The new underwater search phase for MH370 to start next month is going to be difficult, with mapping revealing treacherous mountains, volcanos and deep valleys with depths to 6000m.
The plane disappeared on March 8 with 239 passengers and crew. The only link to its whereabouts was hourly satellite signals picked up by British communications company Inmarsat.
More than 45,000sqkm of the ocean floor of the high-priority search area of 60,000sqkm, 1800km to the west of Perth, has been analysed and mapped and the Australian Transport Safety Bureau expects this phase to end mid-next month.
Two ships, the Dutch-owned Fugro Equator and the Chinese naval vessel Zhu Kezhen, are assembling the bathymetric (depth) map that is being processed into a seamless usable form by Geoscience Australia to support the underwater search.
This month the ATSB, which is leading the multi-national search, also awarded Fugro the contract for the deployment of two specialist vessels, equipment and expertise for the search.
Fugro will use the Fugro Equator and the Fugro Discovery, both fitted with specialist deep-tow survey systems for the work.
The Australian Government has allocated $60 million to the ATSB to carry out the search, which could take up to a year, but it is expected the Chinese and Malaysian gov-ernments will share the cost.
Fugro Survey project director Paul Kennedy said the search would be difficult.
"There are areas that are benign and are going to be fairly straightforward," Mr Kennedy said.
"But then there are some areas that we know are going to be really hard work.
"There are some huge valleys between big mountains, and it's going to be really hard to tow our device through those areas.
"We can do it, it's just going to take a bit longer."