Parts of southern Alaska are under a tsunami warning after a reported 7.5 magnitude earthquake off Sand Point in the Alaska Peninsula coastline. The earthquake struck about 62 miles southeast of Sand Point just before 12:55 p.m., according to the U.S. Geological Survey.The magnitude of the quake was initially determined to be a 7.4 before it was upgraded to 7.5, said Paul Caruso, a geophysicist with the USGS.