Geophysics and Seismology Commons^™

One-Dimensional Weakly Nonlinear Model Equations For Rossby Waves, David Henry, Rossen Ivanov

Articles

In this study we explore several possibilities for modelling weakly nonlinear Rossby waves in fluid of constant depth, which propagate predominantly in one direction. The model equations obtained include the BBM equation, as well as the integrable KdV and Degasperis-Procesi equations.

Independent Evaluation Of The Snodas Snow Depth Product Using Regional Scale Lidar-Derived Measurements, A. R. Hedrick, H. P. Marshall, A. Winstral, K. Elder, S. Yueh, D. Cline

Geosciences Faculty Publications and Presentations

Repeated Light Detection and Ranging (LiDAR) surveys are quickly becoming the de facto method for measuring spatial variability of montane snowpacks at high resolution. This study examines the potential of a 750 km² LiDAR-derived dataset of snow depths, collected during the 2007 northern Colorado Cold Lands Processes Experiment (CLPX-2), as a validation source for an operational hydrologic snow model. The SNOw Data Assimilation System (SNODAS) model framework, operated by the US National Weather Service, combines a physically-based energy-and-mass-balance snow model with satellite, airborne and automated ground-based observations to provide daily estimates of snowpack properties at nominally 1 km resolution …

U-Pb Zircon Geochronology Of Roxbury Conglomerate, Boston Basin, Massachusetts: Tectono-Stratigraphic Implications For Avalonia In And Beyond Se New England, Margaret D. Thompson, Jahandar Ramezani, James L. Crowley

Geosciences Faculty Publications and Presentations

High-precision CA-TIMS ²⁰⁶Pb/²³⁸U zircon dates from sandstone and Brighton igneous rocks associated with Roxbury Conglomerate in the Boston Basin, eastern Massachusetts provide constraints on the age and tectonic significance of these deposits. Detrital zircon suites from Roxbury-related sandstones representing, in ascending order, the Franklin Park Member (proposed name), the Brookline Member and the Squantum Member establish closely comparable maximum depositional ages of 595.14 ± 0.90, 598.87 ± 0.71 and 596.39 ± 0.79 Ma, respectively. The youngest of these is the best maximum age estimate of the conglomerate. Brighton dacite near the base of the Brookline Member and …

Induced Seismicity Of Central Arkansas, Najah Abd

Theses and Dissertations

Enola area is known to generate swarms of earthquakes that are clustered in space and time. The remarkable swarm of the early 80s generated thousands of earthquakes many of them were felt by people lived in the area. More recently, a magnitude 4.4 earthquake took place on May 4, 2001 in the area which was followed by thousands of recorded earthquakes. The main shock was felt widely in the region including the city of Little Rock. On February 27, 2011, North Central Arkansas area was shaken by an earthquake of magnitude 4.7. This earthquake was the biggest to be registered …

Upper Mantle Seismic Anisotropy Beneath The West Antarctic Rift System And Surrounding Region From Shear Wave Splitting Analysis, Natalie J. Accardo, Douglas A. Wiens, Stephen Hernandez, Richard C. Aster, Andrew Nyblade, Audrey D. Huerta, Sridhar Anandakrisnan, Terry Wilson, David S. Heeszel, Ian W.D. Dalziel

Geological Sciences Faculty Scholarship

We constrain azimuthal anisotropy in the West Antarctic upper mantle using shear wave splitting parameters obtained from teleseismic SKS, SKKS and PKS phases recorded at 37 broad-band seismometres deployed by the POLENET/ANET project. We use an eigenvalue technique to linearize the rotated and shifted shear wave horizontal particle motions and determine the fast direction and delay time for each arrival. High-quality measurements are stacked to determine the best fitting splitting parameters for each station. Overall, fast anisotropic directions are oriented at large angles to the direction of Antarctic absolute plate motion in both hotspot and no-net-rotation frameworks, showing that the …

An Analysis Of The Green Knoll Salt Dome, Located In The Southeast Green Canyon, Deep Water Gulf Of Mexico, Randal J. Broussard

LSU New Orleans Theses and Dissertations

The western portion of the Mississippi/Atwater fold belt in the Gulf of Mexico contains what is known as The Green Knoll Salt Dome. The creation and growth of this salt diapir is punctuated by salt deposition, salt migration, sediment loading, and is linked to the “Frampton” fold belt. An indicator of these growth periods is exhibited in an angular unconformity (halo-kinetic sequence boundary) that flanks the diapir. This unconformity developed during the Miocene-Pliocene chronostratigraphic boundary. The “Redwood” (Green Canyon 1001) prospect was drilled after the discovery of middle Miocene sands containing hydrocarbons in the Mad Dog field (GC 826). The …

Fault Coupling And Potential For Earthquakes On The Creeping Section Of The Central San Andreas Fault, Jeremy Maurer, Kaj Johnson

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The 150 km long central section of the San Andreas Fault (CSAF) in central California creeps at the surface and has not produced a large earthquake historically. However, sections of the San Andreas Fault to the north and south are known to have ruptured repeatedly in M~7-8 earthquakes. It is currently unclear whether the creeping CSAF could rupture in large earthquakes, either individually or along with earthquakes on the locked sections to the north and south. We invert Global Positioning System and interferometric synthetic aperture radar data with elastic block models to estimate the degree of locking on the CSAF …

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 …

Finite Difference Modeling Of Surface-~Wave Scattering For Shallow Cavity Detection, Heston Travis Norcott

UNLV Theses, Dissertations, Professional Papers, and Capstones

Data collection and analysis of scattering of Rayleigh-type surface waves are investigated for locating shallowly buried cavities. Surface-based seismic experiments conducted by others at the University of Nevada, Las Vegas (UNLV) Engineering Geophysics Test Site (EGTS) demonstrate scattering of Rayleigh waves caused by buried empty barrels (essentially air-filled cavities). The interpretation of the data is complicated by factors such as the presence of a high-velocity geologic layer just below the cavity.

This research uses a finite-difference seismic wave propagation code to compute time histories for a model that represents the Engineering Geophysics Test Site. By adding cavities to a background …

Mechanical Stratigraphy Of The Mississippian In Osage County, Oklahoma, Caleb James Jennings

Graduate Theses and Dissertations

The Mississippian formation of Oklahoma and Kansas has recently developed as a world class unconventional reservoir with wells producing up to 800 bbl/day. The Mississippian is composed of multiple distinct lithologic zones including limestone, hard chert, and soft tripolitic chert. These zones are difficult to discern with traditional log correlation, but mechanical stratigraphy has the potential to improve previous correlations of the Mississippian.

This study uses full wave sonic logs from Osage County, OK to analyze the elastic properties of the Mississippian. Our work computes isotropic elastic parameters in an effort to partition the Mississippian section into units that may …

3d Seismic Mapping Of Probable Tripolitic Chert Bodies In Osage County, Oklahoma, Richard Craddock Benson

Graduate Theses and Dissertations

The Mississippi Lime play is an important recent oil and gas development in the mid-continent of the United States. In April of 2007, Chesapeake Energy Corporation used horizontal drilling and tracing to bring the Howell 1-33H well online. This well revitalized the Mississippi Lime play, expanding exploration with potential Mississippian reservoirs.

The Mississippian section is a complex carbonate reservoir containing several distinct lithologies. An important Mississippian lithology known from outcrops in Arkansas and Missouri is tripolitic chert, or tripolite; a bleach, highly diagenetically altered, silica rock with high porosity, low density, and high permeability. Tripolite is an important reservoir target …

Using Seismic Reflection To Locate A Tracer Testing Complex South Of Yucca Mountain, Nye County, Nevada, Levi Kryder

UNLV Theses, Dissertations, Professional Papers, and Capstones

Tracer testing in the fractured volcanic aquifer near Yucca Mountain, and in the alluvial aquifer south of Yucca Mountain, Nevada has been conducted in the past to determine the flow and transport properties of groundwater in those geologic units. However, no tracer testing has been conducted across the alluvium/volcanic interface. This thesis documents the investigative process and subsequent analysis and interpretations used to identify a location suitable for installation of a tracer testing complex, near existing Nye County wells south of Yucca Mountain.

The work involved evaluation of existing geologic data, collection of wellbore seismic data, and a detailed surface …

Soil, Snow, Weather, And Sub-Surface Storage Data From A Mountain Catchment In The Rain–Snow Transition Zone, P. R. Kormos, D. Marks, C. J. Williams, H. P. Marshall, Pam Aishlin, D. G. Chandler, James P. Mcnamara

Geosciences Faculty Publications and Presentations

A comprehensive hydroclimatic data set is presented for the 2011 water year to improve understanding of hydrologic processes in the rain-snow transition zone. This type of dataset is extremely rare in scientific literature because of the quality and quantity of soil depth, soil texture, soil moisture, and soil temperature data. Standard meteorological and snow cover data for the entire 2011 water year are included, which include several rain-on-snow events. Surface soil textures and soil depths from 57 points are presented as well as soil texture profiles from 14 points. Meteorological data include continuous hourly shielded, unshielded, and wind corrected precipitation, …

Computer Model Inversion And Uncertainty Quantification In The Geosciences, Jeremy White

USF Tampa Graduate Theses and Dissertations

The subject of this dissertation is use of computer models as data analysis tools in several different geoscience settings, including integrated surface water/groundwater modeling, tephra fallout modeling, geophysical inversion, and hydrothermal groundwater modeling. The dissertation is organized into three chapters, which correspond to three individual publication manuscripts.

In the first chapter, a linear framework is developed to identify and estimate the potential predictive consequences of using a simple computer model as a data analysis tool. The framework is applied to a complex integrated surface-water/groundwater numerical model with thousands of parameters. Several types of predictions are evaluated, including particle travel time …

Data Processing For Oscillatory Pumping Tests, Tania Bakhos, Michael Cardiff, Warren Barrash, Peter K. Kitanidis

CGISS Publications and Presentations

Characterizing the subsurface is important for many hydrogeologic projects such as site remediation and groundwater resource exploration. Methods based on the analysis of conventional pumping tests have the notable disadvantage that at a certain distance, the signal is small relative to the noise due to the effects of recharge, pumping in neighboring wells, change in the level or adjacent streams, and other common disturbances. This work focuses on oscillatory pumping tests in which fluid is extracted for half a period, then reinjected. We discuss a major advantage of oscillatory pumping tests: small amplitude signals can be recovered from noisy data …

A Combined Field And Numerical Approach To Understanding Dilute Pyroclastic Density Current Dynamics And Hazard Potential: Auckland Volcanic Field, New Zealand, Brittany D. Brand, Darren Gravley, Amanda Clarke, Jan Lindsay, Simon H. Boomberg, Javier Agustin-Flores, Károly Németh

Geosciences Faculty Publications and Presentations

The most dangerous and deadly hazards associated with phreatomagmatic eruption in the Auckland Volcanic Field (AVF; Auckland, New Zealand) are those related to volcanic base surges - dilute, ground-hugging, particle laden currents with dynamic pressures capable of severe to complete structural damage. We use the well-exposed base surge deposits of the Maungataketake tuff ring, (Manukau coast, Auckland) to reconstruct flow dynamics and destructive potential of base surges produced during the eruption. The initial base surge(s) snapped trees up to 0.5 m in diameter near their base as far as 0.7-0.9 km from the vent. Beyond this distance the trees were …

Dynamics Of Pyroclastic Density Currents: Conditions That Promote Substrate Erosion And Self-Channelization - Mount St Helens, Washington (Usa), Brittany D. Brand, Chelsea Mackaman-Lofland, Nicholas M. Pollock, Sylvana Bendaña, Blaine Dawson, Pamela Wichgers

Geosciences Faculty Publications and Presentations

The May 18th, 1980 eruption of Mount St. Helens (MSH) produced multiple pyroclastic density currents (PDCs), burying the area north of the volcano under 10s of meters of deposits. Detailed measurements of recently exposed strata from these PDCs provide substantial insight into the dynamics of concentrated currents including inferences on particle-particle interactions, current mobility due to sedimentation fluidization and internal pore pressure, particle support mechanisms, the influence of surface roughness and the conditions that promote substrate erosion and self-channelization. Four primary flow units are identified along the extensive drainage system north of the volcano. Each flow unit has intricate vertical …

Sequential Fragmentation / Transport Theory, Pyroclast Size-Density Relationships, And The Emplacement Dynamics Of Pyroclastic Density Currents – A Case Study On The Mt. St. Helens (Usa) 1980 Eruption, Chelsea Mackaman-Lofland, Brittany D. Brand, Jacopo Taddeucci, Kenneth Wohletz

Geosciences Faculty Publications and Presentations

Pyroclastic density currents (PDCs) are the most dangerous hazard associated with explosive volcanic eruptions. Despite recent advancements in the general understanding of PDC dynamics, limited direct observation and/or outcrop scarcity often hinder the interpretation of specific transport and depositional processes at many volcanoes. This study explores the potential of sequential fragmentation / transport theory (SFT; cf. Wohletz et al. 1989), a modeling method capable of predicting particle mass distributions based on the physical principles of fragmentation and transport, to retrieve the transport and depositional dynamics of well-characterized PDCs from the size and density distributions of individual components within the deposits. …

On The Amount Of Sediment Deposited In Floodplains From The Mississippi River: A Case Study In Cat Island National Wildlife Refuge, Louisiana, Matthew Smith

Honors Capstones

No abstract provided.

Lunar Cold Spots: Granular Flow Features And Extensive Insulating Materials Surrounding Young Craters, Joshua L. Bandfield, Eugenie Song, Paul O. Hayne, Brittany D. Brand, Rebecca R. Ghent, Ashwin R. Vasavada, David A. Paige

Geosciences Faculty Publications and Presentations

Systematic temperature mapping and high resolution images reveal a previously unrecognized class of small, fresh lunar craters. These craters are distinguished by near-crater deposits with evidence for lateral, ground-hugging transport. More distal, highly insulating surfaces surround these craters and do not show evidence of either significant deposition of new material or erosion of the substrate. The near-crater deposits can be explained by a laterally propagating granular flow created by impact in the lunar vacuum environment. Further from the source crater, at distances of ~10-100 crater radii, the upper few to 10s of centimeters of regolith appear to have been “fluffed-up” …

Detection Of An Ultra Low Velocity Zone Beneath Central Mexico With Pcp Waveform Modeling, David James Buckley

Physics

PcP phases from a Guatemalan earthquake recorded at Nevada stations of the International seismic network (IM) display evidence of anomalous seismic structure at the core-mantle boundary (CMB); in particular, pre- and post-cursor phases to PcP and ScP. The data is examined for evidence of an ultra-low velocity zone (ULVZ) by identifying and modeling precursors to PcP. Precursory arrivals to PcP may be generated by the interaction of PcP with a thin layer above the core-mantle boundary (CMB). One-dimensional modeling demonstrates that standard earth models of the core-mantle boundary, which lack ULVZ structure, cannot produce the observed PcP data. …

Geology – Future Continent, Joy Wulke

The Transdisciplinary STEAM+ Journal

Terra Mirabila, a multi-media presentation illustrating the geological story of Stony Creek Granite back through complex sequence of geological events that spanned some 600 million years of early history.

Session F-4: Modeling An Earthquake In Your Classroom, Brian Grublesky

Professional Learning Day

Teachers will model earthquakes using both technology and hands-on inquiry activities. Teachers will have a chance to engineer an “earthquake proof” building and use the engineering process to test and redesign their buildings before being tested on a shake table. We will also discuss how these activities connect not only to the Next Generation Science Standards, but the Common Core State Standards as well.

Slides: Thoughts On Regulatory Mechanisms For Natural Resource Development: Alternatives To Command And Control, Including A Look At Open Source Approaches, Stanley Dempsey

Natural Resource Industries and the Sustainability Challenge (Martz Winter Symposium, February 27-28)

Presenter: Stanley Dempsey, Chairman, Royal Gold

17 slides

Analyst A: Alternatives In Analysis Of The Utexas1 Surface Wave Dataset, Paul Michaels

Geosciences Faculty Publications and Presentations

In February of 2011 an earthquake event caused significant damage and loss of life in Christchurch, New Zealand. Such an event serves as motivation for improved foundation design and characterization of the shallow subsurface. In January of 2013, University of Texas engineers acquired surface wave data which has been made available to the ASCE GeoInstitute Geophysical Engineering Committee for a benchmark project. Participants were invited to process and interpret the common data set. This paper reports the results designated as those of "Analyst A". The active vibroseis and sledgehammer data were combined to produce a composite Rayleigh wave dispersion curve. …

Seismic And Geodetic Evidence For Grounding-Line Control Of Whillans Ice Stream Stick-Slip Events, Martin J. Pratt, J. Paul Winberry, Douglas A. Wiens, Sridhar Anandakrishnan, Richard B. Alley

All Faculty Scholarship for the College of the Sciences

The tidally modulated, stick‐slip events of Whillans Ice Stream in West Antarctica produce seismic energy from three locations near the grounding line. Using ice velocity records obtained by combining time series from colocated broadband seismometers and GPS receivers installed on the ice stream during the 2010–2011 and 2011–2012 austral summers, along with far‐field seismic recordings of elastic waves, we locate regions of high rupture velocity and stress drop. These regions, which are analogous to “asperities” in traditional seismic fault studies, are areas of elevated friction at the base of the ice stream. Slip events consistently initiate at one of two …

Climate- And Eustasy-Driven Cyclicity In Pennsylvanian Fusulinid Assemblages, Donets Basin (Ukraine), Rimma R. Khodjanyazova, Vladimir I. Davydov, Isabel P. Montañez, Mark D. Schmitz

Geosciences Faculty Publications and Presentations

A model of cyclic recurrence (~ 0.6–1.2 myr) of three fusulinid assemblages in the Middle Pennsylvanian siliciclastic–carbonate succession of the Donets Basin is proposed. Each cycle records progressive turnover of assemblages in shallow marine environments in response to sea-level and regional climate change. A Hemifusulina-assemblage (A), adapted to cooler and reduced salinity seawater records the onset of sea level rise accompanied by humid climatic conditions. Sea level high stand is captured by the Beedeina–Neostaffella–Ozawainella–Taitzehoella (or Beedeina-dominated) assemblage (B), characteristic of relatively deeper-water environments. The B assemblage is successively replaced by the most …

Application Of A Hillslope-Scale Soil Moisture Data Assimilation System To Military Trafficability Assessment, Alejandro N. Flores, Dara Entekhabi, Rafael L. Bras

Geosciences Faculty Publications and Presentations

Soil moisture is an important environmental variable that impacts military operations and weapons systems. Accurate and timely forecasts of soil moisture at appropriate spatial scales, therefore, are important for mission planning. We present an application of a soil moisture data assimilation system to military trafficability assessment. The data assimilation system combines hillslope-scale (e.g., 10s to 100s of m) estimates of soil moisture from a hydrologic model with synthetic L-band microwave radar observations broadly consistent with the planned NASA Soil Moisture Active–Passive (SMAP) mission. Soil moisture outputs from the data assimilation system are input to a simple index-based model for vehicle …

Assessing Ability To Forecast Geomorphic System Responses To Climate And Land-Use Changes, Jon D. Pelletier, A. Brad Murray, Jennifer L. Pierce

Geosciences Faculty Publications and Presentations

As the global community faces the effects of ongoing and future climate and land-use changes (C&LUC), geoscientists are called to action to assess the risks associated with such changes, assist with forecasts of future Earth states, quantify hazards to life, and suggest reasonable adaptation strategies. Earth surface scientists have developed conceptual and mathematical models for how geomorphic systems, including those associated with natural hazards that put trillions of dollars in infrastructure and tens of millions of lives at risk, will respond to and give feedback on C&LUC.