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Full-Text Articles in Physical Sciences and Mathematics

A Thermochronometric, Microtextural, And Numerical Modeling Approach To Deciphering The Rock Record Of Deformation Processes In The Wasatch And Denali Fault Zones, Robert G. Mcdermott Dec 2020

A Thermochronometric, Microtextural, And Numerical Modeling Approach To Deciphering The Rock Record Of Deformation Processes In The Wasatch And Denali Fault Zones, Robert G. Mcdermott

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fault zones are the primary features that accommodate movement of Earth’s crust, resulting in the formation of mountain belts and damaging earthquakes. Rocks modified by faulting and brought to Earth’s surface by erosion are archives of the mechanical processes involved in earthquakes and(or) aseismic creep. Thermochronometry is a radioisotopic dating system primarily sensitive to temperature and offers a means to constrain dates and rates of thermal processes. Hematite is common in fault zones, amenable to (U-Th)/He (He) thermochronometry, and exhibits distinct microtextures diagnostic of fault zone mechanics. I apply hematite He thermochronometry and microtextural analyses with a suite of other …


Simulation And Research On Surface Subsidence Caused By Abandoned Goaf Under Earthquake, Tiejun Cui, Yundong Ma, Laigui Wang Jul 2020

Simulation And Research On Surface Subsidence Caused By Abandoned Goaf Under Earthquake, Tiejun Cui, Yundong Ma, Laigui Wang

Journal of System Simulation

Abstract: To understand the overlying rock strata caused by filling and abandoned goaf under earthquake, ensuring that the upper surface of subgrade is not due to the earthquake generating additional settlement which affects normal use, the goaf and the overlying rock strata were simulated with filling rate(0.85, 0.9, 0.95) and earthquake acceleration(0.2 g, 0.3 g, 0.4 g). Simulation using PFC3D as platform, modeling of complex strata, and the introduction of filling and the simulation method of earthquake, the overlying rock strata migration, stress, and the surface of the subgrade settlement characteristics were obtained. The additional earthquake surface subsidence law was …


Mesopause Airglow Disturbances Driven By Nonlinear Infrasonic Acoustic Waves Generated By Large Earthquakes, P. A. Inchin, J. B. Snively, J. Aguilar Guerrero, M. D. Zettergren, A. Williamson, D. Melgar May 2020

Mesopause Airglow Disturbances Driven By Nonlinear Infrasonic Acoustic Waves Generated By Large Earthquakes, P. A. Inchin, J. B. Snively, J. Aguilar Guerrero, M. D. Zettergren, A. Williamson, D. Melgar

Publications

Near-epicentral mesopause airglow perturbations, driven by infrasonic acoustic waves (AWs) during a nighttime analog of the 2011 M9.1 Tohoku-Oki earthquake, are simulated through the direct numerical computation of the 3D nonlinear Navier-Stokes equations. Surface dynamics from a forward seismic wave propagation simulation, initialized with a kinematic slip model and performed with the SPECFEM3D_GLOBE model, are used to excite AWs into the atmosphere from ground level. Simulated mesopause airglow perturbations include steep oscillations and persistent nonlinear depletions up to 50% and 70% from the background state, respectively, for the hydroxyl OH(3,1) and oxygen O(1S) 557.7-nm emissions. Results suggest that …


The Internal Structure Of Beypazarı Blind Thrust Zone Around Çayırhan, Anıl Ardahanlioğlu, Gürol Seyi̇toğlu, Korhan Esat Apr 2020

The Internal Structure Of Beypazarı Blind Thrust Zone Around Çayırhan, Anıl Ardahanlioğlu, Gürol Seyi̇toğlu, Korhan Esat

Bulletin of the Mineral Research and Exploration

The Beypazarı Blind Thrust Zone, which is surrounded by the North Anatolian, the Eskişehir, and the Kırıkkale-Erbaa fault zones, is a recently defined neotectonic structure developed in the NW central Anatolia together with the Eldivan-Elmadağ and the Abdüsselam Pinched Crustal Wedges. In this study, the internal structure of the Beypazarı Blind Thrust Zone has been examined in detail around Çayırhan region. It has been defined that it consists of the Karaköy, Sekli, Nalçabayırı, Uzunbayır blind thrusts, Davutoğlan Back Thrust, and Beypazarı Blind Thrust I-II from North to south, respectively with help of the fault-propagation folds in the study area. The …


Evaluation Of The Potential Geological And Socioeconomic Impacts Of The Imminent Cascadia Megathrust Earthquake, Matthew Pritchard Mar 2020

Evaluation Of The Potential Geological And Socioeconomic Impacts Of The Imminent Cascadia Megathrust Earthquake, Matthew Pritchard

Honors Theses

The Cascadia Subduction Zone on the northwest coast of the United States poses the threat of a devastating megathrust earthquake and subsequent tsunami damaging coastal populations. This paper synthesizes literature to analyze the geologic and socioeconomic effects of this natural disaster, as well as examines the existing warning system infrastructure, and makes recommendations to mitigate the damage. In order to assess the geologic effects of a megathrust earthquake, I investigate the tectonic history, the role of episodic tremor and slip (ETS) in stress buildup, crustal architecture of the subduction zone, and analogous subduction zones such as Chile and Japan. This …


Stochastic Modeling Of Earthquakes And Option Pricing Using Bns-Gamma-Ou Model, Mandela Bright Quashie Jan 2020

Stochastic Modeling Of Earthquakes And Option Pricing Using Bns-Gamma-Ou Model, Mandela Bright Quashie

Open Access Theses & Dissertations

High frequency data are becoming increasingly popular these days. They are fundamental in basically every facet of people’s lives. They are the determining factors in hedging in the field of finance. In geology, they help in the accurate prediction of earthquakes’ magnitude which goes along way to help save lives and properties.

High frequency data are also used more and more frequently for speculations. For this reason, it is important not only for scientists to apply models allowing correct quantification of these data, but also to improve the eciency of these models.

The Black-Scholes model, which is widely used because …


Joint Modeling Of Rayleigh Wave Dispersion And H/V Spectral Ratio Using Pareto-Basedmultiobjective Particle Swarm Optimization, Ersi̇n Büyük, Ekrem Zor, Abdullah Karaman Jan 2020

Joint Modeling Of Rayleigh Wave Dispersion And H/V Spectral Ratio Using Pareto-Basedmultiobjective Particle Swarm Optimization, Ersi̇n Büyük, Ekrem Zor, Abdullah Karaman

Turkish Journal of Earth Sciences

Estimating the shear wave velocity and thickness of geologic units in a sedimentary structure is important for quantifying the local site effect caused by an earthquake. Inversion of the Rayleigh wave dispersion alone is sensitive to the absolute average shear wave velocity, while the H/V spectral ratio is sensitive to velocity contrasts. The solution of these models in a joint system using conventional inversion techniques suffers from difficulties while evaluating partial derivatives, dependencies to the initial model that is sometimes difficult to estimate, and trapping at a local minimum. Herein, a joint model using the Pareto optimality technique with multiobjective …