciences and Mathematics
A dam break is a natural disaster that can cause significant property damage and loss of life. It's useful to identify potential flooding areas downstream in the event of a dam break. In this study both HEC-RAS and OpenFOAM are set up to simulate the inundation map downstream of the Dworshak dam in Idaho. Using the same topographical data from satellite observations, similar computational [...]
Bedform segregation and locking increase storage of natural and synthetic particles in rivers
Published: 2021-09-24
Subjects: Engineering
While the ecological significance of hyporheic exchange and fine particle transport in rivers is well established, these processes are generally considered irrelevant to riverbed morphodynamics. We show that coupling between hyporheic exchange, suspended sediment deposition, and sand bedform motion strongly modulates morphodynamics and sorts bed sediments. Hyporheic exchange focuses fine-particle [...]
Stalagmite evidence for Early Holocene multidecadal hydroclimate variability in Ethiopia
Published: 2021-09-22
Subjects: Geochemistry, Geology, Speleology
A multiproxy oxygen and carbon isotope (d13C and d18O), growth rate and trace element stalagmite paleoenvironmental record is presented for the Early Holocene from Achere Cave, Ethiopia. The annually laminated stalagmite grew from 10.6 to 10.4 ka, and from 9.7 to 9.0 ka with a short hiatus at ~9.25 ka. Using oxygen and carbon isotopic, and cave monitoring data, we demonstrate that the stalagmite [...]
Deep Deconvolution for Traffic Analysis with Distributed Acoustic Sensing Data
Published: 2021-09-23
Subjects: Artificial Intelligence and Robotics, Geophysics and Seismology, Transportation Engineering
Distributed Acoustic Sensing (DAS) is a novel vibration sensing technology that can be employed to detect vehicles and to analyse traffic flows using existing telecommunication cables. DAS therefore has great potential in future "smart city" developments, such as real-time traffic incident detection. Though previous studies have considered vehicle detection under relatively light traffic [...]
Mapping riverbed sediment size from Sentinel 2 satellite data
Published: 2021-10-01
Subjects: Physical Sciences and Mathematics
A comprehensive understanding of river dynamics requires quantitative knowledge of the grain size distribution of bed sediments and its variation across different temporal and spatial scales. Several techniques are already available for grain size assessment based on field and remotely sensed data. However, the existing methods are only applicable on small spatial scales and on short time scales. [...]
A survey of storm-induced seaward-transport features observed during the 2019 and 2020 hurricane seasons
Published: 2021-09-24
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
Hurricanes are known to play a critical role in reshaping coastlines, particularly on the open ocean coast in cases of overwash, but storm induced seaward-directed flow and responses are often ignored or un-documented. Subaerial evidence for seaward sediment transport (outwash, return-flow) increases our understanding of the impact hurricanes have on coastal and barrier island evolution. Towards [...]
An anisotropic equation of state for high pressure, high temperature applications
Published: 2021-09-25
Subjects: Condensed Matter Physics, Geophysics and Seismology, Materials Science and Engineering, Mineral Physics, Physical Sciences and Mathematics, Planetary Geophysics and Seismology, Planetary Mineral Physics
This paper presents a strategy for consistently extending isotropic equations of state to model anisotropic materials over a wide range of pressures and temperatures under nearly hydrostatic conditions. The method can be applied to materials of arbitrary symmetry. The paper provides expressions for the deformation gradient tensor, the lattice parameters, the isothermal elastic compliance tensor [...]
Sustainability without geology? A shortsighted approach
Published: 2021-10-04
Subjects: Education, Life Sciences, Physical Sciences and Mathematics
Over the last few decades, the concept of sustainability has been proposed and championed as the answer to the impending challenges our society will be facing in the future. It has been a rallying opportunity for the broad earth sciences community and a good starting point for such a community to impact societal and policy decisions; however, it has been an opportunity we have largely missed thus [...]