The whole history of the island is involved with its volcanic activity. This activity has formated Santorini throughout the centuries until its nowadays shape and geological structure.
Today, seven craters are located on the Nea Kameni island and one crater on palea Kameni island, just in the middle of caldera. The craters are still smoking even today. This continious gas expansion decreases the possibility of volcanic eruptions.
A submarine volcano named "Columbos" is located in the NW seaside of Santorini, near Oia.The volcano's activity of course, is under research by the Greek Sismologist (Institute for the Study and Monitoring of the Santorini Volcano).