The United States was struck by an earthquake measuring 6.5 on the Richter scale.
It struck the Alaska Peninsula on Monday, the European Mediterranean Seismological Centre (EMSC) said.
The earthquake struck 114km east of the city of Chignik and was a depth of 75km according to the EMSC.
No tsunami warning was issued after it struck.
Meteorologist Matthew Cappucci reported that the quake appeared to be an aftershock of an 8.2 earthquake that happened on July 29.
He said that aftershocks can last for months as well as being strong.
No tsunami threat was issued due to the mainly horizontal slip motion, he added.
Back in July, US was hit by the strongest earthquake in 50 years. The epicentre struck off the coast of Alaska, causing tremors that could be felt throughout the state and setting tsunami alarms blaring.