The changing behavior of silicic lava domes in Kamchatka: Monitoring flow dynamics over four years with high resolution thermal infrared data

J. Byrnes and M. Ramsey, Department of Geology and Planetary Science, 200 SRCC Building, University of Pittsburgh, Pittsburgh, PA 15260

S. Anderson, Department of Science, Black Hills State University, Spearfish, SD 57799

D. Crown, Planetary Science Institute, Tucson, AZ 85719

Synchronous field and spaceborne remote sensing measurements were collected for the active Pu'u 'O'o lava flow field during January 2003. Field data consisted of temperature measurements made with an infrared radiometer and topography measurements made using a high-resolution differential Global Positioning System (dGPS) with an attached laser rangefinder. It provided sub-centimeter relative accuracy and absolute accuracy to better than 10 cm for each positional measurement. Spaceborne remote sensing data were collected by the ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) instrument during the field collection, providing five bands of thermal infrared (TIR) spectral data at 90 m/pixel. These data were collected at night to minimize the effects of solar heating, thereby improving data interpretation by maximizing the relative proportion of signal emitted by the flow.

Our objective is to better understand basaltic lava flow emplacement. The ASTER data are used to provide a synoptic view of the flow field and are supplemented by the field temperature measurements. Together, the field-based and spaceborne remote sensing measurements are used to constrain the proportions of relatively hot and cold surfaces as well as calculate surface temperatures. The TIR spectra are then deconvolved to provide textural information for the lava flow surfaces, which becomes important for understanding flow lobe volatiles, cooling history, and inflation. The thermal characterization of the active lava flow lobes combined with the topographic measurements are used to calculate the rate of flow cooling during crust formation as a function of the rate of vertical thickening of the flow lobe.

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Submitted: IAVCEI General Assembly, Pucón, Chile
Date: November 14 - 19, 2004