How Researchers Mapped The Antikythera Shipwreck In Search of Treasures

As news off the coast of Greece's Antikythera island heralds discoveries of the decade, many are asking how researchers were able to find the treasures that lie at the bottom of the Aegean Sea. Retrieving artifacts from a wreckage, that has sit at the bottom of the Aegean Sea for over 2000 years, researchers equipped with the most state-of-the-art diving technology, some even in beta prototypes, were able this year to finally understand the shipwreck that has confused archaeologists and divers for over a hundred years.

Discovered in 1900 when a team of sponge divers, led by captain Dimitrios Kontos, unexpectedly returned with the arm of a bronze statue, the Antikythera shipwreck has since then become a mystery only solvable by modern science. Lying 55m beneath the surface of the sea, the shipwreck has been all but unobtainable to man, who is limited by the slow progression of scuba and diving equipment in recent years and the lack of light beneath the surface of the crystal blue shores. But now, the way in which researchers are tackling the mystery has changed.

"From robotic mapping systems, to closed circuit rebreathers and a new Atmospheric Diving System (the Exosuit), the 2014 project [sought] to maximize the scientific return from our month in the field" researchers from the Woods Hole Oceanographic Institution said. "Even more importantly, the technologies selected for the project increase safety margins for our operations team."

And the technology that the researchers used came in a total of five forms.

Iver Autonomous Underwater Vehicle (AUV)

Operated by researchers Dr. Oscar Pizzaro and Dr. Stefan Williams of the Australian Centre for Marine Robotics, the AUV was vital in giving divers a realistic view of the dive site and the wreckage that lie below. As its primary objective, the stereocameras collected series of overlapping images of the shipwreck site that were later utilized in the creation of an all-encompassing image for divers to use as a reference when exploring the depths.

"The data was processed using an algorithm known as Simultaneous Localization and Mapping (SLAM), to produce a three-dimensional pixel-resolution map of the wreck" researchers from the Woods Hole Oceanographic Institution said.

Closed Circuit Rebreathers & Diver Propulsion Vehicles

As relocation of the site using sonar is often not effective due to the near proximity of a steep underwater slope adjacent to the shore, divers often have elected to survey the location visually. But diving to those depths for prolonged periods of time still pose great problems to the researchers. This year, in using closed circuit rebreathers with mixed gas and diver propulsion vehicles to move around, they were able to survey with longer and safer bottom times than conventional scuba and an immensely increased range compared to traditional finning.

"Each  diver had more than 30 minutes of bottom time per day, and enjoyed great mental acuity and a larger safety margin than that of previous divers at Antikythera."

Side Scan/Multibeam Sonar

Developed last year for the 2013 project, in collaboration with engineers from Edgetech, the researchers were able to deploy a combination Side Scan/Multibeam Sonar called the "Edgetech 4600 sonar" to map the Antikythera coastline. Collecting data and mapping the entire Antikythera coastline up to a depth of 150 meters, the researchers were able to target the shipwreck just 100 m offshore and better direct observations of the diving teams.