MH370 spur to 'better ocean mapping'

 
Bluefin-21 The Bluefin-21 sub aborted its first dive because it was about to exceed its depth limits

Scientists have welcomed the decision to make all ocean depth data (bathymetry) gathered in the search for missing Malaysia Airlines flight MH370 publicly available.

A detailed survey of 60,000 sq km of seabed is to be undertaken to help refine the hunt for the lost jet.

The depth and shape of Earth's ocean floor is very poorly known.

Leading researchers say the MH370 example should be a spur to gather much better data elsewhere in the world.

The search has been hampered by the lack of a high-resolution view of the bed topography west of Australia.

This was apparent on the very first dive made by an autonomous sub investigating possible sonar detections of the aircraft's cockpit voice and flight data recorders.

It was forced to cut short the mission because it encountered depths that exceeded its operating limit of 4,500m. There are places thought to exceed 7,800m.

Australian Transportation Safety Board (ATSB) officials said this week that an area in the southern Indian Ocean the size of Tasmania would now be subject to a full survey using multibeam echo sounders (MBES).

A Chinese navy vessel, Zhu Kezhen, has already started on the project. It will be joined by a commercial ship in June, with the work likely to take three months.

Drs Walter Smith and Karen Marks have assessed the paucity of bathymetric data in the region in an article for EOS Transactions, the weekly magazine of the American Geophysical Union.

The pair work for the US National Oceanic and Atmospheric Administration (Noaa).

They say only two publicly accessible data-acquisition sorties have been conducted close to where search vessels made possible black box detections, and "both expeditions occurred prior to the use of modern multibeam echo sounders, so depth measurements were collected by single, wide-beam echo sounders that recorded on analogue paper scrolls, the digitizing of which is often in error by hundreds of metres".

Modern MBES uses GPS to precisely tie measurements to a particular location. The equipment can not only sense depth very accurately (to an error typically of 2%), but can also return information on seafloor hardness - something that would be important in looking for wreckage in soft sediment.

Just 5% of a vast region, 2,000km by 1,400km, which includes the search locality, has any sort of direct depth measurement, Smith and Marks say.

The rest - 95% - is covered by maps that are an interpolation of satellite data. These have a resolution no better than 20km. Maps of the arid surface of Mars are considerably better.

Ocean floor The depth numbers in the map are estimates, with 95% of the view built from satellite altimetry data

"The state of knowledge of the seafloor in the MH370 search area, although poor, is typical of that in most of Earth's oceans, particularly in the Southern Hemisphere," the pair write.

"In many remote ocean basins the majority of available data are celestially navigated analogue measurements because systematic exploration of the oceans seems to have ceased in the early 1970s, leaving the ocean floors about as sparsely covered as the interstate highway system covers the United States.

"When these sparse soundings are interpolated by satellite altimetry, the resulting knowledge of seafloor topography is 15 times worse in the horizontal and 250 times worse in the vertical than our knowledge of Martian topography."

Smith and Marks hope that the detailed survey work now being conducted in the search for MH370 will be a catalyst to gather better data in other parts of the globe.

High-resolution bathymetry has myriad uses.

"Better knowledge of the ocean floor means better knowledge of fish habitats. This is important for marine conservation, and could help us find biological resources including new medicines," Dr Smith told BBC News.

"It means also a better ability to assess the mineral resource potential of the seabed. And it means better knowledge of the obstacles to flow that cause turbulence and mixing in the oceans.

"We need this mixing and circulation information to make good models of future climate. All of these things depend on knowing the topography of the sea floor."

The Australian Joint Agency Coordination Centre, which disseminates all information on the hunt for MH370, confirmed that the MBES survey data would be publicly available.

"The bathymetry data gathered in the course of the search for MH370 will become the property of the Australian Government. Recognising the importance of that data, it will be made available to the public via both Australian and international databases," the JACC told the BBC.

Interpolation of ocean-floor shape by satellite

Measuring the seafloor graphic
  • Most ocean maps are derived from satellite altimeter measurements
  • Satellites infer ocean-floor features from the shape of the sea surface
  • They detect surface height anomalies driven by variations in local gravity
  • The gravity from the extra mass of mountains makes the water pile up
  • In lower-mass regions, such as over troughs, the sea-surface will dip
  • Limited high-resolution ship data has calibrated the satellites' maps

On Tuesday, all the raw satellite data from the London telecommunications company Inmarsat was also put in the public domain.

It was this information that led investigators to look for wreckage in the southern Indian Ocean.

 
Jonathan Amos, Science correspondent Article written by Jonathan Amos Jonathan Amos Science correspondent

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  • rate this
    +2

    Comment number 19.

    11.martoon196
    1 Hour ago
    free scales patents on semi conductor technology

    +++

    To which of Freescale's patent(s) do you refer? What is their significance to MH370?

  • rate this
    -1

    Comment number 18.

    Is this revelation of mapping data a wise idea, given the idiots who thought that Google Earth showed the debris?

  • rate this
    +10

    Comment number 17.

    If it had been shot down it would be on YouTube the same day. This plane was already doing weird things whilst it was still on the radar. The way "400 tons of metal just vanished" is by doing this; flying this far south and ploughing into the sea. Yes we have to find it, because people were entrusted to the most minutely detailed transport we have devised, and it was all switched off.

  • rate this
    +9

    Comment number 16.

    11.
    martoon196
    .

    Why continue the lie?

    ------
    The BBC reports the available facts of the story. The other sites you visit report their own fantasies as fact. Do you understand the difference?

  • Comment number 15.

    This comment was removed because the moderators found it broke the house rules. Explain.

  • rate this
    +5

    Comment number 14.

    "Why choose to conquer space when 7/10ths of our own world remain unexplored" - Stromberg, The spy who loved me.

    "Darling it's better, down where it's wetter, take it from me!"
    - Sebastian the crab, The Little Mermaid

  • rate this
    +5

    Comment number 13.

    Its bad enough trying to find the remote control when its lost in the home.

    Imagine that search area becoming oceanic in scale and as deep.

  • rate this
    -8

    Comment number 12.

    theres something not right about this episode.....something happened that is so bad it has to be kept 100% quiet....I suspect the plane was shot down by mistake....its inconcievable in this day and age that 400 tons of metal just vanished .

  • rate this
    -19

    Comment number 11.

    Hello BBC, you do realize this is the age of the internet don't you?

    We know about the call placed from a passengers phone in Diego Garcia, about islanders nearby seeing the plane fly low about free scales patents on semi conductor technology, how some key people went missing and how the US gov now owns key military information...

    Why continue the lie?

  • rate this
    +10

    Comment number 10.

    We talk about the ocean depths, but it is worth noting that the technologically advanced Swiss, who build deep sea subs, have not even properly mapped the floors of their own glacial lakes. Walensee, south of Zurich, is nearly 600 meters deep. i.e. 60 atmospheres.

    It used to be a roman trade route, so anything could be down there.

  • rate this
    +9

    Comment number 9.

    @1
    "The more they map it, the more some greedy corporation will want to mine it - perhaps best to leave the deep unknown, well, unknown."
    There are manganese nodules the size of cannonballs and other valuable material littering the deep ocean floor, just as there is gold in the rocks of Cornwall. It probably (like Cornwall) won't be mined because it costs far more than it would fetch.

  • rate this
    +9

    Comment number 8.

    Fundamentally this plane needs to be found, not just because it provides closure for the relatives, but because knowing what happened and preventing it in future is vital for the safety of every passenger who steps onboard a plane.

  • rate this
    +10

    Comment number 7.

    @3 JohnBA

    Actually the Royal Navy has been surveying the ocean floor for many decades, if not centuries

    it has been a major part of the Royal Navies job and the information is provided to whoever needs it


    http://www.naval-technology.com/projects/echoclasssurveyvesse/

    no doubt your lake of knowledge on this matter and Trident influences your comments

  • rate this
    +9

    Comment number 6.

    There have been more people walking on the moon than have been to the very bottom of our oceans. The difference between Earth sea level and the Vacuum of space is 1 atmosphere (1000 millibar mean). Going underwater, pressure builds at about 1 atmosphere every 10 metres, and the deepest spot in the oceans is about 10.9 Km deep. Most deep diving search subs can't get anywhere near that.

  • rate this
    0

    Comment number 5.

    Oops!! I think that was scales rather than 'sales'... :D This is exactly the problem with software, one mistake, one slip of the keyboard and a 10 becomes a 100 and we all die...

  • rate this
    +14

    Comment number 4.

    When you look at the sales on that map its clear why they haven't found this plane or its data recorders. The problem is that ordinary people simply don't understand scale or the size of the real Earth. - Its big, its very very big...
    We are talking about a needle in 10 or in 100 haystacks.. even assuming they do have the right search region.

  • rate this
    -9

    Comment number 3.

    :) Just think if we ditched trident we'd have a whole fleet of submarines essentially doing nothing, we could pass them quietly to some scientists to map the sea bed of the world and be a friendly neutral country that everyone likes because we map the seabeds and share our data openly.

  • rate this
    -8

    Comment number 2.

    pssst its over there

  • rate this
    -2

    Comment number 1.

    The more they map it, the more some greedy corporation will want to mine it - perhaps best to leave the deep unknown, well, unknown.

 

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