Tsunami warning for Australian islands

A preliminary tsunami warning has been issued to residents of Christmas and Cocos islands following a massive 7.9-magnitude undersea earthquake off the western coast of Indonesia's Sumatra island.

The undersea earthquake, which hit at 6.10pm (2110 AEST), struck in the sea about 100 kilometres south-west of the city of Bengkulu, at a depth of roughly 15 kilometres

The quake was strongly felt in the capital Jakarta, some 600km away, where it caused tall buildings to sway.The Joint Australian Tsunami Warning Centre (JATWC) issued a potential tsunami threat warning at 9.44pm (AEST) on Wednesday saying that a tsunami could start affecting Christmas and Cocos islands from 7pm local time.The centre is seeking confirmation that a tsunami has been generated."People in coastal areas in threatened regions should move out of the water and away from low lying foreshore areas and should then listen for further advice from state emergency authorities," a JATWC statement said."Tsunami warnings will be issued, if necessary, by the regional offices of the Bureau of meteorology in affected states."
UPDATE

Residents of the Cocos and Christmas Islands braced for a tsunami after a SECOND EARTHQUAKE off the coast of Indonesia in 12 hours. The Bureau of Meteorology (BOM) warned a tsunami could hit the two islands off the coast of Western Australia just before 11am (AEST), but nothing happened and the warning was later cancelled. The Christmas Island based-administrator for both islands, Neil Lucas, said he was watching the ocean at the time any tsunami would have hit and nothing happened."The water was just dead flat. I was looking out the window at the wide expanse of water at the time it was predicted to come through here and didn't see a thing," Mr Lucas said. Nothing was reported at Cocos Island either, he said. Christmas and Cocos islands are largely protected from tsunamis because they sit on the top of huge sea mountains and the deep water saps most of the energy out of any surge, he said.
"We're just fortunate here that it's not really a big issue."Emergency services were on standby and residents told to identify a safe area on higher ground that could be quickly and easily reached. An earthquake, reaching 8.4 on the Richter scale, hit 130km off the coast of the Sumatran city of Bengkulu at 9.10pm (AEST) on Wednesday. The quake was followed by an aftershock slightly further north at 9.50am (AEST) on Thursday, measuring 7.9. Geoscience Australia project scientist Dr Jonathan Bathgate said the magnitude of the earthquake was significant and comparable to the quake in Peru last month that killed hundreds of people. "Last night's shock and the aftershock are both significant earthquakes in terms of magnitude," Dr Bathgate said. "With an earthquake of 8.4 you would expect significant damage associated with an earthquake of that size." Dr Bathgate said residents of the Cocos and Christmas Islands were told to stay away from the coast until the tsunami warning was cancelled.