Open Access. Powered by Scholars. Published by Universities.®

Geophysics and Seismology Commons

Open Access. Powered by Scholars. Published by Universities.®

2,548 Full-Text Articles 4,240 Authors 810,400 Downloads 104 Institutions

All Articles in Geophysics and Seismology

Faceted Search

2,548 full-text articles. Page 7 of 82.

Evaluating The Sensitivity Of Crustal Deformation To Bedrock Hydrology In A Mountain Watershed, Brett J. Oliver 2023 University of Montana, Missoula

Evaluating The Sensitivity Of Crustal Deformation To Bedrock Hydrology In A Mountain Watershed, Brett J. Oliver

Graduate Student Theses, Dissertations, & Professional Papers

We evaluate the sensitivity of Earth's elastic deformation to groundwater hydraulic diffusivity using coupled groundwater and elastic deformation models. Seasonal changes in terrestrial water storage cause deformation to the Earth’s crust and deeper interior that is within the observational capacity of GPS instruments. We couple finite difference groundwater simulations with geodetic forward models of crustal displacement to investigate the ability of geodetic deformation to constrain bedrock hydrologic properties. We use MODFLOW-2005 to simulate seasonal changes in groundwater flow and storage, and then use the LoadDef elastic deformation model to forward model surface displacement caused by the change in terrestrial water …


Historical Tsunami Observability For Izu–Bonin–Mariana Sources, Walter Szeliga, Rachelle Reisinger, Breanyn T. MacInnes 2022 Central Washington University

Historical Tsunami Observability For Izu–Bonin–Mariana Sources, Walter Szeliga, Rachelle Reisinger, Breanyn T. Macinnes

Geological Sciences Faculty Scholarship

The Izu–Bonin–Mariana Subduction System (IBM) is one of the longest subduction zones in the world with no instrumental history of shallow focus, great earthquakes (Mw > 8). Over the last 50 years, researchers have speculated on the reason for the absence of large magnitude, shallow seismicity on this plate interface, exploring factors from plate age to convergence rate. We approach the question from a different point of view: what if the IBM has hosted great earthquakes and no documentable evidence was left? To address the question of observability, we model expected tsunami wave heights from nine great earthquake scenarios on the …


Uncertainty Of Icesat-2 Atl06- And Atl08-Derived Snow Depths For Glacierized And Vegetated Mountain Regions, Ellyn M. Enderlin, Colten M. Elkin, Madeline Gendreau, H.P. Marshall, Shad O'Neel, Christopher McNeil, Caitlyn Florentine, Louis Sass 2022 Boise State University

Uncertainty Of Icesat-2 Atl06- And Atl08-Derived Snow Depths For Glacierized And Vegetated Mountain Regions, Ellyn M. Enderlin, Colten M. Elkin, Madeline Gendreau, H.P. Marshall, Shad O'Neel, Christopher Mcneil, Caitlyn Florentine, Louis Sass

Geosciences Faculty Publications and Presentations

Seasonal snow melt dominates the hydrologic budget across a large portion of the globe. Snow accumulation and melt vary over a broad range of spatial scales, preventing accurate extrapolation of sparse in situ observations to watershed scales. The lidar onboard the Ice, Cloud, and land Elevation, Satellite (ICESat-2) was designed for precise mapping of ice sheets and sea ice, and here we assess the feasibility of snow depth-mapping using ICESat-2 data in more complex and rugged mountain landscapes. We explore the utility of ATL08 Land and Vegetation Height and ATL06 Land Ice Height differencing from reference elevation datasets in two …


The Isotropic And Anisotropic Structure Of Antarctica From Seismic Inversion, Zhengyang Zhou 2022 Washington University in St. Louis

The Isotropic And Anisotropic Structure Of Antarctica From Seismic Inversion, Zhengyang Zhou

Arts & Sciences Electronic Theses and Dissertations

This dissertation utilizes multiple techniques of earthquake tomography to investigate the seismic structure of the crust and mantle beneath Antarctica. The isotropic structure of the Antarctic crust and upper mantle is now constrained by several seismic studies, but until now few studies have investigated the anisotropic structure. Therefore, in this study, I focus on the anisotropic structure, which is crucial information to understanding current or historic deformation and flow patterns, as well as the organic process of Antarctica. I use the data from the seismic stations deployed on the Antarctica continent during the past 20 years, as well as other …


Pfas Mass Balance, Donovan Vitale 2022 Western Michigan University

Pfas Mass Balance, Donovan Vitale

Honors Theses

First-generation, PFOS-dominant Aqueous Film Forming Foam (AFFF) concentrate of approximately 200 gallons was released to the sewer system from the Kalamazoo/Battle Creek International Airport on March 30, 2021. The AFFF release migrated to the Kalamazoo Water Reclamation Plant (KWRP), raising plant effluent above the Department of Environment, Great Lakes, and Energy (EGLE) PFOS water quality standard for a total of 46 days post-spill, although the influent concentrations exhibited sharp declines after only 7 days. By sampling influent, effluent, and biosolids daily, the only known long duration, high-frequency PFAS data set of an accidental AFFF release was generated. This study has …


Estimation Of Blast Vibrations By Numerical Modelling And Signal Analysis, Güzin Gülsev UYAR AKSOY, Cemalettin Okay AKSOY, Hasan Eray YAMAN 2022 Bulletin of the Mineral Research and Exploration

Estimation Of Blast Vibrations By Numerical Modelling And Signal Analysis, Güzin Gülsev Uyar Aksoy, Cemalettin Okay Aksoy, Hasan Eray Yaman

Bulletin of the Mineral Research and Exploration

Seismic waves carry all the geological and geotechnical characteristics of the units they pass along the route they travel on. Therefore, seismic waves can be called the signature of the route it passes through. If the blasting point is considered as source, blast-induced seismic waves measured at a certain distance from the source can be revealed and this form can be integrated into the dynamic numerical model, the effects that will occur at any point of the model can be predicted. In this study, seismic waves induced from single-hole blast and a group blast consisting of holes with the same …


Using Anisotropy Of Magnetic Susceptibility (Ams) To Identify A Tectonic Lineation In The Pulo Do Lobo Formation In The Southern Iberian Shear Zone Near Aracena, Spain, Devin Levang 2022 University of Wisconsin-Milwaukee

Using Anisotropy Of Magnetic Susceptibility (Ams) To Identify A Tectonic Lineation In The Pulo Do Lobo Formation In The Southern Iberian Shear Zone Near Aracena, Spain, Devin Levang

Theses and Dissertations

The Southern Iberian Shear Zone (SISZ) is a Variscan-aged suture representing the closure of a small ocean basin during the Carboniferous. The SISZ is bounded on either side by the well-studied, relatively homogeneous Beja-Acebuches Metabasites (BAM) and the complex and heterogeneous accretionary metasedimentary rocks of the Pulo do Lobo (PdL). The SISZ underwent a combination of shortening and lateral shearing known as transpression. Despite a very well-developed tectonic foliation, kinematic interpretation in the PdL is made difficult by a lack of easily identifiable lineations. Anisotropy of magnetic susceptibility (AMS), a geophysical technique measuring the relative anisotropy of magnetic susceptibility axes …


Hydrothermal Alteration Targeting And Geophysical Mineral Exploration Of Eureka And Sylvanite Mining Districts, Southwest New Mexico, Kenneth Singh 2022 University of Texas at El Paso

Hydrothermal Alteration Targeting And Geophysical Mineral Exploration Of Eureka And Sylvanite Mining Districts, Southwest New Mexico, Kenneth Singh

Open Access Theses & Dissertations

As part of the southwestern North American porphyry copper province, mining of natural resources in New Mexico has historically played a crucial role in economic development for over 150 years including this project area in the Little Hatchet Mountains. The northern half of the Little Hatchet Mountains lies in Grant County and includes the Eureka Mining District (EMD) whereas the southern half is in Hidalgo County and includes the Sylvanite Mining District (SMD), 38 miles southeast of Lordsburg. The EMD, a copper and silver-lead mining district from 1880-1961, had a total estimated production from the Laramide veins of 2.9 million …


The Formation Of The 8˚20’ N Seamount Chain, East Pacific Rise, Dorsey Wanless 2022 Boise State University

The Formation Of The 8˚20’ N Seamount Chain, East Pacific Rise, Dorsey Wanless

Geosciences Faculty Publications and Presentations

Near-axis seamounts provide a unique setting to investigate three-dimensional mantle processes associated with the formation of new oceanic crust and lithosphere. Here, we investigate the characteristics and evolution of the 8˚20’N Seamount Chain, a lineament of seamounts that extends ~ 175 km west of the East Pacific Rise (EPR) axis, just north of the fracture zone of the Siqueiros Transform Fault. Shipboard gravity, magnetic, and bathymetric data acquired in 2016 are utilized to constrain models of seamount emplacement and evolution. Geophysical observations indicate that these seamounts formed during four distinct episodes of volcanism coinciding with changes in regional plate motion …


Predictions And Drivers Of Sub-Reach-Scale Annual Streamflow Permanence For The Upper Missouri River Basin: 1989–2018, Kendra E. Kaiser 2022 Boise State University

Predictions And Drivers Of Sub-Reach-Scale Annual Streamflow Permanence For The Upper Missouri River Basin: 1989–2018, Kendra E. Kaiser

Geosciences Faculty Publications and Presentations

The presence of year-round surface water in streams (i.e., streamflow permanence) is an important factor for identifying aquatic habitat availability, determining the regulatory status of streams, managing land use change, allocating water resources, and designing scientific studies. However, accurate, high resolution, and dynamic prediction of streamflow permanence that accounts for year-to-year variability at a regional extent is a major gap in modeling capability. Herein, we expand and adapt the U.S. Geological Survey (USGS) PRObability of Streamflow PERmanence (PROSPER) model from its original implementation in the Pacific Northwest (PROSPERPNW) to the upper Missouri River basin (PROSPERUM), a …


Statistical Analysis Of Aquifer Hydraulic Properties By A Continuous Pumping Tomography Test: Application To The Boise Hydrogeophysical Research Site, Kan Bun Cheng, Gedeon Dagan, Warren Barrash, Michael Cardiff, Avinoam Rabinovich 2022 Tel-Aviv University

Statistical Analysis Of Aquifer Hydraulic Properties By A Continuous Pumping Tomography Test: Application To The Boise Hydrogeophysical Research Site, Kan Bun Cheng, Gedeon Dagan, Warren Barrash, Michael Cardiff, Avinoam Rabinovich

Geosciences Faculty Publications and Presentations

Characterizing aquifer heterogeneity is paramount for accurate flow and transport modeling. In this work, we present a new approach for statistical analysis of hydraulic properties in continuous pumping tomography tests of a phreatic aquifer. The method entails determining equivalent hydraulic conductivity (Keq), specific storage (Ss,eq), and specific yield (Sy,eq) at many locations in the field and then calculating statistical moments of the equivalent properties, assuming they are random space variables. Equivalent properties are defined as the ones pertinent to a homogeneous aquifer for which the head time …


Exploring The Effects Of Tree Roots On Infiltration Process, Nazife Onaral 2022 Western Michigan University

Exploring The Effects Of Tree Roots On Infiltration Process, Nazife Onaral

Masters Theses

Effects of the root structures on soil infiltration dynamics are not clearly defined. Imaging the complex tree root structures and movement of water through the root ball is a challenging task to achieve without damaging the trees and roots by conventional methods. Commonly used methods are invasive, labor-intensive, and not easily accessible. Ground Penetrating Radar (GPR) has commonly been used to characterize soil profiles and it can be a reliable tool to map complex root structures with a novel high-resolution circular data collection technique. Electrical resistivity tomography (ERT) is another reliable geophysical method to image infiltration processes by the change …


(R1978) Heated Laminar Vertical Jet Of Psudoplastic Fluids-Against Gravity, Manisha Patel, M. G. Timol 2022 Sarvajanik College of Engineering and Technology

(R1978) Heated Laminar Vertical Jet Of Psudoplastic Fluids-Against Gravity, Manisha Patel, M. G. Timol

Applications and Applied Mathematics: An International Journal (AAM)

A heated laminar jet of Pseudo-plastic fluid flowing vertically upwards from a long narrow slit into a region of the same fluid which is at a rest and at a uniform temperature is considered. The governing non-linear Partial differential equations (PDEs) for the defined flow problem are transformed into non-linear ordinary differential equations using the effective similarity technique-one parameter deductive group theory method. The obtained non-linear coupled Ordinary differential equations are solved and the results are presented by graphs. The effect of the Prandtl number and Grashof number on the velocity and temperature of the jet flow is discussed. Also, …


Reprocessing Groundwater Resistivity Surveys In The Lower Mesilla Basin, New Mexico, And Texas, Leslie Bernal 2022 University of Texas at El Paso

Reprocessing Groundwater Resistivity Surveys In The Lower Mesilla Basin, New Mexico, And Texas, Leslie Bernal

Open Access Theses & Dissertations

The Mesilla Basin is part of the Rio Grande Basin System. Its northern boundary is definedby the Doña Ana Mountains in New Mexico and to the south by Sierra San Blas, Sierra Almirez, and Sierra La Candelaria in Mexico, where the basin changes its name to Conejos-Médanos. It supplies water for irrigation and public use to the cities of Las Cruces, NM, El Paso, TX, and Ciudad Juárez, Mexico. The southern part of the basin in the U.S. territory, known as the Lower Mesilla Basin, is bounded to the east by the Franklin Mountains, to the west by the Potrillo …


Using Ground Penetrating Radar To Investigate Controls On Pedogenic Calcium Carbonate Distribution In Dryland Critical Zones, Nohemi Valenzuela Garay 2022 University of Texas at El Paso

Using Ground Penetrating Radar To Investigate Controls On Pedogenic Calcium Carbonate Distribution In Dryland Critical Zones, Nohemi Valenzuela Garay

Open Access Theses & Dissertations

Caliche or pedogenic calcium carbonate (CaCO3) layers are a common feature of arid soils, but the environmental controls on their distribution are not fully understood. Caliche layers are thought to play an important role in shallow subsurface water storage and movement, due to their water retention capacity and ability to impede vertical water transport (Hennessy et al., 1983). Therefore, caliche distribution and stability play a role in controlling water distribution in arid lands. However, due to its largely subsurface nature, caliche can be difficult to investigate and map without significant effort. I hypothesize that noninvasive geophysical methods, such as ground-penetrating …


Emplacement Of The Franklin Large Igneous Province And Initiation Of The Sturtian Snowball Earth, Mark D. Schmitz 2022 Boise State University

Emplacement Of The Franklin Large Igneous Province And Initiation Of The Sturtian Snowball Earth, Mark D. Schmitz

Geosciences Faculty Publications and Presentations

During the Cryogenian (720 to 635 Ma ago) Snowball Earth glaciations, ice extended to sea level near the equator. The cause of this catastrophic failure of Earth’s thermostat has been unclear, but previous geochronology has suggested a rough coincidence of glacial onset with one of the largest magmatic episodes in the geological record, the Franklin large igneous province. U-Pb geochronology on zircon and baddeleyite from sills associated with the paleo-equatorial Franklin large igneous province in Arctic Canada record rapid emplacement between 719.86 ± 0.21 and 718.61 ± 0.30 Ma ago, 0.9 to 1.6 Ma before the onset of widespread glaciation. …


Single-Crystal Elasticity Of Earth’S Mantle Transition Zone Minerals And High Pressure-Temperature Phase Equilibrium Experiments On Martian Basalts, Wenyi Zhou 2022 Department of Earth and Planetary Sciences

Single-Crystal Elasticity Of Earth’S Mantle Transition Zone Minerals And High Pressure-Temperature Phase Equilibrium Experiments On Martian Basalts, Wenyi Zhou

Earth and Planetary Sciences ETDs

Wadsleyite and ringwoodite are major minerals in the Earth’s Mantle Transition Zone. Global and local seismic studies have detected strong lateral variations in seismic velocity and anisotropy in the Mantle Transition Zone, reflecting temperature and possible composition variations. Interpretation of these seismic observations requires knowledge of thermoelastic properties of wadsleyite and ringwoodite with different compositions (water and Fe contents) under high pressure-temperature conditions. In this dissertation, we have measured single-crystal elastic properties of wadsleyite and ringwoodite under high pressure-temperature conditions by Brillouin spectroscopy. Based on our measurements and previous experimental results, we further model the effects of water and Fe …


Dense Array Seismic Imaging Of Earth's Crust Using Active And Passive Sources, Evans Awere Onyango 2022 University of New Mexico - Main Campus

Dense Array Seismic Imaging Of Earth's Crust Using Active And Passive Sources, Evans Awere Onyango

Earth and Planetary Sciences ETDs

Imaging Earth’s crust is critical to understanding processes in the near-surface that affect civilization such as the interaction of seismic waves with the near-surface to generate natural or man-made hazards or investigating how the shallow crust affects the distribution of resources. In chapter 1, I processed and analyzed active source seismic data recorded by ~1000 geophones that were acquired over the legacy HADDOCK nuclear test at the Nevada National Security Site. Using seismic reflection and refraction methods, we image the partially collapsed post-detonation structure to better understand the velocity structure in and around the HADDOCK chimney. Results from this work …


Induced Seismicity In The Raton Basin And Global Variability Of The 410-Km Discontinuity, Margaret E. Glasgow 2022 University of new mexico

Induced Seismicity In The Raton Basin And Global Variability Of The 410-Km Discontinuity, Margaret E. Glasgow

Earth and Planetary Sciences ETDs

Natural processes like mantle convection and plate tectonics dominate Earth’s seismic structure. Recently human activities have increasingly influenced the deformation of the shallow crust. In this dissertation, passive source seismology was used to constrain seismic discontinuities in the mantle transition zone and seismogenic structures in induced earthquake settings. Using a novel sampling method and uniform processing approach, I found the 410-km discontinuity is thermally and compositionally variable. Using a machine- learning approach, I found the three main zones of seismicity in the Raton Basin consist of short faults or fault segments with variable orientations. The zone that hosted a Mw …


The Impact Of Contact Geometry On Sea Ice Stress And Fracture At The Scale Of Ice Floes, Michael J. May 2022 Dartmouth College

The Impact Of Contact Geometry On Sea Ice Stress And Fracture At The Scale Of Ice Floes, Michael J. May

Dartmouth College Master’s Theses

Observations of stress and strain at the scale of ice floes are necessary to fill a gap in our understanding of sea ice mechanical behavior. Current climate and ice dynamics models represent ice mechanical properties using stress-strain relationships largely determined at laboratory-scale (<1m) or from regional-scale (10+km) deformation observations. The former scale does not include all mechanisms of deformation operating in the ice pack; the latter aggregates multiple modes of deformation into non-physical fluid analogies. The Sea Ice Dynamics Experiment (SIDEx) was run in Feb-Mar 2021 to fill this gap, observing stress and strain at the scale of sea ice failure processes. Here we present stress sensor observations. Stress gages (N=31) were deployed over a 4.5km2 area in the southern Beaufort Sea to observe in-situ stress. These data were analyzed in the context of deformation observations from satellite imagery and local laser and radar interferometers to explain the drivers of sea ice stress variations before and after fracture. Three case studies between 14 March and 24 March, during which fractures propagated through …


Digital Commons powered by bepress