Photo of the Day

Spruce Tree Snapped Off by the Wave - Seven Miles from its Source. Stump of living spruce tree broken off by the giant wave at Harbor Point, mouth of Lituya Bay. Brim of hat is 12 inches in diameter. This tree is located about seven miles (11.3 kilometers) from where the wave originated. Photo by D.J. Miller, United States Geological Survey.

Spruce Tree Snapped Off by the Wave – Seven Miles from its Source. Stump of living spruce tree broken off by the giant wave at Harbor Point, mouth of Lituya Bay. Brim of hat is 12 inches in diameter. This tree is located about seven miles (11.3 kilometers) from where the wave originated. Photo by D.J. Miller, United States Geological Survey.

World’s Tallest Tsunami

The Empire State Building is 448 metres high (1,470 ft), if you include the antenna spire. Now, imagine a wave that goes up to the 1,720ft (520 metres) and simply destroys all the trees high up in Lituya Bay, a fjord located on the coast of Alaska

Ketchikan, Alaska – Alaska is a land of geological superlatives: Big Mountains, vast spaces, huge earthquakes. So it would stand to reason that an event that happened 58 years is also the largest of its kind ever recorded.

The biggest tsunami in present times struck at Lituya Bay, Alaska on July 9, 1958. This was so big that it is known scientifically as a Mega Tsunami.

The wave was brought on by an enormous 8.3. Some say 8.8. And others say a 9.0 magnitude earthquake that hit the Fairweather Fault and caused a massive earth landslide.

The region had suffered earthquakes previously as it lies on a fault line; however, this was the most dramatic. The tremors were even felt by people in Seattle, Washington.

The earthquake that may have been as powerful as the one that helped destroy?San Francisco in 1906. About 40 million cubic yards of rock ? some of it falling from a height of 3,000 feet ? plunged down the face of Lituya Glacier into Gilbert Inlet at the northern end of the bay.

Sudden water displacement created a wave that shot seaward from the land, and that was certainly a factor in what followed. But similar occurrences in Norway, where fjords are plentiful, never produced a wave remotely close to the size of this one.

The Lituya?Bay mega tsunami was a freak?tsunami (said to be the biggest wave ever)?in Lituya?Bay a large fjord in Alaska.?The reason that this?tsunami is so different to others?is the fact that it ran from the land out to the ocean and was a lot taller?than a regular tsunami.

The wave hit with such power that it swept over the spur of land removing all trees and vegetation from elevations as high as 1,720 feet (524 m.) above sea level. Millions of trees were uprooted and swept away by the wave. It was the highest wave ever documented. For a comparison, the Empire State Building with its antenna is 1,470 feet high.

The wave then continued down the 7-mile length of Lituya Bay, ripping out or snapping off trees on either side of the bay at elevations up to 600 feet and then washed over a sand spit and into the Gulf of Alaska.

The force of the wave stripped the soil off down to bedrock and snapped off large spruce trees, some with trunks up to six feet in diameter.

Wave damage areas along the shorelines of Lituya Bay, viewed from the south. Photo by D.J. Miller, United States Geological Survey.

Wave damage areas along the shorelines of Lituya Bay, viewed from the south. Photo by D.J. Miller, United States Geological Survey.

There were three fishing boats anchored in Lituya Bay on the night the giant wave washed through.

Orville Wagner and his wife, Mickey( it is reported that there may have been some other people onboard as well), were killed when their boat was sunk after being hit by the wave. Bill and Vivian Swanson, who were asleep in the Badger, and Howard Ulrich and his 7-year-old son, Junior, in the 38-foot Edrie, all survived. Both boats were anchored about a mile up Lituya Bay from the entrance.

Howard Ulrich reported hearing a deafening crash that sounded like an explosion, at the head of the bay about 2 1/2 minutes after the earthquake was first felt.

Based on Bill Swanson’s description of the length of time it took the wave to reach his boat after overtopping Cenotaph Island in the middle of the bay, the wave may have been travelling up to 600 mph.

The violent motion of the waters from the earthquake awoke Howard Ulrich, who watched the mountains shaking, and clouds and dust coming from their peaks. After observing the chaos for about two minutes he noticed a gigantic wall of water coming down the inlet toward them, cutting a swath of trees along both shorelines. He estimated the wave as 50 feet to 75 feet high and very steep as it got closer.

Finally realizing that he had to respond, he got a life jacket on his young son, started the engine but was unable to raise the anchor before the wave struck. He had steered the Edrie to face the wave directly and as she rose, the anchor chain snapped. The vessel with Howard and his son was carried toward and possibly over the south shore by the wave, then toward the center of the bay by the backwash.

The water in the bay swashed back and forth for about 30 minutes and then became calm. After keeping the boat under control throughout this violent ordeal, Howard and Junior Ulrich powered out of Lituya Bay by 11 that night.

The Swansons were also very fortunate. The Badger, still at anchor, was lifted up by the wave and carried over the sand spit at the entrance of the bay, stern first and riding the wave like a surfboard. Bill Swanson reported looking down at the top of the trees, estimated at about 80 feet, as they were carried over the spit.

The wave broke and the boat hit the bottom and began taking on water. The Swansons abandoned their sinking boat, and in a small dingy were fortunately rescued by another fishing boat two hours later.

tsu1958lituyainundflanc

The extreme height of the wave and the mechanism of its generation were puzzling.?There were questions as to whether there was sufficient water volume in the inlet at the head of the Bay for such an extreme wave to be generated and to reach such an enormous height.

Several mechanisms?for the extreme wave generation?were proposed but none could be supported?conclusively?by the data on hand at the time. Suggested scenarios for the “Mega-Tsunami” included a combination of tectonic movements associated with the earthquake, collapse of a tidal glacier front,?the possible sudden drainage of a subglacial lake on the Lituya Glacier and?the major sub-aerial rockfall that occurred in Gilbert Inlet, immediately after the earthquake.

The spur of land between Gilbert Inlet and Lituya Bay that received the full force of the wave. Trees and soil were stripped away to an elevation of 1720 feet (524 meters) above the surface of Lituya Bay. Photo by D.J. Miller, United States Geological Survey.

The spur of land between Gilbert Inlet and Lituya Bay that received the full force of the wave. Trees and soil were stripped away to an elevation of 1720 feet (524 meters) above the surface of Lituya Bay. Photo by D.J. Miller, United States Geological Survey.

Wave damage on the south shore of Lituya Bay, from Harbor Point to La Chaussee Spit, southwest of Crillon Inlet. Tree trunks can be seen in the water and tree stumps along the lower shoreline. This location is seven miles (11.3 kilometers) away from where the wave originated. Photo by D.J. Miller, United States Geological Survey.

Wave damage on the south shore of Lituya Bay, from Harbor Point to La Chaussee Spit, southwest of Crillon Inlet. Tree trunks can be seen in the water and tree stumps along the lower shoreline. This location is seven miles (11.3 kilometers) away from where the wave originated. Photo by D.J. Miller, United States Geological Survey.

A map of earthquakes and tsunamis from recent history (tsunamis in yellow). (Woods Hole Oceanographic Institute)

A map of earthquakes and tsunamis from recent history (tsunamis in yellow). (Woods Hole Oceanographic Institute)

Lituya Bay, Alaska is on the northeast shore of the Gulf of Alaska. It is an ice-scoured tidal inlet with a maximum depth of 220 meters and a narrow entrance with a depth of only 10 meters. It is a T-Shaped bay, 7 miles long and up to 2 miles wide. The two arms at the head of the bay, Gilbert and Crillon Inlets, are part of a trench along the Fairweather Fault. On July 8, 1958, a 7.5 Magnitude earthquake occurred along the Fairweather fault with an epicentre near Lituya Bay. The mega-tsunami wave that was generated washed out trees to a maximum altitude of 520 meters at the entrance of Gilbert Inlet. Much of the rest of the shoreline of the Bay was denuded by the tsunami from 30 to 200 meters altitude. During the last 150 years five giant waves have occurred in Lituya. The previous event occurred on October 27, 1936 which washed out trees to a maximum altitude of 150 meters and was not associated with an earthquake.

Photo looking down the Fairweather Fault Trench at the head of Lituya Bay. The front of Lituya Glacier with lateral and medial moraines is seen terminating in Gilbert Inlet. The cliff where the rockslide originated is on the right side of Gilbert Inlet. The opposite valley wall on the left side of Gilbert Inlet received the full force of the big wave, stripping it of soil and trees. Photo by D.J. Miller, United States Geological Survey.

Photo looking down the Fairweather Fault Trench at the head of Lituya Bay. The front of Lituya Glacier with lateral and medial moraines is seen terminating in Gilbert Inlet. The cliff where the rockslide originated is on the right side of Gilbert Inlet. The opposite valley wall on the left side of Gilbert Inlet received the full force of the big wave, stripping it of soil and trees. Photo by D.J. Miller, United States Geological Survey.

Eyewitness Accounts from Survivors

Several fishermen standing in a boat were killed and other boats were able to ride the waves. William A. Swanson and Howard G. Ulrich survived this mega tsunami that travelled at around 600 miles/hour.

Account of Howard G. Ulrich

Howard G. Ulrich and his son, had picked that fateful night for a nice father-son boat trip. They were awakened by earthquake-like sounds and tremors, soon followed by a crash “like an atomic explosion.” They were now staring at the business end of a rapidly approaching mega tsunami.
Mr. Ulrich and his 7-year-old son, on the Edrie, entered Lituya Bay about 8:00 p.m. and anchored in about 5 fathoms of water in a small cove on the south shore. Ulrich was awakened by the violent rocking of the boat, noted the time, and went on deck to watch the effects of the earthquake-described as violent shaking and heaving, followed by avalanching in the mountains at the head of the bay. An estimated 2 1/2 minutes after the earthquake was first felt a deafening crash was heard at the head of the bay. According to Ulrich,

“The wave definitely started in Gilbert Inlet, just before the end of the quake. It was not a wave at first. It was like an explosion, or a?glacier?sluff. The wave came out of the lower part, and looked like the smallest part of the whole thing. The wave did not go up 1,800 feet, the water splashed there.”

Ulrich continued to watch the progress of the wave until it reached his boat about 2 1/2 to 3 minutes after it was first sighted. Being unable to get the anchor loose, he let out all of the chain (about 40 fathoms) and started the engine. Midway between the head of the bay and Cenotaph Island the wave appeared to be a straight wall of water possibly 100 feet high, extending from shore to shore. The wave was breaking as it came around the north side of the island, but on the south side it had a smooth, even crest. As it approached the Edrie the wave front appeared very steep, and 50 to 75 feet high. No lowering or other disturbance of the water around the boat, other than vibration due to the earthquake, was noticed before the wave arrived. The anchor chain snapped as the boat rose with the wave. The boat was carried toward and probably over the south shore, and then, in the backwash, toward the center of the bay. The wave crest seemed to be only 25 to 50 feet wide, and the back slope less steep than the front.

After the giant wave passed the water surface returned to about normal level, but was very turbulent, with much sloshing back and forth from shore to shore and with steep, sharp waves up to 20 feet high. These waves, however, did not show any definite movement either toward the head or the mouth of the bay. After 25 to 30 minutes the bay became calm, although floating logs covered the water near the shores and were moving out toward the center and the entrance. After the first giant wave passed Ulrich managed to keep the boat under control, and went out the entrance at 11:00 p.m. on what seemed to be a normal ebb flow.

Although they described the aftermath of the megatsunami as “something like the end of the world,” they seem to be very nonchalant about their own miraculous survival. Here they are talking about their experience:

Alaskan Super Wave – Mega Tsunami

[youtube https://www.youtube.com/watch?v=yN6EgMMrhdI]

Account of William A. Swanson

Mr. and Mrs. Swanson on the Badger entered Lituya Bay about 9:00 p.m., first going in as far as Cenotaph Island and then returning to Anchorage Cove on the north shore near the entrance, to anchor in about 4 fathoms of water. Mr. Swanson was wakened by violent vibration of the boat, and noted the time on the clock in the pilot house. A little more than a minute after the shaking was first felt, but probably before the end of the earthquake, Swanson looked toward the head of the bay, past the north end of Cenotaph Island and saw what he thought to be the Lituya Glacier, which had “risen in the air and moved forward so it was in sight. It seemed to be solid, but was jumping and shaking.

Big cakes of ice were falling off the face of it and down into the water.” After a little while “the glacier dropped back out of sight and there was a big wall of water going over the point” (the spur southwest of Gilbert Inlet). Swanson next noticed the wave climb up on the south shore near Mudslide Creek. As the wave passed Cenotaph Island it seemed to be about 50 feet high near the center of the bay and to slope up toward the sides. It passed the island about 2 1/2 minutes after it was first sighted, and reached the Badger about 1 1/2 minutes later. No lowering or other disturbance of the water around the boat was noticed before the wave arrived.
The Badger, still at anchor, was lifted up by the wave and carried across La Chaussee Spit, riding stern first just below the crest of the wave, like a surfboard. Swanson looked down on the trees growing on the spit, and believes that he was about 2 boat lengths (more than 80 feet) above their tops. The wave crest broke just outside the spit and the boat hit bottom and foundered some distance from the shore. Looking back 3 to 4 minutes after the boat hit bottom Swanson saw water pouring over the spit, carrying logs and other debris. He does not know whether this was a continuation of the wave that carried the boat over the spit or a second wave. Mr. and Mrs. Swanson abandoned their boat in a small skiff, and were picked up by another fishing boat about 2 hours later.

The cliff on the northeast wall of Gilbert Inlet showing the scar of the 40 million cubic yard (30.6 million cubic meters) rockslide that occurred on the day before this photo. The head of the slide was at an altitude of about 3,000 feet (914 meters), just below snowfield in upper center. The elevation of water in Lituya Bay is sea level. The front of Lituya Glacier is visible in the lower left corner. Photo by D.J. Miller, United States Geological Survey.

The cliff on the northeast wall of Gilbert Inlet showing the scar of the 40 million cubic yard (30.6 million cubic meters) rockslide that occurred on the day before this photo. The head of the slide was at an altitude of about 3,000 feet (914 meters), just below snowfield in upper center. The elevation of water in Lituya Bay is sea level. The front of Lituya Glacier is visible in the lower left corner. Photo by D.J. Miller, United States Geological Survey.

The front of Lituya Glacier on July 10 was a nearly straight, vertical wall almost normal to the trend of the valley. Comparisons with earlier photographs of the glacier taken July 7 indicate that 400 meters of ice had been sheared off of the glacier front.

After the earthquake there was a fresh scar on the northeast wall of Gilbert Inlet, marking the recent position of a large mass of rock that had plunged down the steep slope into the water. The next day after the earthquake and tsunami, loose rock debris on the fresh scar was still moving at some places, and small masses of rock still were falling from the rock cliffs near the head of the scar. The dimensions of the slide on the slope are accurate but the thickness of the slide mass normal to the slope can only be estimated.

The main mass of the slide was a prism of rock that was 730 meters and 900 meters along the slope with a maximum thickness of 90 meters and average thickness of 45 meters normal to the slope, and a centre of gravity at about 600 meters altitude.

It was concluded the rockslide was the major, if not the sole cause of the 1958 giant wave.

The wave hit with such power that it swept completely over the spur of land that separates Gilbert Inlet from the main body of Lituya Bay. The wave then continued down the entire length of Lituya Bay, over La Chaussee Spit and into the Gulf of Alaska. The force of the wave removed all trees and vegetation from elevations as high as 1,720 feet (524 m.) above sea level. Millions of trees were uprooted and swept away by the wave. This is the highest wave that has ever been known.

Almost immediately after the earthquake?and the giant rockfall at the head of Lituya Bay, the massive Mega-Tsunami wave splashed to a maximum height of 1,720 feet on the southeast spur of Gilbert Inlet.?The wave spread across?the rest of the Lituya Bay?wiping everything in its path?on either side, over an area of about 4 square miles (10.4 sq. kms).

lituya-bay-map

The sub-aerial rockfall was considered as the most significant contributor to?the mega-tsunami wave generation. However, a simple mechanism of mass collapse of a portion of the mountain and water volume displacement could not account for the extreme wave height. The present study?of all postulated mechanisms of mega-tsunami generation in Lituya Bay?was undertaken to determine which was the main mechanism that really contributed to the generation of the extreme wave.

Lituya Bay a few weeks after the 1958 tsunami. The areas of destroyed forest along the shorelines are clearly recognizable as the light areas rimming the bay. A fishing boat anchored in the cove at lower left was carried over the spit in the foreground; a boat under way near the entrance was sunk; and a third boat, anchored near the lower right, rode out the wave. Lituya Bay is located in a remote and essentially unsettled part of Alaska. There were however three small boats in the bay at the time of the landslide, the Edrie, the Badger and the Sunmore. The Edrie was at anchor when the wave, at that point about 30 metres high, struck her. Fortunately she rode over the wave and did not sink. The Badger was carried over the spit at the entrance to the fjord and deposited in the open ocean, whereupon she sank. Fortunately the crew survived. The Sunmore tried to outrun the wave but was caught by it and engulfed. The boat and her crew were lost. Photo by D.J. Miller, United States Geological Survey.

Lituya Bay a few weeks after the 1958 tsunami. The areas of destroyed forest along the shorelines are clearly recognizable as the light areas rimming the bay. A fishing boat anchored in the cove at lower left was carried over the spit in the foreground; a boat under way near the entrance was sunk; and a third boat, anchored near the lower right, rode out the wave. Lituya Bay is located in a remote and essentially unsettled part of Alaska. There were however three small boats in the bay at the time of the landslide, the Edrie, the Badger and the Sunmore. The Edrie was at anchor when the wave, at that point about 30 metres high, struck her. Fortunately she rode over the wave and did not sink. The Badger was carried over the spit at the entrance to the fjord and deposited in the open ocean, whereupon she sank. Fortunately the crew survived. The Sunmore tried to outrun the wave but was caught by it and engulfed. The boat and her crew were lost. Photo by D.J. Miller, United States Geological Survey.

Scientists were puzzled for some time by the sheer size of the wave, because they could not identify a mechanism that could have created such a massive reaction. Ultimately, it was discovered that a piece of rock, 2,400 feet by 3,000 feet, and 300 feet thick, had dislodged from the face of the northern wall of the inlet, and fallen 2,000 feet into the bay. In some respects, it created a similar reaction to that which would have occurred if an asteroid had fallen into the water.

The effect of the rock crashing into the water created a localised tidal wave that crashed in opposite direction to the southwest shoreline of Gilbert Inlet.

Such was the force of the water that the wave cleared the piece of land that disconnects Gilbert Inlet from Lituya Bay. The wave then contiuned down the whole length of Lituya Bay, over La Chaussee Spit and into the Gulf of Alaska.

The enormous wave reached a staggering 1,722 feet (525 m) above ocean level. Incredibily, the wave was bigger than the Empire State Building in New York which stands 1,470 ft (448 m) tall. If the wave had been in New York, it would have completely submerged the building and probably have sweapt it away.

The enormous wave reached a staggering 1,722 feet (525 m) above ocean level. Incredibily, the wave was bigger than the Empire State Building in New York which stands 1,470 ft (448 m) tall. If the wave had been in New York, it would have completely submerged the building and probably have sweapt it away.

The third boat was in Lituya Bay at the time of the tsunami. It was anchored near the mouth of the bay and was sunk by the big wave. There are no known survivors? from this boat, and it was believed that there were several people on board.

Unfortunately, there was nothing anyone could have done to prevent any of the deaths. The earthquake was so strong, and the tsunami came so quickly, that there was not time to get to a safe place. It does, however, highlight the importance of documenting such events for posterity, and to consider such extreme events when making development decisions for coastal areas in areas with high seismicity or vulnerability to tsunamis.

Lituya Bay, located within Glacier Bay National Park, along Alaska's southeastern coast.

Lituya Bay, located within Glacier Bay National Park, along Alaska’s southeastern coast.

Prior to the July, 1958 tsunami, Don J. Miller of the United States Geological Survey had been studying evidence for the occurrence of large waves in Lituya Bay. Miller was in Alaska when the July 1958 wave occurred and flew to Lituya Bay the following day. He took the photographs in July and August and had also documented the older waves in Alaska.

Miller was the foremost expert on Lituya Bay in the 1950s and the early 1960s. In his 1960 report, “Giant Waves in Lituya Bay Alaska.” he pointed out evidence of five “giant” waves created primarily by land or glacier slides between 1853 and 1958.

The 1853-54 wave was estimated at 395 feet, the 1874 wave at 80 feet, the 1899 wave at 200 feet, the 1936 wave at 490 feet and the 1958 behemoth swept trees off a hillside at more than 1,720 feet.

In addition to those giant waves, the waters of Lituya Bay had also been the site of several other disasters involving both the native Tlingit tribes and groups of American, British and French explorers and adventurers from the 1780s into the Twentieth Century, according to Philip Fradkin in his 2001 book “Wildest Alaska: Journeys of Great Peril in Lituya Bay.”

Most of these involved the deadly, narrow entrance that featured tide rips and waters running up to 13 knots in either direction. Most notable was a disaster that cost French explorer Jean-Francois La Perouse more than 20 of his sailors. Fradkin also noted that Tlingit oral tradition featured several stories of “giant” waves and mass drownings in the bay.

With such a history of large waves, Lituya Bay should be considered as a dangerous body of water prone to a few large waves every century. When will the next one occur?

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