The quake occurred 16 miles below the surface of the Earth, according to the Pacific Northwest Seismograph Network.
There were no immediate reports of damage or injuries.
Viewers from around puget sound called the KOMO 4 News desk to report feeling a sharp jolt.
Stephen Malone, director of the seismology laboratory at the University of Washington, said the quake occurred below the Earth's surface and was not related to reports of a fireball streaking through the night sky.
"This has all the characteristics of an earthquake, not something from impact," he said.
Scientists said the fireball was probably a meteor and likely disintegrated just before any fragments fell into the Pacific Ocean.
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