Physical Sciences and Mathematics Commons^™

La Yeguada Volcanic Vomplex In The Republic Of Panama: An Assessment Of The Geologic Hazards Using 40ar/39ar Geochronology, Karinne L. Knutsen, William I. Rose, Brian Jicha

Department of Geological and Mining Engineering and Sciences Publications

La Yeguada volcanic complex is one of three Quaternary volcanic centers in Panama. To assess potential geologic hazards, new samples were analyzed using argon analysis (⁴⁰Ar/³⁹Ar), and obtained the following: the most recent eruption occurred approximately 32,000 years ago at the Media Luna cinder cone; the youngest dated eruption from the main dome complex occurred 357 ± 19 ka, producing the Castillo dome unit; Cerro Picacho, a separate dacite dome 1.5 km east of the main complex is 4.47 ± 0.23 Ma; and the El Satro Pyroclastic Flow unit surrounds the northern portion of the volcanic …

The Size Range Of Bubbles That Produce Ash During Explosive Volcanic Eruptions, Kimberly Genareau, Gopal K. Mulukutla, Alexander A. Proussevitch, Adam J. Durant, William I. Rose, Dork L. Sahagian

Department of Geological and Mining Engineering and Sciences Publications

Volcanic eruptions can produce ash particles with a range of sizes and morphologies. Here we morphologically distinguish two textural types: Simple (generally smaller) ash particles, where the observable surface displays a single measureable bubble because there is at most one vesicle imprint preserved on each facet of the particle; and complex ash particles, which display multiple vesicle imprints on their surfaces for measurement and may contain complete, unfragmented vesicles in their interiors. Digital elevation models from stereo-scanning electron microscopic images of complex ash particles from the 14 October 1974 sub-Plinian eruption of Volcán Fuego, Guatemala and the 18 May 1980 …

A Study Of The Impacts Of Freeze-Thaw On Cliff Recession At The Calvert Cliffs In Calvert County, Maryland, Bonnie Elizabeth Zwissler

Dissertations, Master's Theses and Master's Reports - Open

The Calvert Cliffs, which form much of the western coastline of the Chesapeake Bay in Calvert County, Maryland, are actively eroding and destabilizing, resulting in a critical situation for many homes in close proximity to the slope's crest. Past studies have identified that where waves directly interact with the toe of the slope, wave action controls cliff recession; however, where waves do not regularly interact with the slope toe, the past work identified that freeze-thaw controls recession. This study investigated the validity of this second claim by analyzing the recession rate and freeze-thaw behavior of six study sites along the …

Spatial And Temporal Evolution Of The Volcanics And Sediments Of The Kenya Rift, Alexandria L. Guth

Dissertations, Master's Theses and Master's Reports - Open

New volumetric and mass flux estimates have been calculated for the Kenya Rift. Spatial and temporal histories for volcanic eruptions, lacustrine deposition, and hominin fossil sites are presented, aided by the compilation of a new digital geologic map. Distribution of volcanism over time indicates several periods of southward expansion followed by relative positional stasis. Volcanism occurs throughout the activated rift length, with no obvious abandonment as the rift system migrated. The main exception is a period of volcanic concentration around 10 Ma, when activity was constrained within 2° of the equator.

Volumes derived from seismic data indicate a total volume …

Ground-Based And Satellite Remote Sensing Of Paroxysmal Eruptions At Etna Volcano, 2011-2012., Estelle Bonny

Dissertations, Master's Theses and Master's Reports - Open

Mt Etna's activity has increased during the last decade with a tendency towards more explosive eruptions that produce paroxysmal lava fountains. From January 2011 to April 2012, 25 lava fountaining episodes took place at Etna's New South-East Crater (NSEC). Improved understanding of the mechanism driving these explosive basaltic eruptions is needed to reduce volcanic hazards. This type of activity produces high sulfur dioxide (SO2) emissions, associated with lava flows and ash fall-out, but to date the SO2 emissions associated with Etna's lava fountains have been poorly constrained. The Ultraviolet (UV) Ozone Monitoring Instrument (OMI) on NASA's Aura satellite and the …

A Study Of So2 Emissions And Ground Surface Displacements At Lastarria Volcano, Antofagasta Region, Northern Chile, Lucie Guihem Krewcun

Dissertations, Master's Theses and Master's Reports - Open

Lastarria volcano (Chile) is located at the North-West margin of the `Lazufre' ground inflation signal (37x45 km²), constantly uplifting at a rate of ~2.5 cm/year since 1996 (Pritchard and Simons 2002; Froger et al. 2007). The Lastarria volcano has the double interest to be superimposed on a second, smaller-scale inflation signal and to be the only degassing area of the Lazufre signal. In this project, we compared daily SO2 burdens recorded by AURA's OMI mission for 2005-2010 with Ground Surface Displacements (GSD) calculated from the Advanced Synthetic Aperture Radar (ASAR) images for 2003-2010.

We found a constant maximum displacement rate …

Tandem-X High Resolution Dems And Their Applications To Flow Modeling, Kelly M. Wooten

Dissertations, Master's Theses and Master's Reports - Open

Lava flow modeling can be a powerful tool in hazard assessments; however, the ability to produce accurate models is usually limited by a lack of high resolution, up-to-date Digital Elevation Models (DEMs). This is especially obvious in places such as Kilauea Volcano (Hawaii), where active lava flows frequently alter the terrain. In this study, we use a new technique to create high resolution DEMs on Kilauea using synthetic aperture radar (SAR) data from the TanDEM-X (TDX) satellite. We convert raw TDX SAR data into a geocoded DEM using GAMMA software [Werner et al., 2000]. This process can be completed in …

Characterizing The First Historic Eruption Of Nabro, Eritrea: Insights From Thermal And Uv Remote Sensing, Christine Ruth Sealing

Dissertations, Master's Theses and Master's Reports - Open

June 2011 saw the first historic eruption of Nabro volcano, one of an ongoing sequence of eruptions in the Afar-Red Sea region since 2005. It halted air travel in northern Africa, contaminated food and water sources, and displaced thousands from their homes. Due to its remote location, little was known about this event in terms of the quantity of erupted products and the timing and mechanisms of their emplacement. Geographic isolation, previous quiescence and regional civil unrest meant that this volcano was effectively unmonitored at the time of eruption, and opportunities for field study are limited. Using free, publicly available …

Volcanic Processes And Human Exposure As Elements To Build A Risk Model For Volcan De Fuego, Guatemala, Rüdiger P. Escobar Wolf

Dissertations, Master's Theses and Master's Reports - Open

The activity of Fuego volcano during the 1999 - 2013 eruptive episode is studied through field, remote sensing and observatory records. Mapping of the deposits allows quantifying the erupted volumes and areas affected by the largest eruptions during this period. A wide range of volcanic processes results in a diversity of products and associated deposits, including minor airfall tephra, rockfall avalanches, lava flows, and pyroclastic flows. The activity can be characterized by long term, low level background activity, and sporadic larger explosive eruptions. Although the background activity erupts lava and ash at a low rate (~ 0.1 m3/s), the persistence …

Probabilistic Modeling Of Rainfall Induced Landslide Hazard Assessment In San Juan La Laguna, Sololá, Guatemala, Patrice F. Cobin

Dissertations, Master's Theses and Master's Reports - Open

The municipality of San Juan La Laguna, Guatemala is home to approximately 5,200 people and located on the western side of the Lake Atitlán caldera. Steep slopes surround all but the eastern side of San Juan. The Lake Atitlán watershed is susceptible to many natural hazards, but most predictable are the landslides that can occur annually with each rainy season, especially during high-intensity events. Hurricane Stan hit Guatemala in October 2005; the resulting flooding and landslides devastated the Atitlán region. Locations of landslide and non-landslide points were obtained from field observations and orthophotos taken following Hurricane Stan. This study used …

A Comparison Of Pixel-Based Versus Object Oriented Analysis Of Landslides Using Historical Remote Sensing Data, Ren N. Keyport

Dissertations, Master's Theses and Master's Reports - Open

With recent advances in remote sensing processing technology, it has become more feasible to begin analysis of the enormous historic archive of remotely sensed data. This historical data provides valuable information on a wide variety of topics which can influence the lives of millions of people if processed correctly and in a timely manner. One such field of benefit is that of landslide mapping and inventory. This data provides a historical reference to those who live near high risk areas so future disasters may be avoided. In order to properly map landslides remotely, an optimum method must first be determined. …