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

Geophysics and Seismology Commons™

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

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 1141 - 1170 of 2452

Full-Text Articles in Geophysics and Seismology

The Structural Analysis Of Enola And Greenbrier, Arkansas Earthquake Swarms: Cause And Effect?, Minella Majenu Dec 2015

The Structural Analysis Of Enola And Greenbrier, Arkansas Earthquake Swarms: Cause And Effect?, Minella Majenu

Graduate Theses and Dissertations

Almost 20 years after the remarkable earthquake swarm of 1982, near the town of Enola, Arkansas, with more than 40,000 micro-earthquakes, another event revisited the same North-Central Arkansas region in 2001. Nine years later, in 2010, a huge swarm event shook the northern part of Faulkner County, around the city of Guy. The following year, this seismic swarm event apparently migrated southward towards the city of Greenbrier, with an increase in the number of yearly recorded events. A 13km previously unrecognized, NE trending Guy-Greenbrier basement fault was revealed as a result of these swarm events.

Within the vicinity of the …


Hidden Intrabasin Extension: Evidence For Dike-Fault Interaction From Magnetic, Gravity, And Seismic Reflection Data In Surprise Valley, Northeastern California, Noah D. Athens, Jonathan M.G. Glen, Simon L. Klemperer, Anne E. Egger, Valentina C. Fontiveros Nov 2015

Hidden Intrabasin Extension: Evidence For Dike-Fault Interaction From Magnetic, Gravity, And Seismic Reflection Data In Surprise Valley, Northeastern California, Noah D. Athens, Jonathan M.G. Glen, Simon L. Klemperer, Anne E. Egger, Valentina C. Fontiveros

All Faculty Scholarship for the College of the Sciences

The relative contributions of tectonic and magmatic processes to continental rifting are highly variable. Magnetic, gravity, and seismic reflection data from Surprise Valley, California, in the northwest Basin and Range, reveal an intrabasin, fault-controlled, ~10-m-thick dike at a depth of ~150 m, providing an excellent example of the interplay between faulting and dike intrusion. The dike, likely a composite structure representing multiple successive intrusions, is inferred from modeling a positive magnetic anomaly that extends ~35 km and parallels the basin-bounding Surprise Valley normal fault on the west side of the valley. A two-dimensional high-resolution seismic reflection profile acquired across the …


Geophysical Evidence For Mid-Crustal Magma Reservoirs In The Lassen Volcanic Region, California, Samantha Catherine Tavarez Nov 2015

Geophysical Evidence For Mid-Crustal Magma Reservoirs In The Lassen Volcanic Region, California, Samantha Catherine Tavarez

USF Tampa Graduate Theses and Dissertations

Regional-scale complete Bouguer gravity anomalies underlying the Lassen and Shasta -Medicine Lake regions in northern California and southern Oregon are associated with subduction of the Gorda plate beneath North America. These generally negative anomalies reflect where underplating has deepened to form the mantle wedge, and where subduction has given rise to a series of Quaternary volcanoes comprising the southernmost end of the Cascade range. Multiple conductive bodies were identified by Park and Ostos (2013) in their magnetotelluric (MT) study of the broader Lassen volcanic region. Their broadband and long period measurements were conducted along a 250 km profile spanning from …


Streambed And Water Profile Response To In-Channel Restoration Structures In A Laboratory Meandering Stream, Bangshuai Han, Hong-Hanh Chu, Theodore A. Endreny Nov 2015

Streambed And Water Profile Response To In-Channel Restoration Structures In A Laboratory Meandering Stream, Bangshuai Han, Hong-Hanh Chu, Theodore A. Endreny

Geosciences Faculty Publications and Presentations

In-channel structures are often installed in alluvial rivers during restoration to steer currents, but they also modify the streambed morphology and water surface profile, and alter hydraulic gradients driving ecologically important hyporheic exchange. Although river features before and after restoration need to be compared, few studies have collected detailed observations to facilitate this comparison. We created a laboratory mobile-bed alluvial meandering river and collected detailed measurements in the highly sinuous meander before and after installation of in-channel structures, which included one cross vane and six J-hooks situated along 1 bar unit. Measurements of streambed and water surface elevation with sub-millimeter …


Numerical Simulation Of Spring Hydrograph Recession Curves For East Yorkshire Chalk Aquifer, Uk, Nozad Hasan Azeez, Landis Jared West, Simon H. Bottrell Oct 2015

Numerical Simulation Of Spring Hydrograph Recession Curves For East Yorkshire Chalk Aquifer, Uk, Nozad Hasan Azeez, Landis Jared West, Simon H. Bottrell

Sinkhole Conference 2015

The Cretaceous Chalk aquifer is the most important in the UK for the provision of water to public supply and agriculture. The Chalk has both matrix and fracture porosity and is thus best considered as a dual porosity aquifer system. Although the matrix porosity is large, typically around 0.35 in the study area of East Yorkshire, UK (ESI, 2010), pore diameters are typically very small, and the water contained in them is virtually immobile. The high permeability fracture network is responsible for the ability of water to drain; spatial variations in fracture network properties mean conventional approaches to aquifer characterization …


Using Electrical Resistivity Imaging To Characterize Karst Hazards In Southeastern Minnesota Agricultural Settings, Toby Dogwiler, Blake Lea Oct 2015

Using Electrical Resistivity Imaging To Characterize Karst Hazards In Southeastern Minnesota Agricultural Settings, Toby Dogwiler, Blake Lea

Sinkhole Conference 2015

Much of the Driftless Area of southeastern Minnesota is underlain by karstified carbonate bedrock. Land use in this karst terrain is dominated by agriculture, including row crop and dairy operations. The karst in this region is often mantled with up to 15 m of soil and unconsolidated sediments. As a result, underlying karst hazards such as incipient sinkholes are often hidden until they are suddenly revealed by the collapse of subsurface voids. Regionally, the economics of the dairy industry is causing a trend toward the consolidation and expansion of existing operations. As concentrated animal feeding operations (CAFO) or feedlots expand, …


Investigation Of A Sinkhole In Ogle County, Northwestern Illinois, Using Near-Surface Geophysical Techniques, Philip J. Carpenter, Lauren Schroeder Oct 2015

Investigation Of A Sinkhole In Ogle County, Northwestern Illinois, Using Near-Surface Geophysical Techniques, Philip J. Carpenter, Lauren Schroeder

Sinkhole Conference 2015

A sinkhole measuring 40 m in diameter and up to 6.5 m deep occurs within the Nachusa Grasslands, near the town of Franklin Grove, northwestern Illinois. This area, dedicated to prairie conservation and restoration, is owned and operated by The Nature Conservancy. Several meters of unconsolidated sand, gravel, and clay overlie the St. Peter sandstone, beneath which lies karstic Prairie du Chien dolomite. Investigations included EM conductivity profiles, resistivity soundings, 2D resistivity, and ground- penetrating radar (GPR), supplemented by conductivity logs, soil cores, and tree core studies. These data indicate the sandstone averages about 5 m deep near the sinkhole …


Characterization Of Karst Terrain Using Geophysical Methods Based On Sinkhole Analysis: A Case Study Of The Anina Karstic Region (Banat Mountains, Romania), Laurentiu Artugyan, Adrian C. Ardelean, Petru Urdea Oct 2015

Characterization Of Karst Terrain Using Geophysical Methods Based On Sinkhole Analysis: A Case Study Of The Anina Karstic Region (Banat Mountains, Romania), Laurentiu Artugyan, Adrian C. Ardelean, Petru Urdea

Sinkhole Conference 2015

To understand karst topography, we must determine both the nature and the factors that are defining dissolution processes in soluble rocks, as well as the drainage network resulting from these processes. The goal of this paper is to understand the underground drainage direction configuration and, also, the factors that are involved in surface water drainage of the Anina karstic region. In this study we used two complementary geophysical methods, spontaneous potential (SP) and ground penetrating radar (GPR), applied in 5 sinkholes with a funnel shaped aspect. Four of these sinkholes are circular and one of them is elongated NW-SE direction. …


Rollalong Resistivity Surveys Reveal Karstic Paleotopography Developed On Near-Surface Gypsum Bedrock: Lower Pecos Valley, Southeastern New Mexico, Lewis Land Oct 2015

Rollalong Resistivity Surveys Reveal Karstic Paleotopography Developed On Near-Surface Gypsum Bedrock: Lower Pecos Valley, Southeastern New Mexico, Lewis Land

Sinkhole Conference 2015

Following flooding in September 2013, several areas in northern Eddy County, New Mexico were damaged by multiple sinkhole collapses. We conducted rollalong electrical resistivity (ER) surveys for subsurface cavities parallel to roads within and near the community of Lakewood, NM to guide road repairs. The rollalong method allowed us to generate exceptionally long, continuous ER profiles of the survey area. ER surveys attained a maximum exploration depth of 55 to 62 meters over a lateral extent of ~1000 meters, revealing an unconformable surface developed on gypsum bedrock, punctuated by shallow depressions. Subsurface stratigraphy, including clay-rich valley fill sediments, and mudstone …


Pre-Construction Rock Treatment And Soil Modification Program Using Low Mobility Grout To Mitigate Future Sinkhole Development In A 2,787.1 Square Meter (30,000 Sf) Maintenance Facility, Steven W. Shifflett Oct 2015

Pre-Construction Rock Treatment And Soil Modification Program Using Low Mobility Grout To Mitigate Future Sinkhole Development In A 2,787.1 Square Meter (30,000 Sf) Maintenance Facility, Steven W. Shifflett

Sinkhole Conference 2015

The US Army required construction of a 2,787.1 square meters (30,000 sf) maintenance facility supported on shallow foundations at the Fort Campbell Military Installation. During the subsurface investigation a seven foot air-filled void was encountered in the bedrock within the building footprint. Electrical Resistivity Imaging (ERI) was conducted in an attempt to determine the lateral extent of the encountered void and to establish the general prevalence of karst features at the site. Due to uncertainty in the subsurface conditions, a rock treatment and soil modification program was developed which consisted of a series of targeted exploratory grout holes advanced in …


Landslides And Megathrust Splay Faults Captured By The Late Holocene Sediment Record Of Eastern Prince William Sound, Alaska, Shaun P. Finn, Lee M. Liberty, Peter J. Haeussler, Thomas L. Pratt Oct 2015

Landslides And Megathrust Splay Faults Captured By The Late Holocene Sediment Record Of Eastern Prince William Sound, Alaska, Shaun P. Finn, Lee M. Liberty, Peter J. Haeussler, Thomas L. Pratt

Geosciences Faculty Publications and Presentations

We present new marine seismic‐reflection profiles and bathymetric maps to characterize Holocene depositional patterns, submarine landslides, and active faults beneath eastern and central Prince William Sound (PWS), Alaska, which is the eastern rupture patch of the 1964 Mw 9.2 earthquake. We show evidence that submarine landslides, many of which are likely earthquake triggered, repeatedly released along the southern margin of Orca Bay in eastern PWS. We document motion on reverse faults during the 1964 Great Alaska earthquake and estimate late Holocene slip rates for these growth faults, which splay from the subduction zone megathrust. Regional bathymetric lineations help define …


Cordilleran Front Range Structural Features In Northwest Montana Interpreted From Vintage Seismic 2 Reflection Data, Mason Porter Oct 2015

Cordilleran Front Range Structural Features In Northwest Montana Interpreted From Vintage Seismic 2 Reflection Data, Mason Porter

Graduate Theses & Non-Theses

Industry seismic reflection data were collected in 1983 in the Rocky Mountain Cordillera front ranges of northwest Montana. These seismic profiles represent 160 km of deep reflection data that cross the eastern Purcell anticlinorium, Rocky Mountain Trench (RMT), Rocky Mountain Basal Detachment (RMBD), and Lewis thrust. We have reprocessed these data using modern processing techniques including refraction statics, pre-stack time migration (PSTM), and pre- and post-stack depth migration. The RMT contains Tertiary fill to 1 km depth and the RMT fault system has a minimum of 3-4 km of normal displacement. The RMT and Flathead fault systems are interpreted to …


Investigation Of Ambient Seismic Noise Using Seismic Interferometry In Western Montana, Natalia Krzywosz Oct 2015

Investigation Of Ambient Seismic Noise Using Seismic Interferometry In Western Montana, Natalia Krzywosz

Graduate Theses & Non-Theses

Passive seismic interferometry is a process by which ambient noise data recorded at different seismic stations can be cross-correlated to estimate Green's functions. In the past, both surface waves and body waves have successfully been extracted by cross-correlation of ambient noise data on both regional and global scales. In this study, I have generated Matlab code to simulate an application of seismic interferometry on a synthetic model with pre-defined layers and p-wave velocities. For areas with known velocity models, the Matlab code produced in this study can be used to generate synthetic seismograms, and model the effects of cross-correlation on …


A Hydrogeophysical Investigation Of Logan, Mt Using Electrical Techniques And Seismic Refraction Tomography, Taylor Stipe Oct 2015

A Hydrogeophysical Investigation Of Logan, Mt Using Electrical Techniques And Seismic Refraction Tomography, Taylor Stipe

Graduate Theses & Non-Theses

Logan, Montana USA is located on the Gallatin River, one of the three rivers forming the headwaters of the Missouri River. Previous hydrogeological studies have determined that the location at Logan is a possible pinch-point for the local Gallatin watershed where shallow groundwater is expected to discharge into the Gallatin River. However, groundwater monitoring wells indicate dry Tertiary sediments overlying bedrock, suggesting surface and groundwater systems are disconnected. We performed shallow seismic refraction, electrical resistivity, spontaneous potential, and electromagnetic surveys to investigate the groundwater system in the study area. Geophysical measurements were obtained near the Gallatin River and close to …


Seasonal And Diurnal Cycles Of Liquid Water In Snow—Measurements And Modeling, A. Heilig, C. Mitterer, L. Schmid, N. Wever, J. Schweizer, H.-P. Marshall, O. Eisen Oct 2015

Seasonal And Diurnal Cycles Of Liquid Water In Snow—Measurements And Modeling, A. Heilig, C. Mitterer, L. Schmid, N. Wever, J. Schweizer, H.-P. Marshall, O. Eisen

CGISS Publications and Presentations

Evaluating and improving snow models and outflow predictions for hydrological applications is hindered by the lack of continuous data on bulk volumetric liquid water content (��w) and storage capacity of the melting snowpack. The combination of upward looking ground-penetrating radar and conventional snow height sensors enable continuous, nondestructive determinations of ��w in natural snow covers from first surficial wetting until shortly before melt out. We analyze diurnal and seasonal cycles of ��w for 4 years in a flat study site and for three melt seasons on slopes and evaluate model simulations for two different water …


Effects Of Changes In Moisture Source And The Upstream Rainout On Stable Isotopes In Precipitation – A Case Study In Nanjing, Eastern China, Y. Tang, H. Pang, W. Zhang, Y. Li, Shuang-Ye Wu, S. Hou Oct 2015

Effects Of Changes In Moisture Source And The Upstream Rainout On Stable Isotopes In Precipitation – A Case Study In Nanjing, Eastern China, Y. Tang, H. Pang, W. Zhang, Y. Li, Shuang-Ye Wu, S. Hou

Department of Earth, Environment and Sustainability Faculty Publications

In the Asian monsoon region, variations in the stable isotopic composition of speleothems have often been attributed to the "amount effect". However, an increasing number of studies suggest that the "amount effect" in local precipitation is insignificant or even non-existent. To explore this issue further, we examined the variability of daily stable isotopic composition (δ18O) in precipitation from September 2011 to November 2014 in Nanjing, eastern China. We found that intra-seasonal variations of δ18O during summer were not significantly correlated with local rainfall amount but could be linked to changes in the moisture source location and rainout processes in the …


Slip Pulse And Resonance Of The Kathmandu Basin During The 2015 Gorkha Earthquake, Nepal, John Galetzka, Walter Szeliga Sep 2015

Slip Pulse And Resonance Of The Kathmandu Basin During The 2015 Gorkha Earthquake, Nepal, John Galetzka, Walter Szeliga

All Faculty Scholarship for the College of the Sciences

Detailed geodetic imaging of earthquake ruptures enhances our understanding of earthquake physics and associated ground shaking. The 25 April 2015 moment magnitude 7.8 earthquake in Gorkha, Nepal was the first large continental megathrust rupture to have occurred beneath a high-rate (5-hertz) Global Positioning System (GPS) network. We used GPS and interferometric synthetic aperture radar data to model the earthquake rupture as a slip pulse ~20 kilometers in width, ~6 seconds in duration, and with a peak sliding velocity of 1.1 meters per second, which propagated toward the Kathmandu basin at ~3.3 kilometers per second over ~140 kilometers. The smooth slip …


Source Mechanism Of Small Long-Period Events At Mount St. Helens In July 2005 Using Template Matching, Phase-Weighted Stacking, And Full-Waveform Inversion, Robin S. Matoza, Bernard A. Chouet, Phillip B. Dawson, Peter M. Shearer, Matthew M. Haney, Gregory P. Waite, Seth C. Moran, T. Dylan Mikesell Sep 2015

Source Mechanism Of Small Long-Period Events At Mount St. Helens In July 2005 Using Template Matching, Phase-Weighted Stacking, And Full-Waveform Inversion, Robin S. Matoza, Bernard A. Chouet, Phillip B. Dawson, Peter M. Shearer, Matthew M. Haney, Gregory P. Waite, Seth C. Moran, T. Dylan Mikesell

CGISS Publications and Presentations

Long-period (LP, 0.5-5 Hz) seismicity, observed at volcanoes worldwide, is a recognized signature of unrest and eruption. Cyclic LP “drumbeating” was the characteristic seismicity accompanying the sustained dome-building phase of the 2004–2008 eruption of Mount St. Helens (MSH), WA. However, together with the LP drumbeating was a near-continuous, randomly occurring series of tiny LP seismic events (LP “subevents”), which may hold important additional information on the mechanism of seismogenesis at restless volcanoes. We employ template matching, phase-weighted stacking, and full-waveform inversion to image the source mechanism of one multiplet of these LP subevents at MSH in July 2005. The signal-to-noise …


Hydrological Partitioning In The Critical Zone: Recent Advances And Opportunities For Developing Transferable Understanding Of Water Cycle Dynamics, Paul D. Brooks, Jon Chorover, Ying Fan, Sarah E. Godsey, Reed M. Maxwell, James P. Mcnamara, Christina Tague Sep 2015

Hydrological Partitioning In The Critical Zone: Recent Advances And Opportunities For Developing Transferable Understanding Of Water Cycle Dynamics, Paul D. Brooks, Jon Chorover, Ying Fan, Sarah E. Godsey, Reed M. Maxwell, James P. Mcnamara, Christina Tague

Geosciences Faculty Publications and Presentations

Hydrology is an integrative discipline linking the broad array of water-related research with physical, ecological, and social sciences. The increasing breadth of hydrological research, often where subdisciplines of hydrology partner with related sciences, reflects the central importance of water to environmental science, while highlighting the fractured nature of the discipline itself. This lack of coordination among hydrologic subdisciplines has hindered the development of hydrologic theory and integrated models capable of predicting hydrologic partitioning across time and space. The recent development of the concept of the critical zone (CZ), an open system extending from the top of the canopy to the …


Lahar Infrasound Associated With Volcán Villarrica's 3 March 2015 Eruption, Jeffrey B. Johnson, Jose L. Palma Aug 2015

Lahar Infrasound Associated With Volcán Villarrica's 3 March 2015 Eruption, Jeffrey B. Johnson, Jose L. Palma

Geosciences Faculty Publications and Presentations

The paroxysmal 2015 eruption of Volcán Villarrica (Chile) produced a 2.5 h long lahar, which descended more than 20 km within the Rio Correntoso/Turbio drainage and destroyed two small bridges. A three-element infrasound array 10 km from the summit, and 4 km from the lahar’s closest approach, was used to study the flow’s progression. Array processing using cross-correlation lag times and semblance places constraints on the lahar’s dynamics, including detection of an initial flow pulse that traveled from 2 to 12 km at an average speed of 38m/s. Subsequently, the lahar signal evolved to a relatively stationary infrasonic tremor located …


High-Precision U-Pb Ca-Tims Calibration Of Middle Permian To Lower Triassic Sequences, Mass Extinction And Extreme Climate-Change In Eastern Australian Gondwana, I. Metcalfe, J. Crowley, R. S. Nicoll, M. Schmitz Aug 2015

High-Precision U-Pb Ca-Tims Calibration Of Middle Permian To Lower Triassic Sequences, Mass Extinction And Extreme Climate-Change In Eastern Australian Gondwana, I. Metcalfe, J. Crowley, R. S. Nicoll, M. Schmitz

Geosciences Faculty Publications and Presentations

Twenty-eight new high-precision Chemical Abrasion Isotope Dilution Thermal Ionisation Mass Spectrometry U-Pb zircon dates for tuffs in the Sydney and Bowen Basins are reported. Based on these new dates, the Guadalupian-Lopingian/Capitanian-Wuchiapingian boundary is tentatively placed at the level of the Thirroul Sandstone in the lower part of the Illawarra Coal Measures in the Sydney Basin. The Wuchiapingian-Changhsingian boundary is at or close to the Kembla Sandstone horizon in the Illawarra Coal Measures, southern Sydney Basin, in the middle part of the Newcastle Coal Measures in the northern Sydney Basin, and in the middle of the Black Alley Shale in the …


Tracking And Characterization Of Moving Acoustic Sources Using An Infrasound Array At Volcán Santiaguito, Guatemala, Brian R. Terbush Aug 2015

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 Aug 2015

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 Aug 2015

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 …


Recent Seismicity And Regional Extension Aithin Southwestern Montana, Usa, Jessica Szkody Aug 2015

Recent Seismicity And Regional Extension Aithin Southwestern Montana, Usa, Jessica Szkody

Masters Theses

Southwestern Montana has experienced several large damaging earthquakes over the last 100 years, but many minor ones that unveil the nature of the intraplate seismicity. The region in this study is part of two distinct Late Cretaceous tectonic provinces, the Rocky Mountain Foreland Basement (RMFB) and the Cordilleran Fold and Thrust Belt (CFTB). Relationships between the two provinces and their faults show that the focal mechanisms are different. Deep focal mechanisms (between 8 and 10 km) within the RMFB can be placed on a specific fault, with many smaller events falling within the hanging wall. The hypocenters within the hanging …


Automatic Detection And Denoising Of Signals In Large Geophysical Datasets, Gabriel O. Trisca Aug 2015

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 …


Forecasting The Response Of Earth’S Surface To Future Climatic And Land Use Changes: A Review Of Methods And Research Needs, Jennifer L. Pierce, Michael J. Poulos Jul 2015

Forecasting The Response Of Earth’S Surface To Future Climatic And Land Use Changes: A Review Of Methods And Research Needs, Jennifer L. Pierce, Michael J. Poulos

Geosciences Faculty Publications and Presentations

In the future, Earth will be warmer, precipitation events will be more extreme, global mean sea level will rise, and many arid and semiarid regions will be drier. Human modifications of landscapes will also occur at an accelerated rate as developed areas increase in size and population density. We now have gridded global forecasts, being continually improved, of the climatic and land use changes (C&LUC) that are likely to occur in the coming decades. However, besides a few exceptions, consensus forecasts do not exist for how these C&LUC will likely impact Earth-surface processes and hazards. In some cases, we have …


Stable Isotopes Of Hydrothermal Carbonate Minerals In The Butte Porphyry-Lode Deposits, Montana, Ryan Stevenson Jul 2015

Stable Isotopes Of Hydrothermal Carbonate Minerals In The Butte Porphyry-Lode Deposits, Montana, Ryan Stevenson

Graduate Theses & Non-Theses

The stable isotopic compositions of over 90 hydrothermal carbonate minerals in the Butte porphyry-lode system were analyzed. These samples came from the underground workings as well as the active Continental Pit area. Most material came from polymetallic “Main Stage” veins which post-date the porphyry Cu-Mo mineralization of Butte. Some samples from late calcite-stellerite veins were also included in the study. Rhodochrosite d13C and d18O values range from -8.3 to -2.9‰ (average of -6.7±1.0‰) and -1.8 to 12.8‰ (average of 3.6 ±3.4‰) respectively, while calcite d13C and d18O values range from -9.0 to …


Resonance Of Relativistic Electrons With Electromagnetic Ion Cyclotron Waves, Richard Denton, K. Jordanova, J. Bortnik Jun 2015

Resonance Of Relativistic Electrons With Electromagnetic Ion Cyclotron Waves, Richard Denton, K. Jordanova, J. Bortnik

Dartmouth Scholarship

Relativistic electrons have been thought to more easily resonate with electromagnetic ion cyclotron (EMIC) waves if the total density is large. We show that, for a particular EMIC mode, this dependence is weak due to the dependence of the wave frequency and wave vector on the density. A significant increase in relativistic electron minimum resonant energy might occur for the H band EMIC mode only for small density, but no changes in parameters significantly decrease the minimum resonant energy from a nominal value. The minimum resonant energy depends most strongly on the thermal velocity associated with the field line motion …


Laser Vision: Lidar As A Transformative Tool To Advance Critical Zone Science, N. F. Glenn Jun 2015

Laser Vision: Lidar As A Transformative Tool To Advance Critical Zone Science, N. F. Glenn

Geosciences Faculty Publications and Presentations

Observation and quantification of the Earth’s surface is undergoing a revolutionary change due to the increased spatial resolution and extent afforded by light detection and ranging (lidar) technology. As a consequence, lidar-derived information has led to fundamental discoveries within the individual disciplines of geomorphology, hydrology, and ecology. These disciplines form the cornerstones of critical zone (CZ) science, where researchers study how interactions among the geosphere, hydrosphere, and biosphere shape and maintain the “zone of life”, which extends from the top of unweathered bedrock to the top of the vegetation canopy. Fundamental to CZ science is the development of transdisciplinary theories …