The search area for missing Malaysia Airlines flight MH370 has been shifted after a "new credible lead", the Australian Maritime Safety Authority (Amsa) has said.
New data indicated that the plane was travelling faster than first thought and so burned more fuel, reducing the possible distance it travelled south over the Indian Ocean.
As a result the search has moved to an area 684 miles to the north east, Amsa said - an area of about 198,000 sq miles and around 1,150 miles west of Perth, Western Australia. The ocean there is between 2,000m (6,560 feet) and 4,000m (13,120 feet) deep.
The move closer to land is significant in that it will take planes less time to get to the site, allowing them to be search for longer. The site is also now out of the Roaring Forties wind system, meaning improved weather.
The new advice was provided by an international investigation team in Malaysia and is based on analysis of radar data between the South China Sea and the Strait of Malacca before radar contact was lost.
Australian Transport Safety Bureau (ATSB) chief commissioner Martin Dolan said the information was the "most credible lead" to where any wreckage may be located, saying: "This is our best estimate of the area in which the aircraft is likely to have crashed into the ocean."
Five Chinese ships are on their way to the new site, and Australia's HMAS Success is expected to arrive there late tomorrow night, local time.
Weather conditions in the area have improved recently. Four aircraft are already over the search area, with six more to fly over it later, including planes from Australia, Japan, Korea, New Zealand, China and the United States.
A US-towed pinger locator and a robotic underwater vehicle have also been brought to Perth to help with locating and recovering the aeroplane's black box.
John Young, manager of Amsa's emergency response division, said the new information meant the search area had been refined and had now moved on from where satellite images earlier this week suggested there was debris in the ocean.
He dismissed questions suggesting that earlier searches had been a wasted effort, saying: "This is the normal business of search and rescue operations - that new information comes to light, refined analyses take you to a different place."
In a statement, Amsa said: "The Australian Transport Safety Bureau (ATSB), Australia's investigation agency, has examined this advice and determined that this is the most credible lead to where debris may be located."
The potential flight path may be refined further as further analysis yields new information, the ATSB said.
Satellites will now be moved to take images of the new search area.
Flight MH370 from Kuala Lumpur to Beijing went missing with 239 people on board on March 8, sparking an international hunt for clues to help find it.
Authorities in Thailand yesterday said one of its satellites had spotted 300 objects of various sizes suspected to be debris in an area about 1,675 miles south west of Perth. The objects were about 125 miles from the area where a French satellite spotted 122 objects on Sunday .
Planes and ships have been hunting unsuccessfully for more than a week for any sign of debris from the Boeing 777. There have been a number of suggested sightings, but no wreckage has been found.
In a statement on its website, Malaysia Airlines chief executive Ahmad Jauhari Yahya reiterated the company's sorrow at the loss of the plane.
He said: "T he well-being and feelings of family members are and have always been close to our hearts and minds.
"Ever since the disappearance of Flight MH370, Malaysia Airlines' focus has been to comfort and support the families of those involved and support the multi-national search effort. We will continue to do this, while we also continue to support the work of the investigating authorities."
Mr Ahmad Jauhari added that Malaysia Airlines would make arrangements to take family members to Perth if wreckage was found.
American Sarah Bajc - whose partner Philip Wood was among passengers on the flight - said regular changes in approach were "too heartbreaking" and said there needed to be a more Sherlock Holmes-style methodical investigation.
"I've stopped listening to the news. It is too heart breaking - there are so many false leads and then they change their minds and they do something else," she told BBC Radio 4's Today.
"It has proved better for my sanity to just wait for my contacts in the media to inform me if there's something real."
The search was losing "urgency", she suggested.
"We need to be spending our efforts using a logical and a methodical process to solve this. We really need Sherlock Holmes, someone who will look through all the dust and find the real string that is holding this entire situation together.
"We still have a lot to learn."
She said she still believed it was possible the passengers and crew were alive as no concrete evidence had yet been produced and there was some "intentional misdirection" by the authorities.
But she criticised families who were protesting and taking legal action.
"They are covering something up and I'm sure that we will find out in the future," she said.
"But I don't think we are spending our resources wisely pointing fingers and yelling and having fights and taking people to court. I am quite shocked and disappointed that that is the approach so many families are taking.
"The lawyers should go home and wait for there to be at least some sort of conclusion."