Where are the biggest waves on the planet?

The town of Nazaré on the Portuguese coast is famous for having the world’s largest surfable waves thanks to its unique geological structure on the seabed. Athlete Sebastian Steudtner set a world record for surfing the largest wave on October 29, 2020. This wave was up to 26.21 m high and appeared off the coast of Praia do Norte, Nazaré.

Over the past 14 years or so, this small part of the Atlantic has seen many surfing world records. The giant waves are created by the Nazaré Canyon, an underground trench just off the coast of Nazaré. About 227 km long and 5 km deep, this canyon runs perpendicular to the Portuguese coast. It has guided the powerful waves of the Atlantic Ocean towards the coast.

Normally, when large waves from offshore approach the coast, they begin to slow down due to interaction with the seabed. Off Nazaré, however, waves gather in submarine canyons toward the shore and do not lose energy until they reach shore. When the waves arose at the head of the canyon, they hit the shallow bottom and suddenly became very high, according to the book The Nazaré coast, the submarine canyon and the giant waves from the University of Coimbra in 2015.

This effect is only concentrated in a small area. Just a few hundred meters from the meeting point near Praia do Norte, the waves were significantly weaker.

Larger waves are still possible, although usually in exceptional circumstances. One of the highest waves ever recorded occurred on July 10, 1958, when a 7.8 magnitude earthquake rocked the Fairweather Fault in southeast Alaska, sending 90 million tons of rock falling into Lituya Bay.

The wave that followed this event was extremely violent, causing damage in the forest up to 200 meters away in the hills surrounding the bay. In one part of the bay, the waves seemed to rise as high as 524 m, nearly the height of One World Trade Center – the tallest skyscraper in North America and the Western Hemisphere.

In addition, experts estimate that Chicxulub – the asteroid that wiped out the dinosaurs 66 million years ago – may have caused a tsunami up to 1.5 km high radiating from the peninsula in present-day Mexico.