www.iht.com/articles/2004/12/28/news/warning.html

Int. Herald Tribune Wed 29th Dec
HONOLULU When experts at the Pacific Tsunami Warning Center in Honolulu were first alerted that an earthquake had struck off Indonesia, they had no way of knowing that it had generated a devastating tsunami and no way to warn the people most likely to suffer.

“We wanted to try to do something, but without a plan in place then, it was not an effective way to issue a warning, or to have it acted upon,” McCreery said. “There would have still been some time – not a lot of time, but some time – if there was something that could be done in Madagascar, or on the coast of Africa.

The sequence of events as knowledge of the earthquake, the tsunami and the destruction unfolded suggest the speed and precision of science and modern communication, as well as their limits. If there had been a warning system for tsunamis in the Indian Ocean, thousands of people might have had a chance to flee.

The first notice of the earthquake that anyone at the Pacific tsunami center received was a computer-generated page set off by seismic sensors at 2:59 p.m. Saturday, Honolulu time.

The immediate message received by people like Laura S.L. Kong, a U.S. Department of Commerce expert who is the head of a United Nations tsunami education center in Hawaii, included the time of the quake, latitude, longitude and an initial estimate of magnitude of about 8.0.

When office staff members took a close look at available data, they sent out a warning to a list of contacts around the Pacific.

The center was advising of sea level changes in Fiji, Chile and California measured in inches, the echo of a distant event that had sloshed through the straits that connect the oceans.

The warning center also was continuing to refine its estimate of the earthquake, eventually raising it to a magnitude of 9.0, which is 32 times more energetic than the initial estimate of 8.0; the scale is logarithmic.

“Based on it being an 8.0, we assumed the damage would be confined to Sumatra and would be a local tsunami event, one that strikes shore within minutes of the event,” he said.

“We weren’t overly concerned at that point that it was something larger,” he added.

But using another, sometimes more accurate method of measuring, McCreery said the staff had then quickly determined that the magnitude had been closer to 8.5, more intense but still only borderline for generating more distant damage. The center issued a follow-up bulletin.

It was not until they saw news reports of casualties in Sri Lanka that all that changed.

McCreery spoke to the U.S. ambassador to Sri Lanka, who wanted to know whether more giant waves were expected.( it appears that SRi lankans new a 2nd wave was coming in davance so the information appears to have been acted upon

Then he had a conference call with a U.S. State Department official and embassy staff in Madagascar and Mauritius to address potential threats headed their way, and how the local authorities might be notified. With no system in place, however, they would basically be scrambling.

One of the few places in the Indian Ocean that received the message of the quake was Diego Garcia, a speck of an island with a U.S. Navy base, because the Pacific warning center’s contact list includes the Navy. Finding the appropriate people in Sri Lanka or India was harder.

Last year a book on another Indonesian cataclysm, “Krakatoa: The Day the World Exploded,” by Simon Winchester, asserted that that volcano, which set off an even more deadly tsunami when it exploded in 1883, was the world’s first international disaster because new undersea telegraph cables spread the news around the world within a few minutes.

With high-speed data links and the Internet, it takes fewer minutes now, but if the information spreads wide, it does not always go deep.