Two smaller aftershocks from the magnitude 7.5 quake from last Friday shook the coastal area Monday morning, Jan. 14, and again in the evening, according to the Alaska Earthquake Information Center.
The source of the shake was located 68 miles WSW of Craig and measured a magnitude 5.49 ML at 5:55 a.m. Alaska Standard Time. It was felt in Petersburg but no emergency evacuations were ordered.
That evening at 5:56 p.m. another tremor measuring 4.06 ML was recorded. Its epicenter was located 66 miles WSW of Craig.
According to the USGS website, the January 5 M 7.5 earthquake off the west coast of southeastern Alaska occurred as a result of shallow strike-slip faulting on or near the plate boundary between the Pacific and North America plates. At the location of this earthquake, the Pacific plate is moving north-northwestward with respect to the North America plate at a velocity of approximately 51 mm/yr.