The Titanic, which sank on April 14, 1912 was excavated by a French and American Team using sonar. The French Team used a type of sonar known as SAR(Sonar Acoustique Remorque). SAR emits sound waves that rebound off the ocean floor, giving an image of what lies underwater. SAR covers a wider expanse of the ocean floor, and because sonar is able to map 3-D images, it gives a clearer idea of objects beneath the surface.
The bow and main body of the ship.
"After combing the site with new undersea robots, the team was able to verify the ship's identity with cameras and sonar early Sunday morning, according to American and French officials. A French announcement said the wreck was found at a depth of more than 12,000 feet."
-William J. Broad
-William J. Broad
"In collaboration with the Woods Hole Oceanographic Institution, NatGeo recently completed the most comprehensive map of the entire wreckage site of the Titanic. Using using a blown-up sonar survey map of the site along with high resolution photos the team meticulously stitched-together the shots and created a virbrant 3D mosaic taken of the infamous wreck at her final resting spot 2.5 miles beneath the ocean’s surface."