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2020

Earth Sciences

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Articles 301 - 312 of 312

Full-Text Articles in Engineering

Cobalt Partitioning And Solubility In Low-Temperature Carbonate-Hydrothermal Systems, Seth Kurtis Coursey Jan 2020

Cobalt Partitioning And Solubility In Low-Temperature Carbonate-Hydrothermal Systems, Seth Kurtis Coursey

Graduate Research Theses & Dissertations

Cobalt mineralization has been documented in low temperature Mississippi Valley-type (MVT) deposits in southeast Missouri. Lead and zinc are the most economically important metals in these deposits and are contained within galena (PbS) and sphalerite (ZnS), respectively. Cobalt is also mined in some of the deposits with cobalt-bearing ores, e.g., siegenite ((Ni,Co)3S4) and fletcherite (Cu,(Ni,Co)2S4), occurring stratigraphically below main-stage galena and sphalerite. The hydrothermal fluids responsible for cobalt mineralization are thought to be chemically distinct from the predominant MVT ore-bearing fluids and represent a distinct mineralizing event. Cobalt is likely transported as CoCl2 in hydrothermal fluids and sourced from structures …


Rain Generated Lahars Prior To The 2018 Catastrophic Eruption Of Fuego Volcano, Guatemala, Claudia Buondonno Jan 2020

Rain Generated Lahars Prior To The 2018 Catastrophic Eruption Of Fuego Volcano, Guatemala, Claudia Buondonno

Dissertations, Master's Theses and Master's Reports

Fuego volcano is one of the most active and hazardous volcanoes in the world. It is located in the northern part of the Central American Volcanic Arc in Guatemala and its activity can be characterized by long term, low-level background activity, and sporadic larger explosive eruptions. Its historical observations of eruptions date back to 1531, but it has been erupting vigorously since 2002 with major activity throughout 2018, producing three main eruptions in February, June and November. Its almost persistent activity generates major ashfalls, pyroclastic flows, lava flows; when heavy rains mobilize its deposits, they can form damaging lahars. Phenomena, …


Predictive Geohazard Mapping Using Lidar And Satellite Imagery In Missouri And Oklahoma, Usa, Olufeyisayo B. Ilesanmi Jan 2020

Predictive Geohazard Mapping Using Lidar And Satellite Imagery In Missouri And Oklahoma, Usa, Olufeyisayo B. Ilesanmi

Doctoral Dissertations

”Light Detection and Ranging (LiDAR) and satellite imagery have become the most utilized remote sensing technologies for compiling inventories of surficial geologic conditions. Point cloud data obtained from multi-spectral remote sensing methods provide a detailed characterization of the surface features, in particular, the detailed surface manifestations of underlying geologic structures. When combined, point clouds eliminate bias from visual inconsistencies and/or statistical values. This research explores the competence of point clouds derived from LiDAR and Unmanned Aerial Systems (UAS) as a predictive tool in evaluating various geohazards. It combines these data sets with other remote sensing techniques to evaluate the sensitivity …


Geophysical Characteristics Of Nickel And Copper Deposits In Wadi Al Khadra Prospect, Southwestern Of Saudi Arabia, Abdulrahman Ahmed Aljabbab Jan 2020

Geophysical Characteristics Of Nickel And Copper Deposits In Wadi Al Khadra Prospect, Southwestern Of Saudi Arabia, Abdulrahman Ahmed Aljabbab

Doctoral Dissertations

“Three geophysical datasets (self-potential, magnetics, and time - domain electromagnetics) were acquired at Wadi Al Khadra Ni-Cu prospect in southwest Saudi Arabia, and were processed and interpreted for the Saudi Geological Survey. The primary objectives were to map the distribution of metallic mineralization, map structures, verify the integration of the geophysical interpretations and its signatures in conjunction with boreholes information, distinguish the similarities and differences in the integrated interpretation of geophysical data, and design optimal processing and interpretation data parameters. The self-potential tool was used to map the variation in natural surface potential differences to map lateral variations in the …


Dam Impoundments Sediment Mass – Tributaries To The Hudson River, Brian Yellen, Jonathan Woodruff Jan 2020

Dam Impoundments Sediment Mass – Tributaries To The Hudson River, Brian Yellen, Jonathan Woodruff

Data and Datasets

This repository contains data from sediment cores collected during 2017-2018 from 17 impoundments that are located on tributaries to the tidal portion of the Hudson River as part of a larger NERRs collaborative project entitled Dams and Sediment on the Hudson (DaSH). A companion dataset that contains sediment core data from Hudson tidal marshes is archived at UMass Scholarworks data repository. Sediment cores collected from impoundments behind dams were recovered via piston push coring, which tends to minimize compaction and be representative of true sediment thicknesses. The general workflow for cores included (1) splitting; (2) Itrax XRF scanning; (3) subsampling …


The Fluxnet2015 Dataset And The Oneflux Processing Pipeline For Eddy Covariance Data, Gilberto Pastorello, Timothy Arkebauer, Dave P. Billesbach, Anatoly Gitelson, Adam Liska, Andrew Suyker, Elizabeth Walter-Shea, More Than 200 Other Jan 2020

The Fluxnet2015 Dataset And The Oneflux Processing Pipeline For Eddy Covariance Data, Gilberto Pastorello, Timothy Arkebauer, Dave P. Billesbach, Anatoly Gitelson, Adam Liska, Andrew Suyker, Elizabeth Walter-Shea, More Than 200 Other

Adam Liska Papers

The FLUXNET2015 dataset provides ecosystem-scale data on CO2, water, and energy exchange between the biosphere and the atmosphere, and other meteorological and biological measurements, from 212 sites around the globe (over 1500 site-years, up to and including year 2014). These sites, independently managed and operated, voluntarily contributed their data to create global datasets. Data were quality controlled and processed using uniform methods, to improve consistency and intercomparability across sites. The dataset is already being used in a number of applications, including ecophysiology studies, remote sensing studies, and development of ecosystem and Earth system models. FLUXNET2015 includes derived-data products, such as …


Development Of A Sensor Suite For Atmospheric Boundary Layer Measurement With A Small Multirotor Unmanned Aerial System, Kevin A. Adkins, Christopher J. Swinford, Peter D. Wambolt, Gordon Bease Jan 2020

Development Of A Sensor Suite For Atmospheric Boundary Layer Measurement With A Small Multirotor Unmanned Aerial System, Kevin A. Adkins, Christopher J. Swinford, Peter D. Wambolt, Gordon Bease

International Journal of Aviation, Aeronautics, and Aerospace

Small unmanned aerial systems (sUAS) are increasingly being used to conduct atmospheric research. Because of the dynamic nature and inhomogeneity of the atmospheric boundary layer (ABL), the ability of instrumented sUAS to make on-demand 3-dimensional high-resolution spatial measurements of atmospheric parameters makes them particularly suited to ABL investigations. Both fixed-wing and multirotor sUAS have been used for ABL investigations. Most investigations to date have included in-situ measurement of thermodynamic quantities such as temperature, pressure and humidity. When wind has been measured, a variety of strategies have been used. Two of the most popular techniques have been deducing wind from inertial …


Geophysical Assessment Of The Lake Chesterfield Site, Missouri, Diya Ali Ahmad Alfuqara Jan 2020

Geophysical Assessment Of The Lake Chesterfield Site, Missouri, Diya Ali Ahmad Alfuqara

Doctoral Dissertations

"Since construction of the Lake Chesterfield, Missouri in 1986, significant leaks have occurred causing the lake to lose substantive volumes of water. Mitigation efforts, have not solved the problem. Indeed, in June of 2017, the water level in Lake Chesterfield dropped at an alarmingly rapid rate. Prior to authorizing additional mitigation work, the Lake Chesterfield. Home Owners Association (LCHOA) decided to acquire geophysical data across the drained and dry lake bed. These information would help a geotechnical engineering firm determine the most appropriate mitigation plan.

In the summer of 2018, electrical resistivity tomography, multichannel analysis of surface wave, and spontaneous-potential …


Joint Simulation Of Continuous And Categorical Variables For Mineral Resource Modeling And Recoverable Reserves Calculation, Sentle Augustinus Hlajoane Jan 2020

Joint Simulation Of Continuous And Categorical Variables For Mineral Resource Modeling And Recoverable Reserves Calculation, Sentle Augustinus Hlajoane

Dissertations, Master's Theses and Master's Reports

Spatial variability and uncertainty of continuous variables (grade) and categorical variables (rock-types) in mineral evaluation significantly impact the economics of mining projects. The conventional approach of simulating grades using deterministic rock- types is problematic since spatial variability, and uncertainty of grades at rock-type contacts are not well captured in deposits where the grade changes gradually between rock-types. Therefore, jointly simulating these variables can improve confidence (reduce uncertainty) in a resource model. Also, resource classification and recoverable reserve calculation can significantly improve the understanding of the deposit and its economic viability. This research utilized the Plural-Gaussian geostatistical simulation to jointly simulate …


Glaciernet: A Deep-Learning Approach For Debris-Covered Glacier Mapping, Zhiyuan Xie, Umesh K. Haritashya, Vijayan K. Asari, Brennan W. Young, Michael P. Bishop, Jeffrey S. Kargel Jan 2020

Glaciernet: A Deep-Learning Approach For Debris-Covered Glacier Mapping, Zhiyuan Xie, Umesh K. Haritashya, Vijayan K. Asari, Brennan W. Young, Michael P. Bishop, Jeffrey S. Kargel

Electrical and Computer Engineering Faculty Publications

Rising global temperatures over the past decades is directly affecting glacier dynamics. To understand glacier fluctuations and document regional glacier-state trends, glacier-boundary detection is necessary. Debris-covered glacier (DCG) mapping, however, is notoriously difficult using conventional geospatial technology methods. Therefore, in this research for automated DCG mapping, we evaluate the utility of a convolutional neural network (CNN), which is a deep learning feed-forward neural network. The CNN inputs include Landsat satellite images, an Advanced Land Observation Satellite (ALOS) digital elevation model (DEM) and DEM-derived land-surface parameters. Our CNN based deep-learning approach named GlacierNet was designed by appropriately choosing the type, number …


Physical Modeling Of The Krauklis Waves: Insights From Two Experimental Apparatuses, Haitao Cao Jan 2020

Physical Modeling Of The Krauklis Waves: Insights From Two Experimental Apparatuses, Haitao Cao

Dissertations, Master's Theses and Master's Reports

Fractures play an important role in the geological related processes such as hydraulic fracturing, water-water disposal, and volcanic earthquake. Seismic waves can provide useful information from fractures at a relatively low cost. In particular, the acoustic property of fractures containing magmatic or hydrothermal fluids can provide useful information about the fracture size and the fluid composition within the fracture. For instance, in volcanology, the resonant frequency of long-period events that are linked to crack interface waves is used to obtain fluid properties of cracks in magmatic systems. However, in order to rely on seismic data, they should be precisely characterized …


An Evaluation Of Ground-Freezing Methods In The Zone Of Discontinuous Permafrost, Northwest Territories, Elzbieta Mastej Ms Jan 2020

An Evaluation Of Ground-Freezing Methods In The Zone Of Discontinuous Permafrost, Northwest Territories, Elzbieta Mastej Ms

Theses and Dissertations (Comprehensive)

Northwestern Canada is one of the most rapidly warming regions on Earth. The southern limit of the discontinuous permafrost zone is highly sensitive to small climatic fluctuations and presently experiencing a rapid landscape change due to accelerated permafrost thaw, which is further exacerbated by anthropogenic disturbances such as seismic exploration. Recent research has begun to examine both natural and mechanical approaches to minimize permafrost loss, although the utility of such methods in peatland environments is not well understood. This study explored the efficiency of natural and artificial ground cooling processes in a peatland environment by evaluating snow exclusion and thermosyphon …