Two earthquakes shook the US state of Washington, with the tremors that were felt in British Columbia and across the Cascade Mountains in the eastern part of the region.
There were no immediate reports of damage or injury.
The geological survey in the United States reports that a magnitude 4.6 earthquake shook the area of the three lakes, about 64 kilometers northeast of Seattle. This was followed a few minutes later by a magnitude 3.5 aftershock near the town of Monroe, about 48 km north-east of Seattle.
The initial shock was recorded at 2:51 am local time on Friday. The state department of transport stated that the agency would control the bridges, but did not report any damage.
The USGS said it had received reports of people feeling shaken from Vancouver to Wenatchee in Washington state.
Farther south along the Pacific coast, a magnitude 4.9 quake from last week's Southern California earthquakes was felt widely in the region on Friday morning. There were thousands of aftershocks of the 6.4 magnitude earthquake on 4 July and the 7.1 earthquake that occurred the following day.
David Caruso, a geophysicist at the USGS, told the Seattle Times that the Washington earthquake was due to a thrust fault, where one side of a fault moved upward from its side opposite to. Such earthquakes are common in the Cascade mountain range.
Caruso said the north-west earthquake had no connection with the recent earthquakes in California.
Meanwhile, a magnitude 4.9 quake from last week's Southern California earthquakes was felt widely in the region.
The US Geological Survey says the quake occurred at 6:11 am. On Friday it was centered about 8 km north-east of the city of Ridgecrest, in the Mojave desert.
The quake felt very light in the Los Angeles area.
There were thousands of aftershocks of the 6.4 magnitude earthquake on 4 July and the 7.1 earthquake that occurred the following day.
The aftershocks were extinguishing, but should continue for some time. The seismologist Lucy Jones tweeted that the 4.9 earthquake is normal and is having its aftershocks.
The USGS states that the probability of an earthquake of 7.1 or greater has fallen to less than 1%.