SATELLITE REMOTE SENSING OF COLIMA VOLCANO, MEXICO: APPLICATIONS TO MONITORING ERUPTIVE CYCLES USING ASTER DATASETS

Utilizing many approaches to monitoring volcanic activity through eruptive cycles helps provide a broad understanding of volcanic processes. Colima Volcano, located in Colima and Jalisco, Mexico (19°30'50"N and 103°37'0"W) has been active since the 1500’s, with the most recent eruptive cycle starting fifteen years ago. Dome growth and collapse, and generation of pyroclastic flows and convection columns have characterized the current eruption cycle. Examining the geologic and eruptive history of Colima Volcano aids in understanding eruptive cycles. To better understand these cycles, data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is being analyzed to detect and quantify changes that may be difficult to assess through ground-based observations. ASTER, launched in December 1999, provides multispectral data at visible and near infrared (VNIR; 3 bands at 15 m/pixel), shortwave infrared (SWIR; 6 bands at 30 m/pixel), and thermal infrared (TIR; 5 bands at 90 m/pixel) wavelengths. Surface temperatures, vesicularity, and composition may be constrained using ASTER TIR data, and the distribution of new deposits may be constrained using ASTER VNIR data. Since a major eruption in June 2005, we have measured significant changes in the appearance of the volcano, distribution of deposits, and range in surface temperatures. Specifically, we have found a positive correlation between dome growth and increased surface temperature as the dome expands; vesicularity and surface reflectance also appear to change prior to eruptions. Older deposits are also identifiable in the satellite data giving a better perspective of past cycles. By comparing these past eruptions, it may be possible to better predict current and future eruption cycles as well as hazards presented by the volcano and the frequency at which they may occur.