Geophysics and Seismology Commons^™

Estimation Of Porosity And Water Saturation In Dual-Porosity Pyroclastic Deposits From Joint Analysis Of Compression, Shear, And Electromagnetic Velocities, Andrew C. Gase, John H. Bradford, Brittany D. Brand

Geosciences Faculty Publications and Presentations

In situ measurements of porosity and water saturation of pyroclastic deposits have the potential to improve interpretations of geology and hydrology in volcanic regions, and to provide more accurate estimates of dense rock equivalent for volcanic eruptions. However, rock-property models must consider the dual-porosity structure of pyroclastic deposits (i.e., vesicles within pumices and intergranular pores). Vesicularity, intergranular porosity, and water saturation all affect the density, elasticity, and dielectric properties of pyroclastic materials, which control seismic and electromagnetic velocities. The data from active seismic and ground-penetrating radar (GPR) techniques may improve porosity and water saturation estimation if the responses of seismic …

Multi-Channel Ground-Penetrating Radar For The Continuous Quantification Of Snow And Firn Density, Depth, And Accumulation, Tate Meehan

Boise State University Theses and Dissertations

A priority of ice sheet surface mass balance (SMB) prediction is ascertaining the surface density and annual snow accumulation. These forcing data are inputs for firn density models and can be used to inform remotely sensed ice sheet surface processes and to assess Regional Climate Model (RCM) skill. The Greenland Traverse for Accumulation and Climate Studies (GreenTrACS) retrieved 16 shallow firn cores and dug 42 snow pits along the Western percolation zone of the Greenland Ice Sheet (GrIS) during May and June of 2016 and 2017. I deployed and maintained a multi-channel 500 MHz ground-penetrating radar in a multi-offset configuration …

Diverse Eruptive Activity Revealed By Acoustic And Electromagnetic Observations Of The 14 July 2013 Intense Vulcanian Eruption Of Tungurahua Volcano, Ecuador, J. F. Anderson, J. B. Johnson, A. L. Steele, M. C. Ruiz, B. D. Brand

CGISS Publications and Presentations

During the powerful July 2013 eruption of Tungurahua volcano, Ecuador, we recorded exceptionally high amplitude, long‐period infrasound (1,600‐Pa peak‐to‐peak amplitude, 5.5‐s period) on sensors within 2km of the vent alongside electromagnetic signals from volcanic lightning serendipitously captured as interference. This explosion was one of Tungurahua's most powerful vulcanian eruptions since recent activity began in 1999, and its acoustic wave is among the most powerful volcanic infrasound ever recorded anywhere. We use these data to quantify erupted volume from the main explosion and to classify postexplosive degassing into distinct emission styles. Additionally, we demonstrate a highly effective method of recording lightning‐related …

Ice Core Records Of West Greenland Melt And Climate Forcing, H.P. Marshall, T. Meehan

CGISS Publications and Presentations

Remote sensing observations and climate models indicate that the Greenland Ice Sheet (GrIS) has been losing mass since the late 1990s, mostly due to enhanced surface melting from rising summer temperatures. However, in situ observational records of GrIS melt rates over recent decades are rare. Here we develop a record of frozen meltwater in the west GrIS percolation zone preserved in seven firn cores. Quantifying ice layer distribution as a melt feature percentage (MFP), we find significant increases in MFP in the southernmost five cores over the past 50 years to unprecedented modern levels (since 1550 CE). Annual to decadal …

Forecasting The Eruption Of An Open‐Vent Volcano Using Resonant Infrasound Tones, Jeffrey B. Johnson, Leighton M. Watson, Jose L. Palma, Eric M. Dunham, Jacob F. Anderson

CGISS Publications and Presentations

Open‐vent volcanic systems with active degassing are particularly effective at producing infrasound that exhibits resonant tones controlled by the geometry of the volcano's crater. Changes in the infrasound character can thus provide constraints on a crater's lava level, which may vary dynamically in the lead‐up to an eruption. Here we show that the increasing frequency content and damping characteristics of the resonant infrasound at Volcán Villarrica (Chile) relate to lava lake position in its crater/conduit preceding its 2015 eruption. We model the acoustic response of Villarrica's crater to determine that the lake began to rise on 27 February and reached …

Spatial And Temporal Dynamics Of Dissolved Oxygen Concentrations And Bioactivity In The Hyporheic Zone, W. Jeffery Reeder, Annika M. Quick, Tiffany B. Farrell, Shawn G. Benner, Kevin P. Feris, Daniele Tonina

Geosciences Faculty Publications and Presentations

Dissolved oxygen (DO) concentrations and consumption rates are primary indicators of heterotrophic respiration and redox conditions in the hyporheic zone (HZ). Due to the complexity of hyporheic flow and interactions between hyporheic hydraulics and the biogeochemical processes, a detailed, mechanistic, and predictive understanding of the biogeochemical activity in the HZ has not yet been developed. Previous studies of microbial activity in the HZ have treated the metabolic DO consumption rate constant (K_DO) as a temporally fixed and spatially homogeneous property that is determined primarily by the concentration of bioavailable carbon. These studies have generally treated bioactivity as temporally …

Geologic Framework Of The Fang Hot Springs Area With Emphasis On Structure, Hydrology, And Geothermal Development, Chiang Mai Provence, Northern Thailand, Spencer H. Wood, Pichet Kaewsomwang, Fongsaward Suvagondha Singharajwarapan

Geosciences Faculty Publications and Presentations

Geologic mapping, a magnetotelluric survey, well data, and earlier reports are integrated to guide further development of the Fang geothermal system. The Fang Hot Springs originally flowed ~ 20 l s⁻¹ of 90–99 °C water from a 10-hectare area of crystal- line rocks presumed to be of Triassic age. Four wells 92–500 m deep now flow ~ 20 l s⁻¹ of 110–115 °C water and generate 115–250 kWe from the 1989 Ormat binary power plant. Wells are not pumped nor is the spent water re-injected. Temperatures of 130 °C occur in some wells and water chemistry indicates reservoir …

One Diamictite And Two Rifts: Stratigraphy And Geochronology Of The Gataga Mountain Of Northern British Columbia, Athena Eyster, Filippo Ferri, Mark D. Schmitz, Francis A. Macdonald

Geosciences Faculty Publications and Presentations

Neoproterozoic glacial diamictites and rift-related volcanics are preserved throughout the North American Cordillera, yet the nature and timing of both glaciation and rifting are poorly constrained. New geochronological, geochemical, and stratigraphic data from the Cryogenian Gataga volcanics and bounding units at Gataga Mountain, in the Kechika Trough of northern British Columbia, better constrain the age of these rift-related volcanics and suggest that they erupted during glaciation. At Gataga Mountain, three informal sequences are exposed; a basal quartzite, the Gataga volcanics, and an overlying mixed carbonate-siliciclastic succession. The basal quartzite is dominated by cross-bedded sandstone with an intertidal facies assemblage including …

Geothermal Play Fairway Analysis, Phase 3: A Provisional Conceptual Model Of The Camas Prairie, Snake River Plain, Idaho, Lee M. Liberty

CGISS Publications and Presentations

The Snake River Plain (SRP) Geothermal Play Fairway Analysis team identified two regions of interest during Phase 2 studies: the western SRP near Mountain Home, Idaho and Camas Prairie, Idaho. New geological, geochemical, and geophysical (gravity, magnetic, MT, seismic) studies of both areas led to a focus on Camas Prairie for validation during Phase 3. Camas Prairie is an EW-trending half-graben bounded on the north by the Idaho Batholith and on the south by the Mount Bennett Hills. Camas Prairie is bisected by a major NW-trending fault system (The Pothole fault) that separates NW-trending faults to east from ENE-trending faults …

Assessment Of Ground-Based And Aerial Cloud Seeding Using Trace Chemistry, James M. Fisher, Marion L. Lytle, Shawn G. Benner

Geosciences Faculty Publications and Presentations

Targeting seedable clouds with silver iodide in complex terrain adds considerable uncertainty in weather modification studies. This study explores the geographic and temporal distribution of silver iodide associated with an active cloud seeding program in central Idaho snowpack using trace chemistry. Over 4,000 snow samples were analyzed for the presence of a cloud seeding silver iodide (AgI) signature over two winter seasons. The results indicate the following. (1) At sites within 70 km of AgI sources, silver enrichments were detected at 88% of cases involving seeding efforts from ground generators, but none from aircraft seeded cases. (2) Real-time snow collection …

Petrology And Geochronology Of Metamorphic Zircon, Matthew J. Kohn, Nigel M. Kelly

Geosciences Faculty Publications and Presentations

Zircon is unusually well suited for investigating metamorphic processes because it is readily analyzed for U‐Pb ages, it harbors diverse mineral inclusions, and its chemistry can be linked to metamorphic parageneses and P‐T paths. Metamorphic zircon chemistry and ages are relevant only at the sub‐grain micron scale, and consequently many analytical methods, such as depth profiling, have been developed to exploit such spatially resolute infor­mation. Here we review how metamorphic zircon grows, and how its chemistry and inclusion assemblages may be used to link the age of a zircon domain to its metamorphic P‐T condition. Domain‐specific ages and inclusion assemblages …

A Geophysical Characterization Of The Structural Framework Of The Camas Prairie Geothermal System, Southcentral Idaho, Lee Liberty

CGISS Publications and Presentations

Play Fairway Analysis methods, utilizing existing geologic, thermal, geochemical, and geophysical data were employed in an initial assessment of geothermal resources in the Snake River Plain. These efforts identified the Camas Prairie in southcentral Idaho as a region with elevated resource potential. Subsequent efforts included structural and geophysical data collection to identify the most favorable structural settings for exploiting resources in the valley. The present work involved high-resolution gravity, magnetic, magnetotellurics (MT), field mapping, and seismic surveys to further characterize the system and target sites for exploration drilling around Barron’s Hot Springs (BHS) in the southwest part of the valley. …

Combined Assimilation Of Satellite Precipitation And Soil Moisture: A Case Study Using Trmm And Smos Data, Liao-Fan Lin, Ardeshir M. Ebtehaj, Alejandro N. Flores, Satish Bastola, Rafael L. Bras

Geosciences Faculty Publications and Presentations

This paper presents a framework that enables simultaneous assimilation of satellite precipitation and soil moisture observations into the coupled Weather Research and Forecasting (WRF) and Noah land surface model through variational approaches. The authors tested the framework by assimilating precipitation data from the Tropical Rainfall Measuring Mission (TRMM) and soil moisture data from the Soil Moisture Ocean Salinity (SMOS) satellite. The results show that assimilation of both TRMM and SMOS data can effectively improve the forecast skills of precipitation, top 10-cm soil moisture, and 2-m temperature and specific humidity. Within a 2-day time window, impacts of precipitation data assimilation on …

Characterizing Coseismic Ionospheric Disturbance For Surface-Rupturing Earthquakes, Rebekah Faith Lee

Boise State University Theses and Dissertations

Coseismic ionospheric disturbances (CID) are commonly identified using global navigation space system (GNSS) satellites. Little research, however, has focused on using total electron content (TEC) observations to characterize acoustic sources on Earth's surface. For this thesis, I investigate the applicability of an analytical method to invert the TEC for the acoustic wave. The inversion is based on the modeling of a transfer function. Deconvolving the TEC by the transfer function gives the acoustic wave. Inverting for the acoustic wave in this way would remove phase differences in the TEC created by atmospheric-ionospheric coupling. I test the assumption in the model …

Seismic Refraction And Electrical Resistivity Tests For Fracture Induced Anisotropy In A Mountain Watershed, Aida Mendieta

Boise State University Theses and Dissertations

The critical zone (CZ) is the earth’s layer where water, air, rock, and life meet. It is the zone with which humans interact most. The National Research council (2001) defines the CZ as a “heterogeneous, near surface environment in which complex interactions involving rock, soil, water, air, and living organisms regulate the natural habitat and determine the availability of life sustaining resources”. The CZ may extend roughly from the top of the vegetation canopy to the deepest part of the rock column where meteoric water circulates – this is often in the 10 – 30 m range. The upper 1-2 …

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 …

Acoustic And Seismic Fields Of Hydraulic Jumps At Varying Froude Numbers, Timothy J. Ronan, Jonathan M. Lees, T. Dylan Mikesell, Jacob F. Anderson, Jeffrey B. Johnson

Geosciences Faculty Publications and Presentations

Mechanisms that produce seismic and acoustic wavefields near rivers are poorly understood because of a lack of observations relating temporally dependent river conditions to the near-river seismoacoustic fields. This controlled study at the Harry W. Morrison Dam (HWMD) on the Boise River, Idaho, explores how temporal variation in fluvial systems affects surrounding acoustic and seismic fields. Adjusting the configuration of the HWMD changed the river bathymetry and therefore the form of the standing wave below the dam. The HWMD was adjusted to generate four distinct wave regimes that were parameterized through their dimensionless Froude numbers (Fr) and …

Using Isotopes To Constrain Water Flux And Age Estimates In Snow-Influenced Catchments Using The Starr (Spatially Distributed Tracer-Aided Rainfall–Runoff) Model, Pertti Ala-Aho, Doerthe Tetzlaff, James P. Mcnamara, Hjalmar Laudon, Chris Soulsby

Geosciences Faculty Publications and Presentations

Tracer-aided hydrological models are increasingly used to reveal fundamentals of runoff generation processes and water travel times in catchments. Modelling studies integrating stable water isotopes as tracers are mostly based in temperate and warm climates, leaving catchments with strong snow influences underrepresented in the literature. Such catchments are challenging, as the isotopic tracer signals in water entering the catchments as snowmelt are typically distorted from incoming precipitation due to fractionation processes in seasonal snowpack.

We used the Spatially distributed Tracer-Aided Rainfall– Runoff (STARR) model to simulate fluxes, storage, and mixing of water and tracers, as well as estimating water ages …

Assessing A Multi-Platform Data Fusion Technique In Capturing Spatiotemporal Dynamics Of Heterogeneous Dryland Ecosystems In Topographically Complex Terrain, Peter J. Olsoy, Jessica Mitchell, Nancy F. Glenn, Alejandro N. Flores

Geosciences Faculty Publications and Presentations

Water-limited ecosystems encompass approximately 40% of terrestrial land mass and play a critical role in modulating Earth’s climate and provisioning ecosystem services to humanity. Spaceborne remote sensing is a critical tool for characterizing ecohydrologic patterns and advancing the understanding of the interactions between atmospheric forcings and ecohydrologic responses. Fine to medium scale spatial and temporal resolutions are needed to capture the spatial heterogeneity and the temporally intermittent response of these ecosystems to environmental forcings. Techniques combining complementary remote sensing datasets have been developed, but the heterogeneous nature of these regions present significant challenges. Here we investigate the capacity of one …

Lidar Aboveground Vegetation Biomass Estimates In Shrublands: Prediction, Uncertainties And Application To Coarser Scales, Aihua Li, Shital Dhakal, Nancy F. Glenn, Lucas P. Spaete

Geosciences Faculty Publications and Presentations

Our study objectives were to model the aboveground biomass in a xeric shrub-steppe landscape with airborne light detection and ranging (Lidar) and explore the uncertainty associated with the models we created. We incorporated vegetation vertical structure information obtained from Lidar with ground-measured biomass data, allowing us to scale shrub biomass from small field sites (1 m subplots and 1 ha plots) to a larger landscape. A series of airborne Lidar-derived vegetation metrics were trained and linked with the field-measured biomass in Random Forests (RF) regression models. A Stepwise Multiple Regression (SMR) model was also explored as a comparison. Our results …

A Machine Learning Approach To Estimation Of Downward Solar Radiation From Satellite-Derived Data Products: An Application Over A Semi-Arid Ecosystem In The U.S., Qingtao Zhou, Alejandro Flores, Nancy F. Glenn, Reggie Walters, Bangshuai Han

Geosciences Faculty Publications and Presentations

Shortwave solar radiation is an important component of the surface energy balance and provides the principal source of energy for terrestrial ecosystems. This paper presents a machine learning approach in the form of a random forest (RF) model for estimating daily downward solar radiation flux at the land surface over complex terrain using MODIS (MODerate Resolution Imaging Spectroradiometer) remote sensing data. The model-building technique makes use of a unique network of 16 solar flux measurements in the semi-arid Reynolds Creek Experimental Watershed and Critical Zone Observatory, in southwest Idaho, USA. Based on a composite RF model built on daily observations …

Spreading Rate-Dependent Variations In Crystallization Along The Global Mid-Ocean Ridge System, V. Dorsey Wanless, Mark D. Behn

Geosciences Faculty Publications and Presentations

We investigate crustal accretion at mid-ocean ridges by combining crystallization pressures calculated from major element contents in mid-ocean ridge basalt (MORB) glasses and vapor-saturation pressures from melt inclusions and MORB glasses. Specifically, we use established major element barometers and pressures estimated from 192 fractional crystallization trends to calculate crystallization pressures from >9000 MORB glasses across the global range of mid-ocean ridge spreading rates. Additionally, we estimate vapor-saturation pressures from >400 MORB glasses from PETDB and >400 olivine-hosted melt inclusions compiled from five ridges with variable spreading rates. Both major element and vapor-saturation pressures increase and become more variable with decreasing …

Regional Sensitivities Of Seasonal Snowpack To Elevation, Aspect, And Vegetation Cover In Western North America, Nancy F. Glenn

Geosciences Faculty Publications and Presentations

In mountains with seasonal snow cover, the effects of climate change on snowpack will be constrained by landscape-vegetation interactions with the atmosphere. Airborne lidar surveys used to estimate snow depth, topography, and vegetation were coupled with reanalysis climate products to quantify these interactions and to highlight potential snowpack sensitivities to climate and vegetation change across the western U.S. at Rocky Mountain (RM), Northern Basin and Range (NBR), and Sierra Nevada (SNV) sites. In forest and shrub areas, elevation captured the greatest amount of variability in snow depth (16–79%) but aspect explained more variability (11–40%) in alpine areas. Aspect was most …

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 …

Coupling Biophysical Processes And Water Rights To Simulate Spatially Distributed Water Use In An Intensively Managed Hydrologic System, Bangshuai Han, Shawn G. Benner, John P. Bolte, Kellie B. Vache, Alejandro N. Flores

Geosciences Faculty Publications and Presentations

Humans have significantly altered the redistribution of water in intensively managed hydrologic systems, shifting the spatiotemporal patterns of surface water. Evaluating water availability requires integration of hydrologic processes and associated human influences. In this study, we summarize the development and evaluation of an extensible hydrologic model that explicitly integrates water rights to spatially distribute irrigation waters in a semi-arid agricultural region in the western US, using the Envision integrated modeling platform. The model captures both human and biophysical systems, particularly the diversion of water from the Boise River, which is the main water source that supports irrigated agriculture in this …

Volcanic Initiation Of The Eocene Heart Mountain Slide, Wyoming, Usa, Mark D. Schmitz

Geosciences Faculty Publications and Presentations

The Eocene Heart Mountain slide of northwest Wyoming covers an area of as much as 5000 km² and includes allochthonous Paleozoic carbonate and Eocene volcanic rocks with a run-out distance of as much as 85 km. Recent geochronologic data indicated that the emplacement of the slide event occurred at ∼48.9 Ma, using laser ablation inductively coupled plasmamass spectrometry (LA-ICPMS) extracted fromU-Pb zircon ages frombasal layer and injectite carbonate ultracataclasite (CUC). We now refine that age with U-Pb results from a lamprophyre diatreme that is temporally and spatially related to the CUC injectites. The ages for the lamprophyre zircons are …

Modeling The Isotopic Evolution Of Snowpack And Snowmelt: Testing A Spatially Distributed Parsimonious Approach, Pertti Ala-Aho, Doerthe Tetzlaff, James P. Mcnamara, Hjalmar Laudon

Geosciences Faculty Publications and Presentations

Use of stable water isotopes has become increasingly popular in quantifying water flow paths and travel times in hydrological systems using tracer-aided modeling. In snow-influenced catchments, snowmelt produces a traceable isotopic signal, which differs from original snowfall isotopic composition because of isotopic fractionation in the snowpack. These fractionation processes in snow are relatively well understood, but representing their spatiotemporal variability in tracer-aided studies remains a challenge. We present a novel, parsimonious modeling method to account for the snowpack isotope fractionation and estimate isotope ratios in snowmelt water in a fully spatially distributed manner. Our model introduces two calibration parameters that …

Aerodynamic Roughness Length Estimation With Lidar And Imaging Spectroscopy In A Shrub-Dominated Dryland, Aihua Li, Wenguang Zhao, Jessica J. Mitchell, Nancy F. Glenn, Matthew J. Germino, Joel B. Sankey, Richard G. Allen

Geosciences Faculty Publications and Presentations

The aerodynamic roughness length (Z_0m) serves an important role in the flux exchange between the land surface and atmosphere. In this study, airborne lidar (ALS), terrestrial lidar (TLS), and imaging spectroscopy data were integrated to develop and test two approaches to estimate Z_0m over a shrub dominated dryland study area in south-central Idaho, USA. Sensitivity of the two parameterization methods to estimate Z_0m was analyzed. The comparison of eddy covariance-derived Z_0m and remote sensing-derived Z_0m showed that the accuracy of the estimated Z_0m heavily depends on the estimation model and the representation of …

Identifying Irrigated Areas In The Snake River Plain, Idaho: Evaluating Performance Across Composting Algorithms, Spectral Indices, And Sensors, Eric W. Chance, Kelly M. Cobourn, Valerie A. Thomas, Blaine C. Dawson, Alejandro N. Flores

Geosciences Faculty Publications and Presentations

There are pressing concerns about the interplay between agricultural productivity, water demand, and water availability in semi-arid to arid regions of the world. Currently, irrigated agriculture is the dominant water user in these regions and is estimated to consume approximately 80% of the world’s diverted freshwater resources. We develop an improved irrigated land-use mapping algorithm that uses the seasonal maximum value of a spectral index to distinguish between irrigated and non-irrigated parcels in Idaho’s Snake River Plain. We compare this approach to two alternative algorithms that differentiate between irrigated and non-irrigated parcels using spectral index values at a single date …