The world’s largest tsunami was in our backyard
The Fault in the Facts
ANCHORAGE, Alaska (KTUU) - Alaska is home to the largest tsunami ever recorded.
The 1,720-foot wave hit the tall banks of Lituya Bay in Southeast Alaska in 1958. There were two people who were in the bay who died, and four survived.
According to obituaries, family members, and friends, most, if not all the survivors have now passed on.
Since those who witnessed the tsunami are no longer able to tell their tale, in this installment of The Fault in the Facts, a loved one helps bring their family members’ experience to life with the help of words a survivor spoke about his memories before he died.
A magnitude 7.8 earthquake struck on the Fairweather Fault near Elfin Cove on the evening of July 9, 1958, according to the United States Geological Survey.
That quake triggered a massive landslide in Lituya Bay, which in turn caused the tsunami.
“Forty million cubic yards of material — more or less as a coherent block — fell about 1,000 feet into Lituya Bay,” said Alaska Division of Geological and Geophysical Surveys Earthquake Geologist Barrett Salisbury.
When the rock hit the water, it took some air with it, he said.
“That caused a massive wave that ran up the nearby shore about 1,720 feet,” Salisbury said. “So, a mix of the earthquake triggering a landslide and the water conditions there being just right created that gigantic wave.”
To put the size of the massive wave into perspective, the second largest tsunami ever recorded was in Washington State in 1980. The run-up was about 820 feet, which is less than half the size of the Lituya Bay tsunami.
For those familiar with Anchorage, the tallest building in downtown Anchorage is the ConocoPhillips building, which stands at 296 feet. Now imagine nearly six of those buildings stacked on top of each other, and that is about how tall the gigantic tsunami was in Lituya Bay.
The bay has a unique geology. It is “T-shaped” and about 100 miles from Yakutat. Boaters enter its waters through a narrow opening with a spit of land on either side.
As boaters continue through the waters, they pass an island in the middle of the bay, and toward the back wall, there are two glaciers in either side of the points of the “T.”
Under those glaciers is the Fairweather Fault, a powerful fracture in the earth that produced the large quake that sent millions of cubic yards of land from the far wall into the deep water of Lituya Bay.
Salisbury said the cliff that the 1,720-foot wave washed up was extremely close to the landslide and that’s why there was such a big splashing run-up. The cliff was about an eighth of a mile across Gilbert Inlet from the landslide.
USGS Geologist Don Miller was one of the main geologists who researched the event. He visited the bay within hours of the destruction. The journal of notes he took that day included one haunting line: “In Lituya Bay the destruction is unbelievable.”
According to Salisbury, the 1958 tsunami was a pinpoint extreme event that made its biggest impact inside the bay.
“What we do know is that that rock fell over 1,000 yards or so into the water and so, we can model it most readily, almost like an asteroid event, because it was a single block of rock that fell into the water, and that caused a lot of cascading effects,” Salisbury said.
Among the survivors were Howard Ulrich and his 8-year-old boy, Sonny Ulrich. Howard did interviews with BBC and National Geographic about that deadly day before he died in 2014.
“The date was July the 9th, 1958. We came into Lituya Bay about 8 o’clock in the evening,” Howard Ulrich told BBC.
Howard Ulrich’s son and Sonny’s brother, Bruce Ulrich, recounted his loved one’s story to help bring their memories back to life.
“My brother was only eight,” Bruce Ulrich said.
“We went into our favorite anchoring spot and dropped our anchor and made supper and finally about nine o’clock we went to our bunks,” Howard Ulrich told National Geographic.
And not long after, the large quake hit, nearly 45 miles away.
“There was a slight pause. I thought that everything was over with, but some movement up there caught my attention out of the corner of my eye, and so I looked directly up there and what I observed was like an atomic explosion,” Howard Ulrich told BBC. “Of this big splash came a huge wave. It looked like just a big wall of water.”
In the same interview, Sonny said his dad then threw him a life preserver – and told him to start praying.
“Just coal-black and full of logs, just straight up and down,” Howard Ulrich told National Geographic about the water beneath his boat. “It was actually a pretty horrifying looking sight. I just thought you know, this is, this is the end. No, no way you’re going to get out of this.”
Bruce Ulrich said his dad charged into the wave with a boat because his anchor was hung up on the bottom of the bay.
“[I] started pulling all the anchor chain out and when it got to the end of the chain, it just, I thought it was going to pull the bow of the boat under, but it snapped that chain just like it wasn’t even there,” Howard Ulrich told National Geographic.
“He got the boat over the top of the wave,” Bruce Ulrich said, “So did his job.”
Howard Ulrich told National Geographic, “I looked down over the stern of the boat, and we were looking down on the trees and I figured that’s where we were going to end up.”
Bruce Ulrich said his dad was trying to do whatever he could to keep the boat pointed into the waves.
“I had never heard or seen of anything like this. It was unbelievable,” Howard Ulrich told BBC. “I couldn’t imagine what could have caused anything. I kept wondering just what mechanism could cause something like that.”
Even with the force of the world’s largest recorded tsunami, Howard navigated the boat through the water that was sloshing on all sides of the bay.
“Once he had established that he was safe, he was trying to look for those other boats in the bay,” Bruce Ulrich said. “He had to run around all those backwash spouts that were slapping up 20, 30 feet or something in the air, and then of course there started to be a line of trees and logs that were beginning to form up like a big raft. And they were kind of forcing him out of the bay.”
It was later learned that one of the other boats, the Sunmore, was swamped near the bay’s entrance. It went down with Orville and Mickey Wagner on board. They were never found, according to a Geologic Surveys paper written by geologist Don Miller.
Mr. and Mrs. Bill Swanson, who were aboard the third and final boat — which was named the Badger — survived, according to the same paper Miller wrote.
“My father knew them, of course. We were all fishermen,” Bruce Ulrich said.
Three others were killed that night. They were on an island close to Yakutat. No one knows for sure what happened, but according to a UAF Geophysical Institute article, Jeanne Walton and Mr. and Mrs. Robert Tibbles were last seen on Khantaak Island’s shores. The ground is thought to have collapsed beneath them.
No one saw it happen, but minutes later, some noticed the area that was land moments ago, was now covered by water, according to the UAF Geophysical Institute article. The Tibbles’ boat was later found submerged near where they were last seen.
While Bill Swanson miraculously survived this deadly tsunami in Lituya Bay, the place that almost took his life is where he would die nearly four years later. His obituary in Alaska Sportsman shows he died of a heart attack on his boat near the entrance of Lituya Bay. According to Ketchikan’s Sit News, it is the first time he had been back to the bay.
LOOKING TO THE FUTURE
“Alaska’s coastlines are hazardous,” Salisbury said. “And if you enjoy them, which we all do, then you do put yourself at a calculated risk.”
He said it is important to be prepared and know the natural warning signs of earthquakes, landslides, and tsunamis. He said people should also be prepared for the worst because Alaska has seen the worst before.
The massive 1958 tsunami wasn’t the first time a large wave was created in Lituya Bay. It has happened multiple times before.
There are indications of four other instances stretching from the mid-1800s to the mid-1900s — though the 1958 wave is the largest scientists have found.
Eyewitness accounts and evidence from the grounds around Lituya Bay indicate there were disastrous large waves in 1853 or 1854, and again in 1874, 1899, and 1936.
Salisbury said most of the evidence associated with the previous waves were obliterated when the 1958 tsunami swept through the bay. You can no longer see the scars on the banks or the cut trees.
However, scientists who visited the bay before the 1958 tsunami wiped out the greenery were able to photograph the banks of the bay where there were different tree heights based on when and where the previous waves hit the shoreline.
Salisbury said there are absolutely concerns that another destructive wave will come from Lituya Bay again, however other scientists say the probability of the 1958 event repeating is relatively low.
“The earthquakes in that part of the world will continue to happen,” Salisbury said. “The likelihood for more large waves is almost inevitable.”
Salisbury said the Fairweather Fault under Lituya Bay’s glaciers is a major strike-slip fault that moves about 50 millimeters per year. That’s extremely fast.
“That’s a little faster than the San Andreas, whose average slip rate is about 33 or 34 millimeters per year,” Salisbury said. “[The Fairweather Fault] is one of the fastest coastal strikes faults in the world.”
The combination of the geologic factors in the area, including the fault, the potential for major rainstorms to trigger landslides, and the deep fjord land water in Lituya Bay make the chances of another tsunami very likely, Salisbury said.
Any steep slope and glaciated terrain in Alaska and around the world can be very dangerous.
“Understanding that maybe staying away completely is not possible, I would tell folks to be aware of the natural warning signs of large earthquakes and or landslides.”
If you want to learn more about tsunamis in general and how to be prepared for one, check out the Fault in the Facts episode titled “Do tsunamis look like they do on TV?”
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