A powerful earthquake off of southern Sumatra island in Indonesia has triggered a tsunami warning this morning throughout the Indian Ocean Basin.

According to the AP [1]:

The undersea quake had a preliminary magnitude of 7.9 and hit at about 6:10 p.m. (7:10 a.m. EDT), the U.S. Geological Survey said. It was centered 65 miles southwest of Bengkulu, on Sumatra island, at a depth of 9.7 miles, the USGS said.

The Pacific Tsunami Warning Center issued a tsunami warning for wide areas of the region.

''Earthquakes of this size have the potential to generate a widespread destructive tsunami that can affect coastlines across the entire Indian Ocean Basin,'' it said, warning that waves could hit Indonesia and Australia within an hour, and Sri Lanka and India within three hours.

Unfortunately for the people of the Indian Ocean Basin, an early warning system devised after the Asian Tsunami of 2004, which wreaked a lot of the basin and killed nearly 230,000 people, won't be completed until late 2008.

Robert Elliot wrote about these "tsunameters" [2] in this month's issue [3]of Security Management:

 The National Oceanic and Atmospheric Administration (NOAA) joined the Thai government a few months ago in launching the first Deep-ocean Assessment and Reporting of Tsunami (DART) buoy station halfway between Thailand and Sri Lanka, at 9 degrees north lattitude and 89 degrees east longitude. A second will be placed between September and November of this year off of Indonesia. A total of 22 buoys will string along the Sumatra fault line when the project is due to be wrapped up at the end of 2008.

It usually takes an earthquake measuring seven or more on the Richter scale to generate a tidal wave, says Curt Barrett, director of the Indian Ocean Tsunami Warning System for NOAA.

For now, it's just a matter of waiting and taking to higher ground for those affected in the hopes the warning will prove purely cautionary.

For more on the earthquake, read this article [4]from CNN.com.

UPDATE: According to the AP [1], the earthquake was more powerful than previously reported:

The 8.2-magnitude quake off Sumatra badly damaged buildings along the coast and could be felt in at least four countries, with tall buildings swaying as far as 1,200 miles away.

The earthquake also killed seven, injured 100, and triggered "a small tsunami that hit one city on the island of Sumatra, authorities said."