WASHINGTON — Seventy-five years after Amelia Earhart disappeared over the Pacific, a research team is setting off July 2 with high hopes of resolving the mystery surrounding the pioneering aviatrix.

For the tenth time in 23 years, the International Group for Historic Aircraft Recovery (TIGHAR) will set off for Nikumaroro island in Kiribati to establish whether Earhart survived the apparent crash of her aircraft.

"This time, we'll be searching for debris from the aircraft," TIGHAR's founder and executive director Richard Gillespie, himself a pilot and former aviation accident investigator, told AFP.

Earhart vanished on July 2, 1937 at age 39 with navigator Fred Noonan during the final stage of an ambitious round-the-world flight along the equator in a twin-engine Lockheed Electra.

The holder of several aeronautical records, including the first woman to cross the Atlantic by air, Earhart had set off from New Guinea to refuel at Howland Island for a final long-distance hop to California.

In what turned out to be her final radio message, she declared she was unable to find Howland and that fuel was running low.

Several search-and-rescue missions ordered by then-president Franklin Roosevelt turned up no trace of Earhart or Noonan, who were eventually presumed dead at sea.

Conspiracy theories flourished. One contended that Earhart was held by Japanese imperial forces as a spy. Another claimed she completed her flight, but changed her identity and settled in New Jersey.

TIGHAR is working on the hypothesis that the duo reached Gardner Island, then a British possession and now known as Nikumaroro, and managed to survive for an unknown period of time.

Nikumaroro, uninhabited in Earhart's time, and a mere 3.7 miles (six kilometers) long by 1.2 miles (two kilometers) wide, is about 300 miles (480 kilometers) southeast of Howland Island.

This year's TIGHAR expedition will see about 20 scientists depart Hawaii to explore over 10 days both the island and an underwater reef slope at the west end of the island.

It will be equipped with a multi-beam sonar to map the ocean floor, plus a remote-controlled device similar to the one that found the black boxes from the Rio-to-Paris Air France that crashed into the South Atlantic in 2009.

If debris is found, it will be photographed and its location carefully documented for a future expedition, Gillespie said.

Sustaining the search are clues worthy of detective story, including items from the 1930s previously discovered on the island such as a jar of face cream, a penknife blade, the heel of a woman's shoe and a bit of Plexiglas.

Skeletons of birds apparently cooked over a campfire have also contributed to the mystery, and settlers who reached Nikumaroro after 1937 have spoken of the existence of aircraft wreckage.

Bone fragments have meanwhile been subjected to DNA testing that turned out to be inconclusive, said Gillespie, who remains hopeful that parts of Earhart's Electra remain to be found.

The US government is lending technical and diplomatic support to the TIGHAR effort, budgeted at $2 million and otherwise privately funded. A documentary is due to be broadcast on the Discovery cable television channel.