[MUSIC] JOAN CARTAN-HANSEN, HOST: Not every archaeologist works in the soil.
Some search for finds under the sea!
Archaeologists first did underwater excavations to find artifacts in shallow waters.
Scuba divers might search for a shipwreck or find artifacts tossed in the sea thousands of years ago.
Underwater archaeologists use many of the same techniques used by their above-ground colleagues.
They find a site and they mark the area to create a grid.
Sometimes, objects are easy to find.
Sometimes it takes special technology to find things.
These scientists are investigating an underwater World War II battlefield.
They use sonar to help identify wreckage.
And then they take a manned submersible to search 800 feet below the surface.
Once they get closer to objects not seen for decades, they take pictures and other data.
So, they can make a computer model of the submarine and the ships they found.
The hope is to learn how to preserve the site and how to teach others the history of this battle.
For more information about archaeology, check out the Science Trek website.
You'll find it at Sciencetrek.org