Geophysics and Seismology Commons^™

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

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

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 …

Comparing Flow-Through And Static Ice Cave Models For Shoshone Ice Cave, Kaj E. Williams, Christopher Mckay

International Journal of Speleology

In this paper we suggest a new ice cave type: the “flow-through” ice cave. In a flow-through ice cave external winds blow into the cave and wet cave walls chill the incoming air to the wet-bulb temperature, thereby achieving extra cooling of the cave air. We have investigated an ice cave in Idaho, located in a lava tube that is reported to have airflow through porous wet end-walls and could therefore be a flow-through cave. We have instrumented the site and collected data for one year. In order to determine the actual ice cave type present at Shoshone, we have …

Ground-Coupled Air Waves: A Seismological Case Study Of The Explosion Quakes Of The 2007 Eruption Of Pavlof Volcano, Alaska, Cassandra Marie Smith

USF Tampa Graduate Theses and Dissertations

An abnormally high number of explosion quakes were noted during the monitoring effort for the 2007 eruption of Pavlof Volcano on the Alaskan Peninsula. In this study we manually counted the explosion quakes from their characteristic ground-coupled air waves. This study makes an effort at better quantifying the number of explosion quakes and how the characteristic ground-coupled air waves are affected by wind direction and wind speed. Additionally this study investigates how the ground coupled air waves might be used in a monitoring or analysis effort by calculating energy release and gas mass release. Over 3.2x10⁴ quakes were recorded. …

Glaciological Applications Of Terrestrial Radar Interferometry, Denis Voytenko

USF Tampa Graduate Theses and Dissertations

Terrestrial Radar Interferometry (TRI) is a relatively new ground-based technique that combines the precision and spatial resolution of satellite interferometry with the temporal resolution of GPS. Although TRI has been applied to a variety of fields including bridge and landslide monitoring, it is ideal for studies of the highly-dynamic terminal zones of marine-terminating glaciers, some of which are known to have variable velocities related to calving and/or ocean-forced melting. My TRI instrument is the Gamma Portable Radar Interferometer, which operates at 17.2 GHz (1.74 cm wavelength), has two receiving antennas for DEM (digital elevation model) generation, and images the scenes …

The Monica (Monitoring Of Ice Within Caves) Project: A Multidisciplinary Approach For The Geophysical And Paleoclimatic Characterization Of Permanent Ice Deposits In The Southeastern Alps, Renato R. Colucci, Emanuele Forte, Barbara Stenni, Marco Basso Bondini, Mauro Colle Fontana, Costanza Del Gobbo, Daniele Fontana, Doriana Belligoi, Valter Maggi, Marco Filipazzi

The International Workshop on Ice Caves

On days 30 September and 1-2 October 2013, a 7.8 m long ice core has been extracted from a permanent ice cave deposit in the Southeastern Alps (Vasto’s cave, Mt.Canin - Julian Alps). Each 20 to 100 cm long section of the ice core have been immediately stored in plastic bags and preserved thanks to dry ice. The ice samples, thanks to the helicopter, has been subsequently brought on valley and promptly stored in a refrigerated van, made available by BoFrost. Thus the ice cores has been transported intact to the EUROCOLD laboratory in Milan. These operations have been carried …

Characterization Of Two Permanent Ice Cave Deposits In The Southeastern Alps (Italy) By Means Of Ground Penetrating Radar (Gpr), Renato R. Colucci, Daniele Fontana, Emanuele Forte

The International Workshop on Ice Caves

In order to assess the thickness and the inner structure of some permanent ice deposits in two high elevated alpine karstic caves of the Canin massif (Alpi Giulie, Italy), we performed several multi frequency Ground Penetrating Radar (GPR) surveys. The surveys have been conducted within the project MONICA (MOnitoring of Ice within Caves), aimed at the paleoclimatic characterization of the considered cave ice deposits. GPR surveys have proved to be crucial also in finding the most suitable place for carrying out a drilling core. This has been particularly useful in the Vasto’s ice cave (VIC) in which the direct/visual estimation …

New Research In Cave Ledenica In Bukovi Vrh On Velebit Mt In Croatian Dinaric Karst, Mladen Garasic

The International Workshop on Ice Caves

No abstract provided.

Numerical Modeling Of Formation Of A Static Ice Cave – Ningwu Ice Cave, Shanxi, China, Yaolin Shi, Shaohua Yang

The International Workshop on Ice Caves

Ningwu Ice Cave in Shanxi province, China, is the largest Ice cave in China. We use Finite Element Method（FEM) to model the process of heat transfer in the ice cave. We not only calculate thermal conduction in spring, summer and fall, but also calculate the convective heat transfer in winter by introducing an equivalent thermal conductivity of cave air. Our computation shows that the ice cave can be formed within a decade, and reach a stable cyclic state in few centuries. Our calculation also shows that if people set a trap door at the ice cave entrance, especially in winter, …

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 …

Study Of Filled Dolines By Using 3d Stereo Image Processing And Electrical Resistivity Imaging, Mateja Breg Valjavec

International Journal of Speleology

This article deals with doline degradation due to uncontrolled waste dumping in the past in the Logatec Polje in Slovenia. It introduces a concept for determining 3D geometric characteristics (shape, depth, radius, area, and volume) of formerly concave landforms (i.e., recently filled dolines) by using a combination of two methods: (1) photogrammetric stereo processing of archival aerial photographs and (2) electrical resistivity imaging (ERI). To represent, visualize, and study the characteristics of the former surface morphology (i.e., the dolines before they were filled), a digital terrain model (DTM) for 1972 (DTM1972) was made using digital photogrammetry processing of five sequential …

Deciphering Deposits: Using Ground Penetrating Radar And Numerical Modeling To Characterize The Emplacement Mechanisms And Associated Energetics Of Scoria Cone Eruption And Construction, Leah Michelle Courtland

USF Tampa Graduate Theses and Dissertations

Our understanding of tephra depositional processes is significantly improved by high-resolution ground-penetrating radar (GPR) data collected at Cerro Negro volcano, Nicaragua. The data reveal three depositional regimes: (1) a near-vent region on the cone itself, where 10 GPR radargrams collected on the western flank show quantifiable differences between facies formed from low energy normal Strombolian and higher energy violent Strombolian processes, indicating imaging of scoria cone deposits may be useful in distinguishing eruptive style in older cones where the proximal to distal tephra blanket has eroded away; (2) a proximal zone in which horizons identified in crosswind profiles collected at …

Optimized Correlation Of Geophysical And Geotechnical Methods In Sinkhole Investigations: Emphasizing On Spatial Variations In West-Central Florida, Henok Gidey Kiflu

USF Tampa Graduate Theses and Dissertations

Abstract

Sinkholes and sinkhole-related features in West-Central Florida (WCF) are commonly identified using geotechnical investigations such as standard penetration test (SPT) borings and geophysical methods such as ground penetrating radar (GPR) and electrical resistivity tomography (ERT). Geophysical investigation results can be used to locate drilling and field testing sites while geotechnical investigation can be used to ground truth geophysical results. Both methods can yield complementary information. Geotechnical investigations give important information about the type of soil, groundwater level and presence of low-density soils or voids at the test location, while geophysical investigations like GPR surveys have better spatial coverage and …

Short And Long Term Volcano Instability Studies At Concepción Volcano, Nicaragua, Jose Armando Saballos

USF Tampa Graduate Theses and Dissertations

Concepción is the most active composite volcano in Nicaragua, and is located on Ometepe Island, within Lake Nicaragua. Moderate to small volcanic explosions with a volcanic explosivity index (VEI) of 1-2 have been characteristic of this volcano during the last four decades. Although its current activity is not violent, its volcanic deposits reveal stages of violent activity involving Plinian and sub-Plinian eruptions that deposited vast amounts of volcanic tephra in the Atlantic Ocean. These observations, together with the 31,000 people living on the island, make Concepción volcano an important target for volcanological research.

My research focuses on the investigation of …

Unusual Patterns Of Seismicity During Eruptive And Non-Eruptive Periods At The Persistently Restless Telica Volcano, Nicaragua, Melanie Rodgers

USF Tampa Graduate Theses and Dissertations

Telica Volcano, Nicaragua, is a persistently restless volcano with high rates of seismicity that can vary from less than ten events to over a thousand events per day. Low-frequency (LF) events dominate the seismic catalogue and seismicity rates at Telica show little clear correlation with periods of eruption. As such, traditional methods of forecasting of volcanic activity based on increases in seismicity and recognition of LF activity are not applicable. A single seismic station has been operating at Telica since 1993, and in 2010 we installed a broadband seismic and continuous GPS network (TESAND network) at Telica. In this study …

Investigation Of Stress Changes At Mount St. Helens, Washington, And Receiver Functions At The Katmai Volcanic Group, Alaska, With An Additional Section On The Assessment Of Spreadsheet-Based Modules., Heather L. Lehto

USF Tampa Graduate Theses and Dissertations

Forecasting eruptions using volcano seismology is a subject that affects the lives and property of millions of people around the world. However, there is still much to learn about the inner workings of volcanoes and how this relates to the chance of eruption. This dissertation attempts to increase the breadth of knowledge aimed at helping to understand when a volcano is likely to erupt and how large that eruption might be. Chapters 2 and 3 focus on a technique that uses changes in the local stress field beneath a volcano to determine the source of these changes and help forecast …

2d And 3d Imaging Of The Metamorphic Carbonates At Omalos Plateau/Polje, Crete, Greece By Employing Independent And Joint Inversion On Resistivity And Seismic Data, Hamdan Ali Hamdan Dr, Nikos Economou, Giorgos Kritikakis, Nikos Andronikidis, Emmanuil Manoutsoglou, Antonis Vafidis, Pangratis Pangratis, Georgina Apostolidou

International Journal of Speleology

A geophysical survey carried out at Omalos plateau in Chania, Western Crete, Greece employed seismic as well as electrical tomography methods in order to image karstic structures and the metamorphic carbonates (Tripali unit and Plattenkalk group) which are covered by post-Mesozoic deposits (terra rossa, clays, sands and gravels). The geoelectrical sections image the metamorphic carbonates which exhibit a highly irregular relief. At the central part of the plateau the thickness of post-Mesozoic deposits (terra rossa, clays, sands and gravels) ranges from 40-130 m. A 3D resistivity image was generated by inverting resistivity data collected on a grid to the south …

Quasi 3-Dimensional Electrical Resistivity Mapping Of Air-Filled Karst Conduits And Policy Implications, Charles W. Mccrackin

USF Tampa Graduate Theses and Dissertations

This study assesses the capability and practical applications of quasi 3-Dimensional (3D) electrical resistivity surveying (ER) for mapping air-filled karst conduits. Vadose zone caves within the Brooksville Ridge of West Central Florida are relatively similar in architecture, with N-S elongation, and do not consist of an interconnected network of conduits. A high resolution quasi-3D ER survey was performed over two mapped cave systems on the Brooksville Ridge. The resultant survey verified the general effectiveness of quasi-3D ER in locating the two known near-surface cave features. Several other locations in the survey show similar or stronger resistivity anomalies trending in a …

Impacts Of Artificial Reefs On Surrounding Ecosystems, Sarine Manoukian

USF Tampa Graduate Theses and Dissertations

Artificial reefs are becoming a popular biological and management component in shallow water environments characterized by soft seabed, representing both important marine habitats and tools to manage coastal fisheries and resources. An artificial reef in the marine environment acts as an open system with exchange of material and energy, altering the physical and biological characteristics of the surrounding area. Reef stability will depend on the balance of scour, settlement, and burial resulting from ocean conditions over time. Because of the unstable nature of sediments, they require a detailed and systematic investigation.

Acoustic systems like high-frequency multibeam sonar are efficient tools …

Geometry Of The Trachyte Mesa Intrusion, Henry Mountains, Utah: Implications For The Emplacement Of Small Melt Volumes Into The Upper Crust, Paul H. Wetmore, Charles B. Connor, Sarah E. Kruse, Sean Callihan, Geoffrey Pignotta, Ciprian Stremtan, Andrea Burke

Geology Faculty Publications

The Trachyte Mesa intrusion is one of several small satellite bodies to the larger intrusions of the Henry Mountains, Utah. Most previous studies have worked under the assumptions that Trachyte Mesa is blister shaped and intruded into flat and gently NW dipping strata. In this study we combine structural and geophysical data sets to constrain the structural geology of the host lithologies and the unmodified geometry of the intrusion. Trachyte Mesa intrudes a series of northeast trending upright and open folds formed within the Jurassic Entrada Formation. Truncation of these folds at the contact with the overlying Curtis/Summerville formations indicates …

Shallow Slab Fluid Release Across And Along The Mariana Arc-Basin System: Insights From Geochemistry Of Serpentinized Peridotites From The Mariana Fore Arc, Ivan P. Savov, Jeffrey G. Ryan, Massimo D'Antonio, Patricia Fryer

Geology Faculty Publications

Shallow slab devolatilization is not only witnessed through fluid expulsion at accretionary prisms, but is also evidenced by active serpentinite seamounts in the shallow fore-arc region of the Mariana convergent margin. Ocean Drilling Program (ODP) Leg 195 recovered serpentinized peridotites that present a unique opportunity to study the products of shallow level exchanges between the upper mantle and slab-derived fluids. Similar to samples recovered during ODP Leg 125, the protoliths of these fore-arc serpentinized peridotites are mantle harzburgites that have suffered large volume melt extraction (up to 25%) prior to interactions with fluids released from the downgoing Pacific Plate. Samples …

Effect Of Regional Tectonic Setting On Local Fault Response To Episodes Of Volcanic Activity, Diana C. Roman, Philip Heron

Geology Faculty Publications

In this study we examine the interaction of tectonic and volcanically-generated stress fields, and their combined effect on patterns of volcanotectonic (VT) seismicity, by calculating Coulomb stress changes on local faults induced by a constant dike inflation event in a background stress field of systematically varying magnitude and orientation. We find that patterns of VT seismicity (earthquake locations and fault-plane solutions) resulting from dike inflation depend strongly on the relative strength and orientation of background tectonic stresses. Patterns of VT seismicity similar to those predicted by our Coulomb stress models have been observed at several recently active volcanoes, and appear …

Along-Strike Trace Element And Isotopic Variation In Aleutian Island Arc Basalt: Subduction Melts Sediments And Dehydrates Serpentine, Brad S. Singer, Brian R. Jicha, William P. Leeman, Nick W. Rogers, Matthew F. Thirlwall, Jeffrey G. Ryan, Kirsten E. Nicolaysen

Geology Faculty Publications

Trace element and Sr-Nd-Pb isotope compositions of basaltic lavas from 11 volcanoes spanning 1300 km of the Aleutian Island arc provide new constraints on the recycling of elements in melts and fluids derived from subducted oceanic crust and sediment. Despite a nearly twofold variation in the flux of sediment subducted along the Aleutians, proxies indicating the presence of sediment melt in the magma source, including Th/La and Th/Nd, do not vary systematically along strike. In contrast, ratios including B/La, B/Nb, B/Be, Cs/La, Pb/Ce, and Li/Y suggest that the quantity or composition of fluid transferred from the slab into the mantle …

High Crystallinity Si-Ferrihydrite: An Insight Into Its Neel Temperature And Size Dependence Of Magnetic Properties, Thelma S. Berquo, Subir K. Banerjee, Robert G. Ford, R. Lee Penn, Thomas Pichler

Geology Faculty Publications

Ferrihydrite, an antiferromagnetic iron oxyhydroxide with resulting magnetization due to uncompensated spins, is of great importance for the cycling of many trace metals in the environment. Four ferrihydrite samples prepared with 1.3 to 3.5 wt% of Si at different synthesis temperatures (7.5°C, 22°C, 50°C, and 75°C) were studied by temperature-dependent hysteresis loops, ZFC/FC susceptibility curves, ac susceptibility and Mössbauer spectroscopy. The incorporation of Si into the ferrihydrite during synthesis changed the properties of this mineral. Interestingly, seven sharp lines were observed in the X-ray diffraction pattern of the ferrihydrite samples prepared at 50°C and 75°C. In general, both XRD and …

Sinkhole Structure Imaging In Covered Karst Terrain, Sarah E. Kruse, M. Grasmueck, Matthew Weiss, D. Viggiano

Geology Faculty Publications

Ground penetrating radar (GPR) and resistivity techniques have been widely used to map the locations of sinkholes in covered karst terrain. To determine whether a sinkhole is a likely preferential conduit for groundwater flow, however, requires higher-resolution imaging than that used in conventional sinkhole mapping surveys. Field observations combined with simulated surveys for a 15-m diameter 3-m deep sinkhole in west-central Florida are used to assess the resolution of GPR and resistivity surveys targeting the semiconfining unit that floors the sinkhole depression. 2D resistivity surveys clearly show the central depression as well as resistivity contrasts between the cover sediments within …

Spectral Analysis Of Ground Penetrating Radar Response To Thin Sedimentary Layers, Swagata Guha, Sarah E. Kruse, E. E. Wright, U. E. Kruse

Geology Faculty Publications

Ground penetrating radar (GPR) systems utilized in studies of sedimentary deposits generate wavelengths (tens of centimeters) that are commonly much longer than the thickness of bedding (often millimeters to centimeters) within the target strata. Where this is the case, radar profiles represent interference patterns. Simple models of radar response to sequences of thin beds such as those found in coastal deposits show potentially detectable spectral shifts toward higher frequencies in radar returns. Spectral analysis of radar data over barrier beach deposits at Waites Island, South Carolina, shows that returns from packages with heavy mineral laminations are shifted toward higher frequencies …

Modeling Tephra Sedimentation From A Ruapehu Weak Plume Eruption, Costanza Bonadonna, J. C. Phillips, B. F. Houghton

Geology Faculty Publications

We present a two-dimensional model for sedimentation of well-mixed weak plumes, accounting for lateral spreading of the cloud, downwind advection, increase of volumetric flux in the rising stage, and particle transport during fallout. The 17 June 1996 subplinian eruption of Ruapehu produced a bent-over plume that rose to a height of 8.5 km in a wind field with an average velocity of 24 m s⁻¹ and generated a narrow deposit on land extending up to 200 km from vent. The sedimentation from the Ruapehu plume was dominated by coarse ash, with all the blocks and most of the lapilli …

Geochemistry Of Serpentinized Peridotites From The Mariana Forearc Conical Seamount, Odp Leg 125: Implications For The Elemental Recycling At Subduction Zones, Ivan P. Savov, Jeffrey G. Ryan, Massimo D'Antonio, Katherine Kelley, Patrick Mattie

Geology Faculty Publications

Recent examinations of the chemical fluxes through convergent plate margins suggest the existence of significant mass imbalances for many key species: only 20–30% of the to-the-trench inventory of large-ion lithophile elements (LILE) can be accounted for by the magmatic outputs of volcanic arcs. Active serpentinite mud volcanism in the shallow forearc region of the Mariana convergent margin presents a unique opportunity to study a new outflux: the products of shallow-level exchanges between the upper mantle and slab-derived fluids. ODP Leg 125 recovered serpentinized harzburgites and dunites from three sites on the crests and flanks of the active Conical Seamount. These …

Probabilistic Modeling Of Tephra Dispersal: Hazard Assessment Of A Multiphase Rhyolitic Eruption At Tarawera, New Zealand, Costanza Bonadonna, Charles B. Connor, B. F. Houghton, Laura Connor, Marc A. Byrne, A. Laing, T. K. Hincks

Geology Faculty Publications

The Tarawera Volcanic Complex comprises 11 rhyolite domes formed during five major eruptions between 17,000 B.C. and A.D. 1886, the first four of which were predominantly rhyolitic. The only historical event erupted about 2 km³ of basaltic tephra fall (A.D. 1886). The youngest rhyolitic event erupted a tephra fall volume more than 2 times larger and covered a wider area northwest and southeast of the volcano (∼A.D. 1315 Kaharoa eruption). We have used the Kaharoa scenario to assess the tephra fall hazard from a future rhyolitic eruption at Tarawera of a similar scale. The Plinian phase of this eruption …