Western Washington Jolted by 5.0 Quake

In a sharp reminder that western Washington sits astride the seismically active Pacific Rim, an earthquake with a magnitude of 5.0 rumbled through the Seattle-Tacoma area Saturday night.

Though no injuries or major damage were immediately reported, the quake, which hit at 7:11 p.m., was felt from Canada to central Oregon and as far east as Yakima, Wash.

Seismologists at the University of Washington said it was the most significant earthquake to hit the area in 30 years, when a 6.5 temblor caused substantial damage around Puget Sound.

The epicenter was placed about eight miles deep, halfway between Seattle and Tacoma near the town of Federal Way.

Seismologists said it was caused by movement laterally along a fault, and it was not a subduction-type quake, in which the leading edge of one tectonic plate dives under another. A subduction quake has long been anticipated in the Northwest as capable of an 8.0 or greater magnitude.

Skyscrapers swayed in downtown Seattle and grocery stores across a wide area lost items off shelves. The Washington state ferry dock at Vashon Island in Puget Sound was reported to have been damaged.

“It was widely recorded,” said Deiter Weichert of the Pacific Geoscience Centre in Victoria. “It was recorded by all our monitoring stations on Vancouver Island and up the West Coast, even to the Rocky Mountain Trench.”

Drew Graham at KGMI Radio said the tremor “just made a couple things in here swing around.”

Scientists said aftershocks as great as magnitude 4.0 would probably be felt in the coming days.

The largest quake to hit western Washington in recent history was a 7.1 temblor near Olympia in 1949.

Times wire services contributed to this story.