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Latest instalment to the DOI archives -

Courtesy Mike Chillit, who you will see has been very busy...   

The Drift Buoy Clock
Posted on August 25, 2016 by Mike Chillit — Leave a reply

I have endeavored to identify drifters that behaved in a manner similar to the debris we now have in the hope of harnessing that information to more precisely determine where the debris may have originated.

I have identified 17 drifters out of a total of 194 that washed up on land somewhere in the south Indian Ocean basin. That is about all we know about MH370 debris at this point: it went in the water on March 7, 2014 and washed up thousands of kilometers to the west about 15 months later. None of those dates are very precise because neither Malaysia nor Australia has made any effort at all to locate debris on beaches across the south Indian Ocean. We are fortunate; families are fortunate, that people like Blaine Gibson took it upon themselves to search a few beaches within their private means, and found important parts of the aircraft.

So, we know when that debris went into the water, but we don’t know exactly where it washed up on various islands or shores that have so far been scoured (a small percentage of those that need to be examined).

The flaperon that washed up on Reunion Island is probably the best estimate of the time required to get there from wherever it originated. We know the flaperon was physically retrieved and taken into custody on July 29, 2015. There were suggestions at the time that it had been tossing in the surf as far back as late May, but we have no confirmation of that. The rocky, steep shores of Reunion Island certainly make it credible to believe the flaperon predated the July 29 date, but by how much we can only guess. I typically place it there a month before it was taken into custody, June 2015. We are not doing precision work, we are trying to come up with reasonable estimates to enhance our search for the plane.

Using June 2015 means I believe it took the flaperon about 15 months to make the journey from wherever it started (March 2014 to June 2015). And we have both anecdotal and hard evidence of a small pleasure boat being blown from the Exmouth area to the Comoros Island area in 13 months shortly before that. A possible difference is that the boat may have had more exposure to wind than the flaperon. We just don’t know.

France concluded the flaperon drifted partially above the water line due to peculiarities with its specific gravity and buoyancy. Given that information, it is entirely plausible that the flaperon may have indeed been in the surf up to 3 months longer, but I will still use 15 months for my estimate to begin examining the issue.

So the next question that comes up, since we have drifter data that allows us to be fairly specific about drift times during the same time period is: just how long does it take to drift from various places in the east Indian Ocean to reach Reunion Island?

This answer is not as difficult as it may seem. I started with 1,903 NOAA drifters deployed all over the south Indian Ocean between 1979 and this past March. There were well over half a million time, date, and location records associated with those drifters, allowing me to get a robust estimate of drift time.

There is more than one way to estimate drift time, by the way. NOAA’s interpolated data sets include an estimate of drift calculated in centimeters per second, cm/s. That is a useful metric, but also misleading if not used carefully. For example, using that NOAA drift metric results in a drift estimate of 32 km per day, or more, on average. That would be fine if that was what we were interested in knowing. But that isn’t what we need. That metric includes a lot of meandering travel that does not in any way help us solve something like the flaperon drift problem. We want to know the time it takes to get from point A to point B.

A better metric for this particular inquiry is, How far did the buoy drift per day relative to its final destination? When we approach it that way, we need the starting and ending GPS for each drifter, and the number of days in the interval. That turns out to be 12 km per day for this batch of 1,903 buoys. However, within the mix is a range of between less than one km per day to more than 122 km per day. So, I elected to use the median value, which is 8 km per day, 240 km per month. Hand grenades and horseshoes perhaps, but a start.

With that information, I created range rings around Reunion Island. Each ring was 720 km from the next, which is the distance it appears drift will move toward its final destination every 3 months. The following chart shows how that looks.



Drifter #60658110 traveled 4,906 km. If it had ended up at Reunion Island instead, it would have traveled a straight-line distance of 4,451 km. It is important to know that the flaperon appears to have been an “outlier”. That is, only one of the drifters NOAA has released since early 2014 have even come close to Reunion Island, and it was clearly an outlier (drifter #133652). Storms and passing vessels can make strange things happen.
Referring to the chart above again, the fifth ring out approaches Cocos Islands, but still ~4 months away. The difference for that drifter was Cyclone Jack right out of the gate.

We don’t have to focus on the Cocos Island area to use the chart. The same 5th ring intersects the Seventh Arc in the heart of the search area. But what I have to do to the chart yet is add a variable scale. Nothing drifts to Reunion Island from the search area. But some of it drifts north toward Java Island and then west. It takes a long longer.

While I have been unable to find anything relevant to MH370 that drifts from the Perth Australia area to the Mascarene Island area (much less 20+ drifters or pieces of aircraft debris), this is hardly an exact science. It is a crude tool to be sure, and we have to try to use it within its limitations.

I will continue to work on this, but it helps confirm my suspicions that a far more likely place to refocus the search is a bit northeast of Cocos Islands. It isn’t just the debris we have now found that tells us that. It is also the debris that has never appeared anywhere else. Had it come down east of Cocos Island, parts of it would have certainly washed up on that Island, and probably on northwestern Australian beaches, long before now.

Next from over on the AA&MH370 thread we have Ventus putting some serious QON for Senator NX & Co to put to Hoody & Foley at next Estimates...

A few thoughts, from an old head, for Nick-Z and associates.

The Drifteron Project obviously did not just magically "pop-up" the other day.

It had to have been conceived, reviewed, approved, and funded.
All of which takes time, lots of time.
It must have had a significant "gestation period", many months, perhaps well more than twelve of them.

The initial concept proposal was germinated in someone's head.
Whose I wonder, where and when ?
Was he or she in the ATSB, DSTG, CSIRO, ANU, Geo Sciences Aus, or elsewhere ?

Who reviewed the proposal for technical merit and / or feasibility ?

Who approved the project, where and when ?

Who funded the project ?   Defence, ATSB, AMSA, CSIRO, other ?
Which "vote" did it come out of, under Finance Reg (forty something - it has been so long, was it 42) ?

Then the drifterons had to be actually designed and constructed.

Who actually designed them, where and when ?
What were the design requirements and performance parameters ?
What were the acceptance standards ?
Who determined them ?

Who actually built them, where and when ?
Who inspected, tested, and accepted them ?

When were they actually delivered to ATSB Stores, and by whom ?

What is the intended deployment time frame, location(s) and ongoing operational concept ?

How will they be deployed, by ship or by air-drop ? (Presumably by ship)

Who will deploy the Drifterons and mated GDB's ?  
Defence ?  Navy or RAAF ?
CSIRO ?  Their own vessel, or by a "dedicated contractor", or by multiple "vessels of opportunity" ?
ATSB ? (as per CSIRO).
Other ?

Who will track, and recover, and redeploy, both the GDB's and Drifterons ?

Who will get the tracking data, and what will they do with it ?
Will the data be made public in real time ?
Will it be "free to cyberspace" ?

I "really" do want to know.

MTF...P2