Ground deformation at Etna (Italy) and MiyakeJima (Japan) from interferometric PALSAR ALOS data
Pierre Briole(1), Panagiotis Elias(2), Giuseppe Puglisi(3) and Makoto Murakami(4)
(1) Ecole Normale Supérieure, 24 Rue Lhomond, 75005 Paris, France
(2) National Observatory of Athens, I. Metaxa & Vas. Pavlou, 15236 Pendeli, Greece
(3) Istituto Nazionale di Geofisica e Vulcanologia, Piazza Roma, 2, 95125 Catania, Italy
(4) Geographical Survey Institute, 1 Kitasato, 305-0811 Tsukuba, Japan
Eight FBS and FBD PALSAR ALOS data acquired in 2007 and 2008 over Etna and fourteen over Myakejima volcanoes were processed with the ROI-PAC software to produce interferograms on both volcanoes. All couples produce coherent interferograms, even with baselines of 3km or more. Not surprisingly, the coherence is better for short baselines and short intervals between acquisitions. Although Lband is more efficient that Cband in vegetated area, the unfiltered interferograms show clear constrast of coherence depending on the ground cover. Et Etna, several features already observed with ERS and ENVISAT are visible in the ALOS interferograms. The coherence near the top of the volcano is significantly better that that obtained with Cband. Subsidence of a lava flow is observed west of the summit volcano. The known creep along the Pernicana fault, difficult to identify with Cband, seems visible over interferograms sampling one year or even less. Data from MiyakeJima are currently being processed.