I heard something on CNN today about the size of earthquakes; apparently the biggest hit subduction zones, where a crustal plate is slipping under another, as with the big Japanese quake. Does the Atlantic have subduction zones? Thanks, Joe --- On Sat, 3/19/11, erikhansen@thebluezone.net <erikhansen@thebluezone.net> wrote:
From: erikhansen@thebluezone.net <erikhansen@thebluezone.net> Subject: Re: [Utah-astronomy] Atlantic Immune to Tsunamis? To: "Utah Astronomy" <utah-astronomy@mailman.xmission.com> Date: Saturday, March 19, 2011, 12:40 PM
The eastern seabed is very steep, they elude to that being unpredictable. There is some relatively shallow water in the middle of the Atlantic perhaps that will consume some of the energy. I thought the biggest disagreement was about how much water would be displaced. IE wether it happened at once from one quake or from several quakes. It is a huge chunk if it happens at once.
One thing is for sure even of 20 meter wave would devastate Florida.
There are other models that show that a La Palma event would not be as
devastating as once thought:
http://www.ngi.no/en/News-archive/News/PhD-in-Numerical-modelling-of-tsunami...
and some leading tsunami and mega-tsunami scientists disagree that any large or mega-tsunami would come out of La Palma:
http://www.arizonaenergy.org/WaterEnergy/What%20is%20a%20mega-tsunami%20and%...
From this article http://docs.google.com/viewer?a=v&q=cache:e8MugMtbub4J:www.lapalma-tsunami.c... looks like the US would only receive a wave about 3 meter's high. Still power, still big enough to cause some major damage but not the 100m high wave that was talked about in the Discovery presentation on this subject. That material btw, was presented in the Discovery show before it was released to the scientific community and before proper modeling was done. Europe and Africa would receive waves less than 10m high. Again, damaging and big enough to penetrate well inland like the 2004 Indian Ocean the 2011 Japan Tsunami's did, and lives and property are lost, but not that gigantic wave. Finally, no large mega-tsunami has been recorded in the Atlantic or the Pacific Oceans related to a flank collapse. The collapse of Krakatau and Santorin caused devastating and catastrophic waves locally, but those waves never spread out and propagate to distant shores like an earthquake generated tsunami does. Scientific debate will continue on this as well it should and we'll see where the evidence leads. For now, I'll go with the less damaging based on past evidence and current modeling. I may have to, when I have time, compare the estimates here of La Palma to what was misplaced when Krakatau collapsed.
For general info on Tsunami:
http://www.teachervision.fen.com/tsunami/resource/31103.html
On Sat, Mar 19, 2011 at 11:26 AM, <erikhansen@thebluezone.net> wrote:
I recall a story about the Canary Islands El Hierro and La Palma. EL Heirro had a major landslide that created its crescent shape, this landslide was believed to have caused a huge tsunami that reached the east coast of the US with huge waves.
La Palma has a similar fault line that bisects the island. One theory is that is if this fault goes, half of the island would fall into the sea causing a Tsunami that would be several hundred meters in height as it hits the eastern US. Seems geologists are somewhat split, some think the Island will spilt in half over a long period of time, some think it will happen in one catastrophic event.
The evidence at El Hierro seems to suggest it will happen all at once.
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