Actually, if i remember correctly, the Hilo Tsunami (circa 1930's?) was actually a "mega-tsunami". So named, because they are not cause my earthquakes and waves, but because of the displacement caused by massive land slides. That one I believe was actually caused by a landslide in the Alutian islands in Alaska. Interesting note along those lines.... The Canary islands, will (yes, will) cause one of these mega-tsunamis which will (yes, will) cause a 50-100 foot wave, which will (yes, unfortunately, will) wipe out the majority of the eastern US coast. http://www.sibelle.info/oped25.htm JH. Michael Carnes wrote:
It's quite interesting to see how previous tsunamis have affected life in Hawai'i. There was a large tsunami a few decades ago that destroyed much of Hilo on the Big Island. There's a little museum there that's dedicated to that event. The interesting thing I learned there is that not all tsunamis come in as single large waves. In the case of Hilo, it was more like an enormous high tide. The harbor drained and then wave after wave came in, each higher than the one before. I don't know if this is because of Hawai'i's distance from large landmasses or if there's that much variation in the mode of tsunamis. There was substantial loss of life, albeit nothing like this monster in the Indian Ocean. But the warning system is very much in evidence now. There are markers showing high-water marks (scary) and horns up on poles just about everywhere near the coast. They're tested every month or so, and scare the living hell out of tourists. Such a system could have saved a lot of lives last week.
On Dec 30, 2004, at 9:33 AM, James Helsby wrote:
Spent some time studying Geo-physics will finishing up my B.S. at the U. So I'll throw in my two cents.
The earth is always in fluctuation. The fault type that cause the tsunami was a "thrust-fault." That being, that one fault plane was thrust on-top of the other. The motion, and displacement of materials is what caused the overriding water to be shifted in the form of a giant wave, which propagated towards land. The tsunami was literally felt and seen on every ocean beach of the world, just to varying degrees.
The earths rotation and inclination to the sun might well have been changed, but these changes are always happening. Cosmic drag from intense solar radiation can also cause a shift in the rotation speed. However, the mass of the earth made no change; therefore the net effect of any shift in surface materials is negligible. There is no more or less mass on the earth now, then there was last week. Its simply been moved VERY slightly. We are only talking about a change of something like .00001% of the earths surface.
Might not answer anything, but its fun to babble at 9:30 in the morning, before my first coffee.
Cheers, James.
David Dunn wrote:
My wife told me she had heard that yesterday. I didn't think it was true but here is a report from CNN.
Scientists: Quake may have made Earth wobble Wednesday, December 29, 2004 Posted: 2:44 PM EST (1944 GMT)
Scientists believe that a shift of mass toward the Earth's center during the quake caused the planet to spin 3 microseconds faster and to tilt about an inch on its axis. RELATED * Tsunami death toll tops 71,000 * Scientists: Quake shifts islands * Special Report: Waves of destruction LOS ANGELES, California (Reuters) -- The deadly Asian earthquake may have permanently accelerated the Earth's rotation, shortening days by a fraction of a second and caused the planet to wobble on its axis, U.S. scientists said Tuesday.
Richard Gross, a geophysicist with NASA's Jet Propulsion Laboratory in California, theorized that a shift of mass toward the Earth's center during the quake Sunday caused the planet to spin 3 microseconds, or millionths of a second, faster and to tilt about an inch on its axis.
When one huge tectonic plate beneath the Indian Ocean was forced below the edge of another "it had the effect of making the Earth more compact and spinning faster," Gross said.
Gross said changes predicted by his model probably are too minuscule to be detected by a global positioning satellite network that routinely measures changes in Earth's spin, but said the data may reveal a slight wobble.
The Earth's poles travel a circular path that normally varies by about 33 feet , so an added wobble of an inch is unlikely to cause long-term effects, he said.
"That continual motion is just used to changing," Gross said. "The rotation is not actually that precise. The Earth does slow down and change its rate of rotation."
When those tiny variations accumulate, planetary scientists must add a "leap second" to the end of a year, something that has not been done in many years, Gross said.
Scientists have long theorized that changes on the Earth's surface such as tide and groundwater shifts and weather could affect its spin but they have not had precise measurements to prove it, Caltech seismologist Hiroo Kanamori said.
"Even for a very large event, the effect is very small," Kanamori said. "It's very difficult to change the rotation rate substantially."
-----Original Message----- From: utah-astronomy-bounces+david.dunn=albertsons.com@mailman.xmission.com [mailto:utah-astronomy- bounces+david.dunn=albertsons.com@mailman.xmissio n.com] On Behalf Of Cynthia Blue Sent: Thursday, December 30, 2004 8:03 AM To: Utah-Astronomy@mailman.xmission.com Subject: [Utah-astronomy] Earth Change?
Okay... a fellow coworker of mine is stating that he has heard that the Earth's rotation has sped up, and the tilt has changed, because of the earthquake and resulting Tsunami that recently happened.
I haven't surfed the web yet looking for facts, but I asked him where he
found this info, was it on the Onion? =)
Anywhoo... just thought I'd pose the question to you guys. Heard anything? ;)
Cyn
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