Giant Freaky Waves

Freak waves, a.k.a. rogue waves, are thought to be created when smaller sea waves combine by chance to produce extremely large, very short-lived and localized waves. These have been witnessed by seamen, measured with instruments and are believed to have drowned countless ships and crews over the centuries.

All of these have caused tsunamis. As waves go, tsunamis are not particularly complicated. To make your own all you have to do is toss a stone into a placid pond or dump a bucket-load into the waters edge. The only difference is size.

When a glacier calves an apartment-building-sized chunk of ice into the water, it makes waves. The asteroid that created the Chicxulub impact crater off Mexico's Yucatan Peninsula made giant tsunamis, according to geologists who found tsunami debris buried on Caribbean islands. When Krakatua exploded in 1883 its tsunamis hurled large ships onto land like they were toys. Likewise very large earthquakes can shove water in the oceans in such a way to generate a tsunami, like the great Indian Ocean Tsunami of 2004. Quakes can also trigger massive landslides that generate tsunamis.

The most monstrous wave ridden, so far, was 70-feet tall. It rose out of the ocean on Jan. 10, 2006 at a big wave spot called Jaws on the north shore of Maui, Hawaii. The surfer was a 42-year-old Hawaiian named Pete Cabrinha. As with all waves above about 35 feet in height, its speed required Cabrinha to be towed up to speed by a partner on a jet ski. Many surfers suspect that larger waves have been surfed, but they were not documented with photographs, so there is no way to determine their size. Often surfers themselves have only an inkling of the size of the wave they are riding – other than the fact that it’s gigantic.

Cortes Bank is about 105 miles off the coast of Southern California. It’s nothing more than the ridge of an undersea mountain that almost breaks the surface at its highest point, a spot called Bishop Rock. Because Cortes Bank is far out to sea, it catches the brunt of the Pacific Ocean’s most powerful swells. When these fast-moving swells encounter Cortes Bank they rise up suddenly and create waves that might, say some, approach 100-feet. More typical are the 50-foot monsters that are churned out there – comparable to any of those other big wave spots on the planet.

As at all these giant wave zones, the waves are moving at high, open ocean speed and can only be caught by surfers when they are brought up to speed by a partner towing them by personal-water-craft. Once a wave's energy picks up a surfer, the tow-rope is dropped and the surfer rockets down the fast-moving, towering green wall of water.

The record for the longest ride is 37 minutes. The surfer is a Brazilian wave rider named Picuruta Salazar. The wave he surfed was not a typical wave at all. Instead it was what's known as a tidal bore called the "Pororoca" that breaks on the Amazon River in Brazil. The wave carried him 7.8 miles (12.5 km). Like tidal bores on other rivers, the Pororoca is caused by the ocean tide surging upriver in the form of a powerful wave, or bore.

Most people riding a wave at the same time was 73 people. It happened off the coast of Cape Town, South Africa on Sept. 18, 2006. The crowd rode the same wave for about five seconds, which is not really considered that short of a ride in the world of surfing. Those five seconds were enough to break the old record of 44 people on a wave, set in Ireland in five months earlier.

This is a tough one if you aren't up to speed on fictional geography. The largest waves ever measured were from aboard the Royal Research Ship Discovery on Feb. 8, 2000. The ship was in the North Atlantic, 155 miles (250 km) west of Scotland, when it was pummeled for 12 hours by a series of gigantic waves. The scientists onboard, from Britain's National Oceanography Center in Southampton, judged that some of the waves towered 95 feet (29 meters) from trough to crest. Doubt it? Their observations were published in the scientific journal Geophysical Research Letters. Look it up.

On July 9, 1958, a gigantic landslide triggered by an 8.3 magnitude earthquake near Alaska's Lituya Bay sent 40 million cubic yards of rock high plunging from 3,000 feet (914 meters) into the Gilbert Inlet. When all that rock hit the water, it generated a tsunami that roared down the entire length of Lituya Bay and into the Gulf of Alaska.

The exact height of the wave in the bay is known because the rushing water removed millions of trees and other vegetation up to an elevation of 1,720 feet (524 meters) above sea level. There have probably been higher waves, but this is the highest ever measured.

Tsunamis are said to travel at about 300 miles-per-hour and sometimes even faster. That's how they can cross oceans so quickly and why they pack such a deadly punch when they reach shallow waters and shorelines. That speed translates into a lot of force behind the waters that flood ashore.

Another bit of tsunami trivia: The tsunami comes from two Japanese words meaning "harbor wave."

Freak waves, it turns out, are agents of chaos. Early attempts by researchers to model how freak waves are created by the interactions of smaller waves didn't work very well because they assumed things were sort of orderly out there on the oceans. But with swells of all sizes coming from all sorts of directions and intermingling in difficult to predict ways, it became apparent that Chaos Theory had to be called on to try and make sense of it. That research continues today.