Volcanology Commons^™

Detection Of An So2 Plume Over Sapporo, Japan From The Eruption Of Mt. Kasatochi Using A Balloon Sounding Technique, Gary A. Morris, Jun Hirokawa, Masatomo Fujiwara, Fumio Hasebe, Keisuke Ishida, Nicholay Krotkov, Mark R. Schoeberl, Walter Komhyr, Barry Lefer, James Flynn

Physics and Astronomy Faculty Presentations

During the month of August 2008, 10 ozonesondes were launched from Hokkaido University in Sapporo, Japan as part of a study to examine regional pollution during the Olympic period. Seven of these soundings included a second instrument with a filter designed to remove SO2 from the intake air stream. SO2 interferes with the normal chemistry of the electrochemical cell (ECC) method for ozone detection, with the net result being that each molecule of SO2 registers as minus one molecule of O3. Thus the unfiltered sonde reports [O3] - [SO2] while the filtered sonde reports [O3]. Laboratory tests prior to launch …

Geology Of The Southern Reveille Range, Nye County, Nevada, Matthew Alan Mckelvey

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Reveille Range in central Nevada provides a unique window into the mid-Miocene geology and volcanology of the central Great Basin during the "ignimbrite flare up." Although faulted along its margins, the interior of the range is relatively undeformed thus preserving volcanic centers. The Reveille Range contains three mid-Miocene caldera complexes. Previous studies have identified the Goblin Knobs caldera (25.6 Ma) in the central Reveille Range and the caldera of northern Reveille Range (25.3 Ma) to the north. These calderas are completely filled with intracaldera tuffs. This study has identified a younger third caldera located in the southern part of …

Plagioclase Populations And Zoning In Dacite Of The 2004–2005 Mount St. Helens Eruption: Constraints For Magma Origin And Dynamics, Martin J. Streck, Cindy A. Broderick, Carl R. Thornber, Michael A. Clynne, John S. Pallister

Geology Faculty Publications and Presentations

We investigated plagioclase phenocrysts in dacite of the 2004–5 eruption of Mount St. Helens to gain insights into the magmatic processes of the current eruption, which is char­acterized by prolonged, nearly solid-state extrusion, low gas emission, and shallow seismicity. In addition, we investigated plagioclase of 1980–86 dacite.

Light and Nomarski microscopy were used to texturally characterize plagioclase crystals. Electron microprobe analy­ses measured their compositions. We systematically mapped and categorized all plagioclase phenocrysts in a preselected area according to the following criteria: (1) occurrence of zones of acicular orthopyroxene inclusions, (2) presence of dissolution surface(s), and (3) spatial association of 1 …

Petrogenetic Processes Characterizing The Mount Bachelor, Oregon Magmatic System: Open- Versus Closed-System Processes, Sara Elizabeth Johnson

All Master's Theses

Mount Bachelor volcanic chain (MBVC), located in central Oregon, is one of the larger basalt and basaltic-andesite edifices in central Oregon. Preliminary studies have defined how eruptions have changed composition with time, but a detailed assessment of magma chamber processes has not been conducted. To gain a more thorough understanding of the magmatic processes that have contributed to the observed compositional evolution, this study focuses on one of four eruptive episodes, specifically episode III, the most voluminous episode of the four. Magmatic processes are assessed by focusing on both whole-rock and single crystal data.

The geochemistry and textural diversity of …