HR: 1330h
AN: NS23B-07    [Abstracts]
TI: Geophysical Exploration of the Red Rocks Canyon Landfill in Colorado Springs, Colorado
AU: * Calhoun, N
EM: n_calhoun@coloradocollege.edu
AF: Department of Geology, Colorado College, 14 E Cache la Poudre, Colorado Springs, CO 80903 United States
AU: Morin, C
EM: c_morin@coloradocollege.edu
AF: Department of Geology, Colorado College, 14 E Cache la Poudre, Colorado Springs, CO 80903 United States
AU: GY250, s
EM: cbank@coloradocollege.edu
AF: Department of Geology, Colorado College, 14 E Cache la Poudre, Colorado Springs, CO 80903 United States
AU: Bank, C
EM: cbank@coloradocollege.edu
AF: Department of Geology, Colorado College, 14 E Cache la Poudre, Colorado Springs, CO 80903 United States
AB: Our introductory geophysics class conducted a survey of the Red Rocks Canyon landfill to determine its boundaries, depth, type of fill, and groundwater runoff patterns. In the 1970s and 1980s the canyon was filled with domestic waste, and has recently been acquired by the city to extend an existing park. Our results in general portray a heterogenous subsurface and reveal that the landfill likely contains many metallic objects. More specifically we found the following: A negative Bouguer anomaly across the landfill matches a model for a ~25 m thick fill. Resistivity is much lower on the landfill than off, but we could not confirm our hypothesis that the landfill drains water through the north end of the canyon. Our seismic data are inconclusive, we think that our assumption of a planar bottom and seismically homogenous fill is violated. The magnetic data show on average higher total values, large (>1,000 nT) variations and high magnetic gradients on the landfill; because this method is fast and very clearly maps the landfill boundaries we propose a magnetic survey to detect possible unregistered dumps outside the mapped boundaries of the landfill. Measuring ground conductivity utilizing an electromagnetic survey produces significantly higher values on the landfill than off. Additionally, directional anisotropies match the direction of the strike of the geological formations adjacent to the landfill and are more randomly oriented on the landfill.
DE: 0820 Curriculum and laboratory design
DE: 0933 Remote sensing
DE: 1803 Anthropogenic effects
SC: Near-Surface Geophysics [NS]
MN: 2005 Joint Assembly