Major Quake, Papua, Indonesia

A major on-shore earthquake struck the Irian Jaya region of Indonesia this morning, New Zealand time.

4th January 2009

A shallow magnitude 7.6 earthquake struck on-shore near the northern coast of Papua, Indonesia at 8:44 this morning, New Zealand time. The earthquake was located 150 km west-north-west of Manokwari, Papua, Indonesia (170 km east-north-east of Sorong, Papua, Indonesia) at a depth of 35 km, according to preliminary investigations.

The epicentre is 1335 km north of Darwin, Australia and Geoscience Australia has put a provisional magnitude of 7.7 (depth 0 km) on the earthquake, with the epicentre calculated to be on-shore close to the town of Waibeem (east of Koor) in the north-western part of Irian Jaya. This is in close agreement with the USGS calculation. Geoscience Australia estimates that the quake would have caused damage within 200 km of the epicentre, and would have been felt up to 2500 km away.

The Pacific Tsunami Warning Centre, which estimated the quake at magnitude 7.8, issued a bulletin for the event at 8:56 this morning New Zealand time, but the current load on the server prevents it providing the Pacific bulletin at this time. The bulletin issued for the U.S. West Coast and Alaska, where arrival times for any possible waves are between 13 and 18 hours after the quake, advised that a threat to the United States was not expected. However, the bulletin noted that local tsunami were possible near the epicentre of the quake due to underwater landslides triggered by the ground shaking.

Transit time for any wave arriving at New Zealand coasts is estimated to be 12 hours after the quake ”“ sometime around 8:30 tonight. In the absence of any significant waves being reported closer to the earthquake’s epicentre, it is likely that any tidal disturbance on New Zealand’s coasts would be minor.

The Japan Meteorological Agency issued a tsunami advisory at 9:05 a.m., calculating wave heights and arrival times for the Philippines and New Guinea. The estimated wave data was for precautionary purposes, pending the arrival of information about any tsunami activity that was observed. The bulletin estimated a wave of 1 metre height may have reached Berebere in Irian Jaya at 09:26 NZDT, half a metre at Madrid in the Philippines at 10:06, and half a metre at Vanimo, Papua New Guinea at 10:13.

An aftershock of magnitude 5.1 struck the area at 10:31 this morning.

[Compiled from data supplied by the U.S. Geological Survey, Geoscience Australia and Japan Meteorological Agency and their contributing agencies.]

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