Physical Sciences and Mathematics Commons^™

Surface Temperature And Spectral Measurements At Santiaguito Lava Dome, Guatemala, Steve T. M. Sahetapy-Engel, Luke P. Flynn, Andrew J. L. Harris, Gregg J. Bluth, William I. Rose, Otoniel Matias

Department of Geological and Mining Engineering and Sciences Publications

An infrared thermometer, spectroradiometer and digital video camera were used to observe and document short-term evolution of surface brightness temperature and morphology at Santiaguito lava dome, Guatemala. The thermometer dataset shows 40–70 minute-long cooling cycles, each defined by a cooling curve that is both initiated and terminated by rapid increases in temperature due to regular ash venting. The average cooling rate calculated for each cycle range from 0.9 to 1.6°C/min. We applied a two-component thermal mixture model to the spectroradiometer (0.4–2.5 μm) dataset. The results suggest that the observed surface morphology changed from a cool (120–250°C) crust-dominated surface with high …

Numerical Modeling Of Geophysical Granular Flows: 2. Computer Simulations Of Plinian Clouds And Pyroclastic Flows And Surges, Sebastien Dartevelle, William I. Rose, John Stix, Karim Kelfoun, James W. Vallance

Department of Geological and Mining Engineering and Sciences Publications

Geophysical granular flows display complex nonlinear, nonuniform, and unsteady rheologies, depending on the volumetric grain concentration within the flow: kinetic, kinetic-collisional, and frictional. To account for the whole spectrum of granular rheologies (and hence concentrations), we have used and further developed for geophysical-atmospheric applications a multiphase computer model initially developed by U.S. Department of Energy laboratories: (Geophysical) Multiphase Flow with Interphase Exchange. As demonstrated in this manuscript, (G)MFIX can successfully simulate a large span of pyroclastic phenomena and related processes: plinian clouds, pyroclastic flows and surges, flow transformations, and depositional processes. Plinian cloud simulations agree well with the classical plume …

Scattering Matrices Of Volcanic Ash Particles Of Mount St. Helens, Redoubt, And Mount Spurr Volcanoes, O. Muñoz, H. Volten, J. W. Hovenier, B. Veihelmann, W. J. Van Der Zande, L. B. F. M. Waters, William I. Rose

Department of Geological and Mining Engineering and Sciences Publications

We present measurements of the whole scattering matrix as a function of the scattering angle at a wavelength of 632.8 nm in the scattering angle range 3°–174° of randomly oriented particles taken from seven samples of volcanic ashes corresponding to four different volcanic eruptions: the 18 May 1980 Mount St. Helens eruption, the 1989–1990 Redoubt eruption, and the 18 August and 17 September 1992 Mount Spurr eruptions. The samples were collected at different distances from the vent. The samples studied contain large mass fractions of fine particles and were chosen to represent ash that could remain in the atmosphere for …

Particles In The Great Pinatubo Volcanic Cloud Of June 1991:The Role Of Ice, Song Guo, William I. Rose, Gregg J. S. Bluth, M. I. Watson

Department of Geological and Mining Engineering and Sciences Publications

Pinatubo's 15 June 1991 eruption was Earth's largest of the last 25 years, and it formed a substantial volcanic cloud. We present results of analysis of satellite-based infrared remote sensing using Advanced Very High Resolution Radiometer (AVHRR) and TIROS Operational Vertical Sounder/High Resolution Infrared Radiation Sounder/2 (TOVS/HIRS/2) sensors, during the first few days of atmospheric residence of the Pinatubo volcanic cloud, as it drifted from the Philippines toward Africa. An SO₂-rich upper (25 km) portion drifted westward slightly faster than an ash-rich lower (22 km) part, though uncertainty exists due to difficulty in precisely locating the ash cloud. …

Re-Evaluation Of So2 Release Of The 15 June 1991 Pinatubo Eruption Using Ultraviolet And Infrared Satellite Sensors, Song Guo, Gregg J. S. Bluth, William I. Rose, M. I. Watson, A. J. Prata

Department of Geological and Mining Engineering and Sciences Publications

In this study, ultraviolet TOMS (Total Ozone Mapping Spectrometer) satellite data for SO₂ are re-evaluated for the first 15 days following the 15 June 1991 Pinatubo eruption to reflect new data retrieval and reduction methods. Infrared satellite SO₂ data from the TOVS/HIRS/2 (TIROS (Television Infrared Observation Satellite) Optical Vertical Sounder/High Resolution Infrared Radiation Sounder/2) sensor, whose data sets have a higher temporal resolution, are also analyzed for the first time for Pinatubo. Extrapolation of SO₂ masses calculated from TOMS and TOVS satellite measurements 19–118 hours after the eruption suggest initial SO₂ releases of 15 ± 3 …

Explosion Dynamics Of Pyroclastic Eruptions At Santiaguito Volcano, Jeffrey B. Johnson, Andrew J. L. Harris, Steve T. M. Sahetapy-Engel, Rudiger Wolf, William I. Rose

Department of Geological and Mining Engineering and Sciences Publications

In Jan. 2003 we monitored explosions at Santiaguito Volcano (Guatemala) with thermal, infrasonic, and seismic sensors. Thermal data from 2 infrared thermometers allowed computation of plume rise speeds, which ranged from 8 to 20 m/s. Rise rates correlated with cumulative thermal radiance, indicating that faster rising plumes correspond to explosions with greater thermal flux. The relationship between rise speeds and elastic energy is less clear. Seismic radiation may not scale well with thermal output and/or rise speed because some of the thermal component may be associated with passive degassing, which does not induce significant seismicity. But non-impulsive gas release is …

Application Of Well Log Tomography To The Dundee And Rogers City Limestones, Michigan Basin, Usa, Mellisa A. Le M.

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

The Michigan Basin is located in the upper Midwest region of the United States and is centered geographically over the Lower Peninsula of Michigan. It is filled primarily with Paleozoic carbonates and clastics, overlying Precambrian basement rocks and covered by Pleistocene glacial drift. In Michigan, more than 46,000 wells have been drilled in the basin, many producing significant quantities of oil and gas since the 1920s in addition to providing a wealth of data for subsurface visualization.

Well log tomography, formerly log-curve amplitude slicing, is a visualization method recently developed at Michigan Technological University to correlate subsurface data by utilizing …

Hydrogeochemical Controls On Uranium In Aquifers Of The Jacobsville Sandstone, Heidi M. Sherman

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

The occurrence of elevated uranium (U) in sandstone aquifers was investigated in the Upper Peninsula of Michigan, focusing on aquifers of the Jacobsville Sandstone. The hydrogeochemical controls on groundwater U concentrations were characterized using a combination of water sampling and spectral gamma-ray logging of sandstone cliffs and residential water wells. ²³⁵U/²³⁸U isotope ratios were consistent with naturally occurring U. Approximately 25% of the 270 wells tested had U concentrations above the U.S. Environmental Protection Agency Maximum Contaminant Level (MCL) of 30 μg/L, with elevated U generally occurring in localized clusters. Water wells were logged to determine whether …