KIRO 7 Throwbacks

Research: The ‘big one’ could rattle Northwest sooner than first thought

SEATTLE — A major earthquake may hit the Pacific Northwest sooner than scientists originally thought.

New research, published in the journal Marine Geology this week, about the Cascadia Subduction Zone has prompted earthquake experts to re-think the potential timeline and shows that major earthquakes happen more frequently than first thought.

It also brings added importance to earthquake exercises like the "Cascadia Rising" emergency drill that occurred in Washington in June.

Since the 80s, researchers have said major earthquakes occur in our part of the Cascadia Subduction Zone every 500 to 530 years.

But after studying more than 16 times the number of core samples used in previous studies, seismologists now believe devastating quakes occur about every 430 years.

The last devastating earthquake in the area was 315 years ago.

The greater Seattle-area’s last sizeable earthquake, the Nisqually Quake in 2001, may still be fresh in some people's minds, but the kind of quake researchers are referring to is massive – in the magnitude 9.0 range.

The bottom line is that experts now say the chance of a major earthquake in the next 50 years has increased from 8 to 14 percent to 10 to 17 percent.

Another reminder, according to emergency preparedness experts, is to be ready, because no one really knows when such a quake could hit.