Geosciences students/faculty dominated the 2009 Research Day presentations. They won the first and second places!
1st place: APPLICATION OF THE ANGLE DIFFERENCE METHOD FOR INTERACTIVE CHANGE DETECTION OF URBAN SPRAWL. Students: Sean McDermott*, Jason Ready (Environmental Studies); Jessica Nash, Jason Wallin (Geosciences). Faculty Advisor: Jeong C. Seong, Department of Geosciences. *presenting author. 2nd place: LAND USE AND URBANIZATION: CONTAMINANT TRENDS IN LAKE CORE SEDIMENTS OF LAKE PALMER AND LAKE HARRIET, MINNEAPOLIS, MN. Student: Ellie Busse. Department of Geosciences. Faculty Advisor: Pete vanMetre, US Geological Survey, Austin Texas.
The Sigma Xi Scientific Research Society, UWG Chapter, and Research Day
2009 SCIENCE STUDENT RESEARCH PRESENTATIONS
Thursday, March 5, 2009, Callaway 146
12:45 PM Introductory remarks, socializing, preparations for Session I talks
MINERALOGY OF FLOW BANDING AND SCANNING ELECTRON MICROSCOPE STUDY OF INCLUSIONS WITHIN TOPAZ CRYSTALS FROM THE TOPAZ RHYOLITE OF TOPAZ MOUNTAIN, JUAB COUNTY, UTAH
Student: Kimberly E. Cook. Faculty Advisor: Dr. Curtis Hollabaugh, Department of Geosciences Topaz Mountain, located in the Thomas Range of Juab County, Utah, contains extensive lava flows, domes, and tuffs. These structures, caused by the explosive eruptions of F-rich rhyolite lava, are approximately 6.5 million years in age, and are characterized throughout the area by complex flow banding. At outcrop scale, the flow banding is one of the most distinct features of Topaz Mountain and appears to have provided pathways for vapor transport, with crystal-lined vugs concentrated along the flow banding. Within the transported vapor, ions such as F, Si, O, Na, K, Fe, Mg, Ti, Al, Mn, Sr, Pb, Zr, Nb, Hf, Th, and U were able to flow into the vugs, creating not only phenocrysts of feldspar and quartz within the flow, but a plethora of vapor phase minerals within these spaces as well. Over the years, several specimens were collected for the purpose of research at UWG. The research included the creation of polished orthogonal thin sections of rhyolite and topaz crystals, examination with a polarizing microscope for mineral identification, which led to the use of scanning electron microscope to create an elemental map of the inclusions within the topaz. The first set of thin sections revealed that flow banding extended to microscopic level causing an alignment of small crystals within individual bands. The elemental maps were used to identify rare minerals such as pseudobrookite, bixbyite, zircon, and urano-thorite within not only the rhyolite flow, but individual topaz crystals as well.
LAND USE AND URBANIZATION: CONTAMINANT TRENDS IN LAKE CORE SEDIMENTS OF LAKE PALMER AND LAKE HARRIET, MINNEAPOLIS, MN
Student: Ellie Busse Faculty Advisor: Pete vanMetre, US Geological Survey, Austin Texas
The U.S. Geological Survey (USGS) has teamed up with the National Water Quality Assessment program (NAWQA) to complete a national study on lakes, reservoirs, and their watersheds. For over 10 years the USGS in Austin, TX has been studying the effects of urbanization on watersheds. Lake coring and paleolimnology have been used to better understand how water quality has changed within watersheds. This project focused on two lakes in Minneapolis, Minn. Each lake has very different land use and urban development impacting its watershed. Lake Palmer and Lake Harriet are the two lakes chosen for study. Lake Palmer is composed of two lobes, referred to as the east and west lobe. The east lobe has a pristine watershed with no urban development; this lobe represents a “reference” site. In contrast, the watershed of the west lobe has undergone rapid urban sprawl over the past 50 years, representing “new urban”. Lake Harriet was urbanized in the early 20th century; this watershed represents “old urban”. The two lakes are used in this study to compare the impact of different amounts and timing of urbanization. Lake cores were retrieved from Lake Harriet and both lobes of Lake Palmer in 1997. The deposited sediment was analyzed for organochlorine compounds (OCs), metals, radionuclides, and polycyclic aromatic hydrocarbons (PAHs) to investigate trends with land use and urbanization. The results demonstrate that water quality in Lake Harriet and the west lobe of Lake Palmer have been impacted by urban growth. Levels of DDT, PCBs, and lead increased with urbanization. The decrease in concentrations resulted from bans on leaded gasoline and use of DDT and PCBs. In contrast, concentrations of metals and chemicals in the east lobe of Palmer are low and unchanging, correlating to the lack of urbanization in the watershed. A more complex relationship is seen with PAHs, which have been steadily increasing. The increase is still being researched, but results have shown a clear correlation with increased urban sprawl.
PALEOPATHOLOGIES IN THE HOMININ FOSSIL RECORD
Student: Stephanie Blocker
Faculty Advisor: Lisa Paciulli, Department of Anthropology
EARLY POST-MORTEM CHANGES IN ALGAL MORPHOLOGY
Student: Ashley Manning
Faculty Advisor: Dr. Julie K. Bartley, Department of Geosciences
The Proterozoic fossil record is dominated by bacteria and single-celled planktonic eukaryotes (acritarchs), with a few occurrences of macroscopic remains. Acritarchs are generally considered to be eukaryotes, because of their morphological diversity, large size, and the presence of ornamentation in some taxa. However, the relatively simple morphology of these fossils makes them difficult to place securely within Eukaryota and even more challenging to connect these remains to extant taxonomic groups.
Earlier studies of acritarchs reveal the presence of complex cytoskeletal features, suggesting a eukaryotic affinity; other studies suggest that some taphonomic (post-mortem) features additionally support a eukaryotic origin. For example, some acritarchs show signs of folding and tearing of cell walls and deformation during compression that suggest a flexible cell wall and, perhaps, a eukaryotic origin.
In this project we seek to identify features that are preserved or created during early post-mortem decomposition of modern macroscopic eukaryotes. Modern algae were buried in marsh sediment to simulate a natural decomposition environment. Morphology and ultrastructure were observed biweekly via light microscopy and scanning electron microscopy. In several cases, details of cellular structure are lost during early stages of decomposition, making original morphology difficult to distinguish. In other cases, extracellular material decayed, producing a form whose cell wall ultrastructure was distinguishable. In all experimental cases, however, it was possible to recognize each form taxon by gross morphology, cellular organization and/or ultrastructure, suggesting that early decomposition does not obliterate significant morphological features and that features of acritarchs may provide positive evidence of eukaryotic affinity.
2:00 PM break Session II
SPATIO-TEMPORAL ANALYSIS OF WATER QUALITY CHANGE: CARROLL COUNTY, GA, 2001-2008 Students: Jason Wallin*, Terry Allison, (Geosciences); John Griffin (History); Sean McDermott (Environmental Studies); Carlos Rustrian (Economics); William Nutt (Political Sciences & Planning); Valerie Hayes (Biology)Faculty Advisor: Jeong C. Seong, Department of Geosciences
The Center for Water Resources at UWG has collected water quality data since 2001. Using the data collected, our research team analyzed the spatio-temporal patterns of water quality change in nine major water basins throughout Carroll County. The analysis focused on eight parameters found within those nine basins: pH, dissolved oxygen (DO), biochemical oxygen demand (BOD), cadmium (Cd), phosphorous (P), lead (Pb), nitrate nitrite nitrogen (NNN), and fecal coliform. Various techniques were used in the research including correlation analysis, contingency analysis, ANOVA, seasonal Mann-Kendall analysis, remote sensing, and geographic information systems (GIS). Correlation analysis showed more significant correlations amongst parameters in the summer than in the winter, especially with fecal coliform and P. Contingency analysis results showed significant annual and spatial dependencies in Pb and Cd. ANOVA tests were applied with pH, DO, BOD, NNN, fecal coliform, and P, and they showed significant differences over years and basins except for NNN. The (seasonal) Mann-Kendall analysis revealed annual increasing and decreasing trends amongst all parameters during 2001-2008. However, some parameters, such as P and fecal coliform, showed little to no significance in their respected trend. Remote sensing and GIS analyses enabled the visibility and mapping of basins showing high and low concentrations of contamination patterns, which in turn, led to the revealing of major factors contributing to the contamination, such as agricultural and urban land use. This research recognizes the importance of long-term, consistent monitoring and analysis of micro-level water quality changes.
APPLICATION OF THE ANGLE DIFFERENCE METHOD FOR INTERACTIVE CHANGE DETECTION OF URBAN SPRAWL Students: Sean McDermott*, Jason Ready (Environmental Studies); Jessica Nash, Jason Wallin (Geosciences)Faculty Advisor: Jeong C. Seong, Department of Geosciences
Detecting changes with bi-temporal satellite imagery provides both opportunity and challenge. Traditionally images were classified and results were compared; however, it is very time-consuming and accuracies are susceptible to various factors such as season, foliage, classification algorithm, sun angle, and operator. This research focused on the application of an angle difference method (ADM). As an interactive and fast change detection method, ADM uses angle deviation on the scatter plot of normalized bi-temporal bands. After developing the theoretical background of ADM, we tested its performance with 32 satellite imagery to find the best band, angle tolerance, and threshold value. We, specifically, focused on the urban sprawl around major cities in the world -- eight major city suburbs in the U.S. and the other eight around the world. Using bi-temporal (1984-2008) time-series images from Landsat 4, 5 and 7 satellites, we applied ADM to six band pairs in each bi-temporal image set. Results showed the best performance with bands 1 and 7. The best angles tolerance was between ±5 ~ ±7 from the 45o line in the scatter plot. The most productive threshold value that is used for removing shadow and salt/pepper effects during image comparison was between 0.4 and 0.5. The average performance of ADM with all bands was about 60%; however, it was about 85% with the best performing bands (i.e. bands 1 and 7). Urban sprawls were detected more easily in some suburbs than others. Specifically, Atlanta and Moscow were the easiest among the sixteen cities. ADM did not work well with the images with light cloud overcast (ex. Philadelphia) or in dry environment (ex. Phoenix). Specifically, vegetation and urban areas were significantly confused in dry areas. Considering vast amount of space/air-borne imagery collected daily, timely analysis of changes is very important. This research showed that ADM is a very effective approach in detecting changes when used carefully.
CREATING A HISTORICAL STORM SURGE DATA WEB SITE
Student: Andrew Maloof
Faculty Advisor: David M. Bush, Department of Geosciences
Researchers of hurricane impacts often encounter roadblocks when trying to evaluate storm surge history. The National Hurricane Center's Tropical Cyclone Reports contain comprehensive information on each storm, including synoptic history, meteorological statistics, casualties and damages, and the post-analysis best track (six-hourly positions and intensities) dating back only to 1958. Several federal agencies (FEMA, NOAA, Army Corps of Engineers) and some private companies and academic institutions have unpublished reports for some storms but not for all; and especially not for older hurricanes. Access to reports is difficult and even for archived storms the data is often sketchy at best. For early hurricanes a combination of lack of understanding of the importance, lack of reliable surveying devices, and the overwhelming need to concentrate on rescue and recovery efforts probably led to poor storm surge data. For more recent hurricanes, very precise storm surge measurements are available, but often there aren't enough of them, they are unreliable, estimated, or in error. Detailed reports of measurement methodology are often are lacking. Measurements from the fringes of the hurricane landfall area often are not made at all because of lower damages in these areas, and the deeming of such data as unimportant. A georeferenced database is being created of all storm surge measurements in the southeastern United States. All data are evaluated for quality, methodology, and usefulness for scientific inquiry. Links are established to reports, photos, and other pertinent documents. It is hoped that the database will provide the basis for statistical evaluation of the various factors impacting coastal storm surge. In addition, it will be a critical resource for numerical modelers who are in need of such data for model calibration and verification of predictive coastal flooding models. The web site is undergoing constant updating. The web address is www.stormsurgedatabase.org.
Constructed Wetland: A Model for Examining Filtration Efficiency and Quality
Faculty Advisor: Curtis Hollabaugh, Department of Geosciences
The United States Fish and Wildlife Service estimated in 2004 that there are more than 100 million acres of wetlands in the continental United States. Constructed wetlands built to filter treated sewage also become natural habitats, green spaces and wildlife refuges for communities. Wetland sewage reclamation facilities are extremely versatile, able to service a small community of ten or less homes or able to provide enough drinking water for a county with a population over 250,000 several systems of constructed wetlands. Constructed wetlands are much more efficient than the outdated land application method which requires 150 to 250 acres to treat one million gallons of water while the wetlands only require 15 to 25 acres to treat one million gallons of water. With the drought in the southeast, particularly the state of Georgia recycling wastewater is a great asset. More evidence that highlighting advantages of constructed wetlands is that Clayton County, Georgia's reservoir did not go below 77 percent at a time when other reservoirs in the metro Atlanta area fell below 50 percent during 2007-2008. As constructed wetlands become a more prominent treated sewage filtration system research must be done to improve filtration quality and efficiency. A small scale model was designed using Constructed Wetlands Treatment of Municipal Wastewater manual by the Environmental Protection Agency. A freshwater design was used for testing multiple parameters affecting the filtration quality and efficiency. The variables tested include grain size, roundness and different concentrations (high and low) of nutrients. 3:15 PM break
HISTORICAL CHANGES OF GOULDS INLET, GEORGIA, FROM GEOSPATIAL ANALYSIS OF AERIAL PHOTOGRAPHS
Student: Rochelle F. Petruccelli
Faculty Advisor: David M. Bush, Department of Geosciences
Goulds Inlet is a relatively small Georgia inlet running between St. Simons and Sea Islands. Typically, inlet dynamics cause adjacent shorelines to experience varying degrees of erosion and accretion as hydrographic conditions vary seasonally or at longer temporal scales. Goulds Inlet, though seemingly stable, has historically migrated south, hugging the St. Simons shoreline, allowing the Sea Island spit to follow suit, building towards the south. The relative persistence of the inlet channel against St. Simons Island creates shoreline accretion/erosion processes driven by complex linkages between the movements of the ebb channel, asymmetry of the ebb-tidal delta, and migration of the swash bars. Georectified aerial photos of the study area spanning roughly sixty years (1942-2003) were used within ArcGIS to delineate the high-water line (HWL) shoreline, ebb delta shoals, and the middle of the inlet channel and stored as shapefiles. Measurements of spatial and temporal changes of these features were performed within ArcGIS using ArcToolbox and in-house scripts. Shoreline change analyses suggest net long-term accretion along the adjacent shorelines. However, a small segment on the St. Simon's inlet shoulder was identified that has net long-term erosion (shoreline movement averaging about -1.5 m/yr). This portion of the shoreline appears to be less influenced by the ebb delta morphology and more so with the position ebb channel's thalweg and periodic advance and retreat of the Sea Island spit. A few hundred meters south of this shoreline segment, net accretion is occurring along a "bulge" in the shoreline associated with inlet swash bar welding. Inspection of the aerial photos suggests the shoreline position along this region also tends to fluctuate in response to the movement/orientation of the ebb channel and changes in ebb delta symmetry (~ +1 to 7 m/yr). More aerial photos and historical maps are being added to the GIS database to better ascertain long and short-term trends.
Spatial Distribution and Textural Relationships of Accessory Phases in a Layered Amphibolite: Implications for Geochronology and Trace-Element Thermobarometry
Student: Lindsey Elise Hunt
Faculty Advisor: Dr. Christopher Berg, Department of GeosciencesThe metamorphic conditions of the Southern Appalachians are poorly-constrained. Ti- and Zr-bearing accessory minerals, such as titanite, zircon, rutile, and ilmenite are commonly found in metamorphic rocks, and they can be used for geochronologic and/or geothermobarometric calculations, allowing precise correlation of pressure and temperature conditions with time, so long as the minerals are in equilibrium with the rock during metamorphism. The accessory minerals and the metamorphic conditions that formed them are being studied in a banded amphibolite gneiss, a metamorphosed igneous rock, collected in Carrollton, GA. The gneiss consists of two primary layers defined by mineralogy: an amphibole-rich layer and an epidote-rich layer. Sampling of the accessory-phase minerals from this rock will be done by crushing part of the specimen and collecting bulk mineral separates, therefore we must understand the spatial and textural relationships of the minerals within each layer. Petrographic and SEM-EDS analysis of a thin-section of the amphibolite determined that titanite is present in both the amphibole and epidote layers. Titanites in amphibole layers contain inclusions of amphibole, and titanites in epidote layers contain inclusions of epidote. Zircon and ilmenite appear both as inclusions within titanite and in the matrix within each layer. These textures indicate that these minerals were in equilibrium with the rock during metamorphism. However, rutile is present only as inclusions within titanite and is absent from the matrix in either layer. This indicates that rutile was not in equilibrium with the rock during metamorphism, and cannot be used to estimate peak metamorphic conditions.