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

Thousands of locals and travelers have evacuated the Greek island of Santorini amidst a spike in seismic activity.

It welcomes around 3 million visitors per year, but between January 26 and February 8, the Seismology Laboratory of the University of Athens has registered a staggering 12,800 earthquakes in the Santorini-Amorgos zone, the strongest of these was last night at a magnitude of 5.3.