The New York Times
January 7, 2005
TIDE GAUGES
Tsunami's Ripples, Unnoticed, Washed Along Atlantic Coast
By ANDREW C. REVKIN
The tsunami that ravaged countries all around the Indian Ocean also hit the eastern United States, though only the tide gauges noticed.
A tide gauge at Atlantic City recorded the passage of a "train" of waves, just under nine inches from crest to trough, 32 hours after the earthquake struck off Sumatra's west coast on Dec. 26, said Dr. Alexander B. Rabinovich of the Canadian Institute of Ocean Sciences in Sidney, British Columbia. A gauge at Port Canaveral, Fla., recorded 13.4-inch waves 24 minutes later.
Dr. Rabinovich has been spearheading an international effort to chart the course of the fading ripples from the devastating tsunami set off by the earthquake.
The tsunami was so powerful that it swept around the world over the next 36 hours, with its last residual waves perceptibly jostling tide gauges from Russia's remote northeastern Pacific waters to the North Atlantic, scientists said yesterday.
The tsunami ripples would have been imperceptible to Floridians, mingled among the other sloshing of waters there, but were clearly discernible in the data, Dr. Rabinovich said. Other Atlantic gauges detected the waves in Bermuda and the Virgin Islands, he said.
The evidence of the tsunami's passage in the Atlantic is particularly significant, seismologists and oceanographers said, because data on how quake-generated waves move there are scant compared with information available for the Pacific.
The newly discovered records of the Atlantic waves from the Sumatran earthquake should help improve computer simulations of tsunami behavior in the Atlantic, said Dr. Vasily V. Titov, a tsunami expert who works for the National Oceanic and Atmospheric Administration in Seattle. Such simulations can help scientists predict where tsunamis generated in the Atlantic might strike, he said.
The signal of the tsunami's quiet journey once it left the Indian Ocean was detected almost immediately in the Pacific Ocean, where 90 percent of tsunamis occur and tide gauges are specifically designed to catch trains of waves generated by underwater earthquakes, scientists said.
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