MH370 hunt resumes

The first of three special search vessels contracted jointly by Malaysia and Australia arrived on Sunday in a southern swathe of the Indian Ocean where MH370 is thought to have gone down after disappearing on March 8, the Australian Transport Safety Bureau (ATSB) said.

The GO Phoenix, provided by Malaysia, will be joined by the Dutch survey vessel Fugro Discover by Friday. Another Dutch ship, the Fugro Equator, is due to arrive at the end of October, officials said.

Together, the specially equipped ships will use so-called "towfish" - underwater vessels with mounted sonar devices - to scan the rugged ocean floor, sometimes at a depth of around 6.5 kilometers (4 miles).

If the sonar spots something of interest, the towfish will be brought to the surface, fitted with a video camera, and lowered once more toward the seabed.

Mapping the seabed

The new search phase was preceded by a break of four months, during which analysts carefully mapped the sea bed in 60,000-square-kilometer (23,166-square-mile) area where the plane is believed to have run out of fuel and crashed with 239 people on board.

Investigators used transmissions between the Boeing 777 and satellites to determine the most likely crash site. It lies some 1,800 kilometers (1,118 miles) southwest of the Australian city of Perth.

That area was largely unknown to scientists before the mapping process began in May. Two ships used multibeam sonar devices to create preliminary three-dimensional maps.

The seafloor was found to be riddled with deep crevasses, mountains and volcanoes - features which could damage the pricey, delicate search equipment which will be towed just 100 meters (330 feet) above the ocean floor.

'Cautious optimism'

Malaysia and Australia, the two countries with the most passengers on board the ill-fated aircraft, are each contributing 60 million dollars (47.94 million euros) to the search effort.

Mark Dolan, the chief commissioner of the ATSB, which is leading the operation, told the Guardian newspaper that he was only "cautiously optimistic" about the selected search in view of the huge area to be covered.

"In all sorts of ways we're operating towards the limits of the technology that's available," Dolan said, adding: "We're doing this primarily because there are familes of 239 people who deserve an answer."

The fate of the Malaysia Airlines plane, which vanished during a flight from Kuala Lumpur to Beijing, remains one of the world's most mysterious aviation disasters.

tj/ipj (AP, dpa)