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Re: Quakes Shift Whole Island Of Sumatra...


The initial reports said it was an 8.9 magnitude, but later reports have it as a 9.0 (tieing a Russian quake [Kamchatka?] for the 4th strongest known recorded earthquake). The scale is logarithmic which means that a 9 is 10 times more powerful than an 8. [But I really didn't need to tell you that - that's just for our viewers :-) ].

As to the entire island of Sumarta moving 100 feet, the most recent report from CNN/Reuters says:

 "Scientists: Quake shifts islands

 Nicobar and Simeulue farther out to sea

 Tuesday, December 28, 2004 Posted: 10:28 PM EST (0328 GMT)

LOS ANGELES, California (Reuters) -- The massive earthquake that devastated parts of Asia permanently moved the tectonic plates beneath the Indian Ocean as much as 98 feet (30 meters), slightly shifting islands near Sumatra an unknown distance, U.S. scientists said on Tuesday.

A tsunami spawned by the 9.0-magnitude quake off the northern tip of Sumatra killed an estimated 60,000 on Sunday in Indonesia, Thailand, India, Malaysia, Sri Lanka and East Africa.

Satellite images showed that the movement of undersea plates off the northern tip of Sumatra moved the Nicobar Islands and Simeulue Island out to sea by an unknown distance, U.S. Geological Survey geophysicist Ken Hudnut said.

Although the data showed that plates more than 12 miles (20 km) beneath the ocean's surface moved dramatically, scientists will have to use handheld satellite positioning systems at the sites to learn precisely how much the land masses on the surface shifted, Hudnut said."

In addition, another report from CNN/Reuters says:

 "Scientists: Quake may have made Earth wobble

 Wednesday, December 29, 2004 Posted: 10:31 AM EST (1531 GMT)

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 one millionth 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. "

As I write this, the current death tole is above 80,000, and I fully expect the number to reach 125,000-135,000 - just from the tsunamis and earthquake(s). The W.H.O. thinks the number who die from disease and other related aftermaths will double the amount killed directly by the event.

As to my dinosaur reference - all this discussion of plate tectonics and the disaster caused by the resultiing tsunamis is indicative of what might have happened (at least locally) if a large enough bolide hit the earth at the K-T.

BTW: I think _Dilong_ is the most important dinosaur discovery this year, as well.

Allan Edels

From: David Marjanovic <david.marjanovic@gmx.at>
Reply-To: david.marjanovic@gmx.at
To: DML <dinosaur@usc.edu>
Subject: Re: Quakes Shift Whole Island Of Sumatra...
Date: Wed, 29 Dec 2004 15:39:58 +0100

The 9.0-magnitude quake struck 6 miles beneath the ocean

I thought it was 8.9 (isn't 9.0 about, like, half again as strong as 8.9?), and I thought it was 25 km = 15.6 miles beneath the surface?

The quake shoved the entire
island of Sumatra about 100 feet to the southwest.

Incredible indeed. But it's the expected direction. Subduction in one huge jump...

I wonder when we'll hear anything about Australia or Madagascar, let alone the Nicobar and Andaman islands? And is the Malacca Strait shallow enough to have stopped the wave before Singapore -- which is sort of at the end of the funnel?

Oh, uh... dinosaurs. Dinosaurs! I agree that *Dilong* is the most "important" discovery of the year. *Rugops* does deserve some mention for being Africa's first named abelisaur, but that's it.