September 28, 2012 – The Biggest Wave Ever Recorded Measured 1,740 feet: That monster wave was in Lituya Bay on the southern coast of Alaska in 1958. An earthquake measuring 8.3 on the Richter scale hit the area and shook loose an estimated 40 million cubic yards of dirt and glacier from a mountainside at the head of the bay. When the debris hit the water, a massive 1,740-foot wave was created and washed over the headland.
How did the scientists know the wave was so incredibly enormous? To measure the height of the wave, scientists found the high-water mark — the line where the water reached its highest point on land. This probably is not the biggest wave ever, just the biggest documented. Three fishing boats witnessed the Lituya Bay event. Unfortunately, two people on one of the boats were killed. Incredibly, the other two boats rode the waves and their occupants survived.
Technically this wave is described as a “Splash Wave.” The headland beside the Lituya Glacier was swept clean of soil and trees to a height of 1,740 feet by the giant splash wave. The icebergs in the water of Lituya Bay after the event were knocked off the glacier by the landslide falling into the bay.
Rogue Waves, on the other hand, are massive walls of water that dwarf run-of-the-mill storm swells. For ages, mariners have told tales of much bigger midocean waves than had ever been seen, rising more than 200 feet to hammer the ships caught in their sights.
Rogue waves, also known as freak waves, have been the subject of more studies in recent years, due to the availability of ocean-monitoring satellites. The European Space Agency says its MaxWave satellite radar project detected more than 10 rogue waves measuring higher than 82 feet (25 meters) over a three-week period in 2001 — perhaps including the 100-foot whoppers that smashed the windows of the cruise ships Caledonia and Bremen.
A 70-footer washed over the Norwegian Dawn cruise ship in 2005, a 100-footer was reported in 2004 during Hurricane Ivan, and there have been reliable measurements of a 112-foot (34-meter) wave that rose over the USS Ramapo in 1933. Could there have been bigger waves that people didn’t survive to tell about? Maybe so: In “The Bird in the Waterfall,” Jerry Dennis and Glenn Wolff report that computer models can produce theoretical waves as high as 219 feet (67 meters).
The big mystery has to do with the mechanism that causes the waves. A variety of studies, including the MaxWave observations, have shown that cross currents can “focus” the energy of wind-driven waves through “constructive interference.”
Sometimes freak waves can arise without those cross currents. Sustained winds from long-lived storms exceeding 12 hours may enlarge waves moving at an optimum speed in sync with the wind. Seabed topography may play a role as well. A “bump” on the seafloor, for example, could give an extra boost to a wave at just the wrong time.
A forecasting model, for coastal waves, is being applied off the coasts of Maine, the Gulf of Mexico and the Gulf of Alaska.
In February 2000 those onboard a British oceanographic research vessel near Rockall, west of Scotland experienced the largest waves ever recorded by scientific instruments in the open ocean. Under severe gale force conditions a wave recorder measured individual waves of 95 feet.
The Master of Disaster