The following posters represented the geosciences and geography at CUR’s Posters on the Hill, May 5, 2009.
Student: Timothy Brox
Institution: Montana State University – Bozeman Earth Sciences
Faculty Advisor: Brent Christner, Mark Skidmore
Poster title: Microbial Impacts on the Crystalline Structure and Liquid Vein Network of Laboratory Ices: Implications for sub-zero microbial activity
Funding: National Science Foundation Directorate for Geosciences
Abstract: Recent work has demonstrated microbial activity within the liquid filled inter-crystalline veins in ice. These discoveries dramatically increase the extent of the modern biosphere incorporating the large ice sheets of Antarctica and Greenland as biomes, and also hold profound implications for the survival of microorganisms during periods of extensive glaciation during Earth’s history (e.g. “Snowball Earth”) and on other planets (e.g. Mars) and their moons (e.g. Europa). In addition to examining microbial survival and activity in ices at sub-zero temperatures, it is important to characterize the habitat, the inter-crystalline liquid veins. I developed new non-invasive techniques to investigate microbial influences on the physical properties of ice and its liquid vein network. Four sample types were prepared in triplicate and frozen at -10oC: 1) deionized water only, and suspensions of 2) Sporosarcina sp. B-5, an isolate from Taylor Glacier, Antarctica, 3) Chryseobacterium sp. V3519-10, an isolate from the Vostok ice core, Antarctica, and 4) extracellular proteins extracted from Chryseobacterium sp. V3519-10. Chryseobacterium sp. V3519-10 has a 54 kDa extra cellular protein that has the ability to inhibit recrystallization of ice, similar to ice-binding proteins previously found in sea ice microorganisms. The samples with extracellular proteins grew ten times the number of ice crystals than the deionized water samples and the samples with microbes grew two to three times more crystals than the deionized water. This indicates the presence of cold-tolerant microbes and to a greater extent their extracellular proteins significantly impact the vein network and thus the microbial habitat in ice.
Student: Hannah Shepherd
Institution: James Madison University Geology and Environmental Science
Faculty Advisor: Elizabeth Johnson
Poster title: Water Contents of Yellowstone Magmas Estimated from Hydroxyl
Concentrations in Feldspar Phenocryts
Abstract: Over the past 2 million years, Yellowstone has produced three cataclysmic volcanic eruptions as well as many other smaller eruptions. We would like to better understand the cause of the past eruptions at this continental hotspot in order to better evaluate the risk of future eruptions. The water contents of five eruptions of Yellowstone Volcano, Wyoming, (Headquarters Flow, Blue Creek Flow, Lava Creek Tuff, Biscuit Basin Flow, and Canyon Flow) were estimated using measurements of structurally incorporated hydroxyl (OH) in feldspar phenocrysts. Feldspars from the Yellowstone samples were separated from the rock matrix by crushing and picking individual crystals, and were identified using an optical microscope. The feldspar phenocrysts were prepared for infrared analysis by creating two perpendicular doubly-polished thick sections of each crystal. Polarized infrared spectra were obtained on the Fourier-Transform Infrared (FTIR) spectrometer in the Department of Mineral Sciences at the National Museum of Natural History, Smithsonian Institution, Washington, D.C. The water concentration in each eruption was estimated by determining the amount of hydroxyl in each feldspar from the infrared spectra and then using a previously determined relationship between hydroxyl in the feldspar and water in the magma. Based on these measurements, we estimate that the Yellowstone magmas contained less than 1.5 wt% water, which is very low and would not trigger an eruption. Therefore, magmatic water probably did not cause past mega-eruptions at Yellowstone.
Student: Rebecca K. Woiteshek
Institution: Carthage College Geography and Earth Sciences
Faculty Advisor: Julio Rivera
Poster title: Dire Straits: Using GIS to Better Identify and Serve the Urban Poor
Funding: Faith In Christ Ministries
Abstract: This research addresses the problem of identifying communities in dire economic straits and in a state of profound transition within densely populated urban space. Target areas that would benefit from a partnership of local universities and community outreach centers are identified within the network area of a community center located in the Watts neighborhood of Los Angeles, California. Analysis of census data using geographic information systems (GIS) identifies subtle but important physical, economic, and ethnic distinctions that may affect service needs. Field work confirms patterns found in the original GIS analysis. Previous approaches to the problem have defined the community boundary with a radius of one hour’s walking distance. These analyses suggest that these approaches missed broad distinctions within this service district. The community reflects a larger tapestry of culture and language than was previously identified. This project will identify the differences between the sub communities and recommend possible tailored approaches for future research that will assist local community centers to better identify the populations they serve.