American Geophysical Union Convention in San Francisco

Michigan Tech professors and students presented papers at the American Geophysical Union annual meeting. Geology and geological engineering students presented papers on: Gas and ash emissions, Remote Sensing, Seismic Monitoring, Lahar hazards, Volcanic Aerosols, Dome morphology. Travel for the presenters to the AGU Meeting in San Francisco was thanks to: MTU Graduate School, Remote Sensing Institute, and the GMES Department.

 Shown at left is part of the group that attended, these being the volcanology contingent Shown in this series of photos above and left, is the Michigan Tech booth at the AGU convention.

Following are the some of the paper titles, names of presenters and the abstracts:

Observing Popocatepetl's Volcanic Clouds Using MODIS Infrared Data
Matiella, M , Michigan Tech

Rose, W I, Michigan Tech

Watson, I, Michigan Tech

Popocatepetl Volcano, Mexico, is a tropical volcano with significant and persistent
emissions of SO2 and ash. These emissions pose significant hazards to the
large population in close proximity to the volcano and are an important indicator of
eruptive activity (Love et al., 1998, Nature 396: 563-566). Moderate Resolution
Imaging Spectroradiometer (MODIS) satellite imagery provides us with a synoptic
perspective of volcanic emissions and atmospheric interactions, information
unavailable from ground-based or aircraft studies, which can be useful for hazard
mitigation. We report on MODIS data during December 2000 and January 2001
coincident with abundant emissions based on COSPEC data. SO2 masses are
retrieved using the 7.3 mm and 8.6 mm absorption features of SO2
(7.3 $\mu$m method after Prata et al, in press, AGU Volcanism Atmospheric
Monograph; 8.6 mm method after Realmuto et al, 1997, J. Geophys Res 102:
15057-15072). Ash masses are retrieved using silicate absorption features at 11mm and 12 mm (Wen \& Rose, 1994, J Geophys Res 99: 5421-5431).
Furthermore, this data set tests the accuracy of the algorithms and the conditions
under which the algorithms work best, and can be compared to COSPEC
measurements taken by Popocatepetl's monitoring team. We found that MODIS data
often showed more than one volcanic cloud. For example, one MODIS image collected
January 23rd, 2001, at 0450 UT, shows four large eruptions that have dispersed
volcanic clouds over an extensive area of Mexico. Using upper air data and monitoring
records, the movements of the 4 ash clouds are fit with eruption times and winds,
and using retrieval data for SO2 and ash we can derive a time based SO2
and fine ash emission record. The results of these retrievals compliment
ground-based measurements which cannot measure large scale eruptions.

Using Internet-Based Automated Software to Process GPS Data at Michigan Tech University
Crook, A, Michigan Tech

Diehl, J F, Michigan Tech

The Michigan Tech University GPS monument was made operational in October of
2002. The monument, which consists of a concrete pillar extending approximately 10
feet below the surface and protrudes 5 feet above ground, is located at the
Houghton County Memorial Airport (47.171803 degreesN, 88.498361 degrees W). The
primary purpose of the monument is to measure the velocity of the North American
Plate at this location. A Trimble 4000ssi geodetic receiver with a Trimble Zephyr
antenna is used to collect GPS data. The data are sent to a PC where they are
processed using Auto-GIPSY, an internet-based GPS processing utility, which makes
it possible to process GPS data, via email, without having knowledge of how the
software works. Two Perl scripts were written to facilitate automation and to simplify
processing of the GPS data even further. Twelve months of GPS data were
processed, using Auto-GIPSY, which produced a velocity of -24 - 5 mm/yr and
-4 - 6 mm/yr for the X and Y components respectively with an azimuth of
261 degrees with respect to the ITRF2000. This calculated result compares well with
the NNR-NUVEL1A velocity of -17 mm/yr and -1 mm/yr for the X and Y components
respectively with an azimuth of 267 degrees. The results from an alternative online
processing service, the Scripps Coordinate Update Tool (SCOUT) that uses GAMIT,
will also be presented as a comparative method.

Elevated Uranium in Aquifers of the Jacobsville Sandstone
Sherman, H, Michigan Tech

Gierke, J, Michigan Tech

The EPA has announced a new standard for uranium in drinking water of 30 parts per
billion (ppb). This maximum contaminant level (MCL) takes effect for community water
supplies December 2003. The EPA's ruling has heightened awareness among
residential well owners that uranium in drinking water may increase the risk of kidney
disease and cancer and has created a need for a quantified, scientific understanding
of the occurrence and distribution of uranium isotopes in aquifers. The authors are
investigating the occurrence of elevated uranium in northern Michigan aquifers of the
Middle Proterozoic Jacobsville sandstone, a red to mottled sequence of sandstones,
conglomerates, siltstones and shales deposited as basin fill in the 1.1 Ga Midcontinent
rift. Approximately 25% of 300 well water samples tested for isotopic uranium have
concentrations above the MCL. Elevated uranium occurrences are distributed
throughout the Jacobsville sandstone aquifers stretching across Michigan's Upper
Peninsula. However, there is significant variation in well water uranium concentrations
(from 0.01 to 190 ppb) and neighboring wells do not necessarily have similar
concentrations. The authors are investigating hydrogeologic controls on ground water
uranium concentrations in the Jacobsville sandstone, e.g. variations in lithology,
mineralogy, groundwater residence time and geochemistry. Approximately 2000' of
Jacobsville core from the Amoco St. Amour well was examined in conjunction with the
spectral gamma ray log run in the borehole. Spikes in equivalent uranium (eU)
concentration from the log are frequently associated with clay and heavy mineral
layers in the sandstone core. The lithology and mineralogy of these layers will be
determined by analysis of thin sections and x-ray diffraction. A portable
spectrometer, model GRS-2000/BL, will be used on the sandstone cliffs along Lake
Superior to characterize depositional and lithologic facies of the Jacobsville sandstone
in terms of concentrations and ratios of eU, eTh and K. Equipped with borehole
accessories, the spectrometer will be used to log residential drinking wells to
determine a relationship between the uranium concentration of well water and the eU
concentration in the sandstone. Tritium/helium-3 dating will be used to determine
whether ground water uranium concentrations increase with residence time.
PHREEQCI will be used to model dominate aqueous species of uranium and saturation
indices of uranium minerals.

Analysis of the impact of soil heterogeneity on optimal policies for groundwater remediation
Bau, D, Michigan Tech,

Mayer, A S, Michigan Tech

Typical groundwater remediation problems involve the design of the number, location
and flow rate schedule of pumping and injection wells. Simulation models combined
with optimization models are used to rank alternatives while considering management
objectives, e.g. minimizing remediation cost and/or maximizing cleanup efficiency, and
constraints, e.g. the maximum permissible concentrations at selected compliance
sites. Mostly due to both high computational effort required and lack of data, the
simulation models often are based on simplified 2D homogeneous hydrogeologic
settings. The purpose of this work is to investigate how simplifying hypotheses may
affect the final optimal remediation policy. In particular, the analysis addresses the
case of a heterogeneous layered aquifer versus an homogeneous one with an
equivalent (lumped) hydraulic conductivity. To simulate groundwater flow and
contaminant transport, use is made of a fully 3D finite element unsaturated flow
model along with a particle tracking transport code. The flow and transport code is
then coupled to a genetic algorithm model to optimize the specified objective
function. The problem considered is the remediation of a hypothetical
aquifer-contaminant system using pump and treat. The objective is to minimize the
cost of the remediation system. The cost function is a nonlinear function of decision
variables (pumping rates) and state variables (hydraulic heads and contaminant
concentrations). Constraints include limits on hydraulic head and the contaminant
mass remaining in the aquifer at the end of the remediation. The results of
homogeneous and heterogeneous simulations are compared in terms of cost and
values of the decision variables.

Santiaguito Volcano, Guatemala: A Study of Vent Dynamics Over the Past 50 Years

Dalton, M P, Michigan Tech

Bluth, G J, Michigan Tech

Rose, W I, Michigan Tech

October 1902 marked one of the Earth's largest historic eruptions at Santa Maria
volcano, Guatemala. Since 1922, volcanic dome extrusion has been occurring on the
southwest flank of Santa Maria from the continuously active Santiaguito vent
system. Dangerous activity including vertical ash eruptions, avalanches, lava flows,
and pyroclastic flows has been persistent from Santiaguito, requiring observations of
the volcano to be carried out from a distance. Consequently, our understanding of
subsurface processes, such as the shape, size, and position of the magma body and
conduit systems must be inferred by remote measurements. There may be a
correlation at Santiaguito between the effects of subsurface conduit dynamics on
summit vent morphology and subsequent volcanic activity. Our recent observations
have identified the presence of a ring-shaped vent, approximately 150m wide, within
the Santiaguito summit dome, which is thought to represent the surface expression of
a series of fractures generated from the conduit at depth. Thus, a time series of
surface observations of vent geometry and observations of volcanic activity could
help constrain the near surface conduit evolution. An archive of aerial photos from
1947 to 2000, photographs of vent activity from 1969 to present, and 11 hours of
digital video from 2002 and 2003 volcanic activity at Santiaguito will be analyzed to
discover how these observations are related. The objective of this project will be to
better understand the conduit evolution at Santiaguito volcano by documenting
changes in vent morphology over the last 50 years and to correlate these findings
with eruptive history. These results can be further correlated with gas, thermal,
seismic, and other geophysical studies, calculations of dome volume and dome
dimensions, and predictive modeling of Santiaguito's volcanic activity.

Photometric Observations of Aerosol Plumes From Volcanoes in Guatemala, El Salvador, and Nicaragua
Lopez, T M, Michigan Tech

Watson, I, Michigan Tech

Rodriguez, L A, Michigan Tech

Branan, Y K, Michigan Tech

Rose, W I, Michigan Tech

Bluth, G J, Michigan Tech

Visible to near infrared sun-photometers were used to measure spectral optical
depths in order to infer particle size distributions of volcanic aerosols in plumes from
volcanoes in the Central American arc. Data were taken from the following volcanoes
on the listed dates in 2002: Pacaya, Guatemala on January 14, 16, 20 and 21; Santa
Ana, El Salvador on January 24 and 26; San Miguel, El Salvador on January 28; and
San Cristobal, Nicaragua on February 3. These volcanoes were chosen for study
because of: good calibration of the sun-photometer (Pacaya), the presence (and
effects) of a crater lake (Santa Ana) and a paucity of previous measurements (San
Miguel and San Cristobal). The optical properties of these tropospheric volcanic
aerosols will be retrieved after the removal of the background optical depth. Through
the application of the Angstrom equation and a King-type inversion, the Angstrom
coefficients, the particle size distribution, and the effective radius (Reff) will be
determined (Watson and Oppenheimer, 2000; 2001). Through these methods we hope
to increase the understanding of emission and conversion processes of tropospheric
volcanic aerosols. We hope the interpretation of these data will help elucidate
environmental and climatic effects of these aerosols on local to global scales, and
provide insight into modulation of aerosol emissions through the presence of a crater
lake.

Detection and Fate of the August 18 and 28, 2000 Eruption Clouds of Miyakejima, Japan: An Analysis Using TOMS, MODIS, AVHRR, GMS, and ASTER

McCarthy, E, Michigan Tech

Bluth, G, Michigan Tech

Watson, I, Michigan Tech

Rose, W, Michigan Tech

Tupper, A, Darwin Volcanic Ash Advisory Centre, Commonwealth Bureau of Meteorology, Northern
Territory Regional Office, Casuarina, NT 0811 Australia

Kamada, Y, Tokyo Volcanic Ash Advisory Center, Japan Meteorological Agency, Tokyo, Japan

Volcanic eruptions eject ash, sulfur dioxide, and other gases into the atmosphere.
These volcanic products create a variety of hazards, including health and aviation
hazards and changes in climate. Some of the major questions regarding the mitigation
of these hazards include: the mass, extent, and height of the cloud, how long it
takes for SO2 to convert to sulfuric acid, and how long aerosols remain in the
atmosphere. Remote sensing techniques allow: long-term tracking of volcanic clouds
because data are acquired on a regular basis, analysis of eruptions in isolated areas,
and measurements of an entire eruption cloud. New techniques for retrievals have
been developed and new sensors have been launched, however, there has been no
systematic comparison to understand the capabilities of the sensors under varying
environmental and volcanological conditions. In this case study of Miyakejima, Japan,
data from five different satellite sensors are compared and used to produce
constraints on the masses and distributions of ash, SO2, and aerosols released
by the August 18 and 28, 2000 eruptions. Satellite data include: 6 TOMS, 6 MODIS,
11 AVHRR, and 2 ASTER images, as well as 8 days of hourly GMS images. Preliminary
results, comparing TOMS and MODIS, show the August 18 ash and gas cloud drifting
south. Retrievals using the two sensors suggest an ash mass of at least 26 kilotonnes
(kt). The August 28 eruption cloud drifted to the northeast and contained
approximately 11 kt of SO2.

Correlation of SO2 Gas Emissions, Seismicity and Thermal Signals at Santiaguito, Guatemala
Branan, Y K, Michigan Tech

Watson, I , Michigan Tech

Harris, A J, University of Hawai'i, Hawai'i Institute of Geophysics and Planetology

Rose, W, Michigan Tech

Bluth, G J, Michigan Tech

Chigna, G, Insituto Nacional de Sismologia, Vulcanologia, Meteorologia y Hidrologia, Guatemala City, Guatemala

Mota, M, Insituto Nacional de Sismologia, Vulcanologia, Meteorologia y Hidrologia, Guatemala City, Guatemala

With vertical explosions occurring approximately every 40-50 minutes, the Santiaguito
dome at Santa Maria Volcano is an ideal system for examining short-term data
patterns. A 3-week long field experiment was performed in January 2003 at the
Santiaguito Volcano Observatory in order to record high temporal resolution
measurements of volcanic activity. We collected digital seismic data from a single
vertical component seismometer located approximately 4 km southeast of the active
Caliente vent. A portable infrared thermal monitoring unit was deployed daily to
record the temperature of the plume as it left the vent at an acquisition rate of 300
measurements per minute. A miniature ultraviolet spectrometer (MUSE) was also
deployed daily to measure the SO$_{2}$ gas emissions just above the vent. This
instrument is based on the differential optical absorption spectroscopy (DOAS)
technique and allowed for continuous readings at a rate of 36 measurements per
minute from approximately 6.5 km south of the Caliente vent. At abstract time, the
seismic data is not analyzed, but there is a strong correlation between the SO$_{2}$
emission and thermal data showing that the expulsed gas heats the dome extensively
as it is emitted, with a possibility of different signatures indicating certain types of
activity such as pyroclastic flows. It is expected that, with the addition of seismic
data and the application of analysis of periodicity using Fourier Transforms, the data
will elucidate conduit processes, providing additional vital constraints to sub-surface
models.

SO2 loss rates at Lascar volcano, Chile: preliminary results and interpretations from 2002 measurements

Rodriguez, L A, Michigan Tech

Watson, I, Michigan Tech

Tassi, F, Dipartimento di Scienze della Terra, Universita degli Studi di Firenze, Firenze,
Italy

Viramonte, J, Instituto GEONORTE, Facultad de Ciencias Naturales, Universidad Nacional de Salta, Buenos Aires, Salta, Argentina

Poodts, M, Instituto GEONORTE, Facultad de Ciencias Naturales, Universidad Nacional de Salta, Buenos Aires, Salta, Argentina

Rose, W I, Michigan Tech

Bluth, G J, Michigan Tech

The measurement of volcanic SO2 emission rates is commonly performed on
cross sections of the plume some distance downwind from the active vent, some
time after its interaction with other volcanogenic gases (primarily water), particles
and droplets of volcanogenic and/or meteoric origin, and atmospheric gases. The
emission rates being measured therefore do not necessarily represent the real fluxes
emitted by the volcano; instead they are underestimated due to the conversion of
SO2 to SO4 (Oppenheimer et al., 1998). Near source plume
chemistry is not well understood, but can have significant effects on climatologically
active species, which is why it is important to quantify volcanic SO2$conversion rates as a function of meteorological environment and plume age. A mini-UV spectrometer and a Microtops II sun photometer were used to measure SO2 emission rates and aerosol particle size distributions at Lascar volcano, Central Andes, during the months of October and November 2002. Direct gas measurements from fumaroles in the crater were made on November 1. These represent the first gas samples ever collected directly in the crater. Lascar volcano represents one of the end-members of the environmental spectrum, being a high volcano (summit altitude at 5600 meters above sea level) in a dry atmosphere (average 15). Its location allows for simultaneous near-vent and downwind measurements at similar altitudes. Here we present our preliminary results from November 2, 2002, taken at a variety of azimuthal angles (effective distances from the plume) from the vent downwind to about 20 km, during a two-hour period (0900-1100 local time). This represents a time downwind of up to 42 minutes, based on a plume speed of 8 m/sec. Initial interpretations and correlations with the direct measurements are also presented. The data obtained from a Kestrel 4000 weather station will help clarify the effects of Lascar's high, dry, and extremely transmissive atmosphere upon SO2 conversion rates. Landsat TM and ETM+ Time Sequence of Lahar Hazards on Fuego Volcano, Guatemala Reif, S L, Michigan Tech Bluth, G J, Michigan Tech Rose, W I, Michigan Tech Matias, O, INSIVUMEH, Guatemala, Guatemala Volcanic hazards pose a threat to a large number of the world's population, especially secondary hazards due to remobilization of volcanic material such as landslides and lahars. Many hazard-prone areas would benefit by remote sensing tools for hazard mitigation. In this study, we propose to use remote sensing and GIS techniques to map these hazard prone areas around Fuego volcano, Guatemala and provide information to local organizations to assist in mitigation. Fuego is a steep sided volcano with a history of large eruptive events, including the well-studied 1974 eruption, that have extruded a large amount of material onto the upper reaches of its watersheds. The volcano is well studied, but historically more emphasis has been placed on eruption processes. A study of the way material moves down Fuego and to the extent that it moves is needed to help mitigate the range of potential hazards. We propose an in-depth remote sensing survey to map the hazard-prone areas. The study will consist of processing 20 years (15 cloud-free images) of Landsat TM and ETM+ data to look at changes in landforms and vegetation. Vegetation indices will be calculated to locate areas devoid of vegetation and a masking process will be used These area changes will be related to field measurements to create GIS to measure the area of these zones. layers denoting geometry changes in the channels around Fuego. These changes will be loaded into a GIS, along with regional climate data, DEMs, hydrologic data, infrastructure, and information about the known volcanic activity recorded in the area by the local volcanologists. Modeling of lahars using LAHARZ and climate data will also be done to determine an estimate of the amount of material moved and to what distances it can be transported. A field survey undertaken in January 2003 acquired GPS ground truth data of landslide boundaries and channel volumes for the GIS. The deposits that were seen in the channels 10 km from the source of the sediment ranged in thickness from 1.5-8 m. Forward modeling of volcanic aerosols transmissions at different latitudes; quantifying the effects of varying tropospheric water vapor on ash detection. Watson, I M, Michigan Tech Rose, W I, Michigan Tech Realmuto, V J, Visualization and Scientific Animation Group, Jet Propulsion Laboratory, Pasadena, CA Bluth, G J, Michigan Tech Current algorithms for volcanic ash cloud detection by satellite, based upon a difference in transmissivity of silicate ash at 11 and 12 microns, are subject to significant and yet poorly quantified modulation by atmospheric water vapor. In order to investigate these effects we have written an aerosol forward model, based upon Mie-scattering code, and embedded it in a MODTRAN-based atmospheric radiative transfer model. This facilitates investigation of errors associated with inverse solutions derived from satellite data, and more importantly for this study, can be used to vary the atmosphere within which a hypothetical volcanic ash cloud is contained. We have taken images of the most well parameterized ash clouds of the satellite age, the sequence of eruptions of Mt. Spurr in mid to late 1992, and applied the forward model to predict transmission spectra of the ash clouds. Calculations were performed for the ash clouds both within the cloud's original atmosphere and within that of a sequence of eruptions of Soufriere Hills Volcano, Montserrat, in the British West Indies in the late 1990s. Preliminary results indicate a +1-3.5 K brightness temperature difference (BTD) effect associated with increasing the temperature and water vapor content of the atmosphere. This translates to a significant loss of detectability in terms of cloud area; up to half the area of the clouds no longer have a negative brightness temperature difference, and an effect on reducing the optical depth and mass of the cloud. In most cases there was very good agreement between the 'clear ocean' BTD and the modeled effect, suggesting a potential source of in-image calibration for detection algorithms. In terms of mass and optical depth retrievals however, it is obvious that both 11 and 12 micron channel radiances are affected by the presence of water vapor, clearly indicating the need for atmospheric correction before quantifying the size or concentration of ash in clouds from satellite data. Volcanic SO2 Emissions vs. Seismicity - July 2002 LP Swarm, Soufriere Hills Volcano, Montserrat Shannon, J, Michigan Tech Bluth, G, Michigan Tech Edmonds, M, Montserrat Volcano Observatory, Fleming, Montserrat, W. Indies Thompson, G, British Geological Survey, Keyworth, Nottingham, NG125GG United Kingdom Volcanic sulfur dioxide (SO2) measurements of passive plumes have recently improved with the application of Differential Optical Absorption Spectroscopy (DOAS). In January 2002, the Montserrat Volcano Observatory installed two fixed DOAS instruments which collect rapid, continuous measurements of SO2 emissions. For the first time, SO2 fluxes are being collected on a time scale of minutes, allowing short-term changes to be evaluated with respect to atmospheric transport, surface activity, and magmatic source mechanisms. In this study, we investigate relationships between SO2 emissions and seismicity for July 2002 at Montserrat. The seismic data consist of rockfall, long-period rockfall, hybrid, and long-period (LP) waveforms. Seismic energy increased slowly throughout July, culminating in a swarm of long-period earthquakes. The SO2 data used for this study consist of measurements collected every 4-5 minutes from approximately 8 a.m. to 5 p.m. daily by a DOAS instrument positioned at Lovers Lane (~4.5 km west of vent). From July 1-18, seismicity is dominated by rockfalls with intermittent hybrids and LPs. During this time, SO2 fluxes generally increase and coincide with an increasing trend in the number of rockfalls per day. Average daily SO2 fluxes range from 140 to 1256 tonnes/day with an average of 616 tonnes/day. On July 19, however, the average daily SO2 flux decreases from a monthly maximum of 1256 tonnes/day to 227 tonnes/day and continues to average only 326 tonnes/day from July 20-30. July 19 marks a seismic transition into a LP earthquake swarm that continues into August. After the LP swarm begins and SO2 fluxes decrease, however, the number of daily rockfalls remains relatively high. Therefore, it appears that LPs are more strongly linked to SO2 emissions than rockfall activity. Future work will involve investigating short-term (minutes/hours) relationships between seismicity and SO2 emissions. Quantifying Volcanic Emissions of Trace Elements to the Atmosphere: Ideas Based on Past Studies Rose, W I, Michigan Tech Extensive data exist from volcanological and geochemical studies about exotic elemental enrichments in volcanic emissions to the atmosphere but quantitative data are quite rare. Advanced, highly sensitive techniques of analysis are needed to detect low concentrations of some minor elements, especially during major eruptions. I will present data from studies done during low levels of activity (incrustations and silica tube sublimates at high temperature fumaroles, from SEM studies of particle samples collected in volcanic plumes and volcanic clouds, from geochemical analysis of volcanic gas condensates, from analysis of treated particle and gas filter packs) and a much smaller number that could reflect explosive activity (from fresh ashfall leachate geochemistry, and from thermodynamic codes modeling volatile emissions from magma). This data describes a highly variable pattern of elemental enrichments which are difficult to quantify, generalize and understand. Sampling in a routine way is difficult, and work in active craters has heightened our awareness of danger, which appropriately inhibits some sampling. There are numerous localized enrichments of minor elements that can be documented and others can be expected or inferred. There is a lack of systematic tools to measure minor element abundances in volcanic emissions. The careful combination of several methodologies listed above for the same volcanic vents can provide redundant data on multiple elements which could lead to overall quantification of minor element fluxes but there are challenging issues about detection. For quiescent plumes we can design combinations of measurements to quantify minor element emission rates. Doing a comparable methodology to succeed in measuring minor element fluxes for significant eruptions will require new strategies and/or ideas. Integration of Seismic and Video Records of Eruptive Activity on Santiaguito Volcano, Guatemala Dalton, M P, Michigan Tech Head, E M, Michigan Tech Bluth, G J, Rose, Michigan Tech W I, Molina, E, INSIVUMEH, Guatemala City, Guatemala Toorongian, J E, Michigan Tech Santiaguito is a long-lived, dacitic volcanic dome complex, which has now been continuously active since 1922. The volcano's longevity is thought to be related to a large magma body and the pattern of extrusion is notably unsteady. Direct observations of activity are inhibited by logistics, such as cloudy weather at proximal vantage points after mid morning. Activity observable at Santiaguito each morning includes multiple vertical explosions, dome and flow collapses leading to block and ash flows or rock avalanches, steam exhalations and fumarolic discharges. These phenomena were recorded on digital video from an excellent vantage point (the summit of Santa Maria) located 1200 m above and 2.5 km NE of the active Caliente Vent of Santiaguito for about three hours on the morning of January 11, 2003, and from El Brujo Vent, located$\sim$200 m below and 1.2 km W for about four hours on the morning of January 9, 2003. The volcano is also ismically monitored, and we have synchronized the video with digital seismic data processed through the Seisan computer program. Our expected result is a correlated record of seismic data and visually-identified eruptive activity, allowing us to evaluate eruption characteristics. This will be in the form of a digital video of surface activity on Santiaguito with corresponding seismic signals, which will be applicable for education and scientific analysis. By correlating seismic signals to eruptive activity, monitoring agencies that are distant from the volcano can better interpret the incoming seismic data, and communicate a more complete picture of volcanic activity to the surrounding communities. It also allows us to go back through the seismic record from Santiaguito and catalog past eruptive activity. A synchronized seismic and eruptive activity video is also a valuable educational/ outreach tool. With the technique for correlating video and seismic records established, additional types of data (such as temperature and gas readings) can be compared as well. Modeling Of LARSE II Refraction Data In The Western Mojave Desert, California Lim, K, Michigan Tech Lim, K., USGS, 345, Menlo Park, CA Baher, S, USGS, 3 Menlo Park, CA Fuis, G, USGS, Menlo Park, CA The major goals of the LARSE II (Los Angeles Region Seismic Experiment, Part II) are to image the subsurface in Los Angeles region utilizing reflection and refraction surveys, to understand the detailed structure of the subsurface in relation to earthquakes. LARSE II data acquisition was accomplished in October 1999 along the 150km long main line that extended from Santa Monica Bay to the western Mojave Desert. We modeled LARSE II refraction data in the western Mojave Desert using a forward modeling technique, fitting the first arrivals in most cases less than 0.05 second. In general, layers were modeled to match the breaks in slope of the first arrival branches. Three layers over basement were modeled. They have velocities or velocity ranges (in km/s) of 1.0 or less (Layer 1), 2.0-3.4 (Layer 2) and 3.3-3.9 (Layer 3). Preliminary interpretations are as follow: Layer 1, up to 0.2km thick, is unsaturated, unconsolidated Quaternary sediments. Layer 2 and 3, which thicken to a total of 1.5km in the central Mojave Desert, are Quaternary and Tertiary sedimentary rocks. An oil-test well in the southern Mojave Desert bottoms at the base of Layer 3 (1.04 km depth) in the Tertiary rocks. An oil-test well in the northern Mojave Desert bottoms in the basement (quartz diorite) at the depth of 1.01km. Upward steps in basements can be seen on the north and south sides of the western Mojave Desert, at or near mapped faults. In summary, maximum depth to basement is 1.7 km in the western Mojave Desert. TOMS and Volcanic SO2: an Important aid to the Understanding of Volcanism and the Atmosphere Rose, W I, Michigan Tech Bluth, G J, Michigan Tech It is impossible to measure gas fluxes from the ground in a major volcanic event, but the TOMS instrument provided the first quantitative measurements of individual stratospheric eruptions, because SO2 could be measured as well as O3. The measurements were quickly noticed by scientists, because the masses of sulfur erupted often far exceeded what they expected to find, based on petrology and its supposed constraints, by surprising factors of 10 to 100. This result is still not well understood, and is an important driving idea for volcanologic research. TOMS was applied globally and the explosive volcanic flux of SO2 to the atmosphere was compiled for the first time using direct measurements --an important input to earth systems analysis. Comparison of TOMS volcanic cloud SO2 maps with infrared volcanic ash cloud maps showed that there is often spatial separation of gas-rich volcanic clouds emplaced higher in the atmosphere and ash-rich clouds which are lower and which drift in different directions because of windshears. Sequential examination of TOMS data showed that SO2 masses in volcanic clouds increases for 24 hours or more after eruption. The best explanation of this increase is that ice which forms early in volcanic clouds captures SO2 which is then released again as the stratospheric ice sublimes. The presentation will document all of the best examples of the discoveries listed above. Volcanologists and those interested in the mitigation of volcanic cloud hazards have repeatedly suggested that geostationary SO2 and ash sensing capability at higher spatial resolution would provide important new science opportunities. The sensors of the next remote sensing era (MODIS, ASTER, SEVIRI, OMI, ABI) bring us closer to achieving these goals. The Role of TOMS in Understanding the Fates of Volcanic Emissions Bluth, G J, Michigan Tech Rose, W I, Michigan Tech Guo, S, Michigan Tech Carn, S , JCET, University of Maryland Baltimore County, Baltimore, MD The Total Ozone Mapping Spectrometer (TOMS) has observed over 100 eruption s during the past 25 years, from both explosive and effusive sources. The four TOMS instruments (Nimbus-7, Meteor, ADEOS, and Earth Probe) have gen erated an unprecedented archive of eruption data and allowed us to look at processes, in addition to describing individual events. The TOMS sensors are less affected by atmospheric water vapor and optical thickness than i nfrared techniques, and thus are able to return information on the cloud f rom it's early, most concentrated form, to dilute cloudmasses several days later. From the many observations and advances generated from TOMS data, here we document those which pertain to the first few days following emis sion into the atmosphere. Following discrete eruption events, we have observed that the mass of retr ieved SO2 often increases for 1-2 days, independent of any volcanic contri bution. Combining TOMS with other sensor data suggests that significant S O2 is sequestered by ice in the rising plume. Ablation of the ice slowly re-releases SO2, which results in the apparent increase. After 2-3 days, this process appears to be largely complete, and SO2 removal then follows an exponential decay rate. TOMS-derived removal rates of SO2 have ranged from approximately 25 days (e-folding time) for Pinatubo-sized eruptions, to less than one day for smaller or tropospheric eruptions. Within the sa me eruption this rate may vary, as SO2 removal is strongly affected by ads orption onto co-existing ash and ice particles. The removal processes can also be linked to an eruption height threshold, separating eruptions whic h are emplaced above the tropopause and produce potentially long-lasting a tmospheric impacts from those which are rapidly removed from the atmospher e. We have also observed that many eruptions produce a vertical separatio n of gas-rich and ash-rich phases. However, other events have produced no separation, suggesting that the separation may be linked to the eruption dynamics or an early, gas-enriched pulse rather than a post-eruption, grav itational process. Optimization of Engineering Design of Subsurface Environmental Remediation Systems: Development and Testing of Community Benchmark Problems Mayer, A S, Michigan Tech Miller, C T, Center for the Advanced Study of the Environment Department of Environmental Sciences and Engineering University of North Carolina, Chapel Hill, NC It is well established that the design of economically efficient subsurface remediation systems can benefit from the joint use of formal optimization and simulation models. It is also well known that obtaining the optimal solution for such designs is usually difficult and computationally expensive, due to the characteristic nonlinear, nonconvex nature of the solution spaces. We believe that more rapid progress on optimal design methods might result from both improved methods of evaluation and comparison of existing methods on realistic problems and from the investigation of novel methods not yet studied in subsurface remediation field. This work responds to these needs. We have designed a set of systematic test problems to be attacked by the engineering and mathematics community, as a means for benchmarking and comparing optimization approaches. The test problems pose many of the difficulties anticipated in solving real-world problems such as (a) mixed continuous and integer, nonlinear objective functions, (b) the combination of boundary conditions and system parameters gives rise to complex relationships between the objective function, the decision variables, the constraints, and the state variables, (c) evaluation of the objective function is based on solving model equations that are difficult to solve accurately and quickly; and (d) the number and range of decision variables is potentially enormous. The physical problems include water supply design problems in freshwater and freshwater-saltwater systems, a contaminant plume capture zone design problem, and a contaminant plume pump-and-treat design problem. Problem domains are specified in terms of hydraulic conductivity distributions- from homogeneous domains to spatially-correlated random fields- and in terms of confined vs. unconfined conditions. Each problem is specified completely in mathematical and numerical terms, but sufficient flexibility is allowed to provide for a wide range of problem solution approaches. For example, the user is free to select a flow and transport simulator and to specify spatial and temporal discretizations. This paper will describe the test problems and initial results. Lost in Loess: Paleomagnetic investigation into loess and tephra deposits in interior Alaska Semler, L, Michigan Tech., Arnold, K E, Dept. of Geology, Hamilton College, Clinton, NY Williams, D, Dept. of Geography and Geology, Indiana State Univ., Terre Haute, IN Morton, J, Dept. of Geology, College of William and Mary, Williamsburg, VA Layer, P W, Geophysical Institute, Univ. of Alaska Fairbanks, Fairbanks, AK Stone, D B, Geophysical Institute, Univ. of Alaska Fairbanks, Fairbanks, AK Beget, J, Geophysical Institute, Univ. of Alaska Fairbanks, Fairbanks, AK Schaefer, J , Alaska Div. of Geological and Geophysical Surveys, Fairbanks, AK As a part of a NSF-funded Research Experience for Undergraduates (REU) program at the University of Alaska Fairbanks, loess and tephra samples were collected at a road cut near Tok, Alaska, to determine if the site was suitable for paleoclimate reconstruction of the Pleistocene. Oriented cubes and cores were obtained from a section of loess just below the Sheep Creek tephra dated at 190$\pm$20 ka, through the Tetlin tephra (1.2 meters below the Sheep Creek tephra) dated at 630$\pm\$ 50 ka to two meters below the Tetlin tephra. The accumulated amount of
loess between dated tephra layers suggests a span of more than one million years
for the whole section assuming a constant sedimentation rate for the loess. The
samples were measured for natural remanent magnetization (NRM) and magnetic
susceptibility before magnetic cleaning techniques (Alternating Field Demagnetization
and Thermal Demagnetization) were employed. Samples were analyzed using a
cryogenic magnetometer. The demagnetizations show stable magnetic vectors and
demonstrate that loess is a reliable paleomagnetic recorder. At Tok, we found that
the entire section is of normal polarity and shows no sign of the 780 ka
Brunhes-Matuyama polarity reversal, which was expected to be 42 cm below the
Tetlin tephra. Absence of the reversal may be due to discontinuities or other
changes in the sedimentation rate in the loess, a problem with the sampling
methods, or incorrect ages of the tephras. Based on our studies, we feel that
changing rates of loess deposition or other unseen discontinuities are the reason the
reversal was not found. Because of the uncertainty of the depositional history of the
Tok loess, this section is not useful for obtaining a continuous record of ancient
climate.

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