Archaeologists explore ocean floor for clues to early coastal settlement

Anthropologists in the College of Liberal Arts and Sciences are identifying new sites to study archaeology that are fathoms, not feet, under the surface.

Anthropology professor Kevin McBride and doctoral candidate David Robinson are scoping out early coastal human settlement sites, now under water, that could reveal clues to how the Americas were settled.

McBride says early submerged sites may yield evidence of how the earliest coastal residents lived and how they got here.

McBride, who is also director of research at the Mashantucket Pequot Museum and Research Center, was co-director and Robinson, a professional underwater archaeologist, one of the lead field archaeologists on a research expedition off Galveston, Texas, in March.

During the week-long expedition, teams of scientists from several federal agencies and research institutions explored the submerged landscape around the Flower Garden Banks National Marine Sanctuary, 115 miles off the Texas-Louisiana coast in the Gulf of Mexico.

The area, one of 13 U.S. national marine sanctuaries, was chosen because of its interesting geology and biology and its potential to contain preserved landforms with signs of some of America’s earliest inhabitants.

The expedition used the U.S. Navy’s NR-1, the nation’s only nuclear-powered submarine dedicated to underwater research.

The tools of exploration also included a remotely operated vehicle (ROV), and state-of-the-art “telepresence” technology that enabled scientists and educators on shore to track from thousands of miles away what was going on in the Gulf.

McBride monitored the expedition from Mystic, along with co-director Robert Ballard, professor of oceanography at the University of Rhode Island and president of the Institute for Exploration at Mystic Aquarium.

Looking for preserved elements of an old landscape, they surveyed 50-plus miles and found a six mile-long area about 300 feet under water that showed signs of what could be the intact remains of an old coastline and old river channels that would have led from shore to sea.

It’s an area that holds promise for more detailed analysis, he says.

At the height of the last glaciation, more than 20,000 years ago, the sea level was 350 to 400 feet lower than today, so what is now under water was then exposed land.

The NR-1 is able to sink down and roll along the ocean floor on truck tires, allowing scientists to look out through portholes and visually examine features from only a few feet away.

They could also map the sea floor with side-scan sonar while cruising 30-50 feet above the bottom.

“We were essentially going for a walk on the sea floor in an area where there had been an old coastline,” says Robinson.