Posted: 7/6/2011 3:35:55 PM EDT
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Okay so for all you experts out there I have a question in regards to water displacement and actual Tsunami size.
The 9.0 that struck off of the coast of Sri Lanka in 2004 was able to generate a Tsunami that was about a 100ft high so I was just curious of what it would take to generate a Tsunami lets say 1000ft high, short of anything actually impacting in the water to displace it that much, can a 10.0 quake potentially cause a Tsunami that high? Any thoughts? -Dep |
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There has never been a 10.0 in recorded (remembered) history, the largest on record is a 9.5. A 10.0 releases 10 times the energy of a 9.0, everything else depends on location and topography. Is a 1000ft tsunami possible? anything is possible, is there more than a 0.01% chance of one happening in our lifetimes (because of an earthquake or meteor hit)? I doubt it.
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Quoted:
There has never been a 10.0 in recorded (remembered) history, the largest on record is a 9.5. A 10.0 releases 10 times the energy of a 9.0, everything else depends on location and topography. Is a 1000ft tsunami possible? anything is possible, is there more than a 0.01% chance of one happening in our lifetimes (because of an earthquake or meteor hit)? I doubt it. Not saying that it will happen in our lifetime, I'm just curious to find out what it would actually take to cause a Tsunami that high as several individuals pointed out, it does depend on the physical location of the quake and I agree but I would like to know more because I know other factors play important rolls, and there was a possible 12.25 quake that is theorized by the Yucatan Peninsula meteor impact 65mill years ago so there's that magnitude quake to take into account. |
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A less powerful earthquake can also cause a huge tsunami indirectly. Biggest recorded tsunami:
Link
On the night of July 9, 1958 an earthquake [a 7.7] along the Fairweather Fault in the Alaska Panhandle loosened about 40 million cubic yards (30.6 million cubic meters) of rock high above the northeastern shore of Lituya Bay. This mass of rock plunged from an altitude of approximately 3000 feet (914 meters) down into the waters of Gilbert Inlet (see map below). The impact generated a local tsunami that crashed against the southwest shoreline of Gilbert Inlet. 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 contiuned 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 1720 feet (524 meters) above sea level. |
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What causes the wave to grow in height is the slope of the sea floor as it approaches land. The steeper the rise, the faster and higher the wave will stand up.
A long gentle rise will cause the wave to begin rising way out at sea and burn up some of its energy before it gets to shore. |
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Quoted: A less powerful earthquake can also cause a huge tsunami indirectly. Biggest recorded tsunami: Link On the night of July 9, 1958 an earthquake [a 7.7] along the Fairweather Fault in the Alaska Panhandle loosened about 40 million cubic yards (30.6 million cubic meters) of rock high above the northeastern shore of Lituya Bay. This mass of rock plunged from an altitude of approximately 3000 feet (914 meters) down into the waters of Gilbert Inlet (see map below). The impact generated a local tsunami that crashed against the southwest shoreline of Gilbert Inlet. 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 contiuned 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 1720 feet (524 meters) above sea level. Like I said, all about location and topography, push a large amount of water into a confined steep sided space and that is what will result. |
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Quoted:
A less powerful earthquake can also cause a huge tsunami indirectly. Biggest recorded tsunami: Link
On the night of July 9, 1958 an earthquake [a 7.7] along the Fairweather Fault in the Alaska Panhandle loosened about 40 million cubic yards (30.6 million cubic meters) of rock high above the northeastern shore of Lituya Bay. This mass of rock plunged from an altitude of approximately 3000 feet (914 meters) down into the waters of Gilbert Inlet (see map below). The impact generated a local tsunami that crashed against the southwest shoreline of Gilbert Inlet. 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 contiuned 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 1720 feet (524 meters) above sea level. That's what I'm talking about, thanks for that article very interesting, although I must say after a quick read i think what caused the wave to be that high was the factor that such a large amount of rock mass was displaced and the fact that the depth was only 720 and it came from an altitude of 3000ft, that's like throwing a brick into a shallow puddle, the same results will probably be generated and the fact that the area has cliff faces on both sides may have forced the water to build up, but still very interesting read. |
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Quoted: Quoted: A less powerful earthquake can also cause a huge tsunami indirectly. Biggest recorded tsunami: Link On the night of July 9, 1958 an earthquake [a 7.7] along the Fairweather Fault in the Alaska Panhandle loosened about 40 million cubic yards (30.6 million cubic meters) of rock high above the northeastern shore of Lituya Bay. This mass of rock plunged from an altitude of approximately 3000 feet (914 meters) down into the waters of Gilbert Inlet (see map below). The impact generated a local tsunami that crashed against the southwest shoreline of Gilbert Inlet. 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 contiuned 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 1720 feet (524 meters) above sea level. That's what I'm talking about, thanks for that article very interesting, although I must say after a quick read i think what caused the wave to be that high was the factor that such a large amount of rock mass was displaced and the fact that the depth was only 720 and it came from an altitude of 3000ft, that's like throwing a brick into a shallow puddle, the same results will probably be generated and the fact that the area has cliff faces on both sides may have forced the water to build up, but still very interesting read. There is the potential for a similar landslide in the Hawaiian islands, bye bye Honolulu, hundreds of thousands dead.
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Earthquake size has nothing to do with tsunami size.
You can have a 9.5 in the middle of the Pacific and get bubbles. In order for the water to be displaced soil or rock has to move the DEC 04 event lifted something like 10 Sq miles of ocean bed about 3 M (10 ft) in less than 2 seconds. That movment caused the wave. A 5.0 scale quake can cause a similar size wave if it can move a similar scale of ocean bed rock. The biggest tsunamis have been caused by land slides and meteor impacts if you look at the southern coast of madagascar on google earth you will see white chevrans about 4 miles from the beach these are the wash lines of a wave from a meteor impact in the Indian Ocean. Krakatoa a large volcanic erution also caused a very large wave half of the island was blown off and sank into the ocean. The Azores Near Protugal are ready for a similar situation that may cause a 35 ft wave to hit the East coast when the eruption occurs. |
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Quoted: +1Earthquake size has nothing to do with tsunami size. You can have a 9.5 in the middle of the Pacific and get bubbles. In order for the water to be displaced soil or rock has to move the DEC 04 event lifted something like 10 Sq miles of ocean bed about 3 M (10 ft) in less than 2 seconds. That movment caused the wave. A 5.0 scale quake can cause a similar size wave if it can move a similar scale of ocean bed rock. The biggest tsunamis have been caused by land slides and meteor impacts if you look at the southern coast of madagascar on google earth you will see white chevrans about 4 miles from the beach these are the wash lines of a wave from a meteor impact in the Indian Ocean. Krakatoa a large volcanic erution also caused a very large wave half of the island was blown off and sank into the ocean. The Azores Near Protugal are ready for a similar situation that may cause a 35 ft wave to hit the East coast when the eruption occurs. A large underwater landslide could result in a mega-tsunami without any seismic trigger-event.
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Quoted:
Possibly. The richter scale is a base ten logarithm, so a 10.0 on the richter is ten times stronger than a 9.0. 100 ft x 10 = 1000 ft. This is wrong. Each full magnitude represents an approximate 32% increase in the actual energy released. The "10 times" that is too commonly referred to is actually the increase in size of the seismograph trace on the seismograph. Not how much stronger the earthquake is. |
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Quoted:
Earthquake size has nothing to do with tsunami size. You can have a 9.5 in the middle of the Pacific and get bubbles. In order for the water to be displaced soil or rock has to move the DEC 04 event lifted something like 10 Sq miles of ocean bed about 3 M (10 ft) in less than 2 seconds. That movment caused the wave. A 5.0 scale quake can cause a similar size wave if it can move a similar scale of ocean bed rock. The biggest tsunamis have been caused by land slides and meteor impacts if you look at the southern coast of madagascar on google earth you will see white chevrans about 4 miles from the beach these are the wash lines of a wave from a meteor impact in the Indian Ocean. Krakatoa a large volcanic erution also caused a very large wave half of the island was blown off and sank into the ocean. The Azores Near Protugal are ready for a similar situation that may cause a 35 ft wave to hit the East coast when the eruption occurs. This guy paid attention in class. The wave height is a composite function of the amount of water displaced, the velocity of the displacing act, and the characteristics of the ocean floor where it occurred. |
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Quoted:
Possibly. The richter scale is a base ten logarithm, so a 10.0 on the richter is ten times stronger than a 9.0. 100 ft x 10 = 1000 ft. 1000 feet is 10 times TALLER than 100 feet, not ten times BIGGER. Taller is 2D, bigger is 3D, and there's a huge difference. |