February marks the unofficial start of the tourist season in the Greek island of Santorini - when the first cruise ships are due to arrive and the Easter holidays approach. But with thousands of earthquakes shaking the island since January and experts unable to say when they will end,

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

Experts say the Greek island of Santorini has been hit by more than 1,000 earthquakes, but they're not linked to the region's active volcanoes.

Authorities declared a state of emergency on a second Greek island Wednesday as a series of earthquakes continued to rattle the south-eastern Aegean Sea region. The emergency measure announced on the island of Amorgos follows a similar decision for nearby Santorini on Feb.