The greatest earthquake ever recorded struck off the coast of southern Chile on May 22, 1960. Denis Garcia, a resident of the adjacent port town Corral, observed something strange after the shaking ceased.
When he saw Corral Bay, he was looking for his family, not thinking they were safe and on high ground.
The water had receded, leaving the seafloor exposed. Garcia set out to find out more.
He didn’t notice the 40-foot wave approaching him until it was too late.
He clung to a piece of rubble for hours in the whirling water until encountering another survivor and clinging onto the top of a floating house, he recalled interviewers decades later.
Meanwhile, the Pacific was hit by a tsunami. More than 5,000 people are thought to have died as a result of the Great Chilean Earthquake and the tsunami that followed.
Around 80% of tsunamis start along the seismically active “Ring of Fire” in the Pacific Ocean.
The most tsunami-prone areas in the United States include Hawaii, Alaska, and the west coast.
However, mega waves can occur in any ocean and move across the sea twice per decade to create havoc far from their origins.
Denis Garcia was fortunate. The majority of people do not survive a tsunami.
However, there are a few measures you may take to safeguard yourself from natural calamities.
Your specific technique will be determined by where you are, but it will go much more smoothly if you plan ahead of time.
“It’s easy to say, ‘That’s never going to be my problem,’ and it’s also easy to throw up your hands and say, ‘It’s going to be so horrible that there’s nothing I can do,” says Carrie Garrison-Laney, a tsunami and coastal hazard expert at Washington Sea Grant in Seattle.
“Yes, it will be horrible, but…there are some things you can do to be ready in case it happens.”
KNOW THE TSUNAMI IS ON THE WAY
Tsunamis are usually caused when massive amounts of water are displaced by earthquakes near the seafloor.
The water is pushed out in the form of a succession of waves that travel in all directions.
Tsunamis can be triggered by underwater volcanic eruptions, landslides, and even meteorites.
These waves, which can be hundreds of miles long but only a few feet in height, travel at the speed of a jet plane, up to 500 miles per hour, out at sea.
When the waves get close to the shore, they slow down to around 20 or 30 miles per hour and start to develop in size.
When they impact shore, most tsunamis are less than 10 feet tall, although they can reach heights of more than 100 feet.
Areas less than 25 feet above sea level and within a mile of the sea will be the most vulnerable when a tsunami hits.
Tsunamis, on the other hand, can travel up to 10 miles inland. “It’s just kind of relentless,” Garrison-Laney adds, “the water just continues coming and coming and coming for a long time.”
The tsunami could look like a wall of water or, more likely, a flood that is fast rising.
“It won’t look like the enormous, curling waves you see at the beach,” Garrison-Laney predicts.
“It’s a tumultuous torrent that’s swiftly rising and flowing onto the land.”
However, there may be certain warning indications before this occurs.
You must first survive the earthquake, assuming one occurred. Even if a tsunami warning has not been issued, make sure you move to high ground after a major coastal quake.
A local tsunami could be just minutes away if one has been triggered. “If it’s a significant earthquake and you live along the coast, you can’t wait for the authorities,” says Denis Chang Seng, technical secretary for UNESCO’s Intergovernmental Coordination Group for the Tsunami Early Warning and Mitigation System in the North-Eastern Atlantic, Mediterranean, and Connected Seas.
A tsunami can also cause the ocean to recede before it hits, leaving sand and reefs naked, as Denis Garcia observed in 1960.
There may also be a roaring noise, similar to that of a railway or a jet plane.
“You have to be able to discern warning signs from nature,” says Chang Seng.
Meanwhile, tsunami warning centers in Hawaii and Alaska, such as the Pacific Tsunami Warning Center and the National Tsunami Warning Center, will issue a warning.
So keep an eye out for official warnings, sirens, and directions from the authorities in your area.
“If you know a tsunami warning has been issued or you’ve felt the ground shake, you don’t want to wait,” says Laura Kong, director of the International Tsunami Information Center in Honolulu. “It’s time for you to start going.”
BEFORE THE DISASTER ARRIVES, GET TO HIGH GROUND.
If you’re on a boat in the middle of the ocean, stay still. Otherwise, your best line of action will be determined by the amount of time you have before the tsunami strikes.
Assuming you’re on land, your goal is to get away from the coast. Attempt to get to a location that is 100 feet above sea level or two miles from the ocean.
If you’re lucky, the tsunami will have been triggered by a distant earthquake and will take several hours to reach.
If you have one, bring it along with you, as well as your pets. If you’re not sure where to go, you can look for evacuation signs.
However, pay attention to any instructions given by emergency officials, since they may advise you to take a different escape route than you had planned.
Keep going if you’re not sure how far to evacuate. “Don’t stop if you’re 20 feet [above sea level], just keep heading upward,” says Ian Miller, a coastal hazards specialist at Washington Sea Grant in Port Angeles.
Stay away from rivers and streams as you make your way to higher land. “A tsunami can go extremely quickly up the river, and many people have been caught off guard,” Chang Seng explains.
Also, make plans to flee on foot. “If everyone gets in their car at the same time, there will be traffic and no one will be able to get out,” Garrison-Laney explains.
Keep an eye out for downed power lines if there has previously been an earthquake in the region.
Avoid buildings and bridges that may be damaged by heavy debris if an aftershock occurs.
Survival pods designed to protect you from a tsunami are also available, albeit they are expensive and have yet to be proven effective.
It’s possible that you won’t have enough time to go to higher ground before the tsunami hits.
Cross-country racer Ben Brownlee was once invited by the Seattle Times to run the evacuation route from Long Beach Elementary in Washington State, a particularly susceptible peninsula in an earthquake-prone zone.
Brownlee can run a mile in under six minutes and crossed the hazard zone in less than fifteen minutes.
He could have survived an incoming tsunami with no injuries or earthquake rubble to contend with—but only just.
You should presume you’re too close to outrun the wave if you can see it.
When faced with a tsunami, many people must make do with whatever refuge they have.
Vertical tsunami shelters will be useful in this situation. These buildings should be strong enough to survive the onslaught of water, tall enough to clear the danger zone, and situated in areas where the greatest number of people can access them.
The nation’s first tsunami evacuation structure was presented last year at Ocosta Elementary School in Westport, Washington.
The gymnasium at the school is designed to survive an earthquake and tsunami while also providing shelter for over 1,000 people on its roof.
Long Beach is intending to construct a tsunami shelter in the shape of an armored hill.
Other communities are also planning tsunami shelters; in Newport, Oregon, a forested hill is being transformed into a 2,300-person refuge.
If you’re fleeing a tsunami and there aren’t any safe havens accessible, look for a sturdy, reinforced concrete structure.
Head for the roof by climbing as high as you can—at least to the third floor.
“Rather than any of the vacation homes, if there is a major hotel with numerous stories, that would probably be your best choice,” Garrison-Laney explains.
“It would have to be a structure with a substantial concrete foundation, and even that isn’t a guarantee.”
After all, most structures were not designed to resist the pressures that a tsunami will unleash.
If there are no buildings nearby, climb a tree.
WHEN THE WAVE HITS, HANG ON TIGHTLY.
Grab a piece of floating debris if everything else fails. Climbing onto roofs and using them as impromptu life rafts has helped some individuals survive.
If you get caught in the wave, you’ll be faced with choppy water and wreckage.
At this point, survival is purely a matter of chance. “A human will be swept up and carried along as debris; there is no swimming out of a tsunami,” explains Garrison-Laney.
“The water is so clogged with debris that you’ll most likely be crushed.”
The tsunami will eventually recede, dragging cars, trees, and structures behind it. Even if you’ve gotten this far, you’re not completely safe.
A tsunami is made up of several waves, the largest of which may not be the first.
The shores are frequently bombarded with many waves over several hours.
“People have died because they assumed the first wave would be the end of the calamity,” Miller adds.
“There are always follow-on waves…much as there is never just one wave when you throw a stone into a rain puddle.”
So, if you’re high up in a tree or on a building and haven’t gotten the all-clear from emergency personnel, don’t come down just yet.
“I’d probably spend three or four hours up in the tree,” Garrison-Laney says.
Wait until the authorities say it’s safe to return to low-lying areas if you’ve made it to secure terrain.
“Flooding, destroyed homes, and rubbish fires could wreak havoc on the coastline,” Chang Seng warns.
In addition, structures that were not swept away by the tsunami may have been weakened.
Chang Seng drove over a bridge in his native country, the island nation of Seychelles, off the eastern coast of Africa, some hours after the 2004 Indian Ocean tsunami.
“I’d just crossed the bridge in a car when the same bridge fell a few seconds later,” Chang Seng adds.
BE PREPARED AND UNDERSTAND YOUR REGION’S RISK.
Tsunamis can lift boulders and rip structures from their foundations. These giant waves, unlike the ones you see at the beach, stretch the entire water column from the seafloor to the surface.
“It’s incredibly powerful,” Chang Seng explains, “and there’s a lot of energy since a tsunami isn’t simply a surface wave.”
“The entire ocean shifts come in, and sweeps over the coast.”
It’s also difficult to have a wave slam into the shoreline without endangering people.
Within 60 miles of the ocean, more than a third of the world’s population resides.
In 2010, 39 percent of the US population lived in counties that were directly on the ocean, and the coast is only anticipated to get busier.
In the Mediterranean, tsunamis are rare. “It’s the busiest location in the world in terms of commerce and tourism,” says Denis Chang Seng of UNESCO’s Tsunami Unit & Ocean Observation Services Section.
“There’s a tremendous risk [from] tsunamis, even though they’re rare.”
That is why you must be ready if one of these rare but destructive waves hits a beach near you.
“If you live along the seaside, you must prepare a plan for your family,” Chang Seng explains.
If you live or work near the water, be aware of the tsunami evacuation zone.
Plan and practice an evacuation route, and have an emergency kit on hand.
Make sure you’re aware of your community’s disaster plans. “Every tsunami-prone locality should have a tsunami evacuation map that shows where the danger zones are,” Kong advises.
When visiting the beach, you may also find yourself in a danger zone. Tourists are particularly vulnerable to being taken off guard.
“You don’t necessarily want to think about something like that when you’re on vacation,” Miller adds.
If you live in tsunami-prone areas, though, establish a plan for what you’ll do if calamity strikes.
If you’re going to the beach, Miller recommends bringing a flashlight. “Just that one thing,” he says, “could make a significant difference if you have to evacuate at night.”
When a catastrophic tsunami strikes, scientists examine the video footage to see what they might learn.
These videos have a depressing effect on the viewer. “You move from dry land, where everything is normal, to a foot, two feet, several meters, ten feet of water, where everything is floating, including automobiles with people inside,” Kong explains.
“You can hear the crunch of structures being shattered by water.”
Scientists also prepare for tsunamis by running computer simulations to determine which portions of the shoreline are most vulnerable, as well as how much time residents will have before the first wave arrives.
They can then devise a strategy for various eventualities and map out evacuation routes.
Because people were uninformed of the risk, the 2004 Indian Ocean Tsunami, which killed 230,000 people, was so catastrophic.
Because there were no regional warning systems, they were unaware that a tsunami was approaching.
The tsunami, on the other hand, spurred breakthroughs in detection and preparedness,
and the countries surrounding the Indian Ocean are now better prepared.
“Now that we’ve experienced a few of those large, deadly tsunamis,” Garrison-Laney says, “people have a lot better idea of what to do.”
Tsunamis, however, can be unpredictable. A rare tsunami struck Greenland’s west coast earlier this month.
And Japan, the world’s best-prepared country for earthquakes, was still ravaged by the 2011 quake and tsunami, which reached heights of up to 133 feet.
A total of 16,000 people were killed, the majority of whom were killed by the waves.
As a result, residents along the coast should be prepared for the worst-case situation.
This can be difficult in locations that haven’t had a tsunami in a long time, such as the Pacific Northwest, where a tsunami last struck in 1700.
“The primary thing we don’t know,” Garrison-Laney says, “is where the next tsunami will strike.”
“It’s really up to coastal towns to make sure they’re prepared, and hopefully it won’t happen until everyone is.”