PALSAR/ALOS interferometry in the Gulf of Corinth and Patras (Greece). Comparison with ERS and ASAR/ENVISAT results and GPS measurements
Panagiotis Elias(3), Pierre Briole(1), Maya Ilieva(1), Antonio Avallone(2), Rana Charara(1), Anna Belehaki(3), Olga Sykioti(3), Antonis Mouratidis(1) and Themistoklis Herekakis(3)
(1) Ecole Normale Supérieure, 24 Rue Lhomond, 75005 Paris, France
(2) Istituto Nazionale di Geofisica e Vulcanologia, Via Castello D'Aquino, 13, 83035 - Grottaminarda (AV), Italy
(3) National Observatory of Athens, I. Metaxa & Vas. Pavlou, GR-152 36, Greece
Four PALSAR/ALOS images of the area of Aigion and six from the area of Patras (both located around the Gulf of Corinth - Greece) were processed and compared thematically with C-band data and GPS measurements. The rift of Corinth has been long identified as a site of major importance due to its intense geophysical activity. It is one of the world's most rapidly extending continental regions and it has one of the highest seismicity rates in the euro-Mediterranean region. GPS campaigns using a dense network of permanent GPS stations have shown a 1.5 cm per year of north-south extension [Briole et al., 2000]. It has also produced a number of earthquakes with magnitude around 6 or greater: Alkyonides (February 1981, M=6.7), Aigio (June 1995, Mw=6.1), and Galaxidi (November 1992, Mw=5.8). Around the Gulf of Patras, the deformation field is less well known yet, and we hope to improve this knowledge by exploiting the L-band data. This is important for acquiring a better understanding of the ground deformations around the large city of Patras, the lake of Trichonidas and the city of Agrinion where several moderate to large earthquakes were occurred. The target area has a wide zone of sea separating the north from the south part and it is crucial to examine each part separately in order to exclude the sea in the stage of cross-correlation between master and slave image. First results shows very good coherence compared with C-band interferometry. Local permanent GPS measurements are used to address the ionospheric conditions and correlate them with PALSAR/ALOS data. The correlation between coherence and vegetation cover is also among the questions addressed in our study.
Briole P., Rigo A., Lyon-Caen H., Ruegg J., Papazissi K., Mitsakaki C., Balodimou A., Veis G., Hatzfeld D., Deschamps A., Actice deformation of the Corinth Rift, Greece: Results from repeated GPS surveys between 1990 and 1995, J. Geophys. Res., 105, 25,605-25,625, 2000.