How Do You Protect Against a Tsunami?

bjbjLULU JUDY WOODRUFF: And to a very different
kind of science story: how researchers in Japan are trying to limit the most catastrophic
damage from a tsunami. NewsHour science correspondent Miles O’Brien files the last of three reports
from Japan. MILES O BRIEN: Yoshiko Kiuchi (ph) remembers March 11, 2011, as if it were
yesterday. “We got a warning that tsunami would come in two minutes,” she told me. “So,
we escaped by car in a rush, literally with little more than the clothes on our back.”
Her home and her neighborhood in the coastal town of Arahama are gone, pressure-washed
by the epic tsunami. She lives in temporary housing now, but comes back here regularly
to gather what she can out of what remains of her garden. “I will take these flowers
to my temporary house,” she said. “I will plant them in the planter there.” Nearby,
there is plenty of evidence the Japanese are working hard to clean up and rebuild. But
how? The tsunami, not the earthquake, is linked to nearly all the 20,000 deaths here. And
building coastal towns that can repel giant waves is not easy or cheap. That is what they
are working on here at the Port and Airport Research Institute about fifty miles south
of Tokyo. It was open house day when we were here, a chance for people to see and feel
how powerful even a scaled-down version of a tsunami can be. But it is not just for show.
TARO ARIKAWA, marine engineer: All right, go. MILES O BRIEN: Taro Arikawa is an engineer
here. When he is not drenching the public, he is working on a pneumatic breakwater system,
hollow steel pylons buried in the seafloor that telescope when air is pumped in. How
quickly do they come up? TARO ARIKAWA: Three minutes. MILES O BRIEN: Wow. In Wakayama Harbor,
they tested the idea in rough seas. Once they popped above the surface, the pylons reduced
the size of the waves by half. So it is possible to conceive of someday a tsunami barrier for
Japan? TARO ARIKAWA: Yes, maybe. MILES O BRIEN: Really? TARO ARIKAWA: And I will — I will
continue to study the purpose, withstand the tsunami. So, I — we will succeed to construct
the tsunami barrier for the future. MILES O BRIEN: But at no small cost. Arikawa says
a system to protect the entire harbor would cost 10 billion yen, or $130 million, but
it might be worth the money. Coastal engineering professor Akio Okayasu is working on tsunami
protection ideas at the Tokyo University of Marine Science and Technology. He is creating
a detailed database of the inundation from the great tsunami using volunteers to chart
the flotsam from the high water marks up and down the east coast of Japan. With 5,000 readings
and counting, he has found some clear-cut evidence that breakwaters do indeed work.
Kamaishi Bay was protected with a breakwater that apparently reduced the wave height by
nearly two-thirds. AKIO OKAYASU, Tokyo University of Marine Science and Technology: We believe
it did help reduce the height of the tsunami inside of the bay. MILES O BRIEN: It took
a little bit of the power out of it? AKIO OKAYASU: Yes, we say energy. MILES O BRIEN:
But he says breakwaters and seawalls are just part of a system. After all, they cannot build
a huge concrete wall all around Japan. The system, says Professor Okayasu, must include
the people. AKIO OKAYASU: If the people don’t evacuate, the system doesn’t work anyway.
So we need to prepare. How can we make the people feel easy to evacuate? MILES O BRIEN:
That is what they are studying here at Oregon State University’s Hinsdale Wave Lab. Dan
Cox is the director. DAN COX, Hinsdale Wave Research Laboratory, Oregon State University:
One thing that our research is looking at is the role of vertical evacuation. So this
means going up into a building or onto an earthen mound that is still within the inundation
zone, still — you’re still going to be in the flooded zone, but you are much safer just
by going up. MILES O BRIEN: They created a scale model of Seaside, Ore., population 6,400,
watched what happened when big waves rolled in, then fed the data into a computer model.
DAN COX: And the current strategy is only to go up into the hills. MILES O BRIEN: And
if everyone in Seaside did that, Cox predicts 1,700 people would perish because they would
be unable to get to high ground in time. DAN COX: But if we adopt the strategy of vertical
evacuation, then those numbers could change. MILES O BRIEN: If the town had some strategically
located earthquake and wave-hardened towers in the inundation zone, the predicted casualty
count drops to 200. Cox believes it is time to write a tsunami building code in Oregon
that embraces vertical evacuation. DAN COX: Part of it could be either retrofitting old
buildings. So, it still has to withstand the earthquake from the subduction zone. And it
could be building new buildings that are specifically purposed for vertical evacuation. Or it could
be modifying plans for future buildings. MILES O BRIEN: Ten miles south of Seaside, in the
town of Cannon Beach, they want to do just that. The $4 million city hall they would
like to build would double as a tsunami evacuation building. In Japan, they have about a dozen
vertical evacuation structures in tsunami zones. And they have invested much time and
money into ensuring their high-rise buildings do not fall during an earthquake. I went to
the place they call E-Defense outside Kobe. It is home to the largest seismic shake table
in the world. Engineer Takuya Nagae gave me a fascinating tour deep in the bowels of this
massive $400 million facility. TAKUYA NAGAE, seismic engineer: Twelve pistons support vertically,
and five pistons, you know, moves horizontally for each direction. MILES O BRIEN: During
my visit, they were getting ready for another test. About once a month, big structures are
built, furnished and then shaken violently to see what happens. TAKUYA NAGAE: We have
to break that specimen to find the capacity, not just, oh, it’s safe, so we can stop. No,
we have to continue to see the real capacity. MILES O BRIEN: Nagae showed me a stark example
of what they have learned here. This reinforced concrete school building failed during its
shake test, but this one fared much better. It had been retrofitted with steel beams.
TAKUYA NAGAE: So we have to promote retrofitting as much as possible. And we have to enhance
the seismic capacity of cities. And it’s very important to retrofit all type of buildings
designed by old code. MILES O BRIEN: But there is another code here, one that is etched in
stone, which I saw in the remote fishing village of Aneyoshi. The warning on the stone is clear.
It says don’t build your homes below this point. As matter of fact, high water mark
for this latest tsunami is about 300 feet down this road. These stones — and there
are hundreds of them all throughout Japan — are warnings from the ancestors, letting
people know and reminding them of the force of nature. Mostly, they are ignored or forgotten.
In this case, this town listened. No one in this town built a home below the old stone
after the last big tsunami in 1933. Teruo Kimura (ph) was born in this house and now
watches his grandchildren play in the driveway. “Before the tsunami, villagers were living
on the shore,” he told me. “Because the houses were all washed out, villagers built their
houses along this street. So, we are lucky to have houses up here. I haven’t heard anyone
want to live down there.” Of course, Aneyoshi is the exception. People in Japan will return
to their homes in the lowlands by the sea, but not Yoshiko Kiuchi (ph). She lost too
many friends and neighbors. Her garden, her flowers represent a good memory, but not a
longing to return. “No, I was living a happy life,” she said. “This was a very beautiful
place. I do not want to live here anymore.” For many here, no amount of engineering will
be enough to wall off the sadness and the fear. JEFFREY BROWN: It’s Science Thursday
on our website. You will find Hari Sreenivasan’s interview there with a chemistry professor
who writes poems about thermodynamics, kinetics and atomic reactions. You will also — you
also can watch Miles’ previous stories from Japan. urn:schemas-microsoft-com:office:smarttags
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