Tsunami warnings issued following a magnitude-7.7 earthquake off Taiwan on Wednesday disrupted air, bus and ferry services, and local residents and tourists were warned to evacuate to higher ground in many islands of Japan’s southern prefecture of Okinawa. Tsunami alert sirens sounded on Okinawa Island and several other islands, with some residents frightened while others fleeing calmly. “I was surprised when my mobile phone’s alarm rang loud. There have been a lot of earthquakes recently, so I’m scared,” said an employee at a car rental agency on Ishigaki Island. The epicenter was at a depth …