According to the United States Geological Survey (USGS), a tremor with a magnitude of 6.1 hit 184 kilometres (around 114 miles) from the city of Adak, Alaska. The epicentre of the quake was located at a depth of 39 kilometres, the agency said.
The initial report suggested that the magnitude was 6.3, but later revised it to 6.1.
There have been no reports of any casualties, caused by the earthquake.