Sea level has fluctuated more than 100 m (328 ft.) up and down over the course of the Ice Ages. We are currently in a period of high sea level, with the potential for sea level to go even higher in response to the Greenhouse Effect and Global Warming. However, we know relatively little about the opposite extremes of climate and sea level at the height of the last Ice Age. In order to learn more about climate and sea level fluctuations, I was a part of a NOAA sponsored team conducting a multi-tiered project to examine the character of the shelf edge in Bermuda from 60 – 200 m (197 – 656 ft.) depths to find records of sea level low stands. This project has involved multibeam sonar mapping of the vertical cliffs on the platform edge, ROV dives to examine particular points on interest, and now mixed gas, closed circuit rebreather dives to make first hand geological and biological collections and observations. In particular, we were diving on deep relic cave structures and wave cut notches that were formed when sea level was at its lowest point. Our team consisted of a small team of the world’s foremost technical and scientific divers, using state of the art diving equipment, striving to solve puzzles that have until now evaded direct observation.
On June 26, 2011 Dr. Tom Iliffe and I made the deepest dive of the project as well as the deepest manned dive ever conducted in Bermuda; gathering photos, geological samples and biological specimens from the Challenger Sea Mount, a remote extinct volcanic peak near Bermuda. As a result of early findings, NOAA/Ocean Explorers has already named this their flagship project of the year.
Support divers and crew rarely get the attention and thanks that they deserve. These dives would not be possible without a slew of volunteers. Brett Gonzalez has completed a dozen dives in the ocean and still has not seen the sea floor! Graham Maddocks has captained our boat and lead the crew, yet only just had his first opportunity to free dive with a manta ray. So to all our support team: Graham Maddocks, Alex Chequer, Gil Nolan, Brett Gonzalez, Nic Alvarado, Ondrej Hindl, Marcus Cooper, Dr. David Wakeley, Sam Bennett, Dr. Pete Milan, Ken Vickers, Jeff Gardiner, Bobcat Mike, Mac and researchers Robbie Smith, Thad Murdoch and Steve Blasco as well as the entire staff at Triangle Diving, we thank you from the bottom of our hearts. You never stood down. You kept the complacency at bay and we all got home safe. That is the greatest achievement of all.
By Jill Heinerth