ANCHORAGE, Alaska — Communities along a 700-mile (1,127-km) stretch of Alaska's southern coast ordered residents to higher ground after a powerful offshore earthquake Wednesday, but officials quickly downgraded and then canceled a tsunami warning for the region. There were no reports of significant damage.
The earthquake, with a preliminary magnitude of 7.3, struck at 12:37 p.m. local time south of Sand Point, a community of about 600 people on Popof Island, in the Aleutian chain, according to the Alaska Earthquake Center.
There were 40 aftershocks detected within the first three hours, the center said.
''We have seen other earthquakes in the area that have not generated significant tsunami waves, but we're treating it seriously and going through our procedures, making sure communities are notified so they can activate their evacuation procedures,'' said Jeremy Zidek, a spokesperson for Alaska's emergency management division.
The quake was felt as far away as Anchorage, almost 600 miles (966 km) to the northeast.
The National Tsunami Warning Center issued a warning for an area stretching from about 40 miles (64.4 km) southwest of Homer to Unimak Pass, a distance of about 700 miles (1,126 kilometers). Among the larger communities in the area was Kodiak, with a population of about 5,200. The warning was downgraded to an advisory about an hour later, and canceled just before 2:45 p.m.
The highest water level generated by the earthquake in Sand Point was not quite 2.5 inches (6.3 cm) above the tide, the center said.
''There's no damage at the airport, doesn't appear to be any damage at the harbor, no damage to speak of, really,'' Sand Point Police Chief Benjamin Allen said.