Mapping recent lava flows with Radarsat-1 imagery

The sensitivity of radar imagers towards surface roughness and moisture can be used for mapping rock, soil and vegetation. High-resolution Radarsat-1 data were used to map successive lava flows of the Hekla volcano. The volcano erupted in early 2000. It was monitored throughout the eruptive activity using Radarsat-1 Fine beam images. The Radarsat-1 images were compared with those retrieved from the archive, which had been acquired immediately before the event in the course of Radarsat-1 Background Mission and Disaster Watch Program. Radarsat-1 images were interpreted based on the radar tone and texture as a function of the state of lava solidification, and it was possible to distinguish between lava flows of different stages of the eruptive activity. Using the same tonal and textural the interpretations, an attempt was made to trace the past history of the Hekla volcano. Successive lava flows were delineated and are shown on the image map. The study demonstrates the effectiveness of Radarsat-1 fine resolution imagery for lithological mapping and the usefulness of Radarsat-1 data archives that are being built as a result of the satellite´s various baseline acquisitions