The search for the missing Malaysia Airlines plane has shifted after data suggested it was travelling faster than previously thought.
Analysis of radar from before contact with flight MH370 was lost indicated the plane was burning up fuel more quickly and may not have travelled as far south over the Indian Ocean.
The Australian Transport Safety Bureau described the data as the "most credible lead to where debris may be located".
Search teams have been relocated to scour an area 685 miles northeast of the zone they had been operating in.
Some 10 aircraft, including nine military planes, are involved and six ships are being sent to the region.
Experts will also trawl through satellite images of the new search zone to identify any possible crash sites.

The development comes after images from a Thai satellite showed 300 objects ranging from two to 15 metres in size scattered in the sea about 1,700 miles southwest of Perth.
A French satellite spotted more than 120 objects floating in the ocean, while Japan is also reported to have captured aerial images of 10 items.
It is not known whether any of the objects are from the missing Boeing 777, which disappeared on March 8 as it flew from Kuala Lumpur to Beijing.
Search teams are using 10 planes in an attempt to find missing flight MH370 The plane is thought to have crashed with the loss of all 239 people on board after flying thousands of miles off course.
Ahmad Jauhari Yahya, chief executive of Malaysia Airlines, said events of the past week, which included telling passengers' relatives the jet had crashed in the Indian Ocean, had been "difficult for everyone".
"Ever since the disappearance of flight MH370, our focus has been to comfort and support the families of those involved and support the multi-national search effort," he said.
"We will continue to do this, while we also continue to support the work of the investigating authorities."
Prayers and messages of support left on a wall at Kuala Lumpur airport He added: "Whilst we understand there will inevitably be speculation during this period, we do ask people to bear in mind the effect this has on the families of all those on board.
"Their anguish and distress increases with each passing day, with each fresh rumour and with each false or misleading report."
The search for the missing plane resumed after it was suspended earlier this week because of poor weather off the coast of Australia.
Heavy rain, strong winds and low cloud caused reduced visibility and forced aircraft to turn back.
Distraught relatives of the 150 Chinese passengers on board the plane continue to voice their anger and frustration at the speed of the investigation.
Some Chinese insurance companies have started paying compensation to the families, according to the state news agency.
The open seas are relayed onto monitors as the plane flies over
Airforce spotters work in shifts of 20 minutes and scan side to side
The search area is four hours from Australia
Pearce airforce base near Perth is the hub for the air search operation
Ukraine soldiers patrol near the Russia border in Kharkiv
Another weather system is moving in to the search zone. Pic: bom.gov.au
A Japanese P-3 Orion has been out searching for debris
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The Chinese military plane lands after spotting the 'suspicious' objects
There have been several sightings by planes and satellites of objects
A Chinese mother writes a message to her son who was on flight MH370
The southern corridor and the area of ocean being searched 
A Chinese satellite spotted this potential debris on Saturday
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Rescue teams gather to search for the missing
The slip blocked the highway