4.8 quake jolts western Washington

PORT ANGELES — A deep earthquake with a preliminary magnitude of 4.8 beneath the Olympic Mountains jolted much of Western Washington early this morning.

No damage was reported initially following the quake, which was widely felt across the Olympic Peninsula and in much of the Seattle area, said Anthony Qamar, Washington state seismologist.

"Because of its depth, it would cause light damage if any damage," Qamar said.

The temblor occurred at 3:02 a.m. PDT and was centered 31 miles beneath Olympic National Park and about 30 miles south of Port Angeles and 43 miles west of Seattle.

An aftershock registering 2.9 was recorded at 4:56 a.m.

In barely an hour the University of Washington seismology laboratory in Seattle received 200 e-mail quake reports from Olympia at the south end of Puget Sound to Everett, 25 miles north of Seattle, and across the Olympic Peninsula, Qamar said.

The quake occurred in the same deep geological structure as the 6.8 magnitude Nisqually earthquake south of Seattle on Feb. 28, 2001, and was three times as deep and 30 times more powerful than a 3.9 magnitude quake beneath Portland, Ore., on Thursday.

The two recent quakes were in different geological structures and were unrelated, nor is the Olympics quake a likely "precursor for a larger event," he said.

Catastrophic quakes causing widespread damage and deaths would most likely occur in the Cascadia subduction zone off the coast and in slippage between the North American and Juan de Fuca plates of the Earth's crust, Qamar explained.