Sangay Volcano, Ecuador, erupted in early June, sending lava flows and pyroclastic flows down its southeastern flank. A large ash plume rose above 7 km, and was blown westward by the prevailing winds. Ashfall was reported in several cities downwind. The nighttime thermal infrared image acquired by ASTER on June 11 shows the flows in white, and the large ash plume in dark red-brown, indicating its composition is dominated by ash particles. The image covers an area of 24.5 by 46.8 km, and is located at 2 degrees south, 78.4 degrees west.
With its 14 spectral bands from the visible to the thermal infrared wavelength region and its high spatial resolution of about 50 to 300 feet (15 to 90 meters), ASTER images Earth to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched Dec. 18, 1999, on Terra. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and data products.
The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping and monitoring of dynamic conditions and temporal change. Example applications are monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.
The U.S. science team is located at NASA's Jet Propulsion Laboratory in Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate, Washington.
More information about ASTER is available at http://asterweb.jpl.nasa.gov/.