The highest ever documented sea wave was recorded on July 9, 1958, in Lituya Bay, on the southeast part of Alaska. An earthquake set off a sequence of events that resulted in the 1,720 feet megatsunami.
It’s good to note that the highest, badness sea waves don’t rise that quickly. Strong winds at sea usually create waves at ten feet in height on average. It can reach 30 feet when trigged by storms. But, what generates waves that are at the same size of tall buildings, even those high sea waves that surfers crave but causes fear on coastal residents – one word, land.
As any wave reach the shoreline where depth is becoming little and littler, it’s leaning edge also starts to slow down. The force that spurs the wave towards the shore has nowhere else to go but move upward. Thus, making the sea wave go taller. But, unlike the waves that people savor at the beach, tsunamis are propelled by a more potent force and don’t break easily. The energy is dispensed in the entirety of the water column and wavelengths, providing it with its terrifying stability. Sea waves approach the shore as soaring, sweeping water masses.
While that is the typical scenario for most common waves we encounter, the tsunami that science and history books regard as the highest recorded sea wave of modern times was brought by another force. On July 9, 1958, at around 10:15 in the evening, an earthquake at 7.8 magnitudes resulted in a rockslide of about 30.6 million cubic meters in the Gilbert Inlet. Its epicenter was documented as the Fairweather Fault in the center of Lituya Bay, which runs 2 miles wide and 7 miles long.
As inferred by the experts, glaciers, rocks, and other debris fell from a height of an estimated 3,000 feet or 914 meters, and the succeeding events were more than imaginary. It created the largest sea wave recorded history. The megatsunami was measured at around 100 feet or 30 meters to 300 feet or 91 meters. That was just the start, though. The next breaking waves even grew much taller.
As the megatsunami began to travel towards the whole stretch of Lituya Bay, it reached its peak height of around 1,720 feet or 524 meters, close to the Gilbert Inlet. Due to its innate force, everything around was placed in havoc. Land snapped off, and trees were uprooted. The shorelines were entirely wiped out.
At the time of the event, three fishing boats were sailing in Lituya Bay. Two people from the ships managed to surf the megatsunami, as it brought them over the trees and led them back to the sea. Others, however, were swept by the wave and lost their lives.
According to Howard G. Ulrich, one of those who managed to survive the monster tsunami, the sea wave began in the Gilbert Inlet, before the earthquake even ended. Ulrich said that it wasn’t a wave initially but instead seemed to be a blast or a collapsing glacier. He added that the sea wave started from the lower part and appeared to be just the teensiest part of the entire thing. The water splashed and but the wave soar at 1,800 feet. It was when the glacier appeared back when the tall wall of water was created.
To wrap it up, moving tectonic plates and volcanic rumblings result in undersea earthquakes. When those quakes propel the land upward, it creates massive ripples of water that give birth to tsunamis. The volcanic ridge curling around the Pacific Ocean, the Ring of Fire, is the Earth’s most seismically active location in the world. It generates around 80% of the planet’s earthquake. No wonder that most tsunamis rage into Chile and Japan. While landslides both underwater and above can produce sea waves like the historic monster tsunami in Lituya’s, earthquakes are usually the force behind it. Still, as bizarre the world is, they are not always responsible.
More Readings:
- Tsunami (Wikipedia)
- Earthquake (Wikipedia)