The next phase of the hunt for missing Malaysian jet MH370 will move hundreds of miles south, officials have said.
The search will focus on an area 1,800km (1,100 miles) off the city of Perth, Australian Transport Safety Bureau (ATSB) chief Martin Dolan said.
Nearby areas were previously surveyed from the air, but the undersea hunt was directed north after pings were heard.
The jet vanished en route from Kuala Lumpur to Beijing on 8 March with 239 passengers on board.
Experts had hoped that the pings detected shortly after the plane vanished were from its flight-data recorders.
But after weeks of searching the ocean floor, it was concluded that the noises were unrelated to the plane.
Analysis: Jonathan Amos, science correspondent, BBC News
The new search area(s) that the ATSB promise to announce shortly must be tied to the ocean-bed mapping now being conducted by survey ships. Their information is critical to guiding underwater sweeps. Without proper depth data, you cannot choose the most appropriate submersibles to look for MH370 wreckage.
The Australian authorities tell me that the Dutch-owned Fugro Equator is currently working in an area located along the arc where Inmarsat made a seventh and final connection with the lost jet.
China’s Zhu Kezhen is currently in transit and should arrive on station within hours. It will use its echosounder equipment to map an area to the north of Fugro Equator. Together, these ships will describe the exact shape of the sea floor. In places, it is thought to be more than 6km deep.
Search teams have now returned to the initial satellite data to frame the new search area.
“All the trends of this analysis will move the search area south of where it was,” Mr Dolan said.
“Just how much south is something that we’re still working on.”
They expect to make an announcement next week on exactly where the search will take place.
He said it was unlikely the new focus would be as far from land as the aerial surveys had been.
UK firm Inmarsat told the BBC this week that their data had pointed to a “hotspot” – a crash zone of highest probability – to the south-west of the recent undersea search.
But Inmarsat’s analysis is just one of several being used within the investigation team.
Before search teams can start looking for the plane, the seabed will be mapped.
This is being done by Chinese and Dutch vessels.
The ocean in this part of the globe is more than 6km deep in places, and the survey is likely to take three months to complete.
Many of the relatives of the missing passengers have been frustrated by the lack of progress in the search.