A team of scientists and salvagers has ended its expedition without finding any dramatic or conclusive evidence to determine what happened to missing U.S. aviator Amelia Earhart 75 years ago.

The International Group for Historic Aircraft Recovery, which led the search, said on its website this week that it was returning from the field with more questions than answers. It now has what it calls “volumes of sonar data and many hours of high-definition video” to review before knowing the expedition's result.

The team set sail earlier this month from Hawaii for an island near the remote South Pacific nation of Kiribati. It was searching for clues into Earhart's disappearance while she was flying from Papua New Guinea to Howland Island during her quest to fly around the world along the equator.

The team believed Earhart and navigator Fred Noonan landed on Nikumaroro Atoll and briefly survived, based on evidence gathered from the island during past expeditions. The $2 million expedition, financed entirely by private donations, searched the waters off Nikumaroro for the wreckage of Earhart's Lockheed Electra twin-engine airplane.

The team had anticipated 10 days of search operations, but due to equipment problems attributed to the underwater environment, it only had five days on site.

Earhart was the first woman to fly across the Atlantic Ocean in 1928, accompanying a team of male pilots. Four years later she became the first woman to fly the Atlantic solo, and in 1935, she became the first person to fly solo across the Pacific Ocean. Earhart also set a number of altitude records.