Imaging The Subsurface: The Effect Of Logjams On Groundwater-Surface Water Exchange, 2018 Georgia State University
Imaging The Subsurface: The Effect Of Logjams On Groundwater-Surface Water Exchange, Teodora Mitroi, Megan Doughty, Jackie Randall, Kamini Singha
Georgia Undergraduate Research Conference (GURC)
Conventional methods of quantifying subsurface interactions in streams are often insufficient in characterizing hydrological processes and demand better techniques to measure complex dynamics. Point-measurements are incomplete and do not provide direct data on hyporheic exchange, a mixing of surface and subsurface water under and around a stream capable of influencing ecosystem processes. Fortunately, geophysical techniques can improve analysis of the hyporheic zone. For the first time in a field setting, we apply electrical resistivity imaging (ERI) to a mountainous stream below a channel-spanning logjam to estimate the extent of hyporheic exchange. Previous studies suggest logjams increase hydraulic resistance and drive ...
Postseismic Restoration Of The Ecological Environment In The Wenchuan Region Using Satellite Data, 2018 Chinese Academy of Sciences
Postseismic Restoration Of The Ecological Environment In The Wenchuan Region Using Satellite Data, Zhibin Huang, Min Xu, Wei Chen, Xiaojuan Lin, Chunxiang Cao, Ramesh Singh
Mathematics, Physics, and Computer Science Faculty Articles and Research
Using Landsat remote-sensing data combined with geological information extracted from ALOS and Sentinel-1A radar data, the ecological environment was evaluated in the years 2007, 2008, 2013, and 2017 through gray correlation analysis on the basis of the construction of the pressure-state-response model. The main objective of this research was to assess the ecological environment changes in Wenchuan County before and after the earthquake, and to provide reference for future social development and policy implementation. The grading map of the ecological environment was obtained for every year, and the ecological restoration status of Wenchuan County after the earthquake was evaluated. The ...
The Cyrilka Cave—The Longest Crevice-Type Cave In Czechia: Structural Controls, Genesis And Age, 2018 University of Ostrava
The Cyrilka Cave—The Longest Crevice-Type Cave In Czechia: Structural Controls, Genesis And Age, Jan Lenart, Martin Kašing, Petr Tábořík, Natalia Piotrowska, Jacek Pawlyta
International Journal of Speleology
The Cyrilka Cave is the second longest pseudokarst cave and the longest crevice-type cave in Czechia. Developed within the headscarp area of a deep-seated landslide, the cave became a focus of scientific research in recent years when new passages were discovered. Structural analysis provided a general tectonic plan of the cave, as well as more detailed data on geometry and kinematics of the relaxed rock massif. The primary structure of NNE- to ENE-striking bedding is broken by a system of NNE-striking fissures interconnected by two continuous ENE-striking dextral fracture zones. Abundant signs of recent sinistral strike-slips within the rock massif ...
Climate Change And Curtailment: Evaluating Water Management Practices In The Context Of Changing Runoff Regimes In A Snowmelt-Dominated Basin, Amy L. Steimke, Bangshuai Han, Jodi S. Brandt, Alejandro N. Flores
Geosciences Faculty Publications and Presentations
Hydrologic scientists and water resource managers often focus on different facets of flow regimes in changing climates. The objective of this work is to examine potential hydrological changes in the Upper Boise River Basin, Idaho, USA in the context of biophysical variables and their impacts a key variable governing administration of water resources in the region in an integrated way. This snowmelt-dominated, mountainous watershed supplies water to a semi-arid, agriculturally intensive, but rapidly urbanizing, region. Using the Envision integrated modeling framework, we created a hydrological model to simulate hydrological response to the year 2100 using six alternative future climate trajectories ...
Gps Constraints On Deformation In Northern Central America From 1999 To 2017, Part 1 – Time-Dependent Modelling Of Large Regional Earthquakes And Their Post-Seismic Effects, 2018 University of Wisconsin-Madison
Gps Constraints On Deformation In Northern Central America From 1999 To 2017, Part 1 – Time-Dependent Modelling Of Large Regional Earthquakes And Their Post-Seismic Effects, A. Ellis, Charles Demets, P. Briole, Beatriz Cosenza, Omar Flores, Shannon Graham, Marco Guzm´An-Speziale, Douglas Hernandez, Vladimir Kostoglodov, Peter Lafemina, Neal Lord, C´Ecile Lasserre, H´El`Ene Lyon-Caen, Manuel Rodriguez Maradiaga, Robert Mccaffrey, Enrique Molina, Jeffrey Rivera, Robert Rogers, Alejandra Staller
Geology Faculty Publications and Presentations
We use continuous and campaign measurements from 215 GPS sites in northern Central America and southern Mexico to estimate coseismic and afterslip solutions for the 2009 Mw = 7.3 Swan Islands fault strike-slip earthquake and the 2012 Mw = 7.3 El Salvador and Mw = 7.4 Guatemala thrust-faulting earthquakes on the Middle America trench. Our simultaneous, time-dependent inversion of more than 350 000 daily GPS site positions gives the first jointly consistent estimates of the coseismic slips for all three earthquakes, their combined time-dependent post-seismic effects and secular station velocities corrected for both the coseismic and post-seismic deformation. Our geodetic ...
Revelation Of Early Detection Of Coseismic Ionospheric Perturbations In Gps-Tec From Realistic Modelling Approach: Case Study, 2018 Indian Institute of Geomagnetism
Revelation Of Early Detection Of Coseismic Ionospheric Perturbations In Gps-Tec From Realistic Modelling Approach: Case Study, Dhanya Thomas, Mala S. Bagiya, Poikayil Sukumaran Sunil, Lucie Rolland, Anakuzhikkal Sudarsanan Sunil, T. Dylan Mikesell, Srinivas Nayak, Subrahmanyam Mangalampalli, Durbha Sai Ramesh
CGISS Publications and Presentations
GPS-derived Total Electron Content (TEC) is an integrated quantity; hence it is difficult to relate the detection of ionospheric perturbations in TEC to a precise altitude. As TEC is weighted by the maximum ionospheric density, the corresponding altitude (hmF2) is, generally, assumed as the perturbation detection altitude. To investigate the validity of this assumption in detail, we conduct an accurate analysis of the GPS-TEC measured early ionospheric signatures related to the vertical surface displacement of the Mw 7.4 Sanriku-Oki earthquake (Sanriku-Oki Tohoku foreshock). Using 3D acoustic ray tracing model to describe the evolution of the propagating seismo-acoustic wave in ...
Impact Craters On Titan: Finalizing Titan's Crater Population, 2018 The University of Western Ontario
Impact Craters On Titan: Finalizing Titan's Crater Population, Joshua E. Hedgepeth
Electronic Thesis and Dissertation Repository
Titan is one of the most dynamic moons in the solar system. It is smaller than Earth and much colder, yet Titan is eerily similar to Earth, with rivers, rain, and seas, as well as sand seas that wrap around the equator. However, the rivers are made of hydrocarbons rather than water and the sand made of organics rather rock. We can use Titan’s impact craters to study how these processes modify the surface by comparing the craters depths, diameters and rim heights of Titan’s craters with fresh craters. Therefore, we have used the complete data set from ...
Mapping Lower Austin Chalk Secondary Porosity Using Modern 3-D Seismic And Well Log Methods In Zavala County, Texas, 2018 University of Arkansas, Fayetteville
Mapping Lower Austin Chalk Secondary Porosity Using Modern 3-D Seismic And Well Log Methods In Zavala County, Texas, David Kilcoyne
Theses and Dissertations
Establishing fracture distribution and porosity trends is key to successful well design in a majority of unconventional plays. The Austin Chalk has historically been referred to as an unpredictable producer due to high fracture concentration and lateral variation in stratigraphy, however recent drilling activity targeting the lower Austin Chalk has been very successful. The Upper Cretaceous Austin Chalk (AC) and underlying Eagle Ford (EF) units are considered by many to act as a single hydrocarbon system, with communication between these two units largely through expulsion or dewatering fractures, extensional faults or along the AC/EF unconformity. Total porosity for the ...
Seismic Facies Mapping For Source Rock Distribution Of The Rakopi Formation In Deep-Water Taranaki Basin, New Zealand, 2018 University of Arkansas, Fayetteville
Seismic Facies Mapping For Source Rock Distribution Of The Rakopi Formation In Deep-Water Taranaki Basin, New Zealand, Sidney W. Mahanay
Theses and Dissertations
The Taranaki Basin is located off the coast of the north island of New Zealand and is currently the only producing basin in New Zealand. Hydrocarbon accumulation in the Tui, Maari, and Maui fields is sourced to the Late Cretaceous and Paleogene units. Exploration of these units has extended from the continental shelf of the Taranaki Basin into the deep-water to the northwest. The Romney 3D survey and Romney–1 well are some the first public exploration projects to supply data from this area. The objective of this study is to estimate source rock quality and distribution of the Rakopi ...
Fault-Adjacent Damage At The Base Of The Seismogenic Zone And Seismic Anisotropy Of Fold Structures, 2018 University of Maine
Fault-Adjacent Damage At The Base Of The Seismogenic Zone And Seismic Anisotropy Of Fold Structures, Won Joon Song
Electronic Theses and Dissertations
While earthquakes represent a major hazard to life and property, there are a number of open questions about how earthquake faults operate at depth, and how the energy released by earthquakes travels as elastic waves through Earth’s complexly deformed crustal rocks. The aims of my dissertation are to explore (a) the extent of co-seismic damage in an ancient earthquake fault exhumed from great depths, (b) the deformation processes and mechanics of the fault at depth during earthquake cycles, and (c) the role of different rock structures in determining the velocities of seismic waves.
When tectonic plates collide, deformation tends ...
The Geotraces Intermediate Data Product 2017, 2018 Old Dominion University
The Geotraces Intermediate Data Product 2017, Reiner Schlitzer, Robert F. Anderson, Elena Masferrer Dodas, Maeve Lohan, Walter Geibert, Alessandro Tagliabue, Andrew Bowie, Gregory A. Cutter, Peter N. Sedwick, Bettina Sohst
OEAS Faculty Publications
The GEOTRACES Intermediate Data Product 2017 (IDP2017) is the second publicly available data product of the international GEOTRACES programme, and contains data measured and quality controlled before the end of 2016. The IDP2017 includes data from the Atlantic, Pacific, Arctic, Southern and Indian oceans, with about twice the data volume of the previous IDP2014. For the first time, the IDP2017 contains data for a large suite of biogeochemical parameters as well as aerosol and rain data characterising atmospheric trace element and isotope (TEI) sources. The TEI data in the IDP2017 are quality controlled by careful assessment of intercalibration results and ...
Geomechanical Modelling Of Induced Seismicity, 2018 The University of Western Ontario
Geomechanical Modelling Of Induced Seismicity, Bodi Zhao
Electronic Thesis and Dissertation Repository
In recent years, there has been a dramatic increase in seismicity (earthquakes) due to anthropogenic activities related to the unconventional oil and gas exploration in the Western Canada Sedimentary Basin (WCSB) and the central U.S. There are compelling evidences that hydraulic fracturing and wastewater injection operations in those areas play a key role in induced seismicity. To better understand the physical mechanisms involved, this thesis aims to explore the mechanisms responsible for occurrence of induced earthquakes: mainshock-aftershock triggering mechanism and poroelastic response. In the first approach, the obtained results indicate the relationship between the Coulomb stress changes after 4 ...
Hardbottom Characterization And Relationship To The Geologic Framework In Long Bay, South Carolina, 2018 Coastal Carolina University
Hardbottom Characterization And Relationship To The Geologic Framework In Long Bay, South Carolina, Cathryn J. Wheaton
Electronic Theses and Dissertations
Hardbottom seafloor is a common element among sediment-starved portions of the inner continental shelf along the U.S. Atlantic margin. These areas are characterized by indurated sediment surfaces that are heavily altered by biological and physical processes. Long Bay, in northeastern South Carolina, offers ideal environmental conditions for hardbottom exposure with only patchy Holocene sand deposits, interspersed with extensive hardbottom areas. Here we use high-resolution multibeam bathymetry, CHIRP subbottom profiling and electrical resistivity data, along with surficial sediment samples, hardbottom thin sections, and water column radioisotope (radon-222) analysis to investigate the origin and geologic framework of a region of hardbottom ...
Numerical Investigation Of Strength-Reducing Mechanisms Of Mantle Rock During The Genesis Flood, 2018 Center for Advanced Vehicular Systems, Mississippi State University
Numerical Investigation Of Strength-Reducing Mechanisms Of Mantle Rock During The Genesis Flood, Noah Cho, John Baumgardner, Jesse Sherburn, Mark Horstemeyer
The Proceedings of the International Conference on Creationism
This paper reports our efforts to model the effects of grain size, recrystallization, creep, and texture on overall rock strength within the Earth’s mantle during the Genesis Flood. Our study uses experimental rheological data obtained from the mineralogical literature for olivine, which is an important mantle mineral. We apply an Internal State Variable (ISV) constitutive model within the framework of the TERRA finite element code to capture the subscale structures and their associated dynamics, strength, and viscosity effects during the Flood episode. Our numerical investigations, in both 2D and 3D, that include the improved deformation model reveal even more ...
Dense-Array Teleseismic Imaging Of The Southern Albuquerque Basin, 2018 University of New Mexico
Dense-Array Teleseismic Imaging Of The Southern Albuquerque Basin, Tori S. Finlay
Earth and Planetary Sciences ETDs
The southern Albuquerque basin is a complex area of high extension, multiple orogenies, and ongoing uplift from a midcrustal magma body in which geophysical coverage is sparse. In this thesis, I capitalize on recent innovations in dense-array processing techniques to create virtual source reflection profiles from five teleseismic events during the deployment of the Sevilleta array. The Sevilleta array consisted of ~800 vertical component nodes with ~300 m spacing deployed for 10 days in February of 2015. Virtual source reflection profiles are created by using the free surface of the earth as a virtual seismic source, yielding profiles that mimic ...
Review Of Curbing Catastrophe: Natural Hazards And Risk Reduction In The Modern World, 2018 Pennsylvania State University, Mont Alto
Review Of Curbing Catastrophe: Natural Hazards And Risk Reduction In The Modern World, Kira H. Hamman
Timothy H. Dixon. 2017. Curbing Catastrophe: Natural Hazards and Risk Reduction in the Modern World. (New York, NY: Cambridge University Press) 300 pp. ISBN 978-1108113663.
In Curbing Catastrophe, Timothy H. Dixon explores commonalities among natural disasters like Hurricane Katrina, the 2010 earthquake in Haiti, and the meltdown at Fukushima. He identifies communication failure between scientists and policy makers as a major culprit in the devastation that results from such events and offers strategies for improving that communication. He includes optional in-depth scientific and quantitative examinations of the events and the resulting devastation, making the book appropriate for use in teaching ...
Eleven Years Of Mountain Weather, Snow, Soil Moisture And Streamflow Data From The Rain–Snow Transition Zone – The Johnston Draw Catchment, Reynolds Creek Experimental Watershed And Critical Zone Observatory, Usa, 2018 Boise State University
Eleven Years Of Mountain Weather, Snow, Soil Moisture And Streamflow Data From The Rain–Snow Transition Zone – The Johnston Draw Catchment, Reynolds Creek Experimental Watershed And Critical Zone Observatory, Usa, James P. Mcnamara
Geosciences Faculty Publications and Presentations
Detailed hydrometeorological data from the rain-to-snow transition zone in mountain regions are limited. As the climate warms, the transition from rain to snow is moving to higher elevations, and these changes are altering the timing of downslope water delivery. To understand how these changes impact hydrological and biological processes in this climatologically sensitive region, detailed observations from the rain-to-snow transition zone are required. We present a complete hydrometeorological dataset for water years 2004 through 2014 for a watershed that spans the rain-to-snow transition zone (https://doi.org/10.15482/usda.adc/1402076). The Johnston Draw watershed (1.8km2), ranging ...
Integrated Geophysical Methods To Characterize Subsidence In Butte, Montana, U.S.A., Kristen Prudhomme
Graduate Theses & Non-Theses
Geophysical investigations, designed to characterize unique subsidence features of unknown natural origin, provide imaging analysis of potential causes of subsidence. Recent subsidence in the alluvial plain in Butte, Montana is unrelated to historic mining in the area. This study aims to utilize a combined application of shallow electrical resistivity tomography (ERT), self-potential (SP), and frequency-domain electromagnetic (FDEM) methods in order to develop a better understanding of the particular set of hydrogeological and environmental conditions that contribute to this unique phenomena. Geophysical measurements provide lateral and vertical variations of electrical resistivity in the subsurface to a depth of 10 m while ...
Integrated Geophysical Analysis In The Northeastern Gulf Of Mexico, 2018 University of Nebraska-Lincoln
Integrated Geophysical Analysis In The Northeastern Gulf Of Mexico, Mei Liu
Dissertations & Theses in Earth and Atmospheric Sciences
The formation of the Gulf of Mexico (GoM) relates to the breakup of Pangea and opening of the central Atlantic Ocean. The tectonic history of the basin is still being debated due to lack of geological constraints. This project addresses the crustal architecture in the northeastern GoM from integrative analysis of multiple geophysical datasets to provide constraints for the tectonic reconstruction.
The objectives of this study are: 1) to delineate various tectonic zones (continental and oceanic domains) and map the boundary between them, 2) to derive physical properties of the subsurface rocks, 3) to map the major tectonic structures in ...
Infrasound Tornillos Produced By Volcán Cotopaxi’S Deep Crater, 2018 Boise State University
Infrasound Tornillos Produced By Volcán Cotopaxi’S Deep Crater, J. B. Johnson, M. C. Ruiz, H. D. Ortiz, L. M. Watson, G. Viracucha, P. Ramon, M. Almeida
CGISS Publications and Presentations
We characterize and interpret a new type of infrasound signal originating from the summit of Volcán Cotopaxi (Ecuador) that was primarily observed between September 2015 and March 2016, following the 2015 eruptive period. This infrasound waveform is a slowly decaying sinusoid with exceptional low-frequency (fp = 0.2 Hz) and high quality factor (Q = ~10) and resembles the shape of tornillo seismic waveforms. The repeating events, occurring about once per day in early 2016, are stable in frequency content, and we attribute them to excitation of a vertical-walled crater, with radius of about 125mand length of 300 m. Spectral properties ...