The popular Greek tourist island of Santorini has experienced thousands of near-constant earthquakes since Jan. 25, prompting more than 13,000 of the island’s 15,500 residents to leave the island, according to The New York Times.

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 threat of a more major earthquake seems to have subsided on the most visited of the Greek islands but experts disagree on the origin of the tremors that have caused 11,000 of the 15,000 permanent residents to flee.