Full Titanic site mapped for first time

It is hoped the construct will provide new clues about what exactly happened the 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 say. 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 1500 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.

But previous maps of the floor around the wreckage were incomplete, says Parks Stephenson, a Titanic historian. "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 took place 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, Massachusetts, and the Waitt Institute of La Jolla, California. Details on the new findings will be aired in a two-hour documentary on 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 5km/h as they traversed back and forth in a grid, said Paul-Henry Nargeolet, the expedition's co-leader.

The AUVs also took high-resolution photos - 130,000 of them in all - of a smaller three-by-five-kilometre area where most of the debris was concentrated. The photos were stitched together on a computer, creating a map showing debris scattered well beyond the large bow and stern sections that rest about half a mile apart. The map provides a forensic tool with which scientists can examine the wreck site much the way a plane wreck would be investigated.
"When you look at the sonar map, you can see exactly what happened," said Mr Nargeolet, who has been on six Titanic expeditions. Items displayed include a huge tangle of the remains of a deckhouse; a large chunk of the side of the ship; pieces of the ship's bottom; and a hatch cover that blew off of the bow section as it crashed to the bottom. By examining the debris, investigators can now answer questions like how the ship broke apart, how it went down and whether there was a fatal flaw in the design. Computer simulations will re-enact the sinking in reverse, bringing the wreckage debris back to the surface.