Jan 22 (Reuters) - A magnitude 6.2 earthquake struck south of Unalaska in Alaska, a major fishing port with 4,700 full-time residents, on Friday, the Alaska Earthquake Center at the University of Alaska Fairbanks said. The quake struck at 8:17 p.m. (0517 GMT on Saturday), the center said. The United States Geological Survey (USGS), which registered the quake at 6.2 magnitude, said it struck 74 km (46 miles) south of Unalaska at a depth of 3 km (2 miles). The U.S. Tsunami Warning System said there was no tsunami warning after the quake.