Imagine a wall of water so tall it doesn't just flood a coastline—it literally de-forests a mountain. That’s not a scene from a big-budget disaster movie. It actually happened. When people search for the tsunami biggest in history, they usually expect to hear about the devastating 2004 Indian Ocean tragedy or the 2011 Fukushima event. Those were horrifying in terms of human cost, but in terms of sheer physical height? They don’t even come close to what happened in a remote Alaskan fjord called Lituya Bay.
It was huge.
On July 9, 1958, a massive earthquake with a magnitude between 7.8 and 8.3 hit the Fairweather Fault. This wasn't just a little shaking; it triggered a massive rockfall. Roughly 40 million cubic yards of rock—picture a slab of mountain roughly 3,000 feet wide and 2,400 feet long—plummeted 3,000 feet straight down into the narrow waters of Gilbert Inlet at the head of Lituya Bay. The impact was basically like dropping a literal mountain into a bathtub. The result was a megatsunami that reached a staggering run-up height of 1,720 feet.
To put that in perspective, the Empire State Building is only 1,454 feet tall. This wave was taller than the most famous skyscraper in New York.
Why Lituya Bay Holds the Record
You’ve gotta understand the geography to grasp why this wave got so insanely high. Lituya Bay is T-shaped and very narrow. When that rock hit the water, the energy had nowhere to go but up and out. It’s a phenomenon scientists call a "displacement wave." Unlike a typical tsunami caused by the seafloor shifting, this was caused by a massive volume of material entering the water at high velocity.
Don't let the technical terms bore you. This was raw power.
The water didn't just slosh. It surged with enough force to strip every single tree and all the soil right off the bedrock up to that 1,720-foot mark. When researchers like Howard Miller arrived later to survey the damage, they found a distinct "trimline." Below that line, the mountain was bare rock. Above it, the old-growth forest remained. It looked like a giant had taken a razor to the landscape.
💡 You might also like: Why a Man Hits Girl for Bullying Incidents Go Viral and What They Reveal About Our Breaking Point
Honestly, the survival stories from that night are even crazier than the stats. There were three fishing boats in the bay. One boat, the Sunbury, went down with no survivors. But Howard Ulrich and his seven-year-old son on the Edrie somehow rode the wave. Ulrich described it as a wall of water that looked like a solid mountain. He managed to let out his anchor chain, and the boat rose up the face of the wave, snapped the chain, and eventually settled back down as the water receded. They survived.
Then there was Bill and Vivian Swanson on the Badger. Their boat was actually carried over the spit of land at the mouth of the bay. Bill looked down and saw trees beneath him. He literally flew over a forest in a boat before the vessel hit the rocks and sank outside the bay. They escaped in a small skiff.
Misconceptions About Tsunami Height
People often confuse "run-up height" with "flow depth" or "wave height at sea." It’s a common mix-up.
A tsunami in the open ocean might only be a foot or two high. You wouldn't even feel it if you were on a ship. But as it hits shallow water, it slows down and piles up. In the case of the tsunami biggest in history at Lituya Bay, the 1,720 feet refers to the "run-up"—the maximum vertical height on land that the water reached. The actual wave traveling across the bay was likely between 100 and 300 feet tall. Still absolutely terrifying, but the "record" comes from how high it climbed the mountain.
If we talk about the most "deadly" rather than the "biggest," the conversation shifts entirely. The 2004 Sumatra tsunami had waves that reached about 100 feet in some areas, but it killed nearly 230,000 people. Geography makes the difference. Lituya Bay is a wilderness; the Indian Ocean is a densely populated coastline.
The Science of Megatsunamis
Why does this matter now? Because Lituya Bay isn't a one-off.
📖 Related: Why are US flags at half staff today and who actually makes that call?
Geologists and researchers like Dr. Hermann Fritz have spent years modeling the 1958 event. Using hydraulic scale models, they've proven that the impact of the landslide was the primary driver of the height. It wasn't the earthquake itself moving the water; it was the gravity-fed kinetic energy of the falling rock. This has changed how we look at places like the Canary Islands or even some fjords in Norway and Alaska.
There's a lot of debate—and some sensationalism—about "collapse" scenarios. You've probably seen those YouTube videos claiming a chunk of the La Palma volcano in the Canary Islands could fall into the Atlantic and wipe out the East Coast of the US. While the physics of Lituya Bay shows that massive displacement waves are possible, most experts today think the La Palma "mega-disaster" is highly unlikely to happen in one giant piece. It would more likely be a series of smaller, less catastrophic landslides.
Still, the risk is real in specific environments:
- Glacial fjords where melting ice leaves rock walls unstable.
- Volcanic islands with steep, unstable slopes.
- Areas with high seismic activity near deep water.
Other Heavy Hitters in History
While 1958 takes the gold medal, there are other contenders for the tsunami biggest in history depending on how you measure them.
- Mount St. Helens (1980): When the volcano erupted, a massive landslide fell into Spirit Lake. This created a megatsunami with a run-up of about 850 feet. It’s often overshadowed by the eruption itself, but the wave was monstrous.
- Vajont Dam, Italy (1963): This was a man-made disaster. A landslide fell into a reservoir behind a dam. The water surged 820 feet over the top of the dam, destroying several villages below. 2,000 people died.
- Taan Fiord, Alaska (2015): A more recent example that almost no one talked about outside of scientific circles. A mountain slope collapsed into the water, producing a 633-fott run-up. Because it was in a remote area, there were no casualties, but the physical evidence was hauntingly similar to Lituya Bay.
What We Can Learn from the 1720-Foot Wave
Survival in these scenarios is almost entirely about geography and early warning. In Lituya Bay, the survivors were the ones who weren't directly in the path of the initial impact and had enough depth beneath their hulls to avoid being smashed into the seafloor as the wave passed.
But for the rest of us, the takeaway is about awareness of our surroundings. If you're on a coast and you feel a long, rolling earthquake—one that lasts more than 20 or 30 seconds—don't wait for a siren. Just go. Move inland. Get high.
👉 See also: Elecciones en Honduras 2025: ¿Quién va ganando realmente según los últimos datos?
Nature doesn't always give you a polite warning.
The Lituya Bay event was a freak occurrence of perfect (or imperfect) conditions. It required a massive landslide, a narrow deep-water bay, and a confined space to funnel the energy. It's a reminder that the earth is constantly reshaping itself, sometimes in seconds, with forces that dwarf anything humans can build.
Actionable Steps for Tsunami Safety
It’s easy to read about the tsunami biggest in history and feel like it’s just a cool piece of trivia. But if you live near a coast or travel to one, these steps actually matter.
- Learn the natural warning signs: A "roaring" sound like a jet engine or a train is often the first sign of an approaching wave. If the tide suddenly pulls out and exposes the seafloor, that’s a massive red flag.
- Check evacuation maps: Most coastal cities have designated tsunami evacuation routes. Find them before you need them.
- Don't wait for official word: Local authorities may not have time to issue a warning if the earthquake happens just offshore. If the ground shakes hard enough that it’s difficult to stand, the clock has already started.
- Understand your elevation: Use a phone app or a topographic map to find out exactly how high above sea level you are. Knowing you're at 50 feet versus 5 feet can change your survival strategy entirely.
- Keep a "Go Bag" ready: Water, a radio, and a flashlight are basics. If a tsunami hits, power and clean water will be the first things to go.
The 1958 Lituya Bay megatsunami remains the benchmark for nature's power. It stands as a chilling testament to how quickly the world can change. While a 1,700-foot wave is a statistical outlier, the physics that created it are present in many parts of the world today. Staying informed isn't just about being a history buff; it's about respecting the capacity of the planet to do the unexpected.
Check your local geological survey or the NOAA Tsunami Warning Center website for real-time data and specific risk assessments for your area. Being prepared is the only way to navigate the reality of living on a geologically active planet.