The Greek island has a long history of earthquakes, but what is causing the recent series of quakes has scientists perplexed.

ATHENS, Greece — Scientists have detected several thousand earthquakes, the vast majority of them with small magnitudes, in just over two weeks near Greece’s volcanic island of Santorini, the University of Athens’ crisis management committee said Tuesday, adding that a larger quake cannot be ruled out.

Seismologists have noted that the epicentre of the earthquakes is steadily drifting northward in the direction of Amorgos.