The Orphan Tsunami
Japan sits in the Pacific Ring of Fire, so designated because of the terrible turmoil that exists under the ocean, all the way down at the bottom.
Down there are tectonic plates, which aren’t stationary—that’s why we once had Pangea, and now we have distinct continents. These plates constantly smash into one another, creating little tremors underneath all that water.
Imagine you’re carrying a heavy table with some friends, and you happen to smash into a brick wall as you’re trying to turn a corner. Can you feel that jarring up your arms, even shaking your brain inside your skull? That’s the same sort of phenomenon that happens when you feel earthquake tremors.
While the shaking ground is one result from titanic plates smashing into one another, there’s a second phenomenon that results as millions of Mount Everests’ worth of water gets displaced. Imagine incredibly heavy saltwater quickly filling gaps that are created, or jerking upward through unimaginable tectonic force.
Tremors travel faster than waves, so there’s a bit of a warning for folks on land before this water arrives.
The bigger the tremor, the bigger the wave. The people of Japan have long observed this formula, incredibly useful for preparing for waves of overwhelming size to approach. That’s why it was so unusual when there was a tsunami in the year 1700, but there was no warning whatsoever by way of earthquake tremors.
This event is remembered as the Orphan Tsunami.
This tsunami seemed to come out of nowhere, and it was devastating as a result. For centuries, nobody could figure out why this had happened. It was not until the 1990s, in fact, that geologists and historians finally pieced together what happened.
Here’s why I’m telling this story today: there was, in fact, a tectonic disturbance under the ocean, but it was nowhere near the Pacific Ring of Fire. Instead, two plates collided along the Cascadia Subduction Zone, just off the western coast of North America.
This 9.0 magnitude earthquake apparently ruptured a long stretch of the fault line, resulting in unimaginable tons of rapidly displaced water. In other words, the biggest wave I’ve ever heard of started somewhere close to the US states of Oregon and Washington, and traveled across the entire Pacific to Japan, where it was devastating.
I’m blown away by nature almost every day, but this one sort of knocked my socks off. Two continents smashed into one another off the coast of the US and Canada (well, where they are today), and that energy traveled to Japan in the form of water waves.
The Orphan Tsunami connected North America to Japan in a very unexpected way in 1700. A century and a half later, Commodore Matthew Perry connected North America and Japan in a very different way, via gunboat diplomacy.
For the century and a half since then, the relationship between the Japan and the United States, in particular, has evolved a great deal, going from trading partners to adversaries to enemies, and back to trading partners once again. It is this very relationship that allowed scientists and historians to solve this mystery.
You might say the story has come full circle in a way.
Interesting to consider that during the last ice age, the weight on the northern hemesphere would have buldged out the ring of fire and when that catastrophically melted super fast the ring of fire would have pulled back in quickly.
Your post reminded me of two stories from Amanda Ripley's book The Unthinkable: Who Survives When Disaster Strikes—and Why (https://tinyurl.com/56nt62fm). It is a fascinating and insightful book.
However, the 2004 tsunami was different since there were tremors and other signs of a coming tsunami; unfortunately, people took action only in a few cases, as in the two examples below. It is primarily due to people not knowing what actions to take once they saw the signs, except in the two cases below and a few other cases:
“Consider two cities, both very close to the epicenter of the earthquake that set off the 2004 tsunami. Jantang was a coastal village on the northern coast of Sumatra. The residents felt the ground shake, and about twenty minutes later, a roaring wave swept their lives away. The water reached heights of forty-five to sixty feet. All of the village’s structures were destroyed. Over 50 percent of the people were killed.
Langi, on the island of Simeulue, was even closer to the quake. Islanders had just eight minutes after the ground shook to get to high ground—the shortest interval between earthquake and tsunami anywhere and too fast for a buoy-based warning system, had there been one. Waves there reached thirty to forty-five feet—slightly less than the height in Jantang, but still decidedly deadly. As in Jantang, all the town’s buildings were decimated. But in Langi, 100 percent of the eight-hundred-person population survived. No one—not a child, not a grandmother—was lost. “In Langi, when the ground shook, everyone left for higher ground—and stayed there for a while. That was the tradition, no matter what. In 1907, the island had experienced a tsunami, which locals say killed about 70 percent of the population. And the survivors had passed this lesson on through the generations in Langi and other towns. Everyone knew the word smong, the word for tsunami in the Simeulue language.”
And
“Even a child can do better than a fancy warning system, if she has been trusted with some basic information. English schoolgirl Tilly Smith was vacationing with her parents and sister in Thailand in 2004 when the tide suddenly rushed out. Tourists pointed at the fish flopping on the sand. Out on the horizon, the water began to bubble strangely, and boats bobbed up and down. Smith, ten, had just learned about tsunami in her geography class, two weeks earlier. She had watched a video of a Hawaii tsunami and learned all the signs. “Mummy, we must get off the beach now. I think there is going to be a tsunami,” she said. Her parents started warning people to leave. Then the family raced up to the JW Marriott hotel where they were staying and alerted the staff, who evacuated the rest of the beach. In the end, the beach was one of the few in Phuket where no one was killed or seriously hurt.”