(AP)  The U.S. Geological Survey says a powerful magnitude 7.7 earthquake has struck south of Cuba and northwest of Jamaica. It was centered 139 kilometers (86 miles) northwest of Montego Bay, Jamaica, and 140 kilometers (87 miles) west-southwest of Niquero, Cuba. It hit at 2:10 p.m. (1910 GMT) and the epicenter was a relatively shallow 10 kilometers (6 miles) beneath the surface. There are no immediate reports of damage or injuries.  The quake could be felt strongly in Santiago, the largest far-eastern Cuban city.