Greece's civil protection agency said authorities on Crete did not report any injuries or damage from the quake.
Agency official Athanassios Oprianos said the quake's epicenter was quite deep — about 18 miles undersea. He said that, combined with the fact that it occurred 100 miles south of Crete, meant a large part of its force was absorbed before it reached the island.
Greece is one of the most earthquake-prone countries in the world, but the vast majority of quakes cause no damage or injuries.
The Associated Press contributed to this report.