The WSJ reports that just getting the required robotic submersibles to the site would take a month, and once they arrive it could be one to six months before they find the missing airliner, says David G. Gallo, director of special projects at the Woods Hole Oceanographic Institution. Despite this daunting task, he expressed confidence that undersea-exploration specialists would succeed.

The remote area of the southern Indian Ocean where Australian-led search operations are focused lies above part of the Southeast India Ridge, which runs east-west and slopes away from a peak roughly 2,500 metres (8,200 feet) under the surface to a depth of some 4,000 metres (13,000 feet). According to Gallo, the terrain is relatively easy to survey by deep-sea standards compared to the area beneath the south Atlantic Ocean where Air France Flight 447 was located after it crashed in 2009, as reported in WSJ.

“This would not really be as big a challenge as with Air France 447, which went down in much more ridged terrain,” he explained. “This is more gently sloping.”

Oceanographers are able to use mathematical models to calculate where an aircraft originally entered the water once debris is found, Mr. Gallo said. They then either deploy robotic submersibles equipped with sonar to scan the sea floor or use high-resolution cameras to build up a detailed picture of the area, according to the WSJ.

The paper also quoted Gallo as saying this technology could find the aircraft even if the plane’s “black box” is no longer sending out signals.

However, he cautioned that the operation would not be “routine”.

“There’s very few pieces of equipment in the world that can do this,” he said, adding that he is “imploring” relevant authorities to start planning for an undersea search now, given how long the process would take.