An epic earthquake and tsunami leave hard-won knowledge in their aftermath.
By Carl Hoffman
A well-paved two-lane road along Japan’s northeast coast winds through the mountains, gradually descending toward Rikuzentakata. The seaside city, population 23 000, once attracted tourists and elderly Japanese with its gorgeous views and idyllic beaches. A river plunges down short, steep slopes through the town and into the sea.
At the end of March, a week after a magnitude 9,0 earthquake rocked the region, the trees along the road are ready for the first bud of spring. A banal landscape of suburbia passes: homes with children’s bicycles on porches. The parking lot of a 7-Eleven is filled with cars, but its filling station has no fuel.
And then the road descends into downtown Rikuzentakata – and a world crushed. A sickly brown-grey carpet of rubble stretches to the horizon, dotted with bright-red front-end loaders and firetrucks. A few random concrete buildings are still standing, shattered windows gaping, facades strewn with tree limbs and fishing nets. Cadres of responders wearing helmets and face masks advance in slow-moving lines, probing the debris field with long poles. They are looking for the dead.
The mechanics of the disaster are well-known to the world: a massive earthquake, 130 kilometres offshore, produced the tsunami that struck this and other coastal cities. Seeing it firsthand is overwhelming. Rikuzentakata has been reduced to 1 000 hectares of broken wood and twisted steel beams. Evidence of ruined lives is everywhere. Flattened trucks, flipped upside down. A man’s tie in a tree. Photo albums in the mud. A bowl. A sodden teddy bear.
Takehiro Shimamura, a firefighter from the inland city of Saitama, was among the first emergency personnel to enter the city. “People in the high places were crying, in shock with their mouths hanging,” he says. “Along the river we found no one alive, not a person.”
Experts consider Japan’s disaster planning and infrastructure the best in the world. This assessment proved correct when it came to preventing death and damage from the earthquake, the fourth largest ever recorded. The resultant tsunami, however, killed more than 25 000 people, despite the extensive protection built along the east coast.
The destruction taught the world that preparedness is as much a matter of education as of infrastructure. The tsunami was pitiless. For those who knew what to do, survival was possible, but those who hesitated died. “The ones who survived in Japan are the ones who went to higher ground, period,” says Patrick Corcoran, a hazards outreach specialist at Oregon State University. “Do you know where the higher ground is right now?”
On the afternoon of 11 March, Masako Tanaka was in Kesennuma, a coastal city 20 kilometres south of Rikuzentakata. The 57-year-old was making one of her periodic visits to her native Japan from her home in Los Angeles.
Tanaka and her 70-year-old aunt were near Kesennuma’s port when the ground started rumbling. The tremors lasted 6 minutes. “The road was moving like a wave,” she says. “We did not even know if the tsunami was coming right away or not, but somehow I felt that this earthquake was like nothing I had ever experienced in my life.”
During the quake, Japan’s skyscrapers swayed like bamboo trees in the wind, but did not fall. “The biggest takeaway”, says Bozidar Stojadinovic, professor of civil and environmental engineering at University of California, Berkeley, “is that modern building codes worked.”
Japan’s codes are strict, but developers often go further than regulations demand, fitting buildings with devices that act like giant shock absorbers. “Developers are eager to deploy technology because Japanese will pay more money to live in a building with seismic isolators,” Stojadinovic says.
On the other side of the Pacific, where one of the world’s other notable earthquake zones is situated, the focus on preparation is more lax. In the USA’s quakeprone Pacific Northwest, the onus of protection falls on property owners. Local governments often encourage safeguards, but do not mandate them. For example, Seattle offers classes on bolting woodframe homes to foundations and securing water heaters, safeguards required by most insurance companies before they will issue earthquake protection.
Experts say that residents don’t acknowledge the risk, and the area is not as prepared as Japan. “Many structures in the Pacific Northwest are not built to earthquake- resistant standards,” says University of California, Irvine, public health expert Lisa Grant Ludwig. “There’s a lot of brick, and it’s a challenging problem.”
Public infrastructure is another matter. Portland, Oregon, recently installed lateral support walls in and reinforced the brick exteriors of its schools; this year (as PM went to press), voters weighed in on a roughly R4 billion bond that would rebuild nine schools to national seismic safety standards.
These actions are prompted by a grim reality: an earthquake in the Pacific Northwest is not only expected, it’s likely. The subduction fault running from Northern California to Vancouver Island moves an average of once every 150 years. The most recent large quake occurred in January 1700 – making the region 161 years overdue.
The tsunami that destroyed Rikuzentakata and Kesennuma began when the earthquake pushed a 300-kilometre- long, 145-kilometre-wide section of seafloor up about 40 metres. The water displaced by this rupture raced east, its energy dissipating into the Pacific, and west toward the northeast coast of Japan. Japan’s early warning network blared across public address systems and flashed on the screens of computers and mobile electronics.
When the tsunami hit the continental shelf, the wave slowed but grew in height. The surge topped seawalls, some 12 metres high. Kesennuma, like almost every town along the coast, was quickly inundated.
Masako Tanaka learned at a young age to head to high ground after feeling an earthquake. Her home in the coastal city where she grew up, near Kesennuma, was flooded by a tsunami in 1960. But in an unfamiliar town, she wasn’t sure where to go.
“We were patiently driving downtown, but there were so many cars, we could only go inch by inch,” she says. “Then the alert system was warning us to get out of the car and evacuate to the hills. But people do not think to listen. They just kept going in their cars.”
Abandoning their car, they saw a Japanese Coast Guardsman dashing back to his post at the port. Tanaka had just asked him for directions when he saw a video on his cellphone screen. On it was a live feed of the port’s entrance, already frothing with the tsunami surge.
Tanaka and her aunt followed the guardsman to a nearby apartment building. Water gushed into the stairwell as the trio raced up two flights of stairs. The water flooded the stairwell by the time they reached the top; Tanaka’s aunt and the guardsman pulled her up to the roof from chest-high water. From there, the trio made a short leap to a neighbouring four-storey concrete building.
The survivors watched from the roof as water surged through the town. “I could tell that all of the people in cars were swept away by the time we were on the roof,” Tanaka says. The incalculable tide overwhelmed wooden structures. Houses that didn’t instantly disintegrate floated off their foundations. Concrete structures fared better, but the water washed over the roofs of three-storey buildings. Ships, cars and bits of building wreckage ground against one another in the filthy water, which consumed and absorbed anything in its path.
Japan is obsessed with tsunamis. Highwater marks in Japan warn travellers how high previous tsunamis reached. And the government built a network of seawalls, costing billions, to protect the coasts. Yet a tsunami caused March’s staggering death toll. What happened?
“Japan never expected one this big,” says Harry Yeh, an Oregon State University tsunami expert. The odds were in favour of the seawalls – there have been only seven quakes with a magnitude of 8,8 or higher in the 20th century.
But seawalls cannot be dismissed as folly just because an abnormal event defeats them. In fact, researchers have found that small seawalls blunt the momentum of a tsunami even when overwhelmed. “In one of the lab trials, the seawall was physically ripped out of the ground, and the force was still reduced,” says Mary Beth Oshnack, who studied the issue at Oregon State. “When you look at pictures from (post- 2004-tsunami) Thailand, the walls are really damaged, but the buildings behind them have moderate damage.”
The idea of building giant seawalls to guard the US coast has been gaining traction. Texas governor Rick Perry supports them; last year the state formed a coalition of county judges to review a plan to extend a 15-metre R25 billion wall across Galveston Bay. Seattle is committing funds to a R2 billion seawall to replace one built in 1934. With hurricanes and tsunamis threatening national industries and large populations, these ideas seem expensive but prudent. But some experts worry that massive seawalls breed complacency and sap the will to be prepared.
“Projects worth trillions of dollars, with sophisticated infrastructure, are more attractive to policymakers than invisible options such as… strengthening community awareness,” says Jonatan Lassa, who studies disaster risk mitigation at Harvard Kennedy School. “Engineering measures can reduce regular risks, such as cyclones and floods, but may not always protect people from the extremes.” Rikuzentakata’s seawalls stood 6 metres high; the tsunami was twice that. Only education can prepare people for the worst.
“Tsunami preparation is about cultural behaviour,” Corcoran says. “Give me (R10 billion) and I’ll personally talk to every person along the Oregon coast, and they’ll know where to go to higher ground.”
Any serious discussions about disaster preparedness must balance the cost of protection against the chance of a catastrophe happening. “How much insurance do you want to buy?” Berkeley’s Stojadinovic says.
The answer depends on the level of risk. Geologists detect about 40 small quakes each year in the northeastern US, but the region’s buildings have little seismic protection. That’s because the likely frequency of a 7,0 quake hitting the eastern US is about one every 500 years. Society has decided to accept the long odds and not spend the money to guard against this low-probability event. But that choice may come with a price: a modest earthquake in the Northeast could cause more damage than a huge one in better-prepared California.
No matter where you live, Tanaka’s experience may offer the best, most cost-effective lesson: Be prepared. “The single greatest thing people can do is to understand that they will have to take care of themselves,” says Mike Martinet, until recently the executive director of the Office of Disaster Management for 14 cities in the South Bay region of Los Angeles County.
“There are about 3 000 paramedics in greater Los Angeles, a city of 10 million people,” Martinet says. “There just isn’t enough government to take care of that many people, especially when roads and communications stop working.”
The night of the tsunami, Tanaka distributed caramel sea salt brownies from her purse to fellow survivors. They endured snow in a shelter made from a sheet thrown to her by survivors atop a nearby hospital.
Nine days later, Tanaka was no longer a victim. Instead of heading back to Los Angeles, she was serving as a translator and guide for a team of Dutch volunteers and their cadaver dogs, searching the wreckage of her hometown for bodies. “I had to do something for my community,” she says. “I just had an urge that I had to help them out.”
Tanaka and her aunt are alive because she remembered what to do without panicking and acted quickly. Because of that, she’s now able to help others.
Ready for the worst?
Japan and the US have different approaches to infrastructure that can mean life or death during a natural disaster.
|Nuclear Power||1 Japanese plants typically have multiple reactors. Having more reactors in one facility means more hazardous fuel stored on-site and greater risks in the event of a plant-wide incident.||1 American power plants have fewer nuclear reactors, making a plant-wide incident easier to manage. No existing facility in the US has more than three reactors, although one in Georgia will soon have four.|
|2 Japanese plants can’t safely vent hydrogen. Uncooled fuel rods in a damaged reactor produce hydrogen, but many plants have no way to release the gas outside the reactor buildings before it reaches explosive levels, as happened in March.||2 US plants can vent hydrogen into the atmosphere. US reactors have stacks that release the gas outside the building, reducing concentrations below explosive levels, says Ken Brockman, former director of safety for the International Atomic Energy Agency.|
|3 Half of the nation’s nuclear plants have boilingwater reactors. BWRs use the same water to cool the core as to turn the steam turbines, allowing radioactive leaks in the water to travel through the plant.||3 Of the 104 reactors in the US, only 35 are BWRs. Most are pressurised water reactors that have two separate loops of water, one to create steam and another to cool the reactor. This removes a potential path for radiation to spread.|
|Trains||Seismometers relay messages to transformers to command trains to stop during a quake. L-shaped guides mounted on cars can safely halt derailed wheels.||Most trains and tracks outside California aren’t equipped with automatic-shutdown quake sensors, but many trains can detect broken rails and stop.|
|Early-warning systems||Thousands of sensors detect a quake’s primary waves (P-waves), which travel at the speed of sound but cause little damage. The dangerous surface waves (S-waves) arrive later.||The nation’s Advanced National Seismic System, a network of P-wave and S-wave detectors, is only 25 per cent complete. California’s warning system could be completed in five years.|
The defended coastline
When it comes to thwarting tsunamis, layers of protection are best.
1. Raise walls
When a wave breaches a seawall – a high-profile and expensive defence – many call this a total failure. “Obviously, the smaller the wave, the better,” says researcher Mary Beth Oshnack. “But even if the seawall is shorter than the wave, it would still reduce the force of the wave.” The biggest problem with seawalls is that they tend to breed complacency. No wall can be expected to defeat every tsunami, and plans must be made for more layers of preparedness onshore.
2. Construct towers
Damage-resistant shelters can be constructed on high ground, providing a beacon for those fleeing an incoming wave. One such 73 m2 shelter, in Nishiki, Japan, doubles as a disaster archive. Other Japanese emergency facilities flooded during March’s disaster – a grim reminder to model a wave’s potential path before construction.
3. Don't bunch up
“There is a saying that ‘disaster happens when people forget,’” says Futoshi Toba, mayor of Rikuzentakata. “Maybe we can make new concrete homes in higher places.” Japan’s coastline is crowded: very little of the nation is suitable for residential housing. In countries with more space, local authorities can zone larger plots to diminish the number of people living in danger areas. Zoning large plots would also decrease the amount of damaging debris pushed inland by a tsunami.
4. Build high ground
Engineering well-marked, easyto- access hills in tsunami-prone areas gives residents a familiar place to shelter and eases escaperoute crowding. Hydrodynamists can simulate a tsunami’s potential reach, aiding the engineering and placement of such safe areas. As a bonus, these refuges can double as public parks.
Images: Visit www.popularmechanics.co.za/facebook to view images of the aftermath of Japan’s Earthquake taken by Nasa.