Sunday, July 24, 2005

In response to another major earthquake, near India’s Nicobar Islands (in the Indian Ocean, about 690 miles southwest of Bangkok, Thailand), government agencies briefly issued official tsunami warnings. However, it was later determined that the earthquake, although strong, was of a type which does not commonly spawn large tsunamis.

The U.S. Geological Survey’s National Earthquake Information Center reported that the earthquake occurred at 15:42:05 (UTC) on Sunday, July 24, 2005, and registered as a magnitude 7.2 earthquake. Its location is 7.926°N, 92.146°E

The Japan Meteorological Agency reported at 16:11 UTC that an earthquake had occurred at 15:42 UTC near the Indo-Chinese Peninsula (8.7°N, 92.1°E). The scale of this earthquake was estimated by JMA to be 7.3 on the Richter scale, and its seismic center near the Nicobar Islands in the Indian Ocean.

“There is a possibility of a destructive local tsunami in the Indian Ocean,” said the JPA, when it issued its warning. But that possibility did not come to fruition.

This was made clear in a report from the U.S. National Earthquake Information Center, which said in a bulletin that “No tsunami threat exists to coastlines in the Pacific, however earthquakes of this size sometimes generate local tsunamis that can be destructive along coasts located within a few hundred kilometers of the earthquake epicenter. As the center does not have sea level gauges outside the Pacific, they will not be able to detect or measure a tsunami if one occurs. It can be assumed the danger has passed if no tsunami waves are observed near the epicenter within an hour of the earthquake.”

The US Geological Survey’s Waverly Person told the BBC that the event was “unlikely to spark a tsunami”.

The Thai TV station MCOT was reporting at around 1:00 (local time, UTC+7) that everything was under control and there has been no confusion; in Phuket and Trang provinces, the sea level was reported to be at normal levels at that time. At 1:25 (local time), the Thai National Disaster Warning Center cleared the tsunami warning nationwide.

The top federal administrator of the Nicobar Islands, Ram Kapse, told Reuters news agency that there had been no reports of casualties or damage from any of the inhabited islands.