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

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

Earthquakes are not uncommon on Santorini and in 1956 was actually struck by one of the most serious quakes to affect Greece over the past 100 years. A 7.7-magnitude temblor, dubbed the Amorgos earthquake, triggered a roughly 20-meter (65-foot) tsunami, causing significant damage in Amorgos and Santorini and killing more than 50 people.