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Articles 1621 - 1650 of 29939

Full-Text Articles in Geology

118, Scott Brande Jan 2024

118, Scott Brande

All 3D Rock Models

Model 118 - gabbro - igneous rock

SketchFab link: https://sketchfab.com/3d-models/118-1581789f63c4446d9fd60d6a9926f06c


120, Scott Brande Jan 2024

120, Scott Brande

All 3D Rock Models

Model 120 - granite - igneous rock

SketchFab link: https://sketchfab.com/3d-models/120-5fc8bd01a11b4e26b63f971f49205152


125, Scott Brande Jan 2024

125, Scott Brande

All 3D Rock Models

Model 125 - peridotite - igneous rock

SketchFab link: https://sketchfab.com/3d-models/125-492cb73d2ecf4ef099673671533e0fb9


127, Scott Brande Jan 2024

127, Scott Brande

All 3D Rock Models

Model 127 - diorite - igneous rock

SketchFab link: https://sketchfab.com/3d-models/127-21c97cc7e71241d7a9f3925165df9a3f


111, Scott Brande Jan 2024

111, Scott Brande

All 3D Rock Models

Model 111 - andesite - igneous rock

SketchFab link: https://sketchfab.com/3d-models/111-510ba461f1d94a729070b0f30ef0b4e6


128, Scott Brande Jan 2024

128, Scott Brande

All 3D Rock Models

Model 128 - gabbro - igneous rock

SketchFab link: https://sketchfab.com/3d-models/128-3bcbedd3249e4254bffa3233a6977a9e


Daal, Scott Brande Jan 2024

Daal, Scott Brande

All 3D Rock Models

Model DAAL - gabbro - igneous rock

SketchFab link: https://sketchfab.com/3d-models/daal-1-71e1bddbca0b486bb085fd1deb471124


124, Scott Brande Jan 2024

124, Scott Brande

All 3D Rock Models

Model 124 - peridotite - igneous rock

SketchFab link: https://sketchfab.com/3d-models/124-f0f053e2206944f888962f46273686d3


132, Scott Brande Jan 2024

132, Scott Brande

All 3D Rock Models

Model 132 - diorite - igneous rock

SketchFab link: https://sketchfab.com/3d-models/132-330f669b9a684e15a96684a20214ca86


134, Scott Brande Jan 2024

134, Scott Brande

All 3D Rock Models

Model 134 - pumice - igneous rock

SketchFab link: https://sketchfab.com/3d-models/134-c3a2828764bd4e74a43dd32520e0cbf5


130, Scott Brande Jan 2024

130, Scott Brande

All 3D Rock Models

Model 130 - pegmatite - igneous rock

SketchFab link: https://sketchfab.com/3d-models/130-a7623f4cc0c54544bf5bd1180391f007


133, Scott Brande Jan 2024

133, Scott Brande

All 3D Rock Models

Model 133 - pumice - igneous rock

SketchFab link: https://sketchfab.com/3d-models/133-ef1923fe77f84ba0917927dd9eb4334f


Surficial Geologic Map Of The Smiths Grove 7.5-Minute Quadrangle, Kentucky, Meredith Swallom, Bailee Nicole Hodelka, Matthew Massey, Hannah Hayes, Charles Wells Iii, Emily Morris Jan 2024

Surficial Geologic Map Of The Smiths Grove 7.5-Minute Quadrangle, Kentucky, Meredith Swallom, Bailee Nicole Hodelka, Matthew Massey, Hannah Hayes, Charles Wells Iii, Emily Morris

Contract Reports--KGS

The Kentucky Geological Survey (KGS), a state-supported independent research center within the University of Kentucky, is committed to providing accurate and unbiased geologic information on natural resources, environmental issues, and natural hazards in Kentucky. While Kentucky boasts complete coverage by 1:24,000-scale geologic bedrock maps, surficial materials have been largely overlooked, except in regions with thick deposits obscuring the bedrock. Given the increasing trends in economic development and urbanization, detailed surficial geologic mapping has become crucial for supporting geotechnical planning, environmental management, and hazard assessment. In response, KGS has prioritized new, detailed surficial geologic mapping since 2004, specifically targeting areas anticipated …


Storm-Generated Molluscan Thanatocoenosis Along A Carbonate Paleoshoreline: Southern Eleuthera Island, The Bahamas, Ilya Val Buynevich, Michael Savarese, H. Allen Curran, Tara Ingalsbe Jan 2024

Storm-Generated Molluscan Thanatocoenosis Along A Carbonate Paleoshoreline: Southern Eleuthera Island, The Bahamas, Ilya Val Buynevich, Michael Savarese, H. Allen Curran, Tara Ingalsbe

Geosciences: Faculty Publications

Concentrations of large mollusc shells in coastal deposits provide important information about the local malacofauna and potential transport agents, including extreme events [1-4]. Such accumulations are common in the rock record [5,6], with Quaternary examples serving as good time-averaged examples by combining aspects of both the modern biocoenoses and the fossil record. Death assemblages of local organisms (thanatocoenosis) and their preserved record (taphocoenosis) in carbonate settings, where granulometric spectrum may be very limited (e.g., ooilitic sand), can serve as important paleo-environmental indicators, especially when considered in combination with primary sedimentary structures (in outcrops or geophysical images) and in situ biogenic …


The Geodetic Strain Rates From Gnss In The North American-Carribean-Cocos Triple Junction In Guatemala And Implications For Seismic Hazard, Tanaya Kashyap Jan 2024

The Geodetic Strain Rates From Gnss In The North American-Carribean-Cocos Triple Junction In Guatemala And Implications For Seismic Hazard, Tanaya Kashyap

Masters Theses

"Geodetic velocity data are pivotal for deciphering seismic risks, providing initial constraints for crustal surface strain rates. Gaining an understanding of the 2D surface strain tensor across an entire area necessitates knowledge of the surface velocity field, yet geodetic data such as measurements from the Global Navigation Satellite System (GNSS) are dispersed across the Earth’s surface. In the current scope of study, we have employed various methodologies to estimate strain rates in Guatemala, utilizing GNSS velocity data and leveraging the open-source Python tool Strain_2D. Strain_2D facilitates the computation of strain rates through diverse methods applied to the same dataset and …


Post-Glacial Landscape Evolution Of The Lower St. Croix River Valley: The Enigma Of Glacial Lake Grantsburg, The Osceola Bench, And The St. Croix Dells, Hunter Delikowski Jan 2024

Post-Glacial Landscape Evolution Of The Lower St. Croix River Valley: The Enigma Of Glacial Lake Grantsburg, The Osceola Bench, And The St. Croix Dells, Hunter Delikowski

All Graduate Theses, Dissertations, and Other Capstone Projects

The St. Croix River valley (SCRV) is the product of dyssynchronous glacial advance and retreat of several glacial lobes during regional deglaciation of the Late Pleistocene-Early Holocene transition. Additionally, the SCRV has been dramatically shaped by multiple proglacial lake drainage episodes. Therefore, the SCRV is an important case study to understanding the impacts of proglacial lake spillover processes. However, the magnitude, frequency, timing, duration, and geomorphic impacts of these floods remain enigmatic. We focus on a specific reach of the SCRV, which we name the Lower SCRV for the purpose of this study. The lower SCRV contains several anomalous landforms …


Joint Interpretation Of Ert And Self-Potential Data To Characterize The Subsurface Geology And Hydrodynamics Along The Sutherland Supply Canal And Paxton Siphon Inlet, Paxton, Nebraska., M. K. Aboushanab, D. R. Hallum, R. M. Joeckel Jan 2024

Joint Interpretation Of Ert And Self-Potential Data To Characterize The Subsurface Geology And Hydrodynamics Along The Sutherland Supply Canal And Paxton Siphon Inlet, Paxton, Nebraska., M. K. Aboushanab, D. R. Hallum, R. M. Joeckel

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Earth Mri Western Kentucky Fluorspar District 3d Geological Modeling, Devan M. Robinson, Anna Pearson, John B. Hickman, Georgina Lukoczki, William Morton Andrews Jr. Jan 2024

Earth Mri Western Kentucky Fluorspar District 3d Geological Modeling, Devan M. Robinson, Anna Pearson, John B. Hickman, Georgina Lukoczki, William Morton Andrews Jr.

Research Data--KGS

The Illinois–Kentucky Fluorspar District (IKFD) three-dimensional (3D) geological data model plays a critical role in the EarthMRI IKFD project, which aims to utilize the vast and detailed geologic maps and datasets that the Kentucky and Illinois state geological surveys possess to develop a Geographic Information System (GIS)-based 3D geological framework model for the district. The model serves as a framework in which to view the subsurface geological and geochemical data, and to better comprehend the structural and other geologic processes acting on the region as they relate to the locations of critical minerals. The development of the model will also …


Coupling-Informed Data-Driven Scheme For Joint Angle And Frequency Estimation In Uniform Linear Array With Mutual Coupling Present, Yanming Zhang, Wenchao Xu, A. Long Jin, Min Li, Peifeng Ma, Lijun Jiang, Steven Gao Jan 2024

Coupling-Informed Data-Driven Scheme For Joint Angle And Frequency Estimation In Uniform Linear Array With Mutual Coupling Present, Yanming Zhang, Wenchao Xu, A. Long Jin, Min Li, Peifeng Ma, Lijun Jiang, Steven Gao

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes a novel coupling-informed data-driven algorithm tailored for the concurrent estimation of frequency and angle within a uniform linear array (ULA), while addressing the complicating influence of mutual coupling. Leveraging the hybrid dynamic mode decomposition (DMD) methodology, termed as averaged DMD, we incorporate moving average techniques to achieve effective denoising. The averaged DMD further decomposes the received signal into eigenvalues and corresponding eigenvectors. The frequency information is derived from the eigenvalues and the corresponding eigenvectors represent the steering vectors of sources. Subsequently, mutual coupling is informed into the calibration of the steering vector for each source. Specifically, the …


A Hybrid Algorithm To Dual Sparse Sampling Measurement In Time-Resolved Electromagnetic Near-Field Scanning, Yanming Zhang, Steven Gao, Lijun Jiang Jan 2024

A Hybrid Algorithm To Dual Sparse Sampling Measurement In Time-Resolved Electromagnetic Near-Field Scanning, Yanming Zhang, Steven Gao, Lijun Jiang

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Time-resolved electromagnetic near-field scanning is vital for antenna measurement and addressing complex electromagnetic interference and compatibility issues. However, the swift acquisition of high-resolution spatiotemporal data remains challenging due to physical constraints, such as moving the probe position and allowing sufficient time for sampling. This paper introduces a novel hybrid approach that combines Kriging for sparse spatial measurement, compressed sensing (CS) for sparse temporal sampling, and dynamic mode decomposition (DMD) for a comprehensive analysis of dual-sparse sampling electromagnetic near-field data. CS optimizes sparse sampling in the time domain, capitalizing on the inherent sparsity within electromagnetic radiated signals, resulting in reliable representation …


A Data-Driven Approach To Time-Domain Electromagnetic Modeling Based On Dynamic Mode Decomposition, Yanming Zhang, Steven Gao, Lijun Jiang Jan 2024

A Data-Driven Approach To Time-Domain Electromagnetic Modeling Based On Dynamic Mode Decomposition, Yanming Zhang, Steven Gao, Lijun Jiang

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

This paper presents a data-driven methodology that utilizes Dynamic Mode Decomposition (DMD) for the time-domain (TD) electromagnetic (EM) modeling of microwave devices. As an unsupervised machine learning technique, DMD leverages a limited set of unlabeled spatio-temporal electromagnetic (EM) data to determine DMD eigenvalues and eigenmodes. Then, the obtained DMD model reconstructs the dynamics as a series of exponential terms based on linear assumptions. The effectiveness of this approach is demonstrated through the TD EM modeling of photonic crystal waveguides. Comparative analysis with the finite-difference time-domain (FDTD) method shows that the DMD model not only achieves precise modeling but also facilitates …


Novel Re-Crosslinkable Preformed Particle Gels (Rppg) For Parent- And Infill-Well-Fracture Interactions Mitigation, Xiaojing Ge, Adel Alotibi, Ahmed Al-Hlaichi, Yanbo Liu, Tao Song, Junchen Liu, Baojun Bai, Thomas P. Schuman Jan 2024

Novel Re-Crosslinkable Preformed Particle Gels (Rppg) For Parent- And Infill-Well-Fracture Interactions Mitigation, Xiaojing Ge, Adel Alotibi, Ahmed Al-Hlaichi, Yanbo Liu, Tao Song, Junchen Liu, Baojun Bai, Thomas P. Schuman

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Hydraulic fracturing treatments in unconventional infill (or "child") wells can be significantly affected by depletion from existing parent-well, resulting in asymmetrical fracture growth. These issues may lead to excessive load-water production, proppant deposition, casing deformation in the parent well, and unbalanced stimulation of infill wells. To mitigate these effects, various strategies have been proposed, including the use of far-field diverters in child wells and repressurization of parent wells. Additionally, an increasingly popular strategy involves injecting near-wellbore diverters to temporarily plug entry points into the parent wellbores during frac operations on infill wells. To achieve better application, a novel low-cost, self-degradable, …


An Unsupervised Learning Framework For Determining The Excitation Coefficients Using Near-Field Antenna Measurements, Yanming Zhang, Peifeng Ma, Steven Gao, Lijun Jiang Jan 2024

An Unsupervised Learning Framework For Determining The Excitation Coefficients Using Near-Field Antenna Measurements, Yanming Zhang, Peifeng Ma, Steven Gao, Lijun Jiang

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

This article presents a novel unsupervised learning framework based on multiscale dynamic mode decomposition for determining the excitation coefficients of antennas using time-domain near-field measurements. The proposed framework integrates temporal multiscale analysis to extract a joint distribution of frequency, damping factors, and spatial modes, enabling precise extraction of excitation frequencies, rising/falling edges, and phases without labeled data. We validate the effectiveness of the proposed approach through two examples involving on-off keying modulation and a phase-shift dipole antenna. It is found that the proposed method performs well in handling nonstationary excitation signals and proves particularly advantageous for calibrating tunable antenna systems. …


Descriptive Statistical Analysis Of Experimental Data For Wettability Alteration With Smart Water Flooding In Carbonate Reservoirs, Muhammad Ali Buriro, Mingzhen Wei, Baojun Bai, Ya Yao Jan 2024

Descriptive Statistical Analysis Of Experimental Data For Wettability Alteration With Smart Water Flooding In Carbonate Reservoirs, Muhammad Ali Buriro, Mingzhen Wei, Baojun Bai, Ya Yao

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Smart water flooding is a promising eco-friendly method for enhancing oil recovery in carbonate reservoirs. the optimal salinity and ionic composition of the injected water play a critical role in the success of this method. This study advances the field by employing machine learning and data analytics to streamline the determination of these critical parameters, which are traditionally reliant on time-intensive laboratory work. the primary objectives are to utilize data analytics to examine how smart water flooding influences wettability modification, identify key parameter ranges that notably alter the contact angle, and formulate guidelines and screening criteria for successful lab design. …


Und-25, Scott Brande Jan 2024

Und-25, Scott Brande

All 3D Rock Models

Model UND-25 - diorite - igneous rock

SketchFab link: https://sketchfab.com/3d-models/und-25-b0e90e8a6b7c4207a67f070f097b5370


126, Scott Brande Jan 2024

126, Scott Brande

All 3D Rock Models

Model 126 - basalt - igneous rock

SketchFab link: https://sketchfab.com/3d-models/126-c6ef512294fa4a7ebab143a5260cacbf


131, Scott Brande Jan 2024

131, Scott Brande

All 3D Rock Models

Model 131 - pumice - igneous rock

SketchFab link: https://sketchfab.com/3d-models/131-f3771991ac1f4864ad7b9a92835042a5


169, Scott Brande Jan 2024

169, Scott Brande

All 3D Rock Models

Model 169 - chalk - sedimentary rock

SketchFab link: https://sketchfab.com/3d-models/169-0eec274a758747e4b54c37865f5be696


Borneo Stalagmite Evidence Of Significantly Reduced El Niño-Southern Oscillation Variability At 4.1 Kybp, C.M. Theaker, S.A. Carolin, C.C. Day, K.M. Cobb, S. Chen, Pamela R. Grothe, H.O. Couper Jan 2024

Borneo Stalagmite Evidence Of Significantly Reduced El Niño-Southern Oscillation Variability At 4.1 Kybp, C.M. Theaker, S.A. Carolin, C.C. Day, K.M. Cobb, S. Chen, Pamela R. Grothe, H.O. Couper

Earth and Environmental Sciences

The timing and geographic extent of a potential “4.2 ky event” remain highly contested. Here we present records of ENSO variability at 3.8 kyBP and 4.1 kyBP derived from a Borneo stalagmite, which suggest a significant change in ENSO properties between these time intervals. The Borneo records show evidence of significantly reduced ENSO activity at 4.1 kyBP, relative to other measured windows within the Holocene. This reduced ENSO activity coincides with a period of drier conditions and enhanced dust events in the Middle East that took place ∼4.0–4.3 kyBP. The Borneo records show evidence of enhanced ENSO activity at 3.8 …


Assessing Seismic Hazard In Western Kentucky And At The Paducah Gaseous Diffusion Plant: An Overview Of The Issues, Mitigation Strategies, And The Research Conducted By The Kentucky Geological Survey, Zhenming Wang, Seth Carpenter Jan 2024

Assessing Seismic Hazard In Western Kentucky And At The Paducah Gaseous Diffusion Plant: An Overview Of The Issues, Mitigation Strategies, And The Research Conducted By The Kentucky Geological Survey, Zhenming Wang, Seth Carpenter

Bulletin--KGS

The exposure of homes, infrastructure, and critical facilities in western Kentucky, including the Paducah Gaseous Diffusion Plant (PGDP), to potential strong seismic shaking from the New Madrid Seismic Zone (NMSZ) has been a major impetus for decades of effort to characterize seismic hazards by the Kentucky Geological Survey (KGS). The purpose of this report is to provide 1) a summary of the earthquake hazards that affect Kentucky and KGS’s ongoing earthquake research, including seismic monitoring, 2) background on the types of seismic hazards in general and how they are quantified in seismic hazard assessments, including strengths and weaknesses of the …