SOUTH PORTLAND, MAINE — Researchers have pieced together what’s believed to be the first comprehensive map of the entire 3-by-5-mile Titanic debris field and hope it will provide new clues about what exactly happened that night 100 years ago when the superliner hit an iceberg, plunged to the bottom of the North Atlantic and became a legend.
Marks on the muddy ocean bottom suggest, for instance, that the stern rotated like a helicopter blade as the ship sank, rather than plunging straight down, researchers said this week.
An expedition team used sonar imaging and more than 100,000 photos taken from underwater robots to create the map, which shows where hundreds of objects and pieces of the presumed-unsinkable vessel landed after striking an iceberg, killing more than 1,500 people.
Explorers of the Titanic which sank on its maiden voyage from Southampton, England, to New York City have known for more than 25 years where the bow and stern landed after the vessel struck an iceberg. But previous maps of the floor around the wreckage were incomplete, said Parks Stephenson, a Titanic historian who consulted on the 2010 expedition. Studying the site with old maps was like trying to navigate a dark room with a weak flashlight.
“With the sonar map, it’s like suddenly the entire room lit up and you can go from room to room with a magnifying glass and document it,” he said. “Nothing like this has ever been done for the Titanic site.”
The mapping was done in the summer of 2010 during an expedition to the Titanic led by RMS Titanic Inc., the legal custodian of the wreck, along with Woods Hole Oceanographic Institution in Falmouth, Mass., and the Waitt Institute of La Jolla, Calif.
They were joined by other groups, as well as the cable History channel. Details on the new findings at the bottom of the ocean are not being revealed yet, but the network will air them in a two-hour documentary April 15, exactly 100 years after the Titanic sank.
The expedition team ran two independently self-controlled robots known as autonomous underwater vehicles along the ocean bottom day and night. The torpedo-shaped AUVs surveyed the site with side-scan sonar, moving at a little more than 3 miles per hour as they traversed back and forth in a grid along the bottom, said Paul-Henry Nargeolet, the expedition’s co-leader with RMS Titanic Inc.
The AUVs also took high-resolution photos 130,000 of them in all of a smaller 2- by 3-mile area where most of the debris was concentrated. The photos were stitched together on a computer to provide a detailed photo mosaic of the debris.
The result is a map that looks something like the moon’s surface showing debris scattered across the ocean floor well beyond the large bow and stern sections that rest about half a mile apart.
The layout of the wreck site and where the pieces landed provide new clues on exactly what happened. Computer simulations will re-enact the sinking in reverse, bringing the wreckage debris back to the surface and reassembled.