The Feb. 13, 2014, violent eruption of Kelud stratovolcano in Java, Indonesia sent volcanic ash covering an area of 70,000 square miles (181,300 square kilometers), and prompted the evacuation of tens of thousands of people. Earlier 20th century eruptions killed thousands of people, mainly as the result of hot mudflows ("lahars"). This image from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra spacecraft was acquired on Feb. 20, after the eruption had greatly diminished. Ash-covered areas are seen on the north slopes of the volcano (the summit is hidden underneath clouds); ash-choked rivers flow down the west and southwest flanks of the volcano. ASTER's thermal infrared channels show continued activity at the summit. The image covers an area of 14.2 by 16.1 miles (23 by 26 kilometers), and is located at 7.9 degrees south, 112.3 degrees east.
With its 14 spectral bands from the visible to the thermal infrared wavelength region and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), 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, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate, Washington, D.C.
More information about ASTER is available at http://asterweb.jpl.nasa.gov/.