PACIFIC NORTHWEST FACES NEARLY IDENTICAL RISKS TO JAPANESE QUAKE

PACIFIC NORTHWEST FACES NEARLY IDENTICAL RISKS TO JAPANESE QUAKE





3-11-11

CORVALLIS, Ore. – It’s being called one of the largest
recorded earthquakes in world history. Also, according to Robert Yeats,
“This is our wake up call.”

Japan today is struggling with the aftermath of a massive 8.9
earthquake on a subduction zone, a short distance offshore, which
unleashed a devastating tsunami that killed hundreds and has turned
large parts of cities into rubble.

Yeats, a professor emeritus of geology at Oregon State University,
said that if people didn’t already get the message from recent disasters
in Sumatra and Chile, they should pay attention now.

“This is an earthquake of the same type, with about the same
magnitude and proximity that we face here in the Pacific Northwest from
the Cascadia Subduction Zone,” Yeats said. “What you are seeing in
Japan today is what you will also see in our future. Except they are
better prepared than we are.”

One of the world’s leading experts on the Cascadia Subduction Zone,
OSU marine geologist Chris Goldfinger, got an up-close, personal preview
of the forces he’s been studying – he was in Tokyo when the earthquake
hit, ironically attending a meeting on the Sumatra earthquake.

“I’m in the northern outskirts of Tokyo and rode through the quake
and continuous aftershocks ever since,” said Goldfinger, a professor in
OSU’s College of Oceanic and Atmospheric Sciences. “The main shock
lasted an entire five minutes. We were in the middle of a talk and just
bailed and went outside. Here in Chiba, you could literally feel the
plates grinding; the high-frequency P-wave arrival was like nothing I’ve
ever felt.

“Then five minutes of S-waves and feeling sort of seasick,” he added.
“There hasn’t been too much damage in Tokyo that I’ve seen, but
watching the tsunami come in live on television in Sendai and Iwaki –
with ships washing into the town – was amazing.”

Despite the tragic loss of life and billions of dollars in damage
that will result from the Japanese earthquake, Yeats said, they are as
or better prepared for a disaster such as this as anyone in the world.
Their technology, building codes, public education and other programs
for earthquake preparation are exemplary, with scientific initiatives
that date back to the 1890s.

And even though it may seem like there has been an unusually large
number of earthquake disasters in recent years, Yeats said, the past
decade or so doesn’t really stand out all that much in a historic sense.

“It’s not completely regular, there are a few clusters of disasters
at some times more than others,” Yeats said. “But the real message here
is that the Earth is very active and sometimes violent, it always has
been and always will be. We can’t predict these events so we have to
prepare for them.”

Harry Yeh, a professor of engineering at OSU and an internationally
recognized expert on tsunami propagation, also watched the events unfold
on television – with an eye toward the potential of “vertical
evacuation” in coastal cities.

“It’s too early to tell if vertical evacuation on a large scale would
be effective in a massive earthquake such as this, though I did see
many people evacuated to the top of buildings – for example, Sendai
Airport and some school buildings,” Yeh said. “Japanese television
repeatedly mentioned the idea and led people to evacuate to strong
concrete buildings on the third floor or higher.”

OSU experts have worked closely with officials in Cannon Beach, Ore.,
in an initiative to build what would be the nation’s first structure
designed specifically to resist tsunami wave forces and save lives
through this concept of “vertical evacuation.” Those efforts are
ongoing.

Meanwhile, experts at OSU and across the Pacific Northwest are
continuing to learn what they can from each disaster of this type to
gain insights that might one day help save lives here. Much of this work
has been supported by the National Science Foundation, and their
Network for Earthquake Engineering Simulation.

“This is a good rehearsal for us,” said Solomon Yim, a professor of
ocean engineering at OSU and director of the university’s Hinsdale Wave
Research Laboratory, which includes one of the world’s most
sophisticated wave basins specifically designed to study tsunamis. “The
take home message is that what just happened in Japan is going to happen
here. It’s just devastating.

“The forces you’re seeing in Japan are similar to what happened in
Indonesia,” Yim said. “You saw cars and boats and debris slamming into
structures and bridges, those are the types of forces we need to learn
more about in building tsunami resistant structures.”

Improvements in understanding subsea bathymetry would be helpful, OSU
experts said, as well as how wave forces will translate into onshore
runup once they hit land. More work with public outreach and ocean
mapping are also needed, they said.


About Oregon State University: OSU is one
of only two U.S. universities designated a land-, sea-, space- and
sun-grant institution. OSU is also Oregon’s only university to hold both
the Carnegie Foundation’s top designation for research institutions and
its prestigious Community Engagement classification. Its nearly 24,000
students come from all 50 states and more than 90 nations. OSU programs
touch every county within Oregon, and its faculty teach and conduct
research on issues of national and global importance.
Source: http://oregonstate.edu/ua/ncs/archives/2011/mar/massive-japanese-earthquake-nearly-identical-risks-facing-pacific-northwest