The suspected debris from Malaysia Airlines flight MH370 was sighted above a giant undersea chain of volcanoes, says a leading Australian marine geologist.
Robin Beaman, from James Cook University, said that any attempt to retrieve any potential wreckage from the bottom of the southern Indian ocean would require extensive 3D mapping because so little of the sea floor has been mapped in detail.
However, Australian authorities do no have the capacity to chart depths of 3000 metres, which is lower than the average depth of the Indian Ocean, because the only government vessel with the ability to do so was decommissioned in December, Fairfax reports.
A replacement for the decommissioned RV Southern Surveyor is about to undergo sea trials, according to Dr Beaman.
"It's bad timing really. Australia has no capability of mapping these depths," he said.
He said that debris spotted on by satellites and aircraft are just kilometres from a large chain of active underwater volcanoes in the Southeast Indian Ridge.
"On the flanks of the ridge, which is very likely where any crash zone occurred, there has been virtually no.. mapping apart from the odd strip," he said.
"It's all going to have to be remapped, there's no doubt," he said, adding that the complex terrain of the ridgeline would make it difficult to spot debris.
Weather adds to searchers woes
Debris from MH370 is expected to wash up along the WA coast over the next few months as search crews race against the impending winter weather to locate the Boeing 777.
The herculean task of locating MH370 will be the most complex international effort in aviation history and it may be years before the wreckage is found.
It took almost two years to find Air France 447 and that was in calmer mid-Atlantic waters, after debris was found six days after the crash in 2009.
According to the lead investigator of the AF447 crash Alain Bouillard, searchers face a “colossal task” that is “far, far harder” than the two-year search for the Air France plane.
Mr Bouillard said the location of MH370 was “one of the most hostile environments in the world”.
However, searchers were expected to learn from the lessons of the AF447 recovery, observers said.
In that recovery, a team led by the Woods Hole Oceanographic Institution operating full ocean depth autonomous underwater vehicles (AUVs) used sidescan sonar to locate the main debris field at a depth of 4000m. More than 104 bodies were recovered from the wreckage.
Fifty bodies were picked up earlier in the sea and 74 were never found.
Without doubt the biggest challenge in locating and recovering MH370 will be the sea condition with winter swells as high as 25m.
The location of the MH370 is at the convergence of three currents — the South Indian Ocean Current, which becomes the West Australian Current, the Leeuwin Current and the Antarctica Circumpolar Current.
Those underlying currents work below the sea swells that move in a broad easterly or north-easterly direction depending on the frontal activity.
Oceanographer Dr Erik Van Sebille told Channel 7’s Sunrise the currents are extremely strong at up to 2cm a second and would get worse. “And they are only going to get worse”
“The current varies every day and has vortices and debris can move 100km a day (in any direction).”
With the new satellite data from Inmarsat, along with increasing amounts of drift data, searchers will try to zero in on MH370’s initial impact area.
An Australian warship is expected to be tasked with deploying US locator equipment. Yesterday a 5m long 800kg Bluefin drone and a Towed Pinger Locator arrived in Perth on a special G550 jet from the US.
MH370’s black boxes are key to solving the mystery of why the plane veered so far off course.
In theory, the black boxes containing flight data and cockpit voice recordings will continue emitting tracking signals for about another two weeks, with an average audible range of 2km to 3km.
“Picking up a signal from the beacon seems an outside chance,” a member of the team that hunted the black boxes from Air France flight AF447 said that crashed in the Atlantic in 2009
In that accident, the signals were not heard at all because one transmitter failed and the other fell off and was never found.
The sea bed where MH370 is thought to be is up to 5km deep. But the cockpit voice recorder tapes only the last 30 minutes of the pilots’ conversation and investigators will never hear what happened around the time the plane first changed course.