An underwater explorer who found the Titanic and a team of international scientists will soon survey waters off the Greek island of Crete for clues to a once-powerful Bronze Age-era civilization.

The expedition about 75 miles northwest of Crete aims to learn more about the Minoans, who flourished during the Bronze Age, and seeks to better understand seafaring four millennia ago, the scientists said.

U.S. researchers say the Minoans were engaged in broad-based trade with other civilizations, such as the Mycenaeans on mainland Greece and perhaps with peoples as far away as the present-day Middle East.

"No one knows who the Minoans were," said Robert Ballard, an oceanography professor at the University of Rhode Island who discovered the Titanic in the North Atlantic in 1985.

"They don't think they were Greeks ... they think they might actually be Egyptian. Obviously a lot of these mysteries will be solved if we find their ships and especially their cargoes," said Ballard, who is helping lead the expedition.

Ballard's other high-profile discoveries include the remains of former U.S. President John F. Kennedy's sunken World War Two-era boat, the PT-109, in the Solomon Islands in 2002, and two ancient Phoenician ships off Israel in 1999.

The latest expedition begins on June 8 in the Sea of Crete, where scientists using sonar have already identified possible ancient shipwrecks. Using high-tech, underwater equipment, the team will probe the sites more closely, including taking photographs and mapping the area.

Mary Hollinshead, an archeologist at the University of Rhode Island and member of the expedition, said it is clear the Minoans had contact with the Mycenaeans and Egypt and Syria in the Bronze Age, but scholars know little more about the nature of those relationships.

Hollinshead and others are convinced that a key to understanding the links is finding the ships. "We have done some work on land, but what's lacking is material from the sea," she said.

BRONZE AGE SHIPPING

The archeologists also hope for new insight into shipping in the Bronze Age, which lasted from about 3000 BC to about 1100 BC and witnessed a dramatic expansion in sea trade that went beyond the Aegean region.

Much like today, they believe, shipping was comprised of large transit vessels that could sail for long distances and local peddlers who stuck close to the shore.

The parallels may extend further than that. "You don't have just one nationality or one ethnic group running a ship," Hollinshead said. "What we're learning is the questions are much more complex than what we started with."

On another leg of the $1.5 million expedition, University of Rhode Island scientists will study the sea floor around the Greek island of Thera, site of a massive volcanic eruption around 1600 BC.

They will examine the volcano's collapsed crater for the first time with underwater remote-controlled vehicles equipped with high-definition video cameras and temperature sensors.

Thera is also important because it may help better explain the Minoans, whose name derives from Minos, a legendary ruler of Crete and purportedly the son of the Greek god Zeus.

The island, which sank into the sea after the eruption, was home to a society heavily influenced by the Minoans -- from architecture to art and possibly religion, Hollinshead said.

Since the island is buried in volcanic ash, any artifacts found there may be well preserved and hold the best clues to how Minoan culture thrived and why it ultimately waned, she said.