How do we intend to differentiate pieces of wreckage of the Norwich City from the Electra, using a metal detector? The Norwich City was ~1000 times the weight of the Electra, and we know for sure that it was spewing debris for seven+ decades from a wreck that was both longer-lasting and closer to the mouth of Tatiman Passage than the Electra's.
Odds would seem to be less than 1/1000 that any item detected is from the Electra.
My January post above suggests that there may be a natural rate at which aluminum (as opposed to other metals) will sink in the coral sand over time. Combining that with the fact that the sand delta has been growing into the lagoon, is it not possible that there is a stratum (horizontal, curved or sloped) in the sand delta where aluminum debris from the middle decades of the last century ended up? If the answer is a qualified yes, how should one go about determining the location of that strata?
Also, is there any hydrodynamic explanation for the Eastward growth of the sand delta? The causal mechanisms that I can imagine are: 1. a gross migration Eastward of the entire delta due to rising sea levels and bigger storms, and/or 2. deposition of additional sand due to erosion of ocean-facing beaches on Niku. Which mechanism is at work would substantially change where historic debris (from, say, the late 1930's) might be found today.
Under 1. for example, older wreckage might be jumbled together at (or just beneath) the West end of the sand delta. I may be off the mark but I am imagining that the morphology of the ocean-facing side of the delta is something like a sandy beach, with the typical beach face being analogous to the sloping West end of the sand delta (as drawn in the March 2017 edition of TIGHAR Tracks), and the typcical beach step being analogous to the adjacent flat area of the Passage, just to the West of the delta. As any beachcomber knows, most of the heavier stuff ends up on the beach step, which is typically exposed at low tide.
Jon