Posted on 02/27/2010 6:58:21 AM PST by Zakeet
The source of the energy absolutely does matter. An earthquake occurring under the water can only displace enough water to create about a 50 ft wave, and that is when it stacks up on the shore, not when it is actually generated. However, a 50 ft tsunami is still unbelievably devastating, not because f its height, but because of its wavelength.
If the source of a wave is a long, run out landslide, then the amount of water that is displaced increases exponentially. it is landslides that are responsible for 400ft to 1,700 ft waves. No earthquake can cause such.
Landslides and mega tsunamis:
http://www.youtube.com/watch?v=_RMprH-4QC4
A collegue of mine and his Thai wife were up country when the tsunami hit in 2004 but they had just left Phuket where they own a home. His description of the effects made it all the more real what a massive force the wave was.
....and Rush Limbaugh, Glenn Beck, Sean Hannity and ESPECIALLY that Right Wing Prince of DARKNESS Bill O’Reilly!
>>>130 feet?!? If true, that’s a monster, one of the largest, if not he largest, ever recorded.<<<
The 1946 tsunami that obliterated the Scotch Cap lighthouse in Uminak must have been bigger than that - it not only took out a 100-foot high concrete and steel reinforced building located about 100 feet from the high water line, but the reports said that the wave crested at the hill behind it.
The largest wave was at Lituya Bay (also in Alaska) in the 1950s - I think 1957 - and it was more than 1,700 feet high. Believe it or not, a ship anchored in the bay and its crew survived being picked up by the way and being swept out of sea. In that case, an earthquake caused a landslide which swept into the bay, causing the wave. They think Scotch Cap was caused by an underwater landslide.
That same 1946 wave also did a job on Hilo, Hawaii.
So a wave of 130 feet is horrifying but not a record.
>>>In order for an earthquake to cause a 270 ft tsunami, then it must have moved the ocean floor 270 ft, which isn’t very likely. I expect that the wave was caused by an underwater landslide, and not due to ocean floor displacement.<<<
No offense, but the 1964 Alaska earthquake managed to move an entire neighborhood of several hundred homes more than one-quarter mile out into Cook Inlet. The same earthquake took an entire island and lifted it 33 feet in a few minutes; on the other side of the fault, the same earthquake caused the land to drop equally in response. Shifting and moving the ocean floor 270 feet isn’t likely. That’s not the same thing as impossible. However, all the reports I’ve read about Scotch Cap said it was an underwater landslide which caused the wave.
Yes it is possible, depending upon size of the quake, depth of the epicenter, etc. If the Cascadia plate ruptures as in 1700, tsumami's exceeding 100' may well probably hit the Washington/Oregon/BC coast lines
Again, the wave can only be as great as the amount of water displaced.
The only way 100’ tsunamis will hit the west coast is if the ocean floor is displaced by a similar amount.
The west coast could be hit by higher waves if any underwater landslides occur and direct their energy toward that coast.
Furthermore, if a high speed landslide occurred across the pacific and directed a mega tsunami at the west coast, then it could be much higher than 100’.
Imagine this size of the tsunami caused by a three mile wide asteroid impacting the atlantic ocean at 200,000 mph...
I would also like to add that it is entirely possible to run into a 200ft vertical wall of water in the ocean at anytime. Such waves are not generated by storm or quake, but rather, they are unstable rogue waves that steal energy from other waves. They are ship killers, and they can occur anywhere.
Cheers
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.