Photograph Identification: P-43915Mt. Pinatubo, Philippines
This is a false color L-andC-band composite image of the area around Mt. Pinatubo in the Philippines, centered atabout 15 degrees north latitude, 120.5 degrees east longitude. This image wasacquired by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour during orbit 78 on April 13, 1994. The false-color composite is mad by displaying the L-band, HH (horizontally transmitted and received) return in red, theL-band HV (horizontally transmitted and vertically received) return in green, and the C-band HV (horizontally transmitted and vertically received) return in blue. The area shown isapproximately 45 by 68 kilometers (28 by 42 miles). The main volcanic crater onMt. Pinatubo produced by the June 1991 eruptions, and the steep slopes on theupper flanks of the volcano, are easily seen in this image. The red color onthe high slopes show the rougher ash deposited during the 1991 eruption. Thedark drainage features are smooth mudflows which continue to flood the river valleysafter heavy rain. Radar images such as this one can be used to identify theareas affected by mudflows, which are difficult to distinguish visually, andto assess the rate at which the erosion and deposition continues. A key aspectof the second SIR-C/X-SAR mission in October 1994 was to collect a second image of Pinatubo during the summer monsoon season -- new mudflows hadoccurred -- and to evaluate the short-term changes. The 1991 eruption of Mt. Pinatubo is well known for its near-global effects on the atmosphere and climate due to the large amount of sulfur dioxide that wasinjected into the upper atmosphere. What is less widely known is that eventoday the volcano continues to be a major hazard to the people who have returnedto the area around it. Dangerous mudflows (called "LAHARS") are oftengenerated by heavy rains, and these can still sweep down river valleys and washout roads and villages, or bury low lying areas in several meters of mud andvolcanic debris. These mudflows will continue to be a severe hazard around Pinatubo for 10 to 15 years after the eruption.
![[MT. PINATUBO]](PINATUCO.GIF)