Earthquakes rattled Greece’s volcanic island of Santorini every few minutes overnight and into Wednesday as authorities bolstered emergency plans in case the hundreds of temblors over the past few days are a harbinger of a larger quake to come.

Residents on the popular island of Santorini have experienced hundreds of earthquakes this week while researchers have revealed a new magma chamber underneath the Kolumbo submarine volcano.

Greece is preparing for any scenario but experts are optimistic about the tremors that triggered an exodus of residents and visitors from the Aegean Sea island of Santorini.