Timeline of the 2004 Indian Ocean earthquake

Although, National Oceanic and Atmospheric Administration (NOAA) scientists at the Pacific Tsunami Warning Center (PTWC) in Hawaii eventually issued warnings of a possible tsunami from the huge earthquake off Sumatra, the waves outran notification systems at jet speeds of 500 mph (804 km/h) - catching hundreds of thousands of people unaware. Here is a timeline of the the giant earthquake. All times are Coordinated Universal Time (UTC), on Sunday 26 December 2004.

unday, 26th December, 2004

01:07 UTC

Resulting seismic signals received at the NOAA Pacific Tsunami Warning Center (PTWC) from stations in Australia triggered an alarm that alerted watchstanders.

01:10 UTC

PTWC issued a message to other observatories in the Pacific with its preliminary earthquake parameters.

01:14 UTC

PTWC issued a bulletin providing information on the earthquake and stating there was no tsunami threat to the Pacific nations that participate in the Tsunami Warning System in the Pacific (ITSU). These member nations are part of the UNESCO Intergovernmental Oceanographic Commission (IOC) and the International Coordination Group for the Tsunami Warning System in the Pacific (ICG/ITSU). India, Sri Lanka and the Maldives are not part of the Pacific system.

01:23 UTC

A tsunami hits the coast of Indonesia. Banda Aceh, a town in northwest Indonesia, receives seismic sea waves that are 9 meters in height. Effects of the tsunami reach 4 kilometers inland from the coastline. Just minutes prior to the tsunami, southeast Indonesia had sustained damage from the earthquake.

02:04 UTC

PTWC issued a second bulletin revising the earthquake magnitude to 8.5. That bulletin stated no tsunami threat to the Pacific but identified the possibility of a tsunami near the epicentre. No additional information regarding the formation of a tsunami was available. This first notification came 65 minutes after the earthquake and 41 minutes after the wave first made landfall.

02:30 UTC

PTWC attempted to contact the Australia Meteorological Service with no luck but were successful in contacting Australia Emergency Management. They confirmed they were aware of the earthquake.

02:33 UTC

A tsunami hit the coastal villages in Sri Lanka.

02:33 UTC

A tsunami hits the coasts in Thailand. According to many witnesses, the first seismic sea wave hit the coast in Phuket at 02:33 UTC. Khao Lak was hit a few minutes later. A few tourists managed to receive warning calls of big waves from other tourists in Phuket. According to a lot of witnesses the tsunamis, 5-10 meters in height, came in 10 minute periods.

03:30 UTC

Internet newswire reports of casualties in Sri Lanka provided PTWC with the first indications of the existence of a destructive tsunami.

03:45 UTC

Armed with the knowledge of a potentially devastating tsunami, PTWC contacted the US Pacific Command (PACOM) in Hawaii.

03:45 UTC

PTWC received a call from a Sri Lankan Navy Commander inquiring about the potential for further tsunami waves from aftershocks.

04:00 UTC

U.S. Ambassador in Sri Lanka called PTWC to set up a notification system to prepare for the possibility of a large aftershock. He said they would contact the Sri Lankan Prime Minister's office for such notifications. Continuing news reports gave increasing and more widespread casualties.

05:25 UTC

The first reading from the Australian National Tidal Centre gauge at Cocos Island west of Australia gave a reading of 0.5m crest-to-trough.

05:45 UTC

PTWC contacted the Australian Bureau of Meteorology and advised them about the increased earthquake magnitude and the 0.5m reading at Cocos Island, as well as the possibility of a destructive tsunami impact on Australia's west coasts.

06:00 UTC

PTWC re-contacted PACOM to advise of increased earthquake magnitude and potential for further tsunami impacts in the western Indian Ocean.

06:15 UTC

Australia Bureau of Met called PTWC to advise they had issued an alert to their west coast.

06:20 UTC

NOAA National Weather Service Pacific Region director contacted PTWC to report PACOM said no tsunami was observed at Diego Garcia in the Indian Ocean.

08:15 UTC

PTWC spoke with U.S. State Department Operations and advised them about the potential threat to Madagascar and Africa. They set up a conference call with the U.S. embassies at Madagascar and Mauritius, and PTWC advised them of the situation.

15:36 UTC

PTWC issued a third Tsunami Information Bulletin for this event, informing the Pacific that small sea level fluctuations from the Indian Ocean tsunami were being observed in the Pacific, it is assumed caused by energy that was wrapped around the south of Australia.

ources

* [http://www.valtioneuvosto.fi/tiedostot/julkinen/aasia/tutkintaselostus/fi.pdf The 2004 Indian Ocean Earthquake Investigation Report from the Finnish Government] (In Finnish)

External links

* [http://www.noaanews.noaa.gov/stories2004/s2358.htm National Oceanic and Atmospheric Administration (NOAA)]
* [http://www.pmel.noaa.gov/tsunami/Mov/indo_gl2.mov NOAA animation of worldwide spread of the Indian Ocean tsunami] (2.8 MB [http://www.apple.com/quicktime/download QuickTime] movie) - waves reach as far as Iceland, and cross each other southwest of Chile

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