Geophysics and Seismology Commons^™

Application Of Hydrogeophysical Imaging In The Reynolds Creek Critical Zone Observatory, Travis Nielson

Boise State University Theses and Dissertations

The critical zone is defined as the upper most portion of the crust extending from the top of unweathered bedrock to the top of the vegetation canopy. It is the zone in which inorganic rock is transformed into biologically useful soils and saprolites in a process termed weathering. Because the critical zone is the connection between the subsurface and surface it plays a role in a wide variety of biological, hydrologic, and climatic processes. Understanding the critical zone though is inherently difficult because its scale and heterogeneity often means direct sampling methods, e.g. soil pits and cores, under represent the …

Geophysical Investigations Of Pyroclastic Density Current Processes And Deposit Properties At Mount St. Helens, Washington (Usa), Andrew Cleveland Gase

Boise State University Theses and Dissertations

Geophysical imaging has the potential to significantly improve investigations in pyroclastic deposits, either as a means of in situ property estimation or to provide geologic context where exposures do not exist. I perform two geophysical studies set in the deposits of the 1980 eruption at Mount St. Helens, Washington (USA); the aim is to investigate the physical properties and geology of pyroclastic deposits.

Joint petrophysical modeling reveals the dependence of seismic and electromagnetic velocities in pyroclastic deposits on two-phase porosity (vesicularity and inter- granular porosity) and water-saturation. Seismic first arrival travel-time tomography, multi-channel analysis of surface waves, and multi-offset GPR …

Earthquake Segment Boundaries And Tsunamigenic Faults Of The Kodiak Segment, Alaska-Aleutian Subduction Zone, Marlon D. Ramos

Boise State University Theses and Dissertations

The most recent megathrust earthquake to impact the Alaska subduction zone was the M9.2 Great Alaska earthquake of 1964. This multi-segment rupture spanned over 700 km of the plate boundary and engendered both local and trans-Pacific tsunamis. The Kodiak Islands region served as the southwestern limit to rupture. The nature of past megathrust segmentation for the Alaska subduction zone has been largely hypothesized through paleoseismological methods and the Kodiak region in particular has not received a comprehensive geophysical characterization of its inferred segment boundaries.

I analyze multiple geophysical datasets (e.g. seismic reflection, earthquake, potential fields) to understand the spatiotemporal relationships …

Using Near-Infrared Photography To Better Study Snow Microstructure And Its Variability Over Time And Space, Jesse Raymond Dean

Boise State University Theses and Dissertations

The methods typically used to study snow stratigraphy, microstructure, and variability are expensive, cumbersome, and often highly subjective. Near-infrared (NIR) photography is a low-cost, portable tool to rapidly collect high-resolution, objective measurements of snow microstructure and variability. To expand its application, an active-source NIR flash was introduced to the traditionally passive-source method. NIR imagery was collected alongside proven snowpit methods such as manual observation, Snow Fork wetness, and Snow Micro-Penetrometer hardness profiles. NIR photography was also deployed in five pits along a 10.6 km transect in Grand Mesa, CO, to track stratigraphy variations in space. The NIR flash was found …

Continuous Snow Water Equivalent Measurements With Ultra-Wideband Radar: Towards A New Generation Of Real-Time Automated Snow Sensor Arrays, Mark Edward Robertson

Boise State University Theses and Dissertations

Snow accounts for the majority of precipitation in many areas of the Western United States, and accurate measurements of the amount of water contained in the snowpack, known as snow water equivalent (SWE), are therefore important for water resource managers. The National Resources Conservation Service Snow Telemetry (SNOTEL) sites are the current standard remote measurement of SWE, with approximately 800 sites across the Western United States. Measurements at these sites are made by snow pillows, which weigh the overburden pressure of a snowpack, and are relatively expensive to install and maintain. Spring runoff is modeled using a 30-year average of …

Using Infrasound Waves To Monitor Tropospheric Weather And Crater Morphology Changes, Hugo David Ortiz

Boise State University Theses and Dissertations

Infrasound waves generated during volcanic eruptions and recorded near the vent are used to study both changing atmospheric conditions and volcano eruption source characteristics. Infrasound data were recorded for a 32 month period at Volcán Tungurahua (Ecuador) by a five-station network located within 6.5 km from the vent. Infrasound detections made through cross-network correlation indicate cyclic eruptive behavior, which is corroborated by reports from the Ecuadorian monitoring agency. Cross-network correlation lag times are used to compute _10 m resolution infrasound source positions, which take into account NOAA models of local wind and temperature. Variable infrasound-derived source locations suggests source migration …

Geologic, Geochemical, And Geophysical Characterization Of The Gold Deposits Of The Horseshoe Bend Mining District, Idaho: Building A Four Dimensional Model For Ore Exploration, Joshua Ekhoff

Boise State University Theses and Dissertations

The Eocene aged Trans-Challis Fault System of central Idaho provides the tectonic and magmatic framework for a series of Au-Ag and Cu-Mo ore deposits. From its northernmost extension near Butte, Montana to its southwestern terminus in the Boise Basin of south-central Idaho the Trans-Challis Fault System is associated with some of the richest precious metal deposits found in Idaho. However, the southernmost tip of the Trans-Challis Fault System, composed of the Horseshoe Bend and Pearl mining districts, remains understudied, receiving little economic or academic attention. As a result, how the Pearl to Horseshoe Bend mining districts fit within the established …

Lava Lake Eruptive Processes Quantified With Infrasound And Video At Mount Erebus, Antarctica, Alexander Miller

Boise State University Theses and Dissertations

A natural laboratory exists at Mount Erebus where strombolian activity from the lava lake is directly observed from the crater rim. Lava lake eruptions occur when pressurized bubble slugs distend the lake surface before bursting within a few tenths of a second. The unique setting presents an ideal site to quantify bubble growth through infrasound and video analysis. Two infrasound sensors and one video camera recorded eruptions ~330 m from the lava lake in 2006. Infrasound waveforms exhibit a high-amplitude bipolar pulse followed by a coda consisting of about five decaying oscillations. Video records are quantified by tracking the expanding …

Tracking And Characterization Of Moving Acoustic Sources Using An Infrasound Array At Volcán Santiaguito, Guatemala, Brian R. Terbush

Boise State University Theses and Dissertations

Active volcanic processes produce large amounts of acoustic energy within the infrasound band (0-20 Hz). Infrasound-sensitive microphones are often installed in addition to other forms of volcano monitoring equipment to increase the ability to remotely detect volcanic activity. In this study, an array of microphones was deployed without any additional sensor types for 36 hours at Santiaguito, Guatemala, to test the detection capabilities of a standalone microphone array. Array processing was applied to the recorded data, through frequency-domain beamforming and calculating a Fisher statistic (F). A changing F-threshold value was applied to differentiate between desired detections, or …

Defining Antecedent Topography At Coral Pink Sand Dunes, Kane County, Utah: The Influence Of Structural Controls On Dune-Field Boundary Conditions And Holocene Landscape Evolution, Elizabeth Janna Rozar

Boise State University Theses and Dissertations

Dune fields are transient features that record climate signatures through changes in mobility, morphology, and patterning. Aeolian geomorphologists are increasingly recognizing the important role that pre-existing, antecedent topography plays in controlling boundary conditions that affect changes in dune patterning. However, the dynamic relationship between antecedent topography and climate-sensitive boundary conditions is relatively unexplored. Here, I define antecedent topography for the Coral Pink Sand Dunes in southern Utah and show that structural controls play an important role in shaping antecedent geomorphic conditions of this dune field. I use ground-based terrestrial laser scanning (TLS) to produce a high-resolution digital elevation model (DEM), …

Multi-Component Active Source Rayleigh Wave Analysis, Gabriel Gribler

Boise State University Theses and Dissertations

Determining how a building site will respond to earthquake ground shaking plays a critical role in proper construction practices. One critical constraint on how a site responds is the near surface shear wave seismic velocity distribution. One commonly used method for indirectly estimating shear wave velocities is Multichannel Analysis of Surface Waves (MASW), which utilizes a spread of vertical geophones to measure Rayleigh wave dispersion. With this approach, phase velocity vs. frequency dispersion curve picks can be used to estimate shear wave velocities with depth. I investigate the use of two (vertical and horizontal inline) component seismic signals to record …

Automatic Detection And Denoising Of Signals In Large Geophysical Datasets, Gabriel O. Trisca

Boise State University Theses and Dissertations

To fully understand the complex interactions of various phenomena in the natural world, scientific disciplines such as geology and seismology increasingly rely upon analyzing large amounts of observations. However, data collection is growing at a faster rate than what is currently possible to analyze through traditional approaches. These datasets, supplied by the increasing use of sensors and remote sensing, require specialized computer programs to effectively analyze complex and expansive volumes of data.

Elaborating on existing geophysical data processing approaches for infrasound data collected from an avalanche-prone area, this project proposes new techniques for processing large geophysical datasets. These improved techniques …

Seismic Imaging To Constrain Groundwater Models For A Better Understanding And Management Of Water Quality In Coastal Benin, West Africa: A Saltwater Intrusion Problem, Kyle Michael Lindsay

Boise State University Theses and Dissertations

The coastal city of Cotonou in Bénin, West Africa, is a large population center that is facing a serious threat to the sustainability of its fresh water supply. Cotonou relies on groundwater derived from the Godomey aquifer for its domestic water supply. The aquifer is undergoing saltwater intrusion due to an increase in pumping to accommodate a growth in population. Hence, there is substantial interest in better characterizing the groundwater system for the purpose of determining appropriate management strategies to ensure sustainability of this freshwater resource.

I collected seismic reflection data along 15 transects to characterize the geometry of the …

Development And Application Of Tools For Avalanche Forecasting, Avalanche Detection, And Snowpack Characterization, Scott Christopher Havens

Boise State University Theses and Dissertations

Avalanche formation is a complex interaction between the snowpack, weather, and terrain. However, detailed observations typically can only be made at a single point and must be extrapolated over the slope or regional scale. This study aims to provide avalanche forecasters with tools to evaluate the snowpack, avalanche hazard, and avalanche occurrence when manual observations are not feasible.

Avalanches that occur within the new storm snow are a prevalent problem for the avalanche forecasters with the Idaho Transportation Department (ITD) along Highway 21. We have implemented a real time SNOw Slope Stability (SNOSS) model that provides an index to the …

Targeted Full-Waveform Inversion For Recovering Thin- And Ultra-Thin-Layer Properties Using Radar And Seismic Reflection Methods, Esther Babcock

Boise State University Theses and Dissertations

Ground penetrating radar (GPR) and seismic reflection methods are useful geophysical tools for near-surface characterization. Analysis of radar or seismic reflection data can combine velocity analysis with common physical transformations to provide subsurface physical properties such as subsurface porosity, density, and contaminant locations. However, reliable quantitative characterization of thin subsurface layers may be impossible using standard reflection data processing techniques, e.g. velocity analysis, if the layer thickness is below the conventional resolution limits of the data. The limiting layer thickness for layer resolution may be up to ½ or even ¾ of the dominant wavelength (λ) of the …

In-Situ Viscoelastic Soil Parameter Estimation Using Love Wave Inversion, Michael Wayne Morrison

Boise State University Theses and Dissertations

Industry best practices for estimating viscoelastic soil properties employ either crosshole seismic surveys, or ex-situ laboratory testing. The former method can be costly, and its area of investigation limited to a few meters. The latter method samples only a tiny volume from the research area, and requires that samples be disturbed from their native condition. We investigated an alternative method that uses Love wave inversion to estimate layer geometry, shear modulus, and soil viscosity. We derived a method for determining the complex velocity of Love wave modes in horizontally layered viscoelastic media, and used the method to investigate the behavior …

Geophysical Investigations Of The Seattle Fault Zone In Western Washington And A Geothermal System At Mount Princeton, Colorado, Andrew Patrick Lamb

Boise State University Theses and Dissertations

We use an array of existing and modified geophysical techniques to investigate the active Seattle thrust fault zone in western Washington and a geothermal system at Mt. Princeton Colorado. Through the integration of different geophysical methods, we can extend our observations of the surface geology to beneath the subsurface, thereby giving us a greater understanding of the structures and their kinematic interplay.

We find geophysical evidence through the use of potential field and seismic data for the Seattle fault zone extending further to the west than previously thought. We also find evidence that the Seattle fault zone may be linked …

Integrated Geophysical Exploration Of A Known Geothermal Resource: Neal Hot Springs, Clinton Ryan Colwell

Boise State University Theses and Dissertations

I present an integrated geophysical characterization of the Neal Hot Springs geothermal system in eastern Oregon. This newly established 23 MW geothermal production site is located in a region of complex geology and intersecting faults associated with two major extensional systems; the Oregon-Idaho Graben and the western Snake River Plain. The intersection of two dominant fault orientations, coupled with a high geothermal gradient from relatively thin continental crust and radioactive decay from a shallow granitic body, produces the pathways and heat needed for deep water circulation at Neal Hot Springs. New geologic mapping, geochemistry, and measurements from several boreholes in …

A Solution To The Problem Of Interpreting Very Long Time Series Of Ambient Noise As Measured At Very Sparse Networks, Kathryn Teresa Decker

Boise State University Theses and Dissertations

No abstract provided.

Characterization Of Heterogeneous Media With Multicomponent Laser Ultrasonics, Thomas E. Blum

Boise State University Theses and Dissertations

Wave propagation in scattering media is a complicated topic, but scattered elastic waves carry important information about the internal structure of the medium. It is a current topic of research and for the foreseeable future. Advances in theory and applications described in this manuscript benefit from new ways to collect more densely sampled, multicomponent, true-amplitude data.

Thus far, most fracture characterization experiments in the laboratory involve contacting transducers as elastic wave sources and receivers. Similarly, rock properties such as anisotropy and attenuation are also measured with contacting techniques. These type of measurements are well-suited for time-of-flight measurements, but for scattering …

Pattern Recognition In Earthquake Swarms From The 2009 Eruption Of Redoubt Volcano, Alaska, Catherine Jeanne Carlisle

Boise State University Theses and Dissertations

Earthquake swarms at volcanoes are common indicators of unrest and can be used to predict eruptions. However, not all earthquake swarms lead to an eruption but may die off instead. Variabilities in characteristics of swarms can lead to false predictions of an eruption. During the 2009 eruption of Redoubt Volcano in Alaska, there were five earthquake swarms, three of which preceded explosive eruptions and two that did not. These data were used to explore the variable characteristics that may be diagnostic of whether or not an eruption is imminent.

Data were recorded by the Alaska Volcano Observatory throughout the eruption. …

Megathrust Splay Fault Geometry In Prince William Sound, Alaska, Shaun Patrick Finn

Boise State University Theses and Dissertations

I present marine seismic reflection results from Prince William Sound, Alaska that document the location of active faults related to the subduction zone processes.

Subduction zones along convergent margins experience large earthquakes, magnitude >8, with recurrence intervals on the order of centuries. Smaller magnitude earthquakes with shorter recurrence intervals are probable along the same subduction zone fault zones. Convergent margin earthquakes also are associated with high uplift rates and tsunami generation, yet the location and uplift history of most tsunamigenic faults are unknown. In this thesis, I present the processed results of high resolution marine seismic reflection data of Prince …

Statistical Clustering Of Microseismic Event Spectra To Identify Subsurface Structure, Deborah Kay Fagan

Boise State University Theses and Dissertations

Understanding subsurface structure by studying microseismicity influences a wide range of activities, including energy extraction, aquifer storage, carbon sequestration, and seismic hazard assessment. Identifying individual fractures in a larger fault system is key to characterizing, understanding, and potentially mitigating risks of natural or induced seismicity.

A year-long study associated with a carbon dioxide (CO₂) sequestration project was conducted at the Aneth oil field in southeast Utah to record microseismicity at a single downhole geophone array. A previous analysis located events by first identifying event multiplets consisting of highly correlated time-domain waveforms on receivers shallower than the depth of …

Monitoring Co2 Sequestration In Basalt With Elastic Waves, Larry Thomas Otheim

Boise State University Theses and Dissertations

The continued burning of fossil fuels as a source of energy is contributing to greater concentrations of carbon dioxide (CO₂) in the atmosphere. Increased levels of CO₂ in the atmosphere have been linked to an increase of global mean surface temperature. To mitigate the continued release of CO₂, projects to capture this gas at large point sources and sequester it in geologic formations are in place. Carbon dioxide sequestration in basalts promises permanent trapping of the fluid as these rocks react with carbonic acid and precipitate carbonate minerals. It is important to monitor the injection …

Subsurface Characterization Using Head-Wave Artifacts In Seismic Interferometry, Thomas Dylan Mikesell

Boise State University Theses and Dissertations

Seismologists continually work to improve images of the Earth's interior. One new approach is seismic interferometry, which involves cross-correlating the seismic wave field recorded at two receivers to generate data as if one of the receivers was a source. Over the past decade, seismic interferometry has become an established technique to estimate the surface-wave part of the impulse response between two receivers; however, practical limitations in the source-energy distribution have made body-wave recovery difficult and causes spurious energy in the estimated impulse response. Rather than suppress such spurious energy, it can be useful to analyze coherent spurious events to help …

Non-Destructively Mapping The In-Situ Hydrologic Properties Of Snow, Firn, And Glacial Ice With Georadar, Joel Matthew Brown

Boise State University Theses and Dissertations

Ground penetrating radar (GPR) is a useful tool for studying the in-situ properties of glacial ice, firn, and snowpacks. The main focus of this dissertation is improving and expanding methods employed when collecting, processing, and understanding GPR data collected in the Cryosphere, or the snow and ice covered areas of the earth. The data used herein were collected on the Greenland Ice Sheet (GrIS) and on seasonal snowpacks of Western Montana, USA. This document has three sub-topics.

The first sub-topic is comparing the spatial variability of GPR data to the spatial variability of core data collected in two locations within …

Characterization Of Englacial Voids Using Radar Velocity Anisotropy, Joshua D. Nichols

Boise State University Theses and Dissertations

Glacial hydrology plays an important role in the motion and melt of glaciers. The transport of water through glacial ice is still poorly understood. Previous studies show that much of the water is stored and routed through planar voids within the glacier. From borehole observations and previous radar surveys, the voids appear to have a preferential orientation. Transverse waves, including radar waves, and shear seismic waves, travel at different velocities when polarized at different orientations relative to aligned inclusions. I conducted two georadar surveys on Bench glacier, in the Chugach Mountains, AK. Bench glacier has been the field site of …

Numerical Modeling Of Time-Lapse Seismic Experiments To Monitor Co2 Sequestration In A Layered Basalt Reservoir, Murari Khatiwada

Boise State University Theses and Dissertations

Instead of allowing carbon dioxide (CO₂) generated from the burning of hydrocarbons to escape into the atmosphere, CO₂ can be captured and stored. For the long term mitigation of the increasing amount of CO₂ emissions, its sequestration in geological formations is promising. As a measure, its short and long term monitoring is equally important for environmental and health safety issues. The seismic method is proposed as a non-invasive monitoring technique for geological sequestration of CO₂. Based on the positive results obtained from reservoir monitoring during enhanced oil recovery with CO₂ floods, geoscientists plan …

Ground-Penetrating Radar And Thermal Modeling Of Active Layer Thaw Beneath Arctic Streams, Troy Richard Brosten

Boise State University Theses and Dissertations

Seasonal thaw depth beneath arctic streams significantly impacts physical and biological processes within arctic stream environments. The impact of greater seasonal thaw for extended periods of time can alter ecosystems that have, in the past, resulted from more prevalent permafrost environments. Effects of climatic change on arctic stream environments necessitate the need for more information on characteristics of seasonal thaw and processes that occur within the thawed layer. Multiple ground-penetrating radar (GPR) methods and one-dimensional (1D) thermal modeling were used to investigate seasonal thaw beneath arctic streams and determine the dominant thermal process.

Study sites were selected to include stream …

Idaho Earthquakes Of 1905, 1913, And 1916: Intensity, Location, And Magnitude Inferred From Newspaper Accounts, Lynda Koll Harpham

Boise State University Theses and Dissertations

The purpose of this project is to better understand the epicentral location, magnitude, and effects of three southern Idaho earthquakes which occurred in 1905, 1913, and 1916. The three earthquakes are of considerable interest to seismologists owing to their reported proximity to large power dams, multistory buildings, and the nuclear facilities at Idaho National Engineering Laboratory (INEL) in south-central Idaho. structures were built in previous years without assessment of the potential for earthquake damage. Therefore, an understanding of these three earthquakes is important for future development, and for the reevaluation of potential earthquake hazard and adequacy of building codes.

The …