Major Earthquake, Sumatra

A major earthquake struck off the south-western coast of Sumatra at 11:10 p.m. last night, New Zealand time.

The magnitude 8.2 quake was located under the Indian Ocean 130 km south-west of Bengkulu, Sumatra (620 km west-north-west of the Indonesian capital, Djakarta) at a depth of 30 km according to preliminary data.

The Pacific Tsunami Warning Centre issued a bulletin at 11:35 p.m. New Zealand time on Wednesday 12th September 2007 indicating that a tsunami threat did not exist for the Pacific. However, the bulletin pointed out that the PTWC monitors a limited number of sea level gauges outside the Pacific Ocean, so it could not quickly detect a tsunami if one was generated.

The quake is the largest in the world this year, slightly stronger than the magnitude 8.1 quake near the Kuril Islands in January, an 8.1 near the Solomon Islands in April and a magnitude 8.0 event near the coast of Peru in August. However, at this early stage, estimates of the quake’s size range between magnitude 7.9 and 8.2 and further investigation will refine the final value.

Authorities in the area are naturally jittery since the magnitude 9.1 quake and tsunami in the Sumatra-Andaman Islands area in 2004 which killed more than 280,000 people. The Sumatra-Java area has experienced 3 quakes of magnitude 7 or greater since the event of Boxing Day 2004.

At 00:30 Thursday 13th (NZST), the PTWC issued a bulletin advising that an Indian Ocean-wide tsunami watch was in effect, following the detection of a 35 cm wave by a wave gauge at Padang, Indonesia at 21 minutes past midnight. It is still not known whether a destructive wave was generated near the quake’s epicentre.

Early news reports suggest that tall buildings in Djakarta swayed during the quake, and some buildings in Padang and Bengkulu have collapsed.

[Compiled from data supplied by the US Geological Survey and its contributing agencies, and the U.S. National Oceanic & Atmospheric Administration’s Pacific Tsunami Warning Centre.]

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