Geophysics and Seismology Commons^™

Investigating Converted Phases In The Midland Basin, Texas, Using Synthetic Seismograms, Julia Rosenblit

Earth Sciences Theses and Dissertations

Intraplate seismicity in previously aseismic areas within the Permian Basin, Texas, has steadily increased since 2009 (Frohlich et al., 2020). The Midland Basin, the eastern lobe of the Permian, has experienced multiple moderate magnitude earthquakes (M4-6), including the recent 2022 M5.2 Range Hill earthquake. While it is generally accepted that oil and gas development is linked to the seismic activity, and saltwater disposal (SWD) is a significant triggering mechanism in the Midland Basin, understanding the mechanism(s) of shallow (

A Uav Based Cmos Ku-Band Metasurface Fmcw Radar System For Low-Altitude Snowpack Sensing, Adrian Tang, Nacer Chahat, Yangyho Kim, Arhison Bharathan, Gabriel Virbila, Hans-Peter Marshall, Thomas Van Der Weide, Gaurangi Gupta, Raunika Anand, Goutam Chattopadhyay, Mau-Chung Frank Chang

Geosciences Faculty Publications and Presentations

This article presents development of a UAV based frequency modulated continuous wave (FMCW) radar system for remotely sensing the water contained within snowpacks. To make the radar system compatible with the payload requirements of small UAV platforms, the radar electronics are implemented with CMOS technology, and the antenna is implemented as an extremely compact and lightweight metasurface (MTS) antenna. This article will discuss how the high absorption losses of snowpacks lead to dynamic range requirements much stricter than FMCW radars used for automotive and other sensing applications, and how these requirements are met through antenna isolation, leakage calibration and exploitation …

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 …

Extending Active Network Length Versus Catchment Discharge Relations To Temporarily Dry Outlets, Gianluca Botter, James Mcnamara, Nicola Durighetto

Geosciences Faculty Publications and Presentations

River networks are not steady blue lines drawn in a map, since they continuously change their shape and extent in response to climatic drivers. Therefore, the flowing length of rivers (L) and the corresponding catchment-scale streamflow (Q_sur) co-evolve dynamically. This paper analyzes the relationship between the wet channel length and the streamflow of a river basin, formulating a general analytical model that includes the case of temporarily dry outlets. In particular, the framework relaxes the common assumption that when the discharge at the outlet tends to zero the upstream flowing length approaches zero. Different analytical …

Geographically Dependent Thermodynamic And Geochemical Evolution In The Post-Batholith Upper Mantle Beneath The Sierra Nevada: Analysis Of The Blue Knob Xenoliths, Eleanor Ruos

Scripps Senior Theses

Xenoliths entrained in recent (Miocene) volcanics from the Sierra Nevada provide insights into a continuously evolving upper mantle during post-batholith generation periods (early Cenozoic–present). Hypothesized mantle refertilization followed by subsequent delamination of the lithospheric root beneath the Sierra provides a contextual framework for analyzing how the upper mantle responds to such events. This study contributes new geochemical data from the ultramafic xenoliths of Blue Knob, including bulk-rock major and trace element data, thin-section petrography, mineral chemistry and thermobarometry, and oxygen isotopes (delta¹⁸O). Blue knob (Eastern Sierra) data are compared to previous works on xenoliths from Chinese Peak and …

The Influence Of Volcano Edifice Resonance On The Seismic Triggering Of Thermal Activity At Active Volcanoes, Morgana M. Wilke

Dissertations, Master's Theses and Master's Reports

There is an established correlation between large earthquakes and volcanic unrest, however the mechanisms between this connection are not well understood. Relatively small changes in stress within a volcanic system could be enough to initiate a response. One aspect that could serve to amplify small dynamic stress changes is volcanic edifice resonance triggered by surface waves at resonant frequency. In this paper, we investigate the relationship between thermal activity of volcanoes and various minimum thresholds of Love wave amplitudes at resonance caused by teleseismic earthquakes above a 7.0 M. Satellite-derived thermal data from 25 volcanoes are modeled in relation to …

Anomaly Mapping Of Heavy And Light Rare Earth Elements In Central Upper Peninsula Of Michigan Using Geostatistics And Fractal Analysis, Sunday Joseph

Dissertations, Master's Theses and Master's Reports

Rare earth elements (REEs) have gained significant global importance due to their critical role in supporting the transition towards reduced carbon emissions through industrial applications. REEs serve as essential raw materials for various critical components in modern infrastructure, defense systems, and technological advancements. Geochemical and geophysical data are pivotal in assessing the potential of REEs. Geochemical data provide direct insights into the elemental composition of rocks and soils, offering valuable information on the potential presence and dispersion of REEs. However, the complex geological processes that influence the distribution of REEs often exhibit intricate spatial patterns that may not be fully …

Response Of Open Volcanic Systems To Static Stress Changes, Aimee Zimmerman

Dissertations, Master's Theses and Master's Reports

Large earthquakes of magnitude 7.0 or greater can alter volcanic emissions and even trigger eruptions at nearby volcanoes. The stress changes imparted by large earthquakes can cause otherwise stable conditions within the magmatic system to be disturbed, potentially inducing volcanic activity. The extent of the triggering potential is still unknown due to insufficient understanding of the mechanisms involved. We model static stress changes for 174 earthquake-volcano pairs from 2000-2023 at volcanoes within 500 km, computing changes in both the normal stress perpendicular to the direction of horizontal maximum stress and dilatational strain. We then use thermal satellite data to measure …

Sh-Wave Seismic-Reflection Efficiency Technique For Investigating The Wolf Island Fault, New Madrid Seismic Zone, Usa, Stephanie Vicroy

Theses and Dissertations--Earth and Environmental Sciences

The Reelfoot Fault within the New Madrid seismic zone has displacement at seismogenic depth to which the surface expression has unequal displacement. Previous work identified northeast-oriented transpressional fault strands northeast of a bend in the scarp as evidence for a through-going shear-zone, acting as potential accommodation for the observed strain imbalance. This investigation projected the trend of these faults to their intersection with an industry seismic survey at Wolf Island, Missouri, which exhibits a similarly structured faulted zone. We suggest this structure is the continuation of the through-going shear zone representing a previously unknown 22-km-long Quaternary-active fault that can affect …

High Resolution Sedimentary Investigations Of Extant Lakes In North America, John Dilworth

Theses and Dissertations--Earth and Environmental Sciences

Investigation of past lake environments forms the discipline of paleolimnology. Paleolimnological studies seek to evaluate geophysical, geochemical, and ecological proxies and indicators contained within lake sediment archives. Using these potential stores of high-resolution environmental information, questions regarding climate, biological, and geochemical changes experienced by a lake and its watershed can be investigated. This dissertation research utilized lake sediment records from two lakes within North America to study different aspects of environmental change. This dissertation consists of three separate studies presented in three chapters.

Chapter Two presents a retrospective environmental assessment of Jackson Lake, Wyoming to investigate the impacts of dam …

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 …

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. …

Comparative Analysis Of Critical Bond Strength Parameters Of Neat Class G Cement And Fly Ash Enhanced Cement To Steel, C. M. Potter, Andreas Eckert, James A. Jones, Z. Weicheng, M. Meng

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

In subsurface engineering applications, such as wellbore integrity, the interface between cement and steel is integral to expected functionality. The interface between steel and cement is often a structural weak point in many systems, however, the critical parameters for debonding evaluation are poorly understood and derived from outdated experimental procedures. Through experimental debonding tests, this study aims to analyze the tensile bond strength and fracture parameters and their sensitivity to cement composition with a pozzolanic additive (fly ash). Neat Class G cement testing resulted in an average tensile bond strength of 0.223 MPa, an average contact stiffness of 2.94x108 N/m3, …

Earthquakes And Seismic Waves: Solutions For Fermi Questions, March 2024, John Adam

Mathematics & Statistics Faculty Publications

Solution to Question 1: To estimate h, we take the geometric mean of 1 km and 70 km, or ~8 km, and take ρ ≈ 2500 kg/m³.

Hence, δl ≈ 4 × 0.05 × (2.5 × 10³ kg/m³) × (10 m/s²) × (8 × 10³ m) × (2 × 10⁴ m) × 0.1 ÷ (3 × 10¹⁰ kg · m⁻¹ · s⁻²) ≈ 1.3 m. (Note that this is not meant to be an estimate of the width of the Icelandic rock fracture in the photograph, though it appears to be of the right order …

Earthquakes And Seismic Waves, John Adam

Mathematics & Statistics Faculty Publications

This article discusses earthquakes and seismic waves. It explains that earthquakes occur in the crust or upper mantle, with "shallow" earthquakes happening above a depth of 70 km in the crust. The article also introduces the slider-block model, which is a simple model used to understand earthquake behavior. It provides equations to calculate the displacement and maximum slip velocity of the fault based on various factors. The article then presents two questions related to earthquake calculations. Additionally, it mentions Fermi Questions, which are brief questions with estimation techniques.

An Early Byzantine Ecclesiastical Complex At Ashdod-Yam: Correlating Geophysical Prospection With Excavated Remains, Yaniv Darvasi, Alexander Fantalkin, Paul Brindza, Amotz Agnon

Physics Faculty Publications

In this study we show the successful deployment of Ground Penetrating Radar (GPR) together with Electrical Resistivity Surveys (ERS) in guiding the archeological excavations at Ashdod-Yam (southern coast of Israel). This approach enabled the precise identification of excavation targets relating to an Early Byzantine ecclesiastical complex located in a residential neighborhood of the modern city of Ashdod. Applied over the course of five years, the combined use of GPR and ERS, interspersed with phases of archeological excavation, not only facilitated an efficient exploration but also ensured the preservation of valuable historical structures. The geophysical data, corroborated by drone images of …

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 Tensor-Based Data-Driven Approach For Multidimensional Harmonic Retrieval And Its Application For Mimo Channel Sounding., Yanming Zhang, Wenchao Xu, A. Long Jin, Min Li, Ping Yuan, Lijun Jiang, Steven Gao

Electrical and Computer Engineering Faculty Research & Creative Works

In wireless channel sounding, accurately estimating multiple parameters within a multipath signal, such as azimuth, elevation, Doppler shift, and delay, necessitates addressing the challenges posed by the multidimensional harmonic retrieval (MHR) problem. To overcome these complexities, we propose a framework based on high-order dynamic mode decomposition (HODMD) that designed for robustly estimating frequencies of interest from high-dimensional sinusoidal signals, particularly in additive white Gaussian noise conditions. The HODMD approach, a hybrid algorithm amalgamating high-order singular value decomposition (HOSVD) and dynamic mode decomposition (DMD), operates by initially decomposing observed tensorial data into a core tensor and R mode matrices through HOSVD. …

Modeling Apparent Pb Loss In Zircon U-Pb Geochronology, Glenn R. Sharman, Matthew A. Malkowski

Geosciences Faculty Publications and Presentations

The loss of radiogenic Pb from zircon is known to be a major factor that can cause inaccuracy in the U–Pb geochronological system; hence, there is a need to better characterize the distribution of Pb loss in natural samples. Treatment of zircon by chemical abrasion (CA) has become standard practice in isotope dilution–thermal ionization mass spectrometry (ID-TIMS), but CA is much less commonly employed prior to in situ analysis via laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) or secondary ionization mass spectrometry (SIMS). Differentiating the effects of low levels of Pb loss in Phanerozoic zircon with relatively low-precision in situ U–Pb …

Simulation Of Wave Propagation In Granular Particles Using A Discrete Element Model, Syed Tahmid Hussan

College of Graduate Studies: Theses & Dissertations

The understanding of Bender Element mechanism and utilization of Particle Flow Code (PFC) to simulate the seismic wave behavior is important to test the dynamic behavior of soil particles. Both discrete and finite element methods can be used to simulate wave behavior. However, Discrete Element Method (DEM) is mostly suitable, as the micro scaled soil particle cannot be fully considered as continuous specimen like a piece of rod or aluminum. Recently DEM has been widely used to study mechanical properties of soils at particle level considering the particles as balls. This study represents a comparative analysis of Voigt and Best …