It’s not every day that you need to talk to one of the world’s leading experts on goose barnacles of the Indian Ocean, but today is one of those days, so I considered myself very fortunate to get in touch with Charles Griffiths, an emeritus professor of marine biology at the University of Cape Town and author of the seminal paper “South African pelagic goose barnacles (Cirripedia, Thoracica): substratum preferences and influence of plastic debris on abundance and distribution.”
I reached out to Dr Griffiths by email and he graciously answered my questions about the sea life found growing on the Reunion flaperon after I sent him a more detailed version of the picture above.
Is it possible to identify the species of barnacle growing on the debris?
In this case it is possible to identify this as being Lepas anserifera striata on the basis of the small row of pits across the shell, which is characteristic of that subspecies.
Can this tell us anything about where the debris might have been floating?
This is not much clue as the species has a wide global distribution in tropical and subtropical seas.
Can you say in very rough terms how long it takes the barnacles to reach this stage of growth?
I cannot accurately gauge the sizes of the largest specimens from the image but goose barnacles grow spectacularly fast e.g. 21 mm head length ( i.e. Without the supporting stalk) in 21 days cited in one paper I have at hand. I have seen very large barnacles (as long as my finger) growing on a cable known to have only been in the water for 6 weeks!
UPDATE: To clarify a point raised by commenters, I asked Dr Griffiths a follow-up question:
Is it true that barnacles can’t survive in the open ocean? Is it possible for a piece of debris floating far out to see be colonized by Lepas anserifera, or would it need to be in a coastal environment?
No, that is not the case. These goose barnacles are in fact characteristically oceanic beasts and only occur in floating objects in the open sea. Reaching the coast is in fact a death warrant for them and any that get washed up die! Interestingly they seem to know whether an object is floating, so for example are common on kelp that is uprooted and floating but never occur on the same kelp when it is attached.
Can you tell whether the barnacles in that picture are alive or dead? If alive, how long can they live after being washed up?
If you find a washed up item that is fresh (same day) the barnacles will still be opening their shells and waving around their cirri (legs) to try to feed. Obviously in a still image cannot see this. However I can see the cirri projecting from some animals. These would rot away and drop off in a few days in a tropical climate, so this wreckage has only been washed up a couple of days at most. Also crabs and other scavengers love to eat goose barnacles and will clean off most within a couple of days. There is no evidence of feeding damage or headless stalks here, so that suggests to me this wreckage was collected and photographed within a day or two of stranding.
@Gysbreght,
“Since nothing has been found” does not discount the possibility that the flight termination was somewhere close to the 7th arc. The debris may have been too small to detect.
Where do your data error optimised paths terminate, and what flight scenario takes the aircraft there?
@Flitzer-Flyer:
I’m not phantasysing scenerios. I’ve always recommended to follow the data.
@alex: model was built from scratch, calibrated to flight simulation data reported by Mike Exner (with supplemental details of the same sim session reported later in a paper by Brian Anderson), extensively sensitivity-tested, and awash in caveats (it’s only a model).
Re: anywhere on Arc7: while the model could be recalibrated to model any point on Arc7, its current calibration is valid only for a particular speed at fuel exhaustion. If you wanted to understand the impact point distribution around a hypothetical point materially further NE, you’d likely need to revisit the “speed at flameout” assumption. While the “bearing relative to arc7” assumption is surprisingly stable (while the arc curls, so does MH370’s required angle of approach shift as one heads NE – the two mostly offset), you’d still need to think carefully about that assumption, as well.
It’s in a 43Mb Excel (.xlsb) file. Please improve it. (Not being flippant – I mean it: I truly believe in the “wisdom of crowds”.)
https://drive.google.com/file/d/0B-r3yuaF2p72S1BWUzJHWHEzMEE/view?usp=sharing
Perhaps you could read the ATSB Update of October 2014. It is a probability distribution along the 6th arc with the highest densities between 32 and 35 degrees South.
Engines, main undercarriage, wing center section are not “too small to detect”.
@Gysbreght,
I’ve read the ATSB updates, and I understand their approach. The question I asked is … Where do YOUR paths terminate, and importantly what flight scenario takes you there.
Flitzer-Flyer:
You’re not listening. As I said, my paths preferably follow the data, instead of being biased by an imagined scenario. The data, together with an assumed distribution of probable errors, result in the probability distribution shown schematically in the ATSB report. If you have an issue with the ATSB’s error distribution, a single path, not ‘fuzzied’ by an error distribution, is derived in the Inmarsat article in the Journal of Navigation.
@Flitzer/Gsybreght
Of course, I think you are both wrong in your approach. A correct approach to problem solving is not data driven, but rather data informed.
There is a huge difference in the two approaches. To postulate a terminus without having a single plausible notion of causality is very foolish. Data is useful to test and refine a hypothesis. The hypothesis needs to come first. The IG and ATSB have taken a very poor path relative to the MH370 analytics. Of course, this does not mean the conclusion is incorrect. As I always reminded my engineers – even a blind squirrel finds an acorn once in awhile.
@Gysbreght
Clearly there is no point in continuing the discussion if you won’t/can’t answer a simple question.
@ Dennis,
The trouble is in this case there is almost no basis for a hypothesis, or perhaps that one can dream up a whole variety. On the other hand, the BTO/BFO data is real. It doesn’t lead to one specific conclusion. Indeed many potential paths could be derived, but then it is important to try to determine which might be capable of being flown, and the circumstances under which this might be possible.
@DennisW
Perhaps your experience is with engineering based situations where there is no lack of data, in fact normally too much, and the problem is finding a solution that matches that data.
In MH370 there is very, very little data. Lots of solutions can be found that match the data but most have no statistical validity. This often the case in science, particularly in new areas – very little data and lots of exotic theories (e.g. cosmology). The (many) over-complex theories have to be rejected – that doesn’t mean they are necessarily untrue, but are not justified by the limited data.
@Richard/Flitzer
OK, I’ll get off that theme. I respect your point of view.
It seems we have a couple of theoretical bifurcations confronting us.
1> The nature of the flight dynamics post FMT.
2> The nature of the flight dynamics at 00:19
Both profoundly alter the terminus. I’ve already belabored the first issue. The second issue has to do with whether the plane plunged into the sea uncontrolled at high speed or whether is was piloted. In the later case we could be looking at a considerable distance from even the widened search zone. Maybe the flaperon forensics will shed some light on it. I have no reason (or ability) to doubt ALSM’s conclusion, but a another look will be worthwhile.
I understand the BFO at 00:19 supports the plunge, but I am suspicious of the validity of that BFO value coming as soon as it did after a reboot, presumably from a loss of bus power followed by a power restore from the RAT.
Just a few simple questions:
If one believes that the BFO recorded at 00:19 indicates a high rate of descent at that instant, does that mean that RoD was maintained until splash-down?
Does the RAT restore power to the SATCOM system?
@Gysbreght/DennisW,
The RAT does not restore power to the SATCOM. What restored power to the SATCOM was the APU; when the second engine flamed out, the APU automatically starts to attempt to restore power on the aircraft. The RAT is there for instruments and control.
The APU will only run for as long the amount of fuel left in the plumbing and what can be scrounged from a DC fuel pump.
We know it ran long enough to make the final log on.
OZ
@DennisW With all due respect to blind squirrels, a better metaphor is the drunk looking for his wallet under the light post not because he dropped it near there but because it is light there. As I’ve said before, that kind of approach bothers me a lot.
@Arthur
Good one Arthur!! Nothing like a bit of humor to lighten the mood
@Brock McEwen:
I started looking at the excel model. I think I need your email. I started looking at the first 4 formulas and I have some questions.
@OZ
Sorry, I missed your post. Frankly, I don’t know how power is allocated when the APU or RAT is employed. In either case, the BFO value after a reboot has to be considered to be corrupted by the oscillator having power removed and restored.
@DennisW,
You may be right, it’s what the investigators have implied; but the IG seem to differ.
OZ
“The French-led investigation team examining the wing part or flaperon of the vanished Malaysia Airlines (MAS) flight MH370 aircraft has concluded the first phase of inspection work. Australian Joint Agency Coordination Centre (JACC) said the French authorities would in consultation with Malaysia report on the progress in due course. “The French investigation team is working as quickly as possible to provide complete and reliable information,” the agency said in a statement today.”
http://www.themalaysianinsider.com/malaysia/article/french-complete-inspection-work-on-mh370-wing-part
Numbers on the MH 370 flaperon assembly…
http://www.pprune.org/rumours-news/565335-flaperon-washes-up-reunion-island-28.html – post908795
@alex: see cover page:
https://drive.google.com/file/d/0B-r3yuaF2p72ZkNWN1U5bklEbTA/view?usp=sharing