National Geographic: Tsunami - Killer Wave Page #5

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as much as 20,000 in the summer.

Cannon Beach is more prepared

for a tsunami than most towns,

conducting regular tests

of its warning system.

Test, test, test.

But they don't want to frighten

the residents or the tourists,

so the shrill siren is replaced

with something

a little bit friendlier.

The folks in Cannon Beach have

maintained their sense of humor,

but they do take tsunami seriously.

They know they have a lot to lose,

especially here

at Cannon Beach Elementary,

only 400 feet from the ocean.

We're going to add "re"

to the beginning of the word.

So what would be the new word

if you add "re" to the first word?

Brian B?

Regain?

Regain is right.

And how do you spell regain, Nathan?

"R-E-G-A-I-N"

Right.

These kids are well aware

of the tsunami threat.

And they know what to do

when the alarm bell rings.

Let's exit calmly, class.

They have only a few minutes

to get to higher ground.

You guys did it this time

in 13 minutes and 30 seconds.

Great job. Great job.

You hustled all the way up.

I saw people encouraging

one another.

You not only focused on

keeping yourself

and your partner straight,

but you also and safe

but you also were encouraging people

all the way.

I really, really appreciate that.

Great job.

Give yourselves one more hand.

Alright. Great.

Plans are in the works

to relocate the school,

but until then

evacuation drills will continue.

It's the only way

to prevent a catastrophe.

The last tsunami hit Cannon Beach

And in the school playground,

there's chilling evidence

of its power:

The steel swing set bears scars

inflicted by trees,

uprooted and hurled about

by the waves.

Fortunately,

that tsunami struck at night,

when the schoolyard was empty.

The next one could happen anytime.

Cannon Beach is well aware of

the dangers of tsunami.

But there are other towns at risk

along the Pacific Coast...

and many of them are

simply unprepared

For the state of Washington,

there's a resort area

called Long Beach

It's a low-lying sand barrier.

And during the summer months,

sometimes there's as many

as 40 or 50,000 people

that are out there

in recreational activities.

That would be

by far the worst case scenario,

because there's only one way

out of that,

and that poses

a very gruesome picture.

Probably the people couldn't

evacuate in time.

And anything that's not reinforced

concrete would be wiped out.

And it becomes timber in the water,

then causing more damage,

because now it's incorporated

as part of the wave.

Automobiles become floating objects

and they'd be propelled

all over the place.

So as the wave sweeps back

and forth,

it would probably just bulldoze

and leave probably

six or eight inches of sand.

So when it's all over,

it'll be nice smooth sandy beach

without any of man's structures

on it anymore.

Warning systems

and evacuation procedures are

well-established here in Hawaii.

But they're only effective

if people trust them.

Leave the area.

This is an update

on the civil defense tsunami alert.

At this time,

you are advised to stay in your room

until further notice.

Roads out of Waikiki are now closed.

In 1994,

a tsunami warning was issued here

and beaches were evacuated

throughout the islands.

Three hundred thousand people

responded

But this tsunami alert

may have done more harm than good.

Well, in 1994,

there was a large earthquake

in the northwest Pacific Ocean.

It was big enough to have generated

a Pacific-wide tsunami.

The early indications were that

there was significant run-up

of the water in the tidal stations

closest to the earthquake.

So the Pacific Tsunami Warning

Center declared a tsunami warning.

They accurately predicted

the arrival time of the waves,

but they are incapable of predicting

how large the waves

are actually going to be.

When tsunamis occur

as rarely as they do

and with as little money

as is available for research,

we as yet just don't know

how to predict how large

the waves will be.

So in Hawaii the waves

came ashore six inches high.

And unfortunately

most of the public interprets that

as a false alarm,

when in fact

it's just our lack of understanding.

It could've been

a potentially devastating tsunami.

The problem

with over-warning people is

of course,

they lose confidence in the system.

They say,

"Oh, it's just another false alarm,"

and we don't bother.

Or the flip side of this is

they become so cavalier about it

they will actually go to the beach

to see what it is.

So I think it's incumbent upon us

as scientists

to try to find

a more accurate way...

of forecasting the effects of these.

Now the technology

finally exists to do just that.

In a government warehouse

near Dr. Bernard's office,

you can see the future

of tsunami forecasting.

A 20-foot signal buoy,

coupled with advanced wave sensors,

could put an end to false alarms

and help save lives.

Anchored in the middle of the ocean

as part of a Pacific-wide network,

the system will make it possible to

predict the height of tsunami waves

as well as when and where

they'll strike.

Undersea gauges will take the

precise measure of each passing wave

and transmit the data

to the buoy floating above.

A satellite will complete the link

to the tsunami warning center.

The new system

could eliminate false alarms

and build public confidence

in the tsunami warning system.

But there are certain types

of tsunamis

that can strike so suddenly

and with such force that even

the most sophisticated system

would be unable

to provide a warning.

Here in the Hawaiian Islands,

where all of the land is built

by volcanic eruptions,

the islands grow up

from the sea floor,

and then periodically

the sides slide back

down onto the ocean floor.

They've created magnificent cliffs

along the sides of

all of the islands in the chain.

But when those chunks of the islands

slide off onto

the Pacific Ocean floor

as huge landslides

and debris flows...

they have the potential to

generate giant destructive tsunamis

And there's evidence

that they have created waves

as high as 1,000 feet

on some of the islands in the past.

These landslide waves

may be part of Hawaii's future

as well as its past.

Here on the Big Island, a huge crack

in the earth is opening up

It's 60 miles long.

And it's growing wider every year.

Some scientists think

it's gradually detaching one side

of the island from the other.

The great crack is

one of these fault zones.

At one time, it may have actually

had magma in it.

But now, it's probably serving

more like a hinge,

where part of the island

is beginning to slide down

and may someday slip away

toward the ocean floor.

A thousand-foot tsunami on the coast

of Hawaii would be catastrophic.

But a giant tsunami

could happen anywhere,

even without earthquakes, volcanoes,

or landslides.

A few scientists are beginning

to examine another possible cause

extremely remote,

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