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Amelia Earhart Search Forum => The Islands: Expeditions, Facts, Castaway, Finds and Environs => Topic started by: Matthew C Harrison on February 23, 2011, 12:48:28 PM

Title: Sedimentation Analysis
Post by: Matthew C Harrison on February 23, 2011, 12:48:28 PM
A thought occurred to me today, as I read Dr. King's account (http://ameliaearhartarchaeology.blogspot.com/2010/12/why-i-dont-think-well-find-airplane-and.html) of why he believes it is unlikely that the Electra will be found.  If, as Howard Allred suggested, the wreckage of the Electra had been shredded by the action of the surf, and deposited across the opening to the lagoon, wouldn't there be some indication of AL2024 in the coral floor there?

Even if, as Dr. Allred suggested, the aircraft's sheet metal had been reduced to the size of sand granules, there must still be some trace of it there.  Why not go panning for aluminum?

Aluminum, found in sufficient amounts, would almost certainly have come from the Electra.  The City of Norwich could be ruled out, as could be any aluminum imported by the natives from Canton or elsewhere.  We know of no other aircraft as having been lost in the area, unless I'm mistaken.

While I take Dr. King's comments about the unlikely possibility of finding a recognizable airframe as a cautioning against the tendency to demand a smoking gun, it might be worth considering other means by which the existence of the Electra could be identified, even without its airframe being discovered.  The discovery of the "rope," for instance, leads to easy speculation about what other components of the aircraft might have lodged itself in some out of the way coral crevice.

Also, glad to see the increased activity on the forum.  I still read my extensive collection of the old email list from time to time!

LTM, who always did think AU was a better standard than AL.
Matt
Title: Re: Sedimentation Analysis
Post by: Martin X. Moleski, SJ on February 23, 2011, 01:27:53 PM
A thought occurred to me today, as I read Dr. King's account (http://ameliaearhartarchaeology.blogspot.com/2010/12/why-i-dont-think-well-find-airplane-and.html) of why he believes it is unlikely that the Electra will be found.  If, as Howard Allred suggested, the wreckage of the Electra had been shredded by the action of the surf, and deposited across the opening to the lagoon, wouldn't there be some indication of AL2024 in the coral floor there?

Even if, as Dr. Allred suggested, the aircraft's sheet metal had been reduced to the size of sand granules, there must still be some trace of it there.  Why not go panning for aluminum?

Because there could be sources of aluminum sand other than the Electra: boats, ocean trash, wreckage from other aircraft brought to Niku (like the stainless steel exhaust manifold from a B-24 that was recovered during Niku IIII (2001), (http://tighar.org/wiki/Niku_IIII_(2001)) Coastie trash, etc.

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Aluminum, found in sufficient amounts, would almost certainly have come from the Electra.  The City of Norwich could be ruled out, as could be any aluminum imported by the natives from Canton or elsewhere.  We know of no other aircraft as having been lost in the area, unless I'm mistaken.

Strange things do happen.  I don't buy the idea that aluminum sand would "almost certainly have come from the Electra."

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While I take Dr. King's comments about the unlikely possibility of finding a recognizable airframe as a cautioning against the tendency to demand a smoking gun, it might be worth considering other means by which the existence of the Electra could be identified, even without its airframe being discovered.  The discovery of the "rope," for instance, leads to easy speculation about what other components of the aircraft might have lodged itself in some out of the way coral crevice.

Agreed--engines, props, landing gear, wheels ...

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Also, glad to see the increased activity on the forum.

Me, too!
Title: Re: Sedimentation Analysis
Post by: Bruce Thomas on February 23, 2011, 01:49:08 PM
LTM, who always did think AU was a better standard than AL.

Just as Marty was quick to reject the presence of AL as proof-positive of you-know-what ... I would like to also focus on how things may not be what they seem just because of wishful thinking. 

When I read that closing statement of yours, my mind was not in periodic table mode ... my reaction was instead to say, "All right!  War Eagle to you, too!"
Title: Re: Sedimentation Analysis
Post by: Matthew C Harrison on February 23, 2011, 06:27:56 PM
Remember that what's central to the idea isn't finding a few granules of AL (and I'm not talking Crimson Tide!), but establishing a quantitative analysis in which the presence of AL exceeds the threshold which might otherwise be obtained by having a few spare parts (B-24 manifolds) tossed about over the years.  So the minimal presence of other sources of AL wouldn't necessarily jeopardize test results, as I mentioned originally. 

Think parts per million, or some other quantification.  It should be feasible to develop some expectation, along the lines of Dr. Allred's comments, of what quantity of AL granules per sample would be representative of a nearby aircraft wreck.  Truthfully, any statistical representation of al2024 on Niku would be suggestive, and information worth having, at the very least.  And while it would be impossible to argue that some unknown AL boat hull hadn't also been shredded at this same spot, it should be possible to find records of such lost hulls in the area, if any.  And I'm not certain of it, but I suspect al2024 is not a prevalent type of AL in boat hull construction.

Of course, through the collection of multiple samples it would also be possible to create a distribution map, indicating the originating position of the AL...
Title: Re: Sedimentation Analysis
Post by: Ric Gillespie on February 24, 2011, 06:59:19 AM
A sediment study would only show an unusually high concentration of AL if the theory that the Electra was ground to granules is correct.  As Dr. King explained in his blog posting (http://ameliaearhartarchaeology.blogspot.com/2010/12/why-i-dont-think-well-find-airplane-and.html) of December 8, 2010, that opinion was offered by our late-lamented colleague, Howard Alldred (Not "Dr." Howard had a Bachelor of Science degree).  At the time he proposed it, I thought his hypothesis to be improbable in the extreme.  I still think so.  I know of no example of an aircraft in a high-energy surf environment being ground up to unrecognizable bits. Typically they break up into their major components - empennage, outer wing panels, center section, engines, etc. which are then scattered either seaward or shoreward or both depending on the particular circumstances. Aluminum structures exposed to saltwater and air, such as in a tidal environment, eventually corrode away but it takes many years.  I know from first-hand experience that the reef at Tarawa, for example, is littered with surprisingly intact engines and sections of fuselage from aircraft that came to grief during the American invasion of October 1943.

Based on what I've seen in similar cases, it seems to me that if the Electra landed on that reef - as abundant evidence suggests it did - and got hung up on the reef edge - as abundant evidence suggests it did - and if big chunks of it did not wash up on the beach to be noticed by any of the subsequent surveys of the island - which appears to be the case -  then the wreckage must have gone over the edge and down the reef slope.  We now know that the reef slope is extremely steep down to a depth of about 300 m (nearly 1,000 feet) where it begins to shallow out.  Wreckage at that depth would be beyond the effects of wave action and in sufficient darkness to inhibit most coral growth.  If it's there it is findable and I intend to go look.
Title: Re: Sedimentation Analysis
Post by: Matthew C Harrison on February 24, 2011, 09:34:02 AM
If you're right, Ric - and your point seems quite intuitively correct - then sedimentation analysis wouldn't be worth its cost or time.  Better I suppose to investigate ROV options.  Didn't the US Navy do soundings of Niku after the war?  Ah, but I suppose none of the charts they might have made would be of sufficient quality for our purposes.
Title: Re: Sedimentation Analysis
Post by: Dan Swift on February 24, 2011, 11:40:37 AM
Nothing is going to tear apart those engines and the main frame of that plane.  If it went down there, then those heavy pieces are on the bottom.  Probably under sediment there, so will be difficult to find, but hopefully not impossible.