HR: 15:25h
AN: P33D-08    [Abstracts]
TI: The Role of Preflow Topography on the Surface Morphology and Thermal Evolution of Actively Inflating Basaltic Lava Flows
AU: * Anderson, S W
EM: steveanderson@bhsu.edu
AF: Planetary Science Institute, 1700 E. Fort Lowell Rd, Suite 106, Tucson, AZ 85719
AU: * Anderson, S W
EM: steveanderson@bhsu.edu
AF: Black Hills State University, Science Department, Spearfish, SD 57783 United States
AU: Ramsey, M S
EM: mramsey+@pitt.edu
AF: University of Pittsburgh, Department of Geology and Planetary Science, Pittsburgh, PA 15260 United States
AU: Crown, D A
EM: crown@psi.edu
AF: Planetary Science Institute, 1700 E. Fort Lowell Rd, Suite 106, Tucson, AZ 85719
AU: Byrnes, J M
EM: jmbyrnes@usgs.gov
AF: U.S. Geological Survey, Astrogeology Team, Flagstaff, AZ 86001 United States
AU: Stofan, E R
EM: ellen@proxemy.com
AF: Proxemy Research, 20528 Farcroft Lane, Laytonsville, MD 20882 United States
AB: In an attempt to test hypotheses regarding the role of underlying topography on lava flow surface morphology, we acquired pre-, syn- and post-flow topographic data from active pahoehoe flows advancing over hummocky topography at Kilauea volcano, Hawaii. Kilauea volcano (HI) is in a state of eruption that has persisted almost without interruption for over 20 years, and is in a period of activity dominated by resurfacing by inflated pahoehoe flows, with a few a'a' flows forming mainly in steeper areas where strain rates are high. We used a Trimble ProXRS differential GPS (cm-scale accuracy) equipped with a laser rangefinder to rapidly survey the pre-flow topography over several 20m x 20m areas as surface pahoehoe breakouts approached, then repeatedly re-surveyed the area as lava flowed over the surface and inflated. We also used a FLIR ThermaCAM S40 thermal imaging camera to record high-precision video images of the temperature distribution across the surfaces of the active flows in an attempt to understand the evolution of heat loss through their surfaces. Our profiles show the development of more subdued active flow topography in the early stages of emplacement as pre-flow depressions infill. With these data we intend to generate a time series of flow profiles and DEMs over the pre-eruption topography to determine how underlying flow morphology affects 1) flow thickness, 2) the shape of the flow surface, 3) how thickness and shape change as a function of time, and 4) how the surface temperatures and cooling structure changes with time. Pairing high-precision topographic data with temperature data provides an effective method for studying the details of active lava flow evolution over small areas, but is limited for investigating flow-field scale processes. Repeated LIDAR acquisitions over active flow fields combined with detailed thermal imaging should allow for a new generation of studies linking topography to emplacement conditions.
DE: 5480 Volcanism (6063, 8148, 8450)
DE: 8414 Eruption mechanisms and flow emplacement
DE: 8425 Effusive volcanism
DE: 8450 Planetary volcanism (5480, 6063, 8148)
SC: Planetary Sciences [P]
MN: Fall Meeting 2005