Magnitude 9.0 Earthquake - OFF THE WEST COAST OF NORTHERN SUMATRA

USGS Earthquake Hazards ^ | 2004 December 26 00:58:55 UTC

[bd476]

Magnitude 8.1 - OFF THE WEST COAST OF NORTHERN SUMATRA
2004 December 26 00:58:55 UTC

Preliminary Earthquake Report
West Coast and Alaska Tsunami Warning Center/NOAA/NWS

A great earthquake occurred at 00:58:55 (UTC) on Sunday, December 26, 2004. The magnitude 8.1 event has been located OFF THE WEST COAST OF NORTHERN SUMATRA. (This event has been reviewed by a seismologist.)

Magnitude	8.1
Date-Time	Sunday, December 26, 2004 at 00:58:55 (UTC) = Coordinated Universal Time Sunday, December 26, 2004 at 6:58:55 AM = local time at epicenter
Location	3.400°N, 95.700°E
Depth	40 km (24.9 miles) set by location program
Region	OFF THE WEST COAST OF NORTHERN SUMATRA
Distances	235 km (145 miles) S of Banda Aceh, Sumatra, Indonesia 330 km (205 miles) W of Medan, Sumatra, Indonesia 1620 km (1000 miles) NW of JAKARTA, Java, Indonesia 3405 km (2120 miles) SE of NEW DELHI, Delhi, India
Location Uncertainty	Error estimate not available
Parameters	Nst=020, Nph=020, Dmin=>999 km, Rmss=0.98 sec, Gp=101°, M-type=moment magnitude (Mw), Version=1
Source	West Coast and Alaska Tsunami Warning Center/NOAA/NWS
Event ID	at00000264

Location Maps: 10-degree NEIC Maps Did you feel it? Report shaking and damage at your location. You can also view a map displaying accumulated data from your report and others. Historical Moment Tensor Solutions Seismic Hazard Map Historical Seismicity Theoretical P-Wave Travel Times Magnitude 7 and Greater Earthquakes This Year TsunamiBulletin Archive of newsworthy events

[Central Scrutiniser]

Molly Malones is the name of the pub, its like a second home when I am there, damn.

The pub that got blown up in Bali was one I went to often, this is kinda scary.

[steve86]

Updating map:

http://www.gfz-potsdam.de/geofon/seismon/globmon.html

[expatguy]

Now one is allowed near the beach. The army is now there to stop looting. They say with loadspeakers they will shoot looters.

Lots of shops and stuff hit bad.

[Central Scrutiniser]

Maritius and Roderique island could be hit as well as Madagascar.

Damn, Phuket is one of the places I've been plotting to move to when I get laid off.

[steve86]

Is the Northern India quake (near the Bangladesh border) the one the are talking about?

[expatguy]

WE JUST FELT TREMOR HERE!!!

WOW!!

[null and void]

Can I please ask the obvious dumb question?..How do you have two quakes that huge and NOT generate a tsunami?

Good question. The tsunami is caused by water displacement. If a 'quake displaces sea floor UP or DOWN that displaces water. If two plates are merely sliding past each other that causes minimal water displacement, no tsunami.

Unless a slip 'quake causes an underwater landslide...

[edmond246]

India? I'm sorry but is this just another aftershock, is your map incorrect, or well is this normal?

[Strategerist]

It could be an inflated magnitude for a real quake in NE India, as well.....

[expatguy]

WATER IS MOVING IN MY GLASS ON MY DESK!

[Strategerist]

NEIC just had a mag 7.3 aftershock in the Nicobar Islands.....

Really odd all the aftershocks are north of the mainshock location, not south of it.

[commonguymd]

where are you at?

[Strategerist]

It's normal for there to be confusion about the locations and magnitudes of earthquakes immediately after they happen.....

[expatguy]

Shah Alam

[Siegfried]

Here's a seismograph from Mt Rainier showing the arrival at just before 0110 UTC

http://www.pnsn.org/WEBICORDER/VOLC/LO2_SHZ_UW.2004122600.html

Interesting that the pen was swaying up and down in a long period cycle for at least ten minutes before the vibrations started. I wonder if that was caused by longer wavelengths traveling faster through the earth? Maybe a more direct route?

[Central Scrutiniser]

The Rockhard is flooded? Damn, that is far up! The Expat is about 50 meteres in from the Rockhard, across Rat-u-Thit street and down a bit.

I wonder how Karon and Kata beaches are, much flatter, longer beaches, with resorts on the water. The Club Med has no building or anything to block the water...

[Strategerist]

Interesting that the pen was swaying up and down in a long period cycle for at least ten minutes before the vibrations started. I wonder if that was caused by longer wavelengths traveling faster through the earth? Maybe a more direct route?

That's how earthquakes are located. The various types of waves travel at different speeds. Once you figure out the time difference, you can figure out how far away from a given seismometer a quake was, and draw a circle with that radius. If you have three seismographs in widely different places, if you draw three circles, the circles will cross in one place..and that's where the earthquake was located.

[COEXERJ145]

I wonder if that was caused by longer wavelengths traveling faster through the earth?

Most likely. Certain seismic waves travel faster than others.

[expatguy]

Bangla road up to Hard Rock is flooded and the road in front of Aloha and C&N - Hard Rock now is on the 2nd floor - no more on the ground floor.

[Strategerist]

Incedentally that's how you can get screwy quake sizes and locations from these local guys in these countries; their seismographs have trouble showing the wave types of huge quakes because they're so close to the quake the whole seismograph is a confused, saturated mess, and their seismographs aren't very far apart from each other so you don't get a good accurate location. Because NEIC is worldwide, ironically, you get better info from instruments FURTHER from the earthquake if it's a huge quake.