Hour by hour

As he set to work, Sumatra8217;s shores were already a soup of human flotsam. Thailand to the northeast was awash. The pulse of energy transferred from seabed to water, traveling at jetliner speed, was already most of the way across the Bay of Bengal and approaching unsuspecting villagers and tourists, fishermen and bathers, from the 8-foot-high coral strands of the Maldives to the teeming shores of eastern India.

With an eerie time lag, his data would reveal the dimensions of the catastrophe that was unfolding across eight brutal hours on Sunday, one that stole tens of thousands of lives and remade the coasts of much of Asia.

HAWAII
Helpless warners

He wore two beepers, in case one failed. Both chirped. On Christmas afternoon, Barry Hirshorn was asleep. As a geophysicist, he was used to having his rest interrupted. Almost daily, earthquakes announced themselves somewhere, usually modest nuisances, and off went his pagers.

It was just after 3 pm in Honolulu, nearly halfway around the globe from where the earth was trembling. Hirshorn worked at the Pacific Tsunami Warning Center, in Ewa Beach. He was one of five staff scientists entrusted with the big task of alerting Pacific countries and the US military to deadly tsunamis.

At 3:14 pm, 15 minutes after the earthquake struck, they issued a routine bulletin announcing an event off Sumatra with a magnitude of 8.0. It added, 8216;8216;There is no tsunami warning or watch in effect.8217;8217; This referred to the Pacific. The bulletin alerted perhaps 26 countries, including Indonesia and Thailand, though it did not go to other coastal areas of the Indian Ocean, for they were not part of any warning system.

Their instinct was to somehow tell more, to warn the region that it would continue, to reach people who could clear beaches. Someone phoned the International Tsunami Information Center, asking if they knew people in the stricken region. The center simply had no contacts in this distant world.

JAPAN
Looking on

The seismograph at the Matsushiro Seismological Observatory, about 110 miles northwest of Tokyo, is inside a mountain tunnel. 8216;8216;Our job is to identify the epicenter and the size of earthquakes all over the world,8217;8217; said Masashi Kobayashi, an observatory official. Kobayashi said he did not mistake the significance of what got recorded: It showed an earthquake with a magnitude of 8.

Kobayashi said he had calculated the location, as well as the magnitude of the quake. And with that, he realized something else. 8216;8216;When I found it was in the ocean,8217;8217; he said, 8216;8216;I thought the first thing to worry about was tsunami.8217;8217; What Kobayashi did with his information, and concern, is not entirely clear. He said he had made his reports to headquarters. It is not clear what, if anything, his superiors did.

INDONESIA
First losses

As deputy mayor of Banda Aceh, Muhammad Kadir was about the closest thing the townspeople had to an alarm bell when the tsunami hit Indonesia. The 76-year-old Kadir had hurried Sunday morning to a seaside market at the tip of Sumatra for emergency supplies after the initial earthquake struck. It was at the market, a few minutes later, that he said he had looked far out to sea and noticed something strange: The waterline was dipping off to the sides and rising furiously in the middle.

8216;8216;The water separated, then it attacked,8217;8217; he said. 8216;8216;I8217;ve never even seen anything like it in the movies. I couldn8217;t imagine anything like it.8217;8217; After spotting the raging waters, Kadir raced through the town banging on doors and shouting into a mosque. 8216;8216;I told people the water was getting higher and higher 8212; get out.8217;8217;

His mad dash was the closest many people on Sumatra would come to an early warning system. Before the waves subsided, more than 43,000 people in the Aceh region alone would perish.

SRI LANKA
Waves strike

As a separate set of mammoth waves hurtled across the Indian Ocean in the opposite direction, due west, Amir Khan, an off-duty police officer, relaxed in his home in the town of Kalmunai on the east coast of Sri Lanka. Some in Kalmunai remember the ocean8217;s abruptly changing colors from green to a dark, menacing black, as if it were filled with oil. Others remember the water turning white with foam. All recall the first wave8217;s shape: a 10 to 12 foot tall wall of water.

Three subsequent waves, each larger and more powerful than the last, obliterated the neighborhood and reached 700 yards inland. In the first day alone, 1,824 bodies were recovered and buried behind a local mosque.

AUSTRALIA
International inertia

The possibility of tsunamis arising in the Indian Ocean had not completely escaped international attention. During the 1990s, an obscure UN group, the International Coordination Group for the Tsunami Warning System in the Pacific, considered the extension of tsunami alert systems to parts of the globe outside the Pacific, including the Caribbean and Indian Ocean.

At a meeting of the group in Lima, Peru, in 1997, its members had considered proposals to expand the network to the Indian Ocean, particularly because of Indonesia8217;s tectonic activity. Nothing concrete happened. Among the scientists who kept up pressure was Dr Phil Cummins, a seismologist with Australia8217;s geosciences agency. He continued to gather and present evidence that an Indian Ocean tsunami was inevitable, although unpredictable in terms of timing, and posed a grave threat to many countries. He met with no ill will, but with considerable inertia, he said.

Cummins prepared a position paper laying out his arguments. He used a computer model similar to that used by Titov in Seattle to study how tsunamis spread from the great Sumatra quake of 1833. He simulated the quake in a mathematical simulacrum of the ocean, and simulated waves radiated until they struck as far north as eastern India and all around western Australia. The Sumatra shore east of the fault was devastated, and a directional pulse of energy, resulting in higher waves, splayed westward like a shotgun blast.

At the time, the images of those reconstructed virtual waves must have seemed like yet another computer analysis, predicting yet another potential disaster that might or might not occur in this, or the next century. Now, the reconstructions, so similar to what happened last Sunday, carry a disturbing weight.

KENYA
The last victims

Capt. Twalib Hamisi was sitting in his office at the Port Authority in Mombasa, Kenya, when word of the curious water first reached him. A staffer had phoned to report unusual movements in the main port there. 8216;8216;The tide was supposed to be falling, but it was rising,8217;8217; Hamisi, the harbor master, recalled. It was about 1 pm Sunday, and he decided to call other ports in Malindi and Lamu, where workers reported similar water movements.

Then, Hamisi said, the minister of foreign affairs phoned to report the heavy damage in Asia. After realizing the direction the waves were headed, Hamisi called the Port Authority director. 8216;8216;I said: 8216;We have a problem. We have to institute our emergency plan8217;.8217;8217;

The emergency plan was intended for things like oil spills or fires, not tsunamis. But it was all they had. The police were told to evacuate beaches. The news media was called to spread the word. The local authorities were mobilized up and down the coast. Radio messages were sent to commercial fishing vessels and ships. For the wooden dhows that are so common in Kenya and that lack radio communication, the danger was spread by word of mouth.

SEATTLE
A final picture

In Seattle, around the time that waves were sweeping the beaches of Kenya, Titov was close to finishing his model for simulating Indian Ocean tsunamis. He hit enter on his terminal keyboard, and the computer began calculating numbers. As the real tsunami was spending its last destructive power, his virtual tsunami began. It burst out like a shotgun blast from the epicenter of the quake, focused due west from the fault line.

By 4:28 a.m. Sunday morning, the simulation had run its course, and Titov posted his work on the Web, knowing, but still not knowing, since he had seen no news, what had happened. Like everyone else, he became transfixed by television footage of heaving seas and devastation, with one difference, he said: 8216;8216;It feels like I have already seen it.8217;8217;

The New York Times