SUMATRA QUAKE REVISED TO 9.0 MAG

usgs ^

[Brian Mosely]

Magnitude 9.0 - OFF THE WEST COAST OF NORTHERN SUMATRA
2004 December 26 00:58:50 UTC

Preliminary Earthquake Report
U.S. Geological Survey, National Earthquake Information Center
World Data Center for Seismology, Denver

A great earthquake occurred at 00:58:50 (UTC) on Sunday, December 26, 2004. The magnitude 9.0 event has been located OFF THE WEST COAST OF NORTHERN SUMATRA. (This event has been reviewed by a seismologist.)

Magnitude		9.0
Date-Time	Sunday, December 26, 2004 at 00:58:50 (UTC) = Coordinated Universal Time Sunday, December 26, 2004 at 6:58:50 AM = local time at epicenter
Location	3.298°N, 95.779°E
Depth	10 km (6.2 miles) set by location program
Region		OFF THE WEST COAST OF NORTHERN SUMATRA
Distances	250 km (155 miles) SSE of Banda Aceh, Sumatra, Indonesia 320 km (200 miles) W of Medan, Sumatra, Indonesia 1260 km (780 miles) SSW of BANGKOK, Thailand 1605 km (1000 miles) NW of JAKARTA, Java, Indonesia
	Location Uncertainty	horizontal +/- 9.2 km (5.7 miles); depth fixed by location program
Parameters	Nst=157, Nph=157, Dmin=>999 km, Rmss=1.35 sec, Gp= 29°, M-type=moment magnitude (Mw), Version=9
Source	USGS NEIC (WDCS-D)
	Event ID	usslav
Felt Reports	At least 3,000 people killed in Sri Lanka, 2,300 in India, 2,000 in Indonesia, 289 in Thailand, 42 in Malaysia, 8 in Somalia and 2 in Bangladesh by tsunamis. Tsunamis also occurred on the coasts of Maldives and Cocos Island. At least 200 people killed, buildings destroyed or damaged in the Banda Aceh area, Sumatra. Felt widely in Sumatra. Also felt in Bangladesh, India, Malaysia, Myanmar, Singapore and Thailand. This is now the fourth largest earthquake in the world since 1900 and is the largest since the 1964 Prince William Sound, Alaska earthquake.

Today's shallow, thrust-type earthquake occurred off the west coast of northern Sumatra at the interface between the India and Burma plates. In this region, the Burma plate is characterized by significant strain partitioning due to oblique convergence of the India and Australia plates to the west and the Sunda and Eurasian plates to the east. Off the west coast of northern Sumatra, the India plate is moving in a northeastward direction at about 5 cm per year relative to the Burma plate. Preliminary locations of larger aftershocks following today's earthquake show that approximately 1000 km of the plate boundary slipped as a result of the earthquake. Aftershocks are distributed along much of the shallow plate boundary between northern Sumatra (approximately 3 degrees north) to near Andaman Island (at about 14 degrees north).

[Cobra64]

Contact the USGS in Boulder, CO.

[U S Army EOD]

I'm glad he is safe and had his timing down. Just shows you how a week or two can make a difference to your life.

[DollyCali]

That is a marvelous pix.. even with my OLD 13" monitor. thanks

[TomGuy]

The Ten Largest1 Earthquakes of the 20th Century

Location		Date	Magnitude2
1.	Chile	May 22, 1960	9.5
2.	Prince William Sound, Alaska	March 28, 19643	9.2
3.	Andreanof Islands, Aleutian Islands	March 9, 1957	9.1
4.	Kamchatka	Nov. 4, 1952	9.0
5.	Off the coast of Ecuador	Jan. 31, 1906	8.8
6.	Rat Islands, Aleutian Islands	Feb. 4, 1965	8.7
7.	India-China border	Aug. 15, 1950	8.6
8.	Kamchatka	Feb. 3, 1923	8.5
9.	Banda Sea, Indonesia	Feb. 1, 1938	8.5
10.	Kuril Islands	Oct. 13, 1963	8.5

1. In terms of magnitude.

2. Moment magnitude.

3. March 28, 03:36:14 UT (March 27, 5:36 P.M. local time)

Source: National Earthquake Information Center, U.S. Geological Survey.

 

Deadliest Earthquakes on Record

(50,000 deaths or more)

Date	Location	Deaths	Magnitude
Jan. 23, 1556	Shansi, China	830,000	n.a.
July 27, 1976	Tangshan, China	255,0001	8.0
Aug. 9, 1138	Aleppo, Syria	230,000	n.a.
May 22, 1927	near Xining, China	200,000	8.3
Dec. 22, 8562	Damghan, Iran	200,000	n.a.
Dec. 16, 1920	Gansu, China	200,000	8.6
March 23, 8932	Ardabil, Iran	150,000	n.a.
Sept. 1, 1923	Kwanto, Japan	143,000	8.3
Oct. 5, 1948	Ashgabat, Turkmenistan, USSR	110,000	7.3
Dec. 28, 1908	Messina, Italy	70,000– 100,0003	7.5
Sept. 1290	Chihli, China	100,000	n.a.
Nov. 1667	Shemakha, Caucasia	80,000	n.a.
Nov. 18, 1727	Tabriz, Iran	77,000	n.a.
Nov. 1, 1755	Lisbon, Portugal	70,000	8.7
Dec. 25, 1932	Gansu, China	70,000	7.6
May 31, 1970	Peru	66,000	7.8
12684	Silicia, Asia Minor	60,000	n.a.
Jan. 11, 1693	Sicily, Italy	60,000	n.a.
May 30, 1935	Quetta, Pakistan	30,000–  60,000	7.5
Feb. 4, 1783	Calabria, Italy	50,000	n.a.
June 20, 1990	Iran	50,000	7.7

1. Official. Estimated death toll as high as 655,000.

2. Note that these dates are prior to A.D. 1000. No digit is missing.

3. Estimated.

4. No date available.

Source: National Earthquake Information Center, U.S. Geological Survey. Data compiled from several sources.

[gitmo]

Is the Richter Scale a logarithmic scale? Is a 9.0 ten times the blast of an 8.0?

[Strategerist]

I agree CA is way over-due....I think a 9.0 would definetly cause San Francisco to become an Island

The San Andreas is physically incapable of generating a mag 9.0 quake. Magnitude is a pretty basic function of the length and surface area of fault ruptured. SA is a strike-slip fault and simply not long enough to generate above a low 8.

The Cascadia subduction zone off Washington and Oregon and Northern California, is, however, capable of generating a 9.

[DollyCali]

I guess I don't understand the dynamics of the Tsunami.. if East Coast of Africa has been hit & these tidal waves go out concentrically from the earthquake, How could Garcia been missed? I am glad it was (hopefully) but must not really understand this

[Bahbah]

"The San Andreas is physically incapable of generating a mag 9.0 quake.",p>Do you have any information on the New Madrid fault?

[stlnative]

some Diego Garcia Message Yahoo Groups...

http://groups.yahoo.com/group/Diego_Garcia_BIOT/?yguid=188954506

http://groups.yahoo.com/group/usnavalstationdiegogarcia/

[gitmo]

Didn't the wave hit west Africa this afternoon? Were they able to evacuate?

[Strategerist]

Actually what is being used now is called Moment Magnitude, not the Richter scale.

A 9.0 has 10 times the ground motion of an 8...

However, that's not energy per se.

A 9.0 has THIRTY TWO times the ENERGY of an 8.0. Each increase of 1 in Moment magnitude is 32 times the seismic energy.

[commonguymd]

I think out in open water a tsunami is only a few inches in height, but as it approaches shallow areas near a coast it builds to enormous proportions.

[Strategerist]

The nature of the sea floor matters a lot..you can get odd little reflections and shadows for seismic waves.

[Domestic Church]

"Okay, so now what®?"


"Mt St Helens, while not associated with these quakes, appears ready to go"


Godzilla, A penny for your thoughts...is real estate around Seattle about to take a dive?

[Strategerist]

I would suppose it's impossible to generate a 9 off New Mardrid as well.

The fault zone doesn't seem nearly long enough to generate one.

There's been a lot of recent scholarship trying to guess the size of the big New Madrid quakes of the early 1800s. It seems a lot of the numbers thrown around for them may have been inflated; a few people are arguing that none of the quakes were above m 8.

However, because the crust is in such good shape generally in the Midwest, seismic energy really moves much further there than in, say, California. You'll have MUCH more damage 100 miles from a M 7 quake in Missouri than you would 100 miles from an identical M 7 quake in California.

[Slicksadick]

You are correct, Africa was hit some time ago, Diego was passed over many hours before that. Numerous mentions of the Maldives (much closer) having only a 1.3 meter swell. The location of the Diego base, on the Southwest portion of the atoll, most likely protected it from any major damage coming for the north east.

[Strategerist]

There's been no discernable change in activity at Mount St. Helens since this quake.

There's been no elevation in world-wide volcanic activity.

This won't necessarily lead to much of...anything.

[BIGLOOK]

Tet 68, we broke the VCs back; they were still around and nasty little MFs but no longer a formidable force.

68-70 Air War put the NVNAF where it belonged, on the ground or in caves.

I was out of there summer of 71 and so were the I Corps Marines.

72 Easter offensive was Vo Nguyen Giap's big mistake. Nice try but his army got their asses kicked. You'll only hear this once from me but Bravo Zulu, Army!

BIGLOOK. VQ-1, USN

[Bahbah]

"You'll have MUCH more damage 100 miles from a M 7 quake in Missouri than you would 100 miles from an identical M 7 quake in California."

That would not be good news here in St. Louis. I do appreciate the information.

[DollyCali]

I am guessing by it's shape DG is a former volcano "top" and so does NOT have the shallow waters to set up the "hit".. I did read earlier on another thread how the tidal waves are very regular wave like in the open sea.