Intense Crustal Deformation Rates on Nissyros Island (Greece), Deduced from GPS Studies, May Foreshadow a Forthcoming Volcanic Event

Nissyros Volcano lies at the SE part of the Hellenic Volcanic Arc (HVA) and, together with the Thera (Santorini) Volcano comprise the most active volcanoes in the Aegean Sea. The last major episode including freatic explosions and gas emanation tool place during the last century. Since then there was not any kind of similar major activity, until early 1997, when an intense local seismic activity broke out with a simultaneous reactivation of an older fault passing through Mandrakion at the NW part of the island.