Earhart Project Research Bulletin #81
March 10, 2017
Looking in the Right Place

 

The December 2016 issue of TIGHAR Tracks presented the rationale for searching the lagoon for pieces of the Electra:

We know that debris on the reef washes into the lagoon and we have several anecdotal accounts of aircraft wreckage seen in, or possibly on its way into, the lagoon.

We asked TIGHAR Senior Researcher Robert Brandenburg, LCDR USN (ret) if he could quantify how much force would be available in major storm events to wash non-buoyant wreckage through the main passage and into the lagoon. Bob found that wave behavior on coral reefs has been well-researched by the oceanographic community, including data specific to Nikumaroro collected during New England Aquarium expeditions in 2000, 2002, and 2005. When Bob crunched the numbers the answer was surprising. There is no realistic way for non-buoyant debris of any nature to enter the lagoon by being washed through the passage. By the time even a once-in-50-years wave 7.5 meters (24.6 ft.) in height has hit the steep reef face, crossed the reef platform, and transited the long expanse of standing water west of the passage, there is insufficient remaining energy to drive non-floating objects up and over the sand delta at the eastern end. The passage and its western approaches act as a “sump” where debris will be trapped and remain until it corrodes away or is overgrown by coral.

Buoyant debris – tanks, plywood flooring, tires – might make it into the lagoon, where they would likely be driven by wind or flow until they ran aground in the shallows along the lagoon shore. The one piece of shipwreck debris known to have washed into the lagoon was a steel tank that appeared on the lagoon shore about a mile from the passage some time between 1985 and 1999, and was gone by 2011, probably now buried in the deep silt along the shore. The one piece of airplane wreckage said to have been seen in the lagoon circa 1958 was washed up on the lagoon shore directly east of the passage and was reportedly salvaged by local people. If it was a section of plywood cabin flooring with aluminum features still attached, it may have been the source of the putative “heat shields” found in the abandoned village.

These new insights have caused us to alter our search plan for the 2017 Niku IX expedition. A sonar search of the lagoon interior for non-buoyant objects would be pointless, and a metal-detector search of the entire lagoon shore is not possible in the eight days Niku IX will be on site. Although we’ve crossed the passage many times, we’ve never searched the bottom, nor have we made a detailed examination of the large area of standing water to the west. Surviving debris could be difficult to spot visually so the best search method is probably waders and snorkelers with hand-held underwater metal detectors.

Although do-able within the time constraints of the expedition, the search will have to deal with the numerous Blacktip reef sharks who cruise the reef flat. They’re not big. A four footer is a big Blacktip. They don’t bother submerged SCUBA divers but they seem confused by waders or snorkelers splashing along on the surface. Even a small bite from a small shark would put blood in the water and, if you’re some distance from shore, things could get ugly fast.

Niku is always a challenge, but we’ll do our part if you’ll continue to do yours. We have excellent Surf Pro underwater metal detectors courtesy of White’s Electronics. We need to raise enough money to put at least two experienced operators aboard this summer’s Niku IX expedition. Please click HERE to show your support.


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