MH370 The search area for Malaysia Airlines Flight MH370 has moved further south, in the southern Indian Ocean, closer to Perth, Australia.

Based on maps provided by the Australian Transport Safety Bureau (ATSB), the new search area is approximately 1,000 kilometres south-west of where underwater search operations were conducted in April and May using underwater drones and pinger locators.

This area was also the same area where surface searches were conducted from March 28 (Day 21) until April 2 (Day 26), after the first major shift in the south Indian Ocean search areas.

Announcing it this today, Australian Deputy Prime Minister Warren Truss ( left ) said that the area is still along the ‘seventh arc’, where satellites last communicated with the aircraft.

This followed review of existing information by international experts, he said.

“Specialists have analysed satellite communications information - information which was never initially intended to have the capability to track an aircraft - and performed extremely complex calculations,” Truss said.

“The new priority area is still focused on the seventh arc, where the aircraft last communicated with satellite. We are now shifting our attention to an area further south along the arc based on these calculations.”

Truss added that Malaysia and Australia is still working on a memorandum of understanding that outlines the area of cooperation between the two countries, including financial arrangements.

Bathymetric surveys are still ongoing using a Chinese navy vessel and an Australian-contracted vessel, in order to pave way for the next round of underwater search operations that is slated to begin in August and will take months to complete.

Searchers have found no trace of the Boeing 777-200ER aircraft so far, after it disappeared on March 8 while carrying 239 passengers and crew from Kuala Lumpur to Beijing. Today is Day 109 since the flight.

The ASTB has also released a 58-page report today detailing the search operation so far and the considerations taken in determining the search area, such as assumptions made, leads that were dismissed, and data that were analysed.

It says the refinement of its analysis, which started in April, is still ongoing and may result in further changes in the search area.

The search area announced today is the aggregate of the result of five independent analyses.

Search area is 650km long and 93km wide

As it stands, the priority search area (marked orange in map above) is 60,450 square kilometres in size, measuring 650 kilometres long and 93 kilometres wide.

The medium priority area (marked blue) surrounding the priority search area is larger still, measuring 240,000 square kilometres. For comparison, Malaysia’s entire land area measures about 330,000 square kilometres.

“This (orange) area is intended to be the priority area for deployment of the underwater search assets obtained through the request for tender (RFT).

“Should additional assets become available, then underwater sections in the medium (blue) area may also be searched,” the report said.

The RFT mentioned in the report refers to Australia’s ongoing open tender process to hire contractors to conduct the search operation.

The report explained that the large search area is the result of the limited data available for determining MH370’s probable crash site.

In addition, it said the radio frequency of the satellite ‘handshakes’ between the aircraft and a communications satellite overhead - which is the main lead in the search - is “very sensitive”, with small changes in the measurements resulting in a large shift in the search area.

“A 10 Hertz variation in the fixed frequency bias can result in the derived flight path at the arc moving 1,000 kilometres,” the report said.