Geography, Nature and Habitation of Nisyros Volcano

This chapter outlines the general aspects of the unique geographical situation of the small island of Nisyros in the southeast Aegean Sea as a dormant, conical shaped and caldera bearing stratovolcano. Nisyros is located between the islands of Kos and Tilos within a prehistoric volcanic field that generated the largest volcanic eruption in the eastern Mediterranean (Kos Plateau Tuff), which devastated the entire Dodecanese area 161,000 years ago. The island benefits largely from its volcanic features, the nutrient-rich volcanic soil giving rise to all-year-round lush herbaceous vegetation and hosting a large variety of plants and animals. It profits since historical times from several thermal springs at sea level aligned in major fault zones. The northern and eastern slopes of Nisyros volcano as well as its neighbouring island Yali are covered with voluminous pumice deposits, which are mined on a large scale. The active hydrothermal system in the southern part of the caldera floor has been explorated for geothermal energy , but the initiative was abandoned due to high-risk performance and continuous micro seismicity. In 1996 and 1997 seismic activity started with earthquakes of magnitudes up to 5.5 and with hypocentres down to 10 km depth, damaging many houses in the major town of Mandraki. Tourism is today the major economy of the island. Daily, hundred of tourists visit the impressive hydrothermal explosion craters at the caldera floor, attracted by its fuming fumaroles and mud pools.