July 9, 2012 - The search for Amelia Earhart is about to continue in the pristine waters of this tiny uninhabited island, Nikumaroro, between Hawaii and Australia.
Carried out by the International Group for Historic Aircraft Recovery (or TIGHAR), which has long been investigating the last, fateful flight taken by Earhart 75 years ago, the search will focus on finding pieces of Earhart's Lockheed Electra aircraft in the waters off this deserted island in the southwestern Pacific republic of Kiribati.
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The Alternate Theory
Earhat and Fred Noonan both mysteriously vanished while flying over the Pacific Ocean on July 2, 1937 during a record attempt to fly around the world at the equator.
The general consensus has been that Earhart's twin-engined plane had run out of fuel and crashed in the Pacific Ocean, somewhere near her target destination Howland Island.
But according to TIGHAR's researchers there is an alternative scenario: the plane might have landed on the flat reef of the uninhabited coral atoll and stayed there for several days before being washed over the reef edge by rising tides.
The Search Begins
On July 3, TIGHAR researchers left Honolulu, Hawaii, aboard the University of Hawaii oceanographic research ship R/V Ka Imikai-O-Kanaloa.
"We bunkered for the trip with 46,000 gallons of fuel. We should get to Nikumaroro about midnight July 11, but of course this is subject to change as weather, wind, sea state, and so on combine in different ways," Ric Gillespie, TIGHAR's executive director, said.
'Most Exciting Breakthrough'
The underwater search for the plane wreckage relies on what Gillespie called "the most exciting breakthrough" -- a photograph of the island's western shoreline taken three months after Amelia's disappearance.
Shot by British Colonial Service officer Eric R. Bevington in October 1937, during an expedition to assess the suitability for future settlement and colonization of Nikumaroro, the grainy photo reveals an apparent man-made protruding object on the left side of the frame.
Forensic imaging analyses of the photo suggest that the mysterious object is consistent with the shape and dimension of the upside-down landing gear of Earhart's plane.
On the Water
The deep water search will concentrate on the reef slope off the west end of Nikumaroro.
Most of the action will take place on the water.
"The objective of the expedition is to locate, identify, and photograph any and all surviving aircraft wreckage," said Gillespie.
Indeed, archaeological expeditions to Nikumaroro, have already led to the discovery of a number of artifacts which, combined with archival research, provide strong circumstantial evidence for a castaway presence on the southeast end of Nikumaroro, at a place which the researchers named "Seven Site"
"The expedition will test the hypothesis that the more massive parts of the aircraft traveled down the reef slope and came to rest in, as yet, unexplored depths," Gillespie said.
The researchers have already established that the reef slope reaches a depth of 3,300 feet more than a mile out from the reef edge. "If the hypothesis is correct, the wreckage should be well within the proposed search area," Gillespie said.
Documentary Coming in August
The high-tech underwater search, which will be captured by a film crew from Discovery Channel and aired as a documentary in August, will rely on a topedo-shaped Autonomous Underwater Vehicle (AUV) called Bluefin-21 made by Bluefin Robotics and a Remote Operated Vehicle (ROV).
While the AUV, which will be operated by Phoenix International Holdings Inc , is capable of simultaneous multi-beam and side-scan data collection and black-and- white still photography down to 4,921 feet, the ROV -- a TRV 005 robot made by Submersible Systems Inc. -- is capable of reaching depths of 3,300 feet.
The robots and equipment, some 29,500 pounds of technology, have been moved about 22,000 miles by FedEx.
The hunt will begin with the researchers mapping the search area. They will use the SeaBeam, a multi-beam sonar that's hull-mounted on the expedition vessel. In shallower areas a multi-beam sonar mounted on the AUV will be used.
"Because we are anticipating arriving at night, the first order of business will be to do a mapping run with the SeaBeam standing out from the island. You do not want to tangle with that reef at night. Then as dawn breaks we will be able to stand in and do more runs with the SeaBeam and start setting up the AUV," Gillespie said.
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Side Scan Sonar
After creating an accurate map of the undersea topography, the researchers will identify possible targets using high-resolution, side-scan sonar mounted on the Autonomous Underwater Vehicle (AUV).
Able to take black-and-white pictures, the battery-powered robotic submersible is scheduled to work in six-hour search sessions.
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The final step would involve investigating suspicious- looking targets using the ROV and its high-definition video camera.
Tethered to the expedition vessel, the ROV is "flown" to the desired location by an operator in a dedicated control van installed aboard the expedition vessel.
"The ROV is equipped with sector-scan sonar and has powerful lights and high-definition video cameras to provide real-time imagery to the operator. The robot even has manipulator arms to remove obscuring objects," Gillespie said.
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Gillespie remarked that no recovery of wreckage is contemplated.
"If wreckage is found, the imagery acquired on this expedition will be used to mount a subsequent recovery expedition equipped to safely retrieve and properly conserve whatever remains of the aircraft," he said.
He admits that there are several possible scenarios that could defeat TIGHAR's efforts to find the wreckage. For example, the plane could have floated away for miles before sinking, or it could have broken up, sunk close to the island and been buried by underwater landslides.
And of course, there is also the possibility that TIGHAR's hypothesis about Earhart's location proves incorrect.
"What would close the case, in a negative sense, would be the discovery of some presently unknown event or events that present a reasonable alternative explanation for all the various threads of evidence that point to the Earhart/Noonan flight ending at Nikumaroro," Gillespie told Discovery News.
"We're constantly looking for and debating possible alternative explanations. The strength of the case is in the abundance and diversity of the separate threads of investigation that all seem to point to the same conclusion," Gillespie said.
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