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Full-Text Articles in Geophysics and Seismology

Tracking Induced Seismicity In The Fort Worth Basin, Texas And Northern Oklahoma Using Local And Large-N Style Arrays, Louis Quinones Oct 2021

Tracking Induced Seismicity In The Fort Worth Basin, Texas And Northern Oklahoma Using Local And Large-N Style Arrays, Louis Quinones

Earth Sciences Theses and Dissertations

Since 2008, earthquake sequences within the Fort Worth Basin (FWB), north Texas, have been linked to wastewater disposal activities related to unconventional shale gas production. Here, I present my work analyzing and cataloging a complete record of the seismicity occurring within the basin over a period of more than a decade (2008-2020). Analysis of the catalog reveals that the earthquakes generally occur within the Precambrian basement along steeply dipping normal faults, and while overall seismicity rates have decreased since 2016, new faults have become active. I observe strong spatial and temporal correlations between the earthquake locations and wastewater disposal well …


Prevention And Preparedness Of The Messina-Reggio Calabria Strait: An Earthquake Forecasting And Didactic Project, Francesco Di Stefano, Gioacchino Giampaolo Giuliani, Dimitar Ouzounov, Daniele Cataldi, Cristiano Fidani, Angelo D'Errico, Giulia Fioravanti Sep 2021

Prevention And Preparedness Of The Messina-Reggio Calabria Strait: An Earthquake Forecasting And Didactic Project, Francesco Di Stefano, Gioacchino Giampaolo Giuliani, Dimitar Ouzounov, Daniele Cataldi, Cristiano Fidani, Angelo D'Errico, Giulia Fioravanti

Mathematics, Physics, and Computer Science Faculty Articles and Research

This contribution is addressed to an introductive university course on the correlation existing between radon emission and earthquakes processes held following a flipped-class approach where students receive didactic materials prior to face-to-face lessons. This research was initially started to investigate the real correlation between Radon emission from the Earth and the occurrence of strong earthquakes by using measurements of hourly Radon flow variation. During quiet seismogenic conditions, we observe an unvarying level of Radon emission in the air. Before a strong earthquake, substantial variations of Radon (222Rn) concentration have been observed in the air, probably because of the …


Shallow Rupture Propagation Of Pleistocene Earthquakes Along The Hurricane Fault, Ut, Revealed By Hematite (U-Th)/He Thermochronometry And Textures, Madison P. Taylor, Alexis K. Ault, Margaret L. Odlum, Dennis L. Newell Sep 2021

Shallow Rupture Propagation Of Pleistocene Earthquakes Along The Hurricane Fault, Ut, Revealed By Hematite (U-Th)/He Thermochronometry And Textures, Madison P. Taylor, Alexis K. Ault, Margaret L. Odlum, Dennis L. Newell

Geoscience Faculty Research

The material properties and distribution of faults above the seismogenic zone promote or inhibit earthquake rupture propagation. We document the depths and mechanics of fault slip along the seismically active Hurricane fault, UT, with scanning and transmission electron microscopy and hematite (U-Th)/He thermochronometry. Hematite occurs as mm-scale, striated patches on a >10 m2 thin, mirror-like silica fault surface. Hematite textures include bulbous aggregates and cataclasite, overlain by crystalline Fe-oxide nanorods and an amorphous silica layer at the slip interface. Textures reflect mechanical, fluid, and heat-assisted amorphization of hematite and silica-rich host rock that weaken the fault and promote rupture propagation. …


Trace Fossils, Algae, Invertebrate Remains And New U-Pb Detrital Zircon Geochronology From The Lower Cambrian Torneträsk Formation, Northern Sweden, Stephen Mcloughlin, Vivi Vajda, Timothy P. Topper, James L. Crowley, Fan Liu, Ove Johansson, Christian B. Skovsted Sep 2021

Trace Fossils, Algae, Invertebrate Remains And New U-Pb Detrital Zircon Geochronology From The Lower Cambrian Torneträsk Formation, Northern Sweden, Stephen Mcloughlin, Vivi Vajda, Timothy P. Topper, James L. Crowley, Fan Liu, Ove Johansson, Christian B. Skovsted

Geosciences Faculty Publications and Presentations

Nineteen ichnotaxa, together with algal and invertebrate remains, and various pseudo-traces and sedimentary structures are described from the Torneträsk Formation exposed near Lake Torneträsk, Lapland, Sweden, representing a marked increase in the diversity of biotic traces recorded from this unit. The “lower siltstone” interval of the Torneträsk Formation contains mostly simple pascichnia, fodinichnia and domichnia burrows and trails of low-energy shoreface to intertidal settings. The assemblage has very few forms characteristic of high-energy, soft-sediment, foreshore or upper shoreface environments (representative of the Skolithos ichnofacies).

Uranium-lead (U-Pb) LA-ICPMS analysis of zircon from a thin claystone layer within the “lower siltstone” interval …


A Mélange Of Subduction Ages: Constraints On The Timescale Of Shear Zone Development And Underplating At The Subduction Interface, Catalina Schist (Ca, Usa), K. M. Harvey, S. Walker, P. G. Starr, S. C. Penniston-Dorland, M. J. Kohn, E. F. Baxter Sep 2021

A Mélange Of Subduction Ages: Constraints On The Timescale Of Shear Zone Development And Underplating At The Subduction Interface, Catalina Schist (Ca, Usa), K. M. Harvey, S. Walker, P. G. Starr, S. C. Penniston-Dorland, M. J. Kohn, E. F. Baxter

Geosciences Faculty Publications and Presentations

The presence of mélange at the subduction interface influences numerous geochemical and geophysical processes. However, the relationship between the timescales of mélange development, deformation, and resultant mass transport is poorly understood. Here, we use Sm-Nd garnet geochronology to elucidate the timing of peak metamorphism for five garnet amphibolite tectonic blocks from the amphibolite-facies mélange zone of the Catalina Schist (Santa Catalina Island, CA). Ages range from 108 to 116 Ma and do not appear to correlate with the peak metamorphic temperature recorded by each block (between 640 and 740°C). The lack of correlation between age and peak temperature favors the …


Coupled Inversion Of Hydraulic And Self-Potential Data From Transient Outflow Experiments To Estimate Soil Petrophysical Properties, Jing Xie, Yian Cui, Qifei Niu Sep 2021

Coupled Inversion Of Hydraulic And Self-Potential Data From Transient Outflow Experiments To Estimate Soil Petrophysical Properties, Jing Xie, Yian Cui, Qifei Niu

Geosciences Faculty Publications and Presentations

Hydraulicproperties of soils could play an important role in affecting the partitioning of precipitation in the critical zone. In addition to traditional approaches, in the last two decades, many geophysical methods have been used to aid the hydrologic characterization and measurement of geological materials. In particular, the self-potential (SP) method shows great potential in these hydrogeophysical applications. The objective of this study is to evaluate whether the addition of SP data can improve the estimation of hydraulic properties of soils in an outflow experiment. A stochastic, coupled hydrogeophysical inversion was developed, in which the governing equations were solved using the …


(Re)Proposal Of Three Cambrian Subsystems And Their Geochronology, Ed Landing, Gerd Geyer, Mark D. Schmitz, Thomas Wotte, Artem Kouchinsky Sep 2021

(Re)Proposal Of Three Cambrian Subsystems And Their Geochronology, Ed Landing, Gerd Geyer, Mark D. Schmitz, Thomas Wotte, Artem Kouchinsky

Geosciences Faculty Publications and Presentations

The Cambrian is anomalous among geological systems as many reports divide it into three divisions of indeterminate rank. This use of “lower”, “middle”, and “upper” has been a convenient way to subdivide the Cambrian despite agreement it consists of four global series. Traditional divisions of the system into regional series (Lower, Middle, Upper) reflected local biotic developments not interprovincially correlatable with any precision. However, use of “lower”, “middle”, and “upper” is unsatisfactory. These adjectives lack standard definition, evoke the regional series, and are misused. Notably, there is an almost 50 year use of three Cambrian subsystems and a 1997 proposal …


Evaluation Of Geohazards In The Cape Girardeau Area Using Lidar And Gis, Southeast Missouri, Usa, Olufeyisayo B. Ososami, J. David Rogers, Francisca Oboh-Ikuenobe Aug 2021

Evaluation Of Geohazards In The Cape Girardeau Area Using Lidar And Gis, Southeast Missouri, Usa, Olufeyisayo B. Ososami, J. David Rogers, Francisca Oboh-Ikuenobe

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The New Madrid Seismic Zone (NMSZ) has historically recorded some of the largest intensity earthquakes in North America, including significant earth movements that resulted in about 2000 felt earthquakes during 1811-1812. The region continues to experience mass wasting due to earth movements. The aim of this study is to understand the influence of geologic variables on mass wasting processes in the greater Cape Girardeau area, which forms the commercial center of Missouri's fertile "Bootheel" region. Earth movement susceptibility was evaluated in Cape Girardeau and Bollinger counties and portions of Stoddard and Scott counties by mapping potential landslide features on topographic …


Stratigraphic Evidence Of Two Historical Tsunamis On The Semi-Arid Coast Of North-Central Chile, Jessica M. Depaolis, Tina Dura, Breanyn Macinnes, Lisa L. Ely, Marco Cisternas, Matías Carvajal, Hui Tang, Hermann M. Fritz, Cyntia Mizobe, Robert L. Wesson, Gino Figueroa, Nicole Brennan, Benjamin P. Horton, Jessica E. Pilarczyk, D. Reide Corbett, Benjamin C. Gill, Robert Weiss Aug 2021

Stratigraphic Evidence Of Two Historical Tsunamis On The Semi-Arid Coast Of North-Central Chile, Jessica M. Depaolis, Tina Dura, Breanyn Macinnes, Lisa L. Ely, Marco Cisternas, Matías Carvajal, Hui Tang, Hermann M. Fritz, Cyntia Mizobe, Robert L. Wesson, Gino Figueroa, Nicole Brennan, Benjamin P. Horton, Jessica E. Pilarczyk, D. Reide Corbett, Benjamin C. Gill, Robert Weiss

Geological Sciences Faculty Scholarship

On September 16, 2015, a Mw 8.3 earthquake struck the north-central Chile coast, triggering a tsunami observed along 500 km of coastline, between Huasco (28.5°S) and San Antonio (33.5°S). This tsunami provided a unique opportunity to examine the nature of tsunami deposits in a semi-arid, siliciclastic environment where stratigraphic and sedimentological records of past tsunamis are difficult to distinguish. To improve our ability to identify such evidence, we targeted one of the few low-energy, organic-rich depositional environments in north-central Chile: Pachingo marsh in Tongoy Bay (30.3°S).

We found sedimentary evidence of the 2015 and one previous tsunami as tabular …


Fragmentation Theory Reveals Processes Controlling Iceberg Size Distributions, Jan Åström, Sue Cook, Ellyn M. Enderlin, David A. Sutherland, Aleksandra Mazur, Neil Glasser Aug 2021

Fragmentation Theory Reveals Processes Controlling Iceberg Size Distributions, Jan Åström, Sue Cook, Ellyn M. Enderlin, David A. Sutherland, Aleksandra Mazur, Neil Glasser

Geosciences Faculty Publications and Presentations

Iceberg calving strongly controls glacier mass loss, but the fracture processes leading to iceberg formation are poorly understood due to the stochastic nature of calving. The size distributions of icebergs produced during the calving process can yield information on the processes driving calving and also affect the timing, magnitude, and spatial distribution of ocean fresh water fluxes near glaciers and ice sheets. In this study, we apply fragmentation theory to describe key calving behaviours, based on observational and modelling data from Greenland and Antarctica. In both regions, iceberg calving is dominated by elastic-brittle fracture processes, where distributions contain both exponential …


Timescales Of Impact Melt Sheet Crystallization And The Precise Age Of The Morokweng Impact Structure, South Africa, Gavin G. Kenny, Claire O. Harrigan, Mark D. Schmitz, James L. Crowley, Corey J. Wall Aug 2021

Timescales Of Impact Melt Sheet Crystallization And The Precise Age Of The Morokweng Impact Structure, South Africa, Gavin G. Kenny, Claire O. Harrigan, Mark D. Schmitz, James L. Crowley, Corey J. Wall

Geosciences Faculty Publications and Presentations

Impact cratering was a fundamental geological process in the early Solar System and, thus, constraining the timescales over which large impact structures cool is critical to understanding the thermal evolution and habitability of early planetary crusts. Additionally, impacts can induce mass extinctions and establishing the precise timing of the largest impacts on Earth can shed light on their role in such events. Here we report a high-precision zircon U–Pb geochronology study of the Morokweng impact structure, South Africa, which appears to have a maximum present-day diameter of ∼80 km. Our work provides (i) constraints on the cooling of large impact …


Diatoms Of The Intertidal Environments Of Willapa Bay, Washington, Usa As A Sea-Level Indicator, Isabel Hong, Benjamin P. Horton, Andrea D. Hawkes, Robert J. O.Donnell Iii, Jason S. Padgett, Tina Dura, Simon E. Engelhart Aug 2021

Diatoms Of The Intertidal Environments Of Willapa Bay, Washington, Usa As A Sea-Level Indicator, Isabel Hong, Benjamin P. Horton, Andrea D. Hawkes, Robert J. O.Donnell Iii, Jason S. Padgett, Tina Dura, Simon E. Engelhart

Geological Sciences Faculty Scholarship

An understanding of the modern relationship between diatom species and elevation is a prerequisite for using fossil diatoms to reconstruct relative sea level (RSL). We described modern diatom distributions from seven transects covering unvegetated subtidal environments to forested uplands from four tidal wetland sites (Smith Creek, Bone River, Niawiakum River, and Naselle River) of Willapa Bay, Washington, USA. We compared our diatom dataset (320 species from 104 samples) to a series of environmental variables (elevation, grain-size, total organic carbon (TOCSOM), and porewater salinity) using hierarchical clustering and ordination. While no single variable consistently explains variations in diatom assemblages …


Unoccupied Aircraft Systems (Uass) Reveal The Morphological Changes At Stromboli Volcano (Italy) Before, Between, And After The 3 July And 28 August 2019 Paroxysmal Eruptions, Jeffrey B. Johnson Aug 2021

Unoccupied Aircraft Systems (Uass) Reveal The Morphological Changes At Stromboli Volcano (Italy) Before, Between, And After The 3 July And 28 August 2019 Paroxysmal Eruptions, Jeffrey B. Johnson

Geosciences Faculty Publications and Presentations

In July and August 2019, two paroxysmal eruptions dramatically changed the morphology of the crater terrace that hosts the active vents of Stromboli volcano (Italy). Here, we document these morphological changes, by using 2259 UAS-derived photographs from eight surveys and Structure-from-Motion (SfM) photogrammetric techniques, resulting in 3D point clouds, orthomosaics, and digital surface models (DSMs) with resolution ranging from 8.1 to 12.4 cm/pixel. We focus on the morphological evolution of volcanic features and volume changes in the crater terrace and the upper part of the underlying slope (Sciara del Fuoco). We identify both crater terrace and lava field variations, with …


Pervasive Changes In Stream Intermittency Across The United States, Kendra E. Kaiser Aug 2021

Pervasive Changes In Stream Intermittency Across The United States, Kendra E. Kaiser

Geosciences Faculty Publications and Presentations

Non-perennial streams are widespread, critical to ecosystems and society, and the subject of ongoing policy debate. Prior large-scale research on stream intermittency has been based on long-term averages, generally using annually aggregated data to characterize a highly variable process. As a result, it is not well understood if, how, or why the hydrology of non-perennial streams is changing. Here, we investigate trends and drivers of three intermittency signatures that describe the duration, timing, and dry-down period of stream intermittency across the continental United States (CONUS). Half of gages exhibited a significant trend through time in at least one of the …


An Exploration Of Passive Seismology: Applying Seismic Methods For Traditional And Exotic Source Characterization, David Lewis Guenaga Aug 2021

An Exploration Of Passive Seismology: Applying Seismic Methods For Traditional And Exotic Source Characterization, David Lewis Guenaga

Open Access Theses & Dissertations

As seismology continues to develop both theoretical and observational, so does its ability to be used in various applications. In this Dissertation, I develop and apply new approaches to five distinct projects (chapters 2-6), leveraging large and small high-quality targeted datasets to decipher fundamental and applied processes utilizing the full seismic wavefield. The first chapter introduces this Dissertation by providing broad context, continuity, and technical information about each of the five projects. Specifically, chapter 2 explores a seismic sensorâ??s ability to detect opera in Oak Ridge National Laboratory, TN, using a misfit power spectral density detector. Chapter 3 outlines work …


Kinematics Of The Exceptionally-Short Surge Cycles Of Sít’ Kusá (Turner Glacier), Alaska, From 1983 To 2013, Andrew Nolan, William Kochtitzky, Ellyn M. Enderlin, Robert Mcnabb, Karl J. Kreutz Aug 2021

Kinematics Of The Exceptionally-Short Surge Cycles Of Sít’ Kusá (Turner Glacier), Alaska, From 1983 To 2013, Andrew Nolan, William Kochtitzky, Ellyn M. Enderlin, Robert Mcnabb, Karl J. Kreutz

Geosciences Faculty Publications and Presentations

Glacier surges are periodic episodes of mass redistribution characterized by dramatic increases in ice flow velocity and, sometimes, terminus advance. We use optical satellite imagery to document five previously unexamined surge events of Sít’ Kusá (Turner Glacier) in the St. Elias Mountains of Alaska from 1983 to 2013. Surge events had an average recurrence interval of ~5 years, making it the shortest known regular recurrence interval in the world. Surge events appear to initiate in the winter, with speeds reaching up to ~25 m d−1. The surges propagate down-glacier over ~2 years, resulting in maximum thinning of ~100 …


Void Hunting: Ambient Noise Tomography For Spatio-Temporal Subsurface Imaging And Monitoring In Karst Environments, John B. Paustian Aug 2021

Void Hunting: Ambient Noise Tomography For Spatio-Temporal Subsurface Imaging And Monitoring In Karst Environments, John B. Paustian

Boise State University Theses and Dissertations

Karst environments are characterized by voids, i.e. sinkholes and conduits of varying size that arise from the active dissolution of carbonate rock by acidic groundwater. These voids, whether air-, water-, or soil-filled, can be difficult to image using near-surface geophysical methods due to the limited investigation depths of most active-source methods. In addition, due to the significant effort it takes to collect active-source data, investigators are often unable to monitor spatio-temporal variations in the subsurface. The ability to detect, image, and monitor subsurface voids improves the understanding of processes that create and transform voids, a vitally important insight across a …


Fundamental Resonant Frequencies Derived From Shallow Sediment Properties For The Charleston, South Carolina Area, William Dale Schermerhorn Aug 2021

Fundamental Resonant Frequencies Derived From Shallow Sediment Properties For The Charleston, South Carolina Area, William Dale Schermerhorn

Boise State University Theses and Dissertations

Large historic earthquakes, low velocity near surface sediments, a poor understanding of earthquake sources, and a growing population base for the Charleston, South Carolina area suggest robust site response and active fault maps are needed. A Boise State University team acquired 14 km of new surface-based seismic data to obtain surface wave dispersion curves and reflection images for the southern isoseismal region of the 1886 earthquake. From these data, I generate shear wave velocity (Vs)-depth profiles through a grid search approach. I integrate my results with other published data to develop a soil thickness and high frequency fundamental resonance maps …


Assessing Controls On Ice Dynamics At Crane Glacier, Antarctic Peninsula Using A Numerical Ice Flow Model, Rainey Aberle Aug 2021

Assessing Controls On Ice Dynamics At Crane Glacier, Antarctic Peninsula Using A Numerical Ice Flow Model, Rainey Aberle

Boise State University Theses and Dissertations

The widespread retreat of glaciers and the collapse of ice shelves along the Antarctic Peninsula has been attributed to atmospheric and oceanic warming, which promotes mass loss. However, several glaciers on the eastern peninsula that were buttressed by the Larsen A and B ice shelves prior to collapse in 1995 and 2002, respectively, have been advancing in recent years. This asymmetric pattern of rapid retreat and long-term re-advance is similar to the tidewater glacier cycle, which can occur largely independent of climate forcing. Here, I use a width- and depth-integrated numerical ice flow model to investigate glacier response to ice …


Laboratory Measurement Of Electrical And Hydraulic Properties Of Regolith Over Granitic Bedrock, Taylor James Bienvenue Aug 2021

Laboratory Measurement Of Electrical And Hydraulic Properties Of Regolith Over Granitic Bedrock, Taylor James Bienvenue

Boise State University Theses and Dissertations

Characterizing water flux within the critical zone (CZ) is essential for a multitude of studies and applications related to irrigation, drainage, water management, and contaminant transport. Trying to measure water flux in the critical zone, specifically in the subsurface, is difficult due to the associated structural heterogeneity and complex interactions taking place between biological, chemical, and physical processes. Current methods (i.e., inferred from soil suction and soil moisture measurements) to characterize water flux within the critical zone can be time consuming and are not directly related to water flux. Recent literature has provided evidence that self-potential (SP) is a promising …


Dynamic Mass Loss From Greenland's Peripheral Glaciers, Katherine E. Bollen Aug 2021

Dynamic Mass Loss From Greenland's Peripheral Glaciers, Katherine E. Bollen

Boise State University Theses and Dissertations

While global glacier mass balance has decreased rapidly over the last two decades, mass loss has been greatest in regions with marine-terminating glaciers. In Greenland, peripheral glaciers and ice caps (GICs) cover only ~5% of Greenland’s area but contributed ~14-20% of the island’s ice mass loss between 2003-2008. Although Greenland GIC’s mass loss due to surface meltwater runoff have been estimated using atmospheric models, mass loss due to changes in ice discharge into surrounding ocean basins (i.e., dynamic mass loss) remains unquantified. Here, we use the flux gate method to estimate discharge from Greenland’s 594 marine-terminating peripheral glaciers between 1985 …


Seismic Imaging Of Active And Ancient Co2 Pathways In The Little Grand Wash Fault, Jonathan Yelton Aug 2021

Seismic Imaging Of Active And Ancient Co2 Pathways In The Little Grand Wash Fault, Jonathan Yelton

Boise State University Theses and Dissertations

Understanding the migration behavior of carbon dioxide (CO2) during long-term geological storage is crucial to the success of carbon capture and sequestration technology. I explore p-wave and s-wave seismic properties across the Little Grand Wash fault in east-central Utah, a natural CO2 seep and analogue for a long-failed sequestration site. Travertines dated to at least 113,000 k.y. and geochemical surveys confirm both modern and ancient CO2 leakage along the fault. Outgassing is currently focused in damage zones where the total fluid pressure may reduce the minimum horizontal effective stress. Regional stress changes may be responsible for decadal- to millennial-scale changes …


An Integrative Approach For Environmental Assessment And Water Resources Management Using Direct Current Resistivity (Dc), Geographic Information System (Gis), Remote Sensing, And Gain And Loss Method, Dina Ragab Desouki Abdelmoneim Aug 2021

An Integrative Approach For Environmental Assessment And Water Resources Management Using Direct Current Resistivity (Dc), Geographic Information System (Gis), Remote Sensing, And Gain And Loss Method, Dina Ragab Desouki Abdelmoneim

Boise State University Theses and Dissertations

Sustainable water resource management is a crucial national and global issue (Currell et al., 2012). In arid areas, groundwater is often the major source of water or at least a crucial supplement to other freshwater resources for agriculture, industry and domestic consumption (Vrba and Renaud, 2016). The complexity associated with groundwater-surface water interactions creates uncertainty about water resource sustainability in semi-arid environments, especially with urbanization and population growth. Flood irrigation in the early 1900s increased the shallow groundwater table in the Treasure Valley (TV), but with increasing irrigation efficiencies, they have been declining since the 1960s with a mean decline …


3-D Ambient Noise Tomography Of Llaima Volcano, Chile, Claudia Kristina Rossavik Aug 2021

3-D Ambient Noise Tomography Of Llaima Volcano, Chile, Claudia Kristina Rossavik

Boise State University Theses and Dissertations

Llaima is a glaciated, basaltic-andesitic stratocone in the South-Central Andean Volcanic Zone. It is one of the largest and most active volcanoes in Chile. However, uncertainty remains regarding the depths and geometry of where magma is stored and the routes which it takes towards the Earth's surface. To provide a structural framework for the interpretation of petrological and geochemical data, I apply ambient noise tomography (ANT) to produce a 3-D shear wave velocity (vs) model of Llaima's magmatic plumbing. The results of this project show slow shear wave velocity anomalies within the upper 8 km of the …


Analysis Of Gravity For The Crustal Structure Of Nepal Himalaya, Kapil Prasad Phuyal Aug 2021

Analysis Of Gravity For The Crustal Structure Of Nepal Himalaya, Kapil Prasad Phuyal

Graduate Theses/Dissertations

Nepal Himalaya is situated in the central portion of the seismically active Himalayan Orogenic Belt, which is geologically segmented by four major mega fault structures: Main Frontal Thrust (MFT), Main Boundary Thrust (MBT), Main Central Thrust (MCT), and the South Tibetan Detachment System (STDS). The MFT, MBT, and MCT are part of the basal decollement Main Himalayan Thrust (MHT) which accommodates the convergence between the Indian and Eurasian Plate. The 2015 Gorkha Earthquake occurred within the MHT system, MHT system itself had been seismically locked since the 1934 Nepal-Bihar Earthquake, complicating the geometry depth of MHT. Available land and airborne …


Integrated Geophysical Analysis Over Bathymetrists Seamounts And The Sierra Leone Rise, Alexa Fernandez Jul 2021

Integrated Geophysical Analysis Over Bathymetrists Seamounts And The Sierra Leone Rise, Alexa Fernandez

UCARE: Research Products

The Bathymetrists Seamounts (BSM) are located northeast of the Sierra Leone Rise in the Atlantic Ocean. The northern seamounts have a southwest to northeast trend which is contrary to the current eastward motion of the African tectonic plate where they reside. The geological history and crustal structures of these features are poorly understood. The goal of this study is to integrate multiple geophysical data to better understand the crustal architecture and tectonic history of the BSM.

The seismic refraction study from Jones et al. (2015) was used as the baseline for isostatic modeling. This dataset suggested the presence of magmatic …


Developing A Database Of Seismic Data Over The Cascadia Subduction Zone, Khawlh Al Farsi Jul 2021

Developing A Database Of Seismic Data Over The Cascadia Subduction Zone, Khawlh Al Farsi

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

An inevitable megathrust earthquake is expected in the Cascadia subduction zone that will affect the population of the coast of southwestern British Columbia and the northwest of the United States. In this active tectonic margin, the Juan de Fuca oceanic plate is subducting beneath the North American continental plate, causing unevenly distributed seismic activity. The major goal of this geophysical research project is to study the tectonic structures of the Cascadia subduction zone in order to comprehend the geology of the region and investigate the seismic hazards. The primary objective of this project is to develop a geophysical database of …


Computer Simulations Of Diffusional Isotope Effects And Dynamical Properties Of Silicate Melts, Haiyang Luo Jul 2021

Computer Simulations Of Diffusional Isotope Effects And Dynamical Properties Of Silicate Melts, Haiyang Luo

LSU Doctoral Dissertations

Silicate melts have served as transport agents in the chemical and thermal evolution of Earth. Diffusional isotope effect in silicate melts is the key to interpret isotope variations in lots of geological samples. Isotopic mass dependence of diffusion is commonly expressed as (Di/Dj)=(mj/mi)^β, where Di and Dj are diffusion coefficients of two isotopes whose masses are mi and mj. However, how the dimensionless empirical parameter β depends on temperature, pressure, and composition remains poorly constrained. Viscosity and electrical conductivity are two fundamental dynamical properties of silicate melts needed to constrain melt distribution in Earth's interior but remain unclear for most …


Snow Covered With Dust After Chamoli Rockslide: Inference Based On High-Resolution Satellite Data, Sansar Raj Meena, Kushanav Bhuyan, Akshansha Chauhan, Ramesh P. Singh Jun 2021

Snow Covered With Dust After Chamoli Rockslide: Inference Based On High-Resolution Satellite Data, Sansar Raj Meena, Kushanav Bhuyan, Akshansha Chauhan, Ramesh P. Singh

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The high-resolution multi-temporal PlanetScope image of 7 February 2021 clearly shows the fall of a large part of the Nanda Ghunti glacier (Uttarakhand) down in the base of the valley from a height of about 2000 m. The recorded seismic signals at the local seismic networks, close to the Joshimath station, show the occurrence of the fall of the first glacier block followed by another block which corresponds to the seismic signal recorded the second time. The timings of signals recorded from the seismic station are related to the visual sign of local dust in the valley after the fall …


Silicate Melt Inclusions In The New Millennium: A Review Of Recommended Practices For Preparation, Analysis, And Data Presentation, D. Schwartz Jun 2021

Silicate Melt Inclusions In The New Millennium: A Review Of Recommended Practices For Preparation, Analysis, And Data Presentation, D. Schwartz

Geosciences Faculty Publications and Presentations

Mineral-hosted melt inclusions have become an important source of information on magmatic processes. As the number of melt inclusion studies increases, so does the need to establish recommended practice guidelines for collecting and reporting melt inclusion data. These guidelines are intended to ensure certain quality criteria are met and to achieve consistency among published melt inclusion data in order to maximize their utility in the future. Indeed, with the improvement of analytical techniques, new processes affecting melt inclusions are identified. It is thus critical to be able to reprocess any previously published data, such that reporting the raw data is …