by Associated Press
SEATTLE (AP) — The University of Washington reports the 3.7 magnitude quake under Whidbey Island came from the same zone that produced the 6.8 Nisqually quake in 2001.
Seismology lab coordinator Bill Steele says the 5:09 a.m. Wednesday shaking that woke up some Puget Sound residents is a wake-up call to Western Washington residents that a much bigger quake is likely in the future.
Steele says the quake was centered 36 miles deep, in the Juan de Fuca tectonic plate, the same source as the 7.1 Olympia quake in 1949.
The “big one” could come from that plate slipping under the North America plate. That interface has produced quakes of magnitude 8 or 9 about every 500 years. The last one was about 300 years ago.
The last “megathrust” quake — commonly referred to as “the big one” — happened in the Northwest in 1700.
The “big one” could also bring a tsunami as high as 80 to 100 feet, similar to the one that struck Sumatra in 2004.
On the Web: http://www.pnsn.org/recenteqs/Quakes/uw07011209.htm
