July 31, 2003

R/V Knorr arrived on target from Sinop and carried out its first open ocean test dive with its new remotely operated vehicle (ROV) HERCULES. After this test dive, HERCULES was brought back to the surface and a series of adjustments were made to the ROV.

While those repairs and modifications were being made, the R/V KNORR carried out a systematic survey of the area around Site 82. The objective of this survey was to begin a series of east-west survey lines covering an area of about 200 square nautical miles that was thought to have been above sea level some 7,500 years ago when the Black Sea was 155 meters lower than it is today. Two sonar systems were mounted on the hull of KNORR for this survey. The first is a multi-narrow beam sonar called SEABEAM than can compile a topographic map of the landscape over which the ship is passing. The second sonar is a \"sub-bottom\" sonar whose signal can penetrate into the ocean floor to reveal its sub-surface features. In particular, the scientists were interesting in mapping a geology formation that is capped by what is called an \"angular unconformity\". An angular unconformity is an ancient surface etched across this early landscape by rivers, prior to the refilling of the Black Sea. By tracing this formation seaward, the scientists were seeking to prove that the angular unconformity ended at the shore of the ancient Black Sea at a depth of 155 meters.

Before this survey could be fully completed, and it will be at a later date, HERCULES was ready to go back into the water in hopes of finding what is called "Site 82", an unusual series of stone blocks and wood that some of the scientist believe might represent a site of human occupation prior to the refilling of the ancient Black Sea.

"Site 82" was located at 2300 hours and HERCULES is presently undertaking an intense sampling program.

Dr. Robert Ballard

Immersion Program: 
JASON Learning: A Partnership of Sea Research Foundation and National Geographic