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Articles 1 - 30 of 53

Full-Text Articles in Mining Engineering

Thermal Conduction Simulation Based On Reconstruction Digital Rocks With Respect To Fractures, Haiyuan Yang, Li Zhang, Ronghe Liu, Xianli Wen, Yongfei Yang, Roohollah Askari, Et. Al. Jul 2019

Thermal Conduction Simulation Based On Reconstruction Digital Rocks With Respect To Fractures, Haiyuan Yang, Li Zhang, Ronghe Liu, Xianli Wen, Yongfei Yang, Roohollah Askari, Et. Al.

Michigan Tech Publications

Effective thermal conductivity (ETC), as a necessary parameter in the thermal properties of rock, is affected by the pore structure and the thermal conduction conditions. To evaluate the effect of fractures and saturated fluids on sandstone’s thermal conductivity, we simulated thermal conduction along three orthogonal (X, Y, and Z) directions under air- and water-saturated conditions on reconstructed digital rocks with different fractures. The results show that the temperature distribution is separated by the fracture. The significant difference between the thermal conductivities of solid and fluid is the primary factor influencing the temperature distribution, and the thermal conduction mainly depends ...


Landslides Near Enguri Dam (Caucasus, Georgia) And Possible Seismotectonic Effects, Alessandro Tibaldi, Paolo Oppizzi, John S. Gierke, Thomas Oommen, Nino Tsereteli, Zurab Gogoladze Jan 2019

Landslides Near Enguri Dam (Caucasus, Georgia) And Possible Seismotectonic Effects, Alessandro Tibaldi, Paolo Oppizzi, John S. Gierke, Thomas Oommen, Nino Tsereteli, Zurab Gogoladze

Department of Geological and Mining Engineering and Sciences Publications

The Enguri dam and water reservoir, nested in the southwestern Caucasus (Republic of Georgia), are surrounded by steep mountain slopes. At a distance of 2.5 km from the dam, a mountain ridge along the reservoir is affected by active deformations with a double vergence. The western slope, directly facing the reservoir, has deformations that affect a subaerial area of 1.2 km2. The head scarp affects the Jvari–Khaishi–Mestia main road with offsets of man-made features that indicate slip rates of 2–9 cm yr−1. Static, pseudostatic and Newmark analyses, based on field and seismological data ...


Assessment Of Post-Wildfire Debris Flow Occurrence Using Classifier Tree, Priscilla Addison, Thomas Oommen, Qiuying Sha Jan 2019

Assessment Of Post-Wildfire Debris Flow Occurrence Using Classifier Tree, Priscilla Addison, Thomas Oommen, Qiuying Sha

Department of Geological and Mining Engineering and Sciences Publications

Besides the dangers of an actively burning wildfire, a plethora of other hazardous consequences can occur afterwards. Debris flows are among the most hazardous of these, being known to cause fatalities and extensive damage to infrastructure. Although debris flows are not exclusive to fire affected areas, a wildfire can increase a location’s susceptibility by stripping its protective covers like vegetation and introducing destabilizing factors such as ash filling soil pores to increase runoff potential. Due to the associated dangers, researchers are developing statistical models to isolate susceptible locations. Existing models predominantly employ the logistic regression algorithm; however, previous studies ...


Investigation Of Long Term Pillar Stability In An Abandoned Gypsum Mine Based On Dissolution Models, Mohammadhossein Sadeghiamirshahidi Jan 2019

Investigation Of Long Term Pillar Stability In An Abandoned Gypsum Mine Based On Dissolution Models, Mohammadhossein Sadeghiamirshahidi

Dissertations, Master's Theses and Master's Reports

The abandoned Domtar Mine in Grand Rapids, MI underlies Interstate I-196. The mine operated for over 140 years, mining a 30-meter-deep, four-meter thick gypsum seam. In 2000, the mine was abandoned with the removal of the mine’s dewatering pumps allowing groundwater to flood the mine. The initial flooding resulted in saturating the mine pillars along with some amount of pillar dissolution. Overtime, gypsum dissolution would cease as the water becomes saturated with the gypsum dissolution products. The mine, however, is located adjacent to the Grand River and has groundwater moving through the mine resulting in the potential for continuing ...


Monitoring The Impact Of Groundwater Pumping On Infrastructure Using Geographic Information System (Gis) And Persistent Scatterer Interferometry (Psi), Kirsten Deprekel, El Hachemi Bouali, Thomas Oommen Dec 2018

Monitoring The Impact Of Groundwater Pumping On Infrastructure Using Geographic Information System (Gis) And Persistent Scatterer Interferometry (Psi), Kirsten Deprekel, El Hachemi Bouali, Thomas Oommen

Department of Geological and Mining Engineering and Sciences Publications

Transportation infrastructure is critical for the advancement of society. Bridges are vital for an efficient transportation network. Bridges across the world undergo variable deformation/displacement due to the Earth’s dynamic processes. This displacement is caused by ground motion, which occurs from many natural and anthropogenic events. Events causing deformation include temperature fluctuation, subsidence, landslides, earthquakes, water/sea level variation, subsurface resource extraction, etc. Continual deformation may cause bridge failure, putting civilians at risk, if not managed properly. Monitoring bridge displacement, large and small, provides evidence of the state and health of the bridge. Traditionally, bridge monitoring has been executed ...


The Ozone Monitoring Instrument: Overview Of 14 Years In Space, Pieternel F. Levelt, Joanna Joiner, Johanna Tamminen, J. Pepijn Veefkind, Pawan K. Bhartia, Simon Carn, Et. Al. Apr 2018

The Ozone Monitoring Instrument: Overview Of 14 Years In Space, Pieternel F. Levelt, Joanna Joiner, Johanna Tamminen, J. Pepijn Veefkind, Pawan K. Bhartia, Simon Carn, Et. Al.

Michigan Tech Publications

This overview paper highlights the successes of the Ozone Monitoring Instrument (OMI) on board the Aura satellite spanning a period of nearly 14 years. Data from OMI has been used in a wide range of applications and research resulting in many new findings. Due to its unprecedented spatial resolution, in combination with daily global coverage, OMI plays a unique role in measuring trace gases important for the ozone layer, air quality, and climate change. With the operational very fast delivery (VFD; direct readout) and near real-time (NRT) availability of the data, OMI also plays an important role in the development ...


Engineering Decision Making Under Uncertainties, Snehamoy Chatterjee Oct 2017

Engineering Decision Making Under Uncertainties, Snehamoy Chatterjee

TechTalks

Uncertainty is an inherent component of any engineering problem. Uncertainty comes at different stages of an engineering project with different level of complexities. Decision making by neglecting uncertainty may leads to an incorrect solution for a project. Our research focuses on identification and quantification of different sources of uncertainness, and bringing uncertainties within the decision making framework. We are developing algorithms for uncertainty evaluation of spatial and temporal data by integrating multiple source and multiple scale data types, and stochastic optimization models to take into account multiple objectives and constraints. We are applying our research on mining, geology, and geo-hydrology ...


Reference Data Set Of Volcanic Ash Physicochemical And Optical Properties, A. Vogel, S. Diplas, A. J. Durant, A. S. Azar, M. F. Sunding, William I. Rose, A. Sytchkova, C. Bonadonna, K. Krüger, A. Stohl Sep 2017

Reference Data Set Of Volcanic Ash Physicochemical And Optical Properties, A. Vogel, S. Diplas, A. J. Durant, A. S. Azar, M. F. Sunding, William I. Rose, A. Sytchkova, C. Bonadonna, K. Krüger, A. Stohl

Department of Geological and Mining Engineering and Sciences Publications

Uncertainty in the physicochemical and optical properties of volcanic ash particles creates errors in the detection and modeling of volcanic ash clouds and in quantification of their potential impacts. In this study, we provide a data set that describes the physicochemical and optical properties of a representative selection of volcanic ash samples from nine different volcanic eruptions covering a wide range of silica contents (50–80 wt % SiO2). We measured and calculated parameters describing the physical (size distribution, complex shape, and dense-rock equivalent mass density), chemical (bulk and surface composition), and optical (complex refractive index from ultraviolet to near-infrared ...


Electromagnetic Signal Feedback Control For Proximity Detection Systems, Adam K. Smith Jan 2017

Electromagnetic Signal Feedback Control For Proximity Detection Systems, Adam K. Smith

Dissertations, Master's Theses and Master's Reports

Coal is the most abundant fossil fuel in the United States and remains an essential source of energy. While more than half of coal production comes from surface mining, nearly twice as many workers are employed by underground operations.

One of the key pieces of equipment used in underground coal mining is the continuous mining machine. These large and powerful machines are operated in confined spaces by remote control. Since 1984, 40 mine workers in the U. S. have been killed when struck or pinned by a continuous mining machine. It is estimated that a majority of these accidents could ...


Controlling Properties Of Agglomerates For Chemical Processes, Joseph A. Halt Jan 2017

Controlling Properties Of Agglomerates For Chemical Processes, Joseph A. Halt

Dissertations, Master's Theses and Master's Reports

Iron ore pellets are hard spheres made from powdered ore and binders. Pellets are used to make iron, mainly in blast furnaces. Around the time that the pelletizing process was developed, starch was proposed as a binder because it’s viscous, adheres well to iron oxides, does not contaminate pellets and is relatively cheap. In practice, however, starch leads to weak pellets with rough surfaces – these increase the amount of dust generated within process equipment and during pellet shipping and handling. Thus, even though the usual binder (bentonite clay) contaminates pellets, pelletizers prefer it to starch or other organics.

This ...


Ignimbrites To Batholiths, Chad Deering Dec 2016

Ignimbrites To Batholiths, Chad Deering

TechTalks

Ignimbrites sample large magma reservoirs in the Earth’s upper crust, sometimes digging deep enough to link the volcanic realm with the plutonic world. Integrating textural, petrological, geochemical, and geochronological information on such deposits with geophysical signals suggest incremental growth and evolution of subvolcanic magma bodies that are dominated by high crystallinity mush zones, but sometimes remain sufficiently liquid to erupt. The eruptible upper portions are either extracted melt from the mush and constitute only a small volumetric fraction of the vertically extensive mushy batholithic magma body. The high-flux, ignimbrite flare-up phases are typically preceded by waxing magmatism that prime ...


A Petrophysical Evaluation For Permeability Of A Gas Reservoir In The Taranaki Basin, New Zealand, Musa Cetin Jan 2016

A Petrophysical Evaluation For Permeability Of A Gas Reservoir In The Taranaki Basin, New Zealand, Musa Cetin

Dissertations, Master's Theses and Master's Reports

The goal of this study was to evaluate permeability and study the controls on permeability in a gas saturated formation. Conventional well logs, mineral identification crossplots and empirical models were applied to analyze different lithologic and diagenetic features and to examine the effect that these features may have on the reservoir. An unusual feature was observed, and required detailed examination: there existed (in two wells) five zones of lower resistivity (higher water saturation) above the gas-water contact. This is unexpected, as above that contact, the water is usually at irreducible water saturation. I conclude that the lower resistivity (the higher ...


The Dispersion And Selective Flocculation Of Hematite Ore, Howard James Haselhuhn Iii Jan 2015

The Dispersion And Selective Flocculation Of Hematite Ore, Howard James Haselhuhn Iii

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

Iron ore is one of the most important ores in the world. Over the past century, most mining of iron ore has been focused on magnetite (Fe3O4). As the name suggests, magnetite is magnetic in nature and is easily separated from gangue (unwanted) minerals through magnetic separation processes. Unfortunately, the magnetite ore bodies are diminishing. Because of this, there has been a recent drive to pursue technology that can economically separate hematite (Fe2O3) from its gangue minerals as hematite is a much more abundant source of iron. Most hematite ore has a very small liberation size that is frequently less ...


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 Nov 2013

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 ...


Method For Coating Mineral Granules To Improve Bonding To Hydrocarbon-Based Substrate And Coloring Of Same, Bowen Li, Ralph Hodek, Domenic Popko, Jiann-Yang Hwang Oct 2013

Method For Coating Mineral Granules To Improve Bonding To Hydrocarbon-Based Substrate And Coloring Of Same, Bowen Li, Ralph Hodek, Domenic Popko, Jiann-Yang Hwang

Michigan Tech Patents

Provided are compositions comprising stamp sand granules embedded in asphalt, where the stamp sand granules comprise a silane coating. Additionally provided are methods of making a silane-coated stamp sand, the methods comprising combining stamp sand granules and a silane solution to form a mixture and drying the mixture. Additionally provided are methods of covering a surface, the methods comprising combining silane-coated particles and asphalt to provide a mixture and distributing the mixture on the surface.


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 Aug 2013

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 ...


Selecting An Electrical Power Source At The Scoping Level For A Mining Project, Christopher Dawson Van Arsdale Jan 2012

Selecting An Electrical Power Source At The Scoping Level For A Mining Project, Christopher Dawson Van Arsdale

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

The electrical power source is a critical component of the scoping level study as the source affects both the project economics and timeline. This paper proposes a systematic approach to selecting an electrical power source for a new mine. Orvana Minerals Copperwood project is used as a case study. The Copperwood results show that the proposed scoping level approach is consistent with the subsequent much more detailed feasibility study.


Hydrometeor-Enhanced Tephra Sedimentation: Constraints From The 18 May 1980 Eruption Of Mount St. Helens, Adam J. Durant, William I. Rose, A. M. Sarna-Wojcicki, S. Carey, A. C. M. Volentik Mar 2009

Hydrometeor-Enhanced Tephra Sedimentation: Constraints From The 18 May 1980 Eruption Of Mount St. Helens, Adam J. Durant, William I. Rose, A. M. Sarna-Wojcicki, S. Carey, A. C. M. Volentik

Department of Geological and Mining Engineering and Sciences Publications

Uncertainty remains on the origin of distal mass deposition maxima observed in many recent tephra fall deposits. In this study the link between ash aggregation and the formation of distal mass deposition maxima is investigated through reanalysis of tephra fallout from the Mount St. Helens 18 May 1980 (MSH80) eruption. In addition, we collate all the data needed to model distal ash sedimentation from the MSH80 eruption cloud. Four particle size subpopulations were present in distal fallout with modes at 2.2 Φ, 4.2 Φ, 5.9 Φ, and 8.3 Φ. Settling rates of the coarsest subpopulation closely ...


Ice Nucleation And Overseeding Of Ice In Volcanic Clouds, Adam J. Durant, R. A. Shaw, William I. Rose, Y. Mi, G. G. J. Ernst May 2008

Ice Nucleation And Overseeding Of Ice In Volcanic Clouds, Adam J. Durant, R. A. Shaw, William I. Rose, Y. Mi, G. G. J. Ernst

Department of Geological and Mining Engineering and Sciences Publications

Water is the dominant component of volcanic gas emissions, and water phase transformations, including the formation of ice, can be significant in the dynamics of volcanic clouds. The effectiveness of volcanic ash particles as ice-forming nuclei (IN) is poorly understood and the sparse data that exist for volcanic ash IN have been interpreted in the context of meteorological, rather than volcanic clouds. In this study, single-particle freezing experiments were carried out to investigate the effect of ash particle composition and surface area on water drop freezing temperature. Measured freezing temperatures show only weak correlations with ash IN composition and surface ...


Atmospheric Chemistry Of A 33–34 Hour Old Volcanic Cloud From Hekla Volcano (Iceland): Insights From Direct Sampling And The Application Of Chemical Box Modeling, William I. Rose, Genevieve A. Millard, Tamsin A. Mather, Donald E. Hunton, Bruce Anderson, Clive Oppenheimer, Brett F. Thornton, Terrence M. Gerlach, Albert A. Viggiano, Yutaka Kondo, Thomas M. Miller, John O. Ballenthin Oct 2006

Atmospheric Chemistry Of A 33–34 Hour Old Volcanic Cloud From Hekla Volcano (Iceland): Insights From Direct Sampling And The Application Of Chemical Box Modeling, William I. Rose, Genevieve A. Millard, Tamsin A. Mather, Donald E. Hunton, Bruce Anderson, Clive Oppenheimer, Brett F. Thornton, Terrence M. Gerlach, Albert A. Viggiano, Yutaka Kondo, Thomas M. Miller, John O. Ballenthin

Department of Geological and Mining Engineering and Sciences Publications

On 28 February 2000, a volcanic cloud from Hekla volcano, Iceland, was serendipitously sampled by a DC-8 research aircraft during the SAGE III Ozone Loss and Validation Experiment (SOLVE I). It was encountered at night at 10.4 km above sea level (in the lower stratosphere) and 33–34 hours after emission. The cloud is readily identified by abundant SO2 (≤1 ppmv), HCl (≤70 ppbv), HF (≤60 ppbv), and particles (which may have included fine silicate ash). We compare observed and modeled cloud compositions to understand its chemical evolution. Abundances of sulfur and halogen species indicate some oxidation of sulfur ...


Halogen Emissions From A Small Volcanic Eruption: Modeling The Peak Concentrations, Dispersion, And Volcanically Induced Ozone Loss In The Stratosphere, G. A. Millard, T. A. Mather, D. M. Pyle, William I. Rose, B. Thornton Oct 2006

Halogen Emissions From A Small Volcanic Eruption: Modeling The Peak Concentrations, Dispersion, And Volcanically Induced Ozone Loss In The Stratosphere, G. A. Millard, T. A. Mather, D. M. Pyle, William I. Rose, B. Thornton

Department of Geological and Mining Engineering and Sciences Publications

Aircraft measurements in the Hekla, Iceland volcanic plume in February 2000 revealed large quantities of hydrogen halides within the stratosphere correlated to volcanic SO2. Investigation of the longer-term stratospheric impact of these emissions, using the 3D chemical transport model, SLIMCAT suggests that volcanic enhancements of H2O and HNO3 increased HNO3·3H2O particle availability within the plume. These particles activated volcanic HCl and HBr, enhancing model plume concentrations of ClOx (20 ppb) and BrOx (50 ppt). Model O3 concentrations decreased to near-zero in places, and plume average O3 remained 30% lower after two weeks. Reductions in the model O3column reduced UV ...


Advantageous Goes Ir Results For Ash Mapping At High Latitudes: Cleveland Eruptions 2001, Yingxin Gu, William I. Rose, David J. Schneider, Gregg J. S. Bluth, M. I. Watson Jan 2005

Advantageous Goes Ir Results For Ash Mapping At High Latitudes: Cleveland Eruptions 2001, Yingxin Gu, William I. Rose, David J. Schneider, Gregg J. S. Bluth, M. I. Watson

Department of Geological and Mining Engineering and Sciences Publications

The February 2001 eruption of Cleveland Volcano, Alaska allowed for comparisons of volcanic ash detection using two-band thermal infrared (10–12 μm) remote sensing from MODIS, AVHRR, and GOES 10. Results show that high latitude GOES volcanic cloud sensing the range of about 50 to 65°N is significantly enhanced. For the Cleveland volcanic clouds the MODIS and AVHRR data have zenith angles 6–65 degrees and the GOES has zenith angles that are around 70 degrees. The enhancements are explained by distortion in the satellite view of the cloud's lateral extent because the satellite zenith angles result in ...


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 Oct 2004

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 ...


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 Aug 2004

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 ...


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 Aug 2004

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 ...


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 May 2004

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 ...


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 Apr 2004

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 ...


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 Mar 2004

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 ...


Quantitative Shape Measurements Of Distal Volcanic Ash, William I. Rose, Colleen M. Riley, Gregg J. Bluth Jan 2003

Quantitative Shape Measurements Of Distal Volcanic Ash, William I. Rose, Colleen M. Riley, Gregg J. Bluth

Department of Geological and Mining Engineering and Sciences Publications

Large-scale volcanic eruptions produce fine ash (< 200 μm) which has a long atmospheric residence time (1 hour or more) and can be transported great distances from the volcanic source, thus, becoming a hazard to aircraft and public health. Ash particles have irregular shapes, so data on particle shape, size, and terminal velocities are needed to understand how the irregular-shaped particles affect transport processes and radiative transfer measurements. In this study, a methodology was developed to characterize particle shapes, sizes , and terminal velocities for three ash samples of different compositions. The shape and size of 2,500 particles from 1) distal fallout (~100 km) of the October 14, 1974 Fuego eruption (basaltic), 2) the secondary maxima (~250 km) of the August 18, 1992 Spurr eruption (andesitic), and 3) the Miocene Ash Hollow member, Nebraska (rhyolitic) were measured using image analysis techniques. Samples were sorted into 10 to 19 terminal velocity groups (0.6-59.0 cm/s) using an air elutriation device. Grain size distributions for the samples were measured using laser diffraction. Aspect ratio, feret diameter, and perimeter measurements were found to be the most useful descriptors of how particle shape affects terminal velocity. These measurement values show particle shape differs greatly from a sphere (commonly used in models and algorithms). The diameters of ash particles were 10-120% larger than ideal spheres at the same terminal velocity, indicating that irregular particle shape greatly increases drag. Gas-adsorption derived surface areas are 1 to 2 orders of magnitude higher than calculated surface areas based on measured dimensions and simple geometry, indicating that particle shapes are highly irregular. Correction factors for surface area were derived from the ash sample measurements so that surface areas calculated by assuming spherical particle shapes can be corrected to reflect more realistic values.


Sizes And Shapes Of 10-Ma Distal Fall Pyroclasts In The Ogallala Ggroup, Nebraska, William I. Rose, C. M. Riley, S. Dartevelle Jan 2003

Sizes And Shapes Of 10-Ma Distal Fall Pyroclasts In The Ogallala Ggroup, Nebraska, William I. Rose, C. M. Riley, S. Dartevelle

Department of Geological and Mining Engineering and Sciences Publications

Size distributions of distal ashfall particles from correlated 10-Ma layers in Nebraska, measured using laser diffraction methods, are lognormal with mode diameters of ∼90 mm. This ashfall is ∼100% bubble-wall shards of rhyolite glass and apparently represents a distal ashfall from an eruption 1400 km away. Measured terminal velocities of these ash particles are 0.2–18 cm/s, consistent with Stokes Law settling of spherical particles with diameters of 9–50 mm. Surface area of the ash particles, measured with gas adsorption, is 20–30 times the surface area of equivalent Stokes spheres. These results highlight the effects of ...