Ground deformation study of KOS island (SE Greece) based on Squee-SAR™ interferometric technique

The SE part of the Hellenic Volcanic Arc (HVA), including Kos, Yali and Nisyros islands, is geodynamically very active and of high tectonic unrest, where the largest volumes of volcanic products were emitted during the past 160,000 years. The SqueeSAR™ Interferometric technique based on ENVISAT radar data has been applied in Kos to spatially and temporally study the ground deformation for the period 2003-2010. The observed LOS velocity field, with values ranging between -4 to +4 mm/yr, combined with small standard deviation velocity (<;1.4 mm/yr) and acceleration (-0.5 to 1.5 mm/yr²) values reveal an almost linear type of ground deformation. These small velocity values in conjunction with intermediate seismicity occurring only off-shore, indicate ground deformation of aseismic local character. The strongest subsidence is associated with local geothermal areas, as well as rural areas due to intense water pumping. Motions along the main faulting zones have also been clearly identified.