The ocean can be absolutely lethal when it sets its mind to it, and it’s even worse when its power combines with extraordinary events like earthquakes or volcanic eruptions. The massive displacement of water often leads to the formation of giant waves, but to find the largest wave ever recorded, we must travel 62 years into the past, to a fjord in southeastern Alaska...
Traditional waves are generated by wind currents and tidal changes. In general, they create a very pleasant experience for beachgoers... but let’s change the parameters for a moment and imagine a wave over 30 meters high. As if that weren’t enough, this wave emerges from a fjord and unleashes all its fury toward the ocean.
It seems like a classic example of a disaster movie... but this actually happened. In fact, that very event created the largest wave ever documented. To find out more, we need to travel to southeastern Alaska. The so-called Lituya Bay is a fjord located on the Fairweather Fault, connected to the Gulf of Alaska. Its dimensions: a length of 11 kilometers (other sources indicate 14.5 km), a maximum width of 3.2 kilometers, and a depth of 220 meters. A beautiful place, judging by online images... but everything changed on the night of July 9, 1958.
The Largest Wave in the World
At 22:15, an earthquake with a moment magnitude of 7.8 struck the region, causing a rockslide of 30 million cubic meters, equivalent to 90 million tons. The impact of so much material at once (falling almost as a 'monolithic unit' according to experts) was so strong that it was heard 80 kilometers away, and the inevitable water displacement triggered a megatsunami that essentially swept the fjord.
Available data indicate that the height of the megatsunami was over 30 meters, but the most chilling part was what happened next. The wave advanced on the coast with so much energy that it reached a maximum of 524 meters, devastating all local vegetation in its path. Five people lost their lives, two of them aboard a fishing boat.
A team of researchers at the University of Malaga managed to combine all the information about the event and develop a 3D simulation of the wave's advance in the bay. The 1958 earthquake allowed specialists to confirm the concept of megatsunami, but they are convinced it wasn't the first in the region. It is estimated that Lituya Bay suffered a total of five events in the last 150 years, each erasing much of the evidence of the previous one.
Now, the title of "the largest wave in the world" could always change hands. A young surfer named António Laureano claims to have ridden a wave of 30.9 meters in October 2020, a measurement made by a team from the University of Lisbon. Will we need to rewrite the books? We'll find out soon.
Sources: NPCA, Smithsonian, Surfer Today, Wikipedia
