CORVALLIS — The big one is coming soon, researchers say.
A new Oregon State University study concluded that the South Coast -- around Coos Bay -- has a 40 percent chance of experiencing a local earthquake and tsunami sometime in the next 50 years.
The study cites evidence of earthquakes and tsunamis on the West Coast dating back 10,000 years.
'We now have the data," said Chris Goldfinger, the study's lead scientist.
'The average time between earthquakes is 240 years. It's been 312 years since the last earthquake. Furthermore, we've passed 75 percent of the known intervals."
Goldfinger said the statistics and percentages are difficult to conceptualize, even for him.
Bottom line: 'This may not be hundreds of years away," he said. 'We may not have that kind of time."
Odds are worse
According to Goldfinger's research, the South Coast -- from around Florence to Eureka, Calif. -- has a much higher chance of experiencing a powerful earthquake than nearby areas
Cascadia fault line earthquakes and tsunamis leave a record in the sediment that scientists are able to carbon date. They have discovered and dated 19 so far.
Between each massive earthquake that affects the entire fault, a separate quake occurs only in the part of the fault near Coos Bay.
'Since the last one was a big one, the next is likely to be southern," Goldfinger said.
'That is the only clue we have, and that's not much."
Goldfinger guesses this quake might be smaller -- 8.0 magnitude instead of about 9.0 -- but still big enough to cause wide-scale destruction.
Witness to tsunami
With this evidence in hand, Goldfinger hopes local communities will begin preparing immediately. He knows firsthand the destructive power of earthquakes and tsunamis -- he was attending an earthquake summit in Japan when the 2010 tsunami struck.
'Without any warning at all, it changed everything," he said.
'These are things you think about, they're theoretical, then suddenly it is there. You have to deal with whatever happens at that point."
Goldfinger said he was in a meeting when the shaking started. At first, the scientists found it ironic. Then they timed the quake and realized it was the biggest Japan had ever experienced.
'We realized there was a big tsunami on the way," Goldfinger said.
'And we were just spectators. There is nothing more useless in an actual earthquake than an earthquake geologist."
People, get ready
The South Coast need not be caught so off guard, Goldfinger said. Individuals can prepare by earthquake-proofing their houses. Strap down water heaters so they don't fall and break the gas line; bolt houses to their foundations; move heavy object to lower shelves.
Local governments should also begin immediately to build tsunami infrastructure, including evacuation signs and sirens. The Oregon Emergency Management department plans to meet with coastal communities to discuss such plans in the coming years.
Goldfinger's study also might be used to improve building codes, said Art Frankel, who works with the U.S. Geological Survey and the University of Washington.
Earlier this year, the Department of Geology and Mineral Industries hosted a tsunami rally and a tsunami evacuation drill to help Coos County residents prepare.
Each person needs a 72-hour kit with necessities. Store three weeks of food, medicine, and hygiene supplies. Make a plan to escape, and a plan to connect with loved ones afterward.
'A lot of people get scared and give up," Goldfinger said. 'They say, 'There's nothing we can do about it.' There is a lot of things you can do to help turn it from a disaster to just a really bad day."
Reporter Jessie Higgins can be reached at 541-269-1222, ext. 240, or firstname.lastname@example.org.