Contribution of remote sensing techniques to the identification and characterization of Miocene calderas, Lesvos Island, Aegean Sea, Hellas

Remote sensing techniques were combined with field investigations in order to locate and accurately characterize volcanic structures in the 17 my volcanic field of Lesvos Island, which are difficult to recognize due to erosion and faulting. Landsat Thematic Mapper (Landsat-TM) and Satellite Pour Observer la Terre Panchromatic (SPOT-Pan) satellite images as well as the Digital Elevation Model (DEM) of the study areas were digitally processed in order to reveal specific geological characteristics related with caldera structures such as topographic caldera rims and floors, ring faults, areas of hydrothermal alteration, drainage networks and lava domes, both internal and external to caldera structures. Six caldera structures have been recognized, of which four have been identified for the first time and are reported here (Sigri, Mesotopos, Agra and Skalohori calderas). The calderas of Stipsi and Vatoussa have been previously reported in the literature but their revised geometry and dimensions are reported here.