Focus of Underwater Search for Missing Flight MH370 Shifts South

So far over 106,000 square kilometers of the so-called ‘7th arc’ search area, pictured in shaded gray, have already been surveyed (Surveyed area in yellow). Graphic courtesy ATSB

By David Fickling

(Bloomberg) — Underwater vehicles will search for the missing Malaysian Airline System Bhd.’s Flight 370 further south than previously expected, after analysts revised their views of the plane’s last movements.

Priority regions for a deep-sea sonar search “will most likely extend south of the previous ‘orange’ priority area’,” the Australian Transport Safety Bureau said in a statement on its website. Three search vessels are preparing to start a yearlong scan of the ocean bottom for wreckage of the aircraft, which disappeared March 8 with 239 people on board.

The search in 6.3 kilometer-(3.9 mile) deep waters of the Indian Ocean off Western Australia aims to find remains of the Boeing Co. 777-200. The only clues to the aircraft’s final resting place have been data exchanges with an Inmarsat Plc satellite, which indicated it ditching along an arc of ocean west of Perth.

“Recent refinement to the analysis has given greater certainty about when the aircraft turned south into the Indian Ocean,” the Safety Bureau said on its website. The working group planning the search zones also had a better understanding of satellite ground station operations during the final flight of the Malaysia Airlines aircraft.

Malaysia Airlines is controlled by Khazanah Nasional Bhd., Malaysia’s sovereign wealth fund.

Bathymetric data models conducted in the search area have revealed newly discovered features on the sea floor, such as remnant volcanoes, ridges up to 300 meters high and canyons up to 1,400 meters deep. Graphic courtesy ATSB

The revised priority search zone extends to a latitude of around 35 degrees south, according to a map published online, compared with a southern limit of about 32 degrees south in a previous map published June 24.

The Malaysian-contracted GO Phoenix search vessel will arrive at the underwater search area on Oct. 1, and search for about 20 days, according to the statement.

Two vessels operated by Fugro NV under a contract with the Australian government are also heading to the search zone. The Fugro Equator will start deep-sea sonar searches around the end of October after a ship-based seafloor scan is complete and the Fugro Discovery will arrive in Australia around Oct. 2, where a crew and equipment will be mobilized.