- SEATTLE (www.nando.net) -- The next time you visit a Pacific Ocean beach,
you may find a new addition to the signs that warn of dangerous undertows
and rip tides.
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- The blue-and-white signs show a person
running from a giant wave. The message: "Tsunami hazard zone. In case
of earthquake, go to high ground or inland."
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- Tsunami is the Japanese name for renegade
sea waves up to 100 feet high that are generated by earthquakes or landslides.
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- And the person on the sign is likely
out of luck trying to outrun the wave looming behind him. While the waves
don't maintain their 500 mph top speed on shore, the pace of 30 mph to
50 mph is more than humans can do on foot.
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- That's why the federal government and
the states of California, Oregon, Washington, Alaska and Hawaii want to
improve the technology used to detect tsunamis and increase civil-disaster
planning and public education.
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- "We know that we're due for a big
one," said George Crawford, earthquake program coordinator for Washington
state's emergency management division.
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- The threat is not new.
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- Most of the 132 people killed in Alaska's
1964 Good Friday earthquake were victims of tsunamis. About 20 of the estimated
121 tsunami victims were outside Alaska as the waves ravaged other parts
of the West Coast.
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- In Hawaii, tsunamis are the deadliest
natural threat, blamed for more than 300 deaths since the 1940s.
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- Over the past century, there has been
an average of one damaging tsunami per year in the Pacific basin, with
a 100-year toll of about 70,000 people. In just three years, from 1992-1994,
a half dozen tsunamis over 15 feet tall killed more than 2,300 people.
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- But the threat has taken on new urgency
with evidence in the past 15 years that a coastal earthquake zone from
Northern California to British Columbia -- the Cascadia subduction zone,
where plates of the Earth's crust are colliding -- is capable of generating
giant quakes that could send tsunamis crashing ashore in a matter of minutes.
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- It really hit home in April 1992, when
a 7.2-magnitude quake struck off the coast of California's Humboldt County.
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- "It created a massive amount of
damage in Northern California ... and it produced a small tsunami"
about 1-3 feet high, said Eddie Bernard, director of the Pacific Marine
Environmental Laboratory here and chairman of the National Tsunami Hazard
Mitigation Program.
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- "Now, this was the first time that
California had had a subduction-zone earthquake and an accompanying tsunami,"
Bernard said. "That woke up everybody."
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- Before that, officials had believed there
would be hours of lead time for a tsunami threat.
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- "Humboldt really turned all of that
on its head," said Richard Eisner, regional administrator for the
coastal region of California's emergency-services agency.
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- The U.S. Senate asked the National Oceanic
and Atmospheric Administration to assess the threat and state preparedness.
But as Bernard began organizing meetings, he found that the federal officials
responsible for issuing tsunami warnings, and the local officials responsible
for dealing with the results, didn't know much about each other.
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- A steering group of representatives from
federal agencies and the five states came up with a three-pronged approach:
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- ----Hazard assessment. A center was set
up last year in Newport, Ore., to help produce "tsunami inundation
maps," showing coastal areas that would be flooded by tsunamis. Local
officials can use the maps to plot evacuation routes or decide locations
for critical facilities such as fire stations and hospitals.
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- ----Warning guidance. The region's network
of seismic stations is being expanded and upgraded to better track the
source and type of earthquakes for NOAA's tsunami warning centers at Ewa
Beach, Hawaii, and Palmer, Alaska. A series of at-sea buoys that detect
water-pressure changes also are planned, to detect tsunamis and determine
their size. And research and warning centers are integrating their computer
systems, so each can have access to data from the others' arrays of seismometers.
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- ----Mitigation. The "tsunami hazard
zone" signs are one example, along with signs marking evacuation routes,
informational brochures, school-evacuation drills, warning systems such
as sirens, and other local efforts.
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- The "inundation maps" offer
insights, but aren't intended to dictate land-use planning.
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- "What you can say is that in general,
if an earthquake occurs like we envision and if a tsunami is produced like
we envision, then this area will probably be flooded," Bernard said.
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- "If your house is in the middle
of it, that doesn't necessarily mean you're going to get blown away, but
I would recommend that you figure out a way to protect your family in the
event this happens."
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- Congress appropriated $2.3 million for
the joint effort this fiscal year and the same amount last year, with the
states contributing as well.
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- "Our problem is like everybody else:
It's resources," said Jim Mackin, mitigation officer for the Alaska's
emergency-services division.
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- "When they're made available and
there's not a lot of strings on it, it's great," he said. "What
we need to do in Alaska is different from what they need to do in Oregon
and California."
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- From NOAA's standpoint, a major goal
of the program is to eliminate false alarms that cause unnecessary evacuations,
such as one in October 1994, when a magnitude 8.1 earthquake off Russia's
Kuril Islands spawned a tsunami. The wave turned out to be a wash in U.S.
territory -- but not before disrupting life in numerous West Coast communities.
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- Warnings issued by NOAA's tsunami warning
centers now are based strictly on the size and location of an earthquake
-- an ultra-conservative approach for safety. It's not known whether a
tsunami has actually been generated until the wave reaches one of a series
of tide gauges around the Pacific.
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- If the tsunami is small or nonexistent,
the warning is quickly called off. The planned deep-sea buoys -- a half
dozen of them from Alaska to Chile -- should be able to tell quickly whether
-- and how big -- a tsunami has formed.
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- False alarms are pricey: Hawaii has calculated
the cost of a statewide evacuation at $40 million per day, mostly due to
lost business, said Barbara Hendrie, spokeswoman for Hawaii State Civil
Defense.
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- "The more changes that come about
in the accuracy of notification and alerting the public, the better,"
said Hendrie, who described Hawaiians as "sitting ducks."
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- "These waves are just incredible
-- what they can do and how far inland they can go."
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- Bernard agrees.
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- "If we're going to be the nation's
warning center we'd better make doggone sure that when we issue a warning
people, one, know what it means and, two, take the appropriate action,"
he said.
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- "We can't just stick our head in
the sand and say, 'Well, they'll take care of it somehow.' "
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