[Peetwo]

CSIRO revives debate for 7th Arc North search -   

By Lucy Marks, via the other Aunty today... :

MH370: Search for missing flight narrows to specific area along 'the seventh arc'

By Lucy Marks
Video: The search for MH370 narrows (ABC News)

The 2014 disappearance of Malaysian Airlines flight MH370 remains one of the greatest mysteries in aviation history.

Now, scientists believe they've narrowed down the potential search area to a fraction of space that was searched in December 2016.

CSIRO researchers say they're more confident than ever in the precise location, which has been missed by the work that scoured the ocean floor, as well as the aerial surveillance.
But how did they get to this point?

Investigators have known for some time that the plane crashed somewhere along a line known as the seventh arc, to the west of Western Australia.

They came to this conclusion by looking at the plane's last transmission on March 8, 2014, and then examining a large search area in the Indian ocean, which was partially based on how far the plane could have glided.

Photo: The plane crashed somewhere along this line, known as the seventh arc. (Supplied)

That position was at latitude 39 to 36 degrees south along the seventh arc, but nothing turned up in the hunt.

Last December, they thought an area that spanned 25,000 kilometres at latitude 32 to 36 degrees south, pictured below outlined in orange, was the right place to look.

Within that new region outlined in December, they have since narrowed it down greatly to a relatively small area near 35 degrees south.

The most recent research by the CSIRO has strengthened scientists' belief this is where the plane may be found.
Play (2.3 MB)
GIF: MH370's known flight path, the search area, and where the debris washed up

Is there hope of finding MH370?

"We think we know quite precisely where the plane is," Dr David Griffin from the CSIRO told a national marine conference in Darwin.

He said while the physical search was suspended in January this year, the work had continued in Australian laboratories, modelling ocean drift.

Photo: The purple area was the original search area, and the orange area is the updated position. (Supplied: David Griffin)

What's ocean drift modelling?

That's a scientific method that involves looking at what the ocean currents were doing on the day of the crash, and matching it with where debris has and hasn't landed, such as the piece of wing, called the flaperon, which landed on Reunion Island off the eastern coast of Africa.

What we know about MH370


Mystery still surrounds the case of Malaysia Airlines flight MH370 with investigators still to determine how the plane ended up in the Indian Ocean.

It can direct scientists towards where the plane might have landed based on where the debris turned up.

Dr Griffin said another piece of debris washed up in Tanzania, and apart from the location of the discovery being a vital clue, the specific damage to the piece of the plane was able to tell investigators the plane had a fast and hard landing.

It's a theory boosted by the fact the flaperon, which is designed to reduce speed, hadn't been deployed either.

The observation that no debris has washed up on the West Australian coast is also an important clue.

It means the ocean current must have been flowing in a particular direction — and not towards Australia, which Dr Griffin says leads back to only one place on the arc where the plane had crashed. Again, that's 35 degrees south.

"There's a strong current crossing across the seventh arc at [latitude] 35 degrees south, so we think the plane crashed into that current going to the north-west," Dr Griffin said.

"That explains why debris didn't arrive in Australia."

The scientists used satellite technology to precisely calculate the height of the sea level, down to the centimetre, which is a key to figuring out where the ocean was flowing on March 8, 2014.

A detailed map of the sea level can reveal where the ocean currents are and what speed they're going.

"And so that's the basis of how we know this current was flowing across the seventh arc at this time," Dr Griffin said.

Where to from here?

The physical search of the ocean floor and aerial surveillance has already cost $180 million. It was suspended until authorities said they needed "credible evidence" to resume searching.

The CSIRO has handed over this work to the appropriate authorities, who will decide whether to resume the search for MH370.

Since April, when the last update on the flaperon modelling was reported, the scientists have said they're more confident than ever they're on the money.

"Since then we've been further scrutinising that work, and being a bit bolder to realise that 'yes, the answer has been there since December', that 'yes, actually there really is only a very small number of places which are consistent with all the evidence'."

Photo: CSIRO researchers lower an actual Boeing 777 flaperon into the water. (Supplied: CSIRO)

MTF...P2
Ps Funny how the ATSB doesn't get mentioned once in that article...