Indian Ocean sea floor unmapped

Any attempt to retrieve the wreckage of doomed flight MH370 will have to navigate an uncharted chain of giant underwater volcanoes, an Australian marine geologist says.

Robin Beaman from James Cook University said the active search zone in the Indian Ocean lays above a sea floor with an average depth of 3000m that has not been mapped in detail.

FULL COVERAGE: The search for MH370

He told Fairfax Media any recovery operation would first require extensive 3D mapping of the area, likely by ships with deep ocean multibeam echo sounders.

Such devices can map a sea floor by sending out sound pulses in the shape of a fan directly under the ship and on either side.

But the only Australian ship capable of charting such a depth, the RV Southern Surveyor, was decommissioned last December, Dr Beaman said.

Its replacement was still being built in Singapore, he added.