July 13, 2012 -- As the search for Amelia Earhart's plane probes the waters off Nikumaroro, a tiny uninhabited island in the southwestern Pacific republic of Kiribati, a new paper has reconstructed what may have happened to the legendary aviator 75 years ago.
Written by Thomas King, the senior archaeologist on Amelia Earhart search project, the paper summarizes 23 years of interdisciplinary research by the International Group for Historic Aircraft Recovery (or TIGHAR). It will be published by the academic journal Pacific Studies in October.
"In the Earhart case, strong circumstantial evidence supports the hypothesis that the pilot and navigator Fred Noonan landed their Lockheed Electra 10E safely on Nikumaroro, made repeated efforts to radio for help, and eventually died as castaways," King told Discovery News.
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Earhart sent her final radio transmission on July 2, 1937 during a record attempt to fly around the world at the equator.
Earhart and navigator Fred Noonan disappeared in the final minutes of a flight from Lae, New Guinea, to Howland Island in the Pacific.
At 07:42 local time, as she flew toward the target destination, Earhart called the Coast Guard cutter Itasca, stationed at Howland Island for support.
"We must be on you, but cannot see you -- but gas is running low. Have been unable to reach you by radio. We are flying at 1,000 feet," she said.
Earhart's final inflight radio message went out an hour later, at 08:43.
"We are on the line 157 337. We will repeat this message. We will repeat this on 6210 kilocycles. Wait," she said.
What happened after that last radio message has remained a mystery for 75 years.
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The Hypothetical Reconstruction
TIGHAR researchers believe that Earhart and Noonan reached the vicinity of Howland Island, but were unable to see it, perhaps due to difficult morning light conditions or because they were somewhat off-course to the south.
Unable to communicate with the Itasca, and to see Howland Island, they flew southeast and in the late morning sighted Nikumaroro, at that time known as Gardner Island.
According to the researchers' hypothetical reconstruction, the pair made an emergency landing on the island's northwest reef flat, north of the wreck of the British steamer SS Norwich City, which went aground on the island's reef in 1929.
A desert atoll, less than five miles long and 1.5 miles wide, with a lagoon at its center, Nikumaroro is far from a dreamy island getaway.
The island has no fresh water and has roasting temperatures often exceeding 100 degrees Fahrenheit -- even in the shade.
The island is wooded in indigenous forest dominated by the Buka, a large tropical softwood tree, feral coconut and shrubs known as Scaevola frutescens.
The island was uninhabited when Earhart disappeared in 1937, but was colonized in late 1938, with the colony lasting until 1963.
As soon as they landed, Earhart and Noonan are believed to have begun sending dozens of radio distress calls using the Electra's equipment.
TIGHAR re-examined all the 120 known reports of radio signals suspected or alleged to have been sent from the Earhart aircraft after 12 noon on July 2, 1937 through July 18, 1937, when the official search ended.
They concluded that 57 out of the 120 reported signals are credible.
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After a few days, however, TIGHAR postulates that flood tides lifted the Electra and carried it over the reef edge, leaving behind the landing gear, which was inadvertently photographed by British Colonial Service officer Eric R. Bevington three months later in October 1937
The airplane either broke up in the surf on the reef edge, or was obscured by waves when the U.S.S. Colorado flyers flew over on July 9 during high tide.
The Colorado flyers also did not see Earhart and Noonan.
"TIGHAR's experience is that in the highly contrasting visual environment of the Nikumaroro shore it is very difficult to see people on the ground from the altitude flown by the Colorado planes," King said.
Fred Noonan's Fate
Noonan may have not survived long. The content of some of the recovered radio messages suggests that he may have been injured in the landing.
Exploring the Island
With the plane lost, TIGHAR believes that Earhart -- and Noonan, if still alive -- went to explore the island. They carried with them a few supplies, such as cosmetics for protection from the equatorial sun and Earhart's compact with its handy mirror.
When he visited the island three months later, the British officer, Bevington, reported signs of someone's "overnight bivouac" near the lagoon on the southwestern side of the island.
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Map of the Island
From the western reef slope, where she landed, Earhart is thought to have reached an area that TIGHAR calls the Seven Site, in the island's remote southeast end.
There she may have survived for some days or weeks, but finally succumbed, probably to thirst.
Crabs Consumed Remains
TIGHAR researchers believe that her body was largely consumed by the site's numerous hermit and coconut crabs, leaving only 13 bones, a few artifacts, and the remains of her cooking fires.
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Indeed, a partial skeleton was found in 1940 at the Seven Site.
The remains were recovered by British Colonial Service Officer Gerald Gallagher and described in a forensic report.
According to that report, the bones probably belonged to an individual "more likely female than male," "more likely white than Polynesian or other Pacific Islander," and "most likely between 5 feet, 5 inches and 5 feet, 9 inches in height."
Unfortunately the bones have been lost.
A woman's shoe, an empty bottle and a sextant box whose serial numbers are consistent with a type known to have been carried by Noonan were also found near the bones.
Amelia may have survived on Nikumaroro for weeks and possibly months, according to Ric Gillespie, executive director of TIGHAR.
Archaeological investigations at the Seven Site unearthed significant clues that suggest a castaway presence.
"We found several small and large fires. The fire features contained bird, fish, and turtle bones. We also found two clusters of giant clam shells," King said.
He added that many of the clams appeared to have been opened by someone who tried to pry them apart on the hinge side, others have been opened by smashing them with rocks.
Whoever camped there was catching small reef and lagoon fish, cooking them on the coals, not consuming the heads, and disposing of their bones in the fires.
"None of this behavior is consistent with fishing and fish preparation by indigenous Pacific islanders," said King.
Apart from the fire features, the researchers also found a knife that was beaten apart to detach the blades, and several broken, partially-melted bottles in the remains of a cooking fire. They were probably used to boil or distill drinking water.
"These objects tell a fascinating story of ingenuity, survival and, ultimately, tragedy," Gillespie said.
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As Amelia struggled to survive on the island, King proposes that the wreckage of the Electra aircraft broke up and was distributed down the face of the reef, where some of it was collected by villagers.
TIGHAR has found aircraft parts in the colonial village, but has been unable to tie them specifically to Earhart's plane.
Larger and heavier pieces may still lie obscured on the reef slope, or at the point below 1000 feet where the slope becomes less acute than it is higher up.
As the expedition continues to find the plane, we may learn the answers soon.
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