The Wavefront of Death

An animation of the how the killer waves propagated across the Bay of Bengal is featured on the International Coordination Group for the Tsunami Warning System in the Pacific website. More information is provided here. An earlier Belmont Club post speculated that the wavefront was still hours away from the Indian subcontinent after impact on Thailand. That was incorrect. The time difference between the wave's impact on Phuket and landfall on Sri Lanka was only about 30 minutes.

A log of warnings issued by the Pacific tsunami warning system is shown here. The earthquake on the western side of Sumatra took place at 0059Z 26 DEC 2004, initially rated at 8.0 on the Richter Scale. The first tsunami warning bulletin was issued at 0114Z 26 DEC 2004 -- about fifteen minutes later. It was 09:15 in the morning in Bangkok. The wave was still an hour away from Phuket. Although the recipients of the warning were the members of the Pacific group there may have been enough information in the first bulletin to ring alarm bells had any trained person concerned with the Indian Ocean read it.

TSUNAMI BULLETIN NUMBER 001 PACIFIC TSUNAMI WARNING CENTER/NOAA/NWS ISSUED AT 0114Z 26 DEC 2004 THIS BULLETIN IS FOR ALL AREAS OF THE PACIFIC BASIN EXCEPT ALASKA - BRITISH COLUMBIA - WASHINGTON - OREGON - CALIFORNIA.
.................. TSUNAMI INFORMATION BULLETIN ..................
THIS MESSAGE IS FOR INFORMATION ONLY. THERE IS NO TSUNAMI WARNING OR WATCH IN EFFECT.
AN EARTHQUAKE HAS OCCURRED WITH THESE PRELIMINARY PARAMETERS

ORIGIN TIME - 0059Z 26 DEC 2004
COORDINATES - 3.4 NORTH 95.7 EAST
LOCATION - OFF W COAST OF NORTHERN SUMATERA
MAGNITUDE - 8.0

EVALUATION
THIS EARTHQUAKE IS LOCATED OUTSIDE THE PACIFIC. NO DESTRUCTIVE TSUNAMI THREAT EXISTS BASED ON HISTORICAL EARTHQUAKE AND TSUNAMI DATA. THIS WILL BE THE ONLY BULLETIN ISSUED FOR THIS EVENT UNLESS ADDITIONAL INFORMATION BECOMES AVAILABLE. THE WEST COAST/ALASKA TSUNAMI WARNING CENTER WILL ISSUE BULLETINS FOR ALASKA - BRITISH COLUMBIA - WASHINGTON - OREGON - CALIFORNIA.

On 0204Z 26 DEC 2004 a second bulletin was issued. It concluded that there was still no danger to the Pacific. The waves were only minutes away from Phuket and the rest is history.