By Jan TenBruggencate
Advertiser Science Writer
Deep in the Southern Ocean, Honolulu biologist and chiropractor Porter Turnbull and a team of scientists and photographers are studying the massive iceberg known as B-15, which sheared off the Antarctic Ross Ice Shelf a year ago.
They are part of the Ice Island expedition, conducting biological, climate and other studies atop, inside ice caves and under the berg, using a helicopter, remote-controlled deep submersible craft, divers in suits designed for freezing waters and more. They operate off the ship Braveheart, a former Japanese research vessel, which left New Zealand Jan. 17.
The two-month mission is sponsored by National Geographic, the New England Aquarium, Bermuda Underwater Exploration Institute and Kurtis HD Partners.
"The team will use B-15 as a platform to observe and document whale, seabird, seal and open ocean invertebrate life (jellyfish, krill, salps) around the iceberg. It is also believed that the iceberg may contain relics from two historic camps, which were established by Admiral Byrd and Roald Amundsen," according to the mission’s Web site, iceisland.net.
Turnbull serves as science and medical director for the Ice Island mission. Before leaving, he said he hoped to dive along the iceberg, study the albatrosses of the Southern Ocean and other forms of bird and marine life.
A surfer, he also won’t pass up a chance to catch Southern Ocean icy swells: "Wes and I are bringing surfboards painted to mimic orcas, as a deterrent to the Leopard Seals," Turnbull said of cinematographer and mission co-leader Wes Skiles.
When B-15 cracked off the Ross Ice Shelf, it was 170 miles long, 25 miles wide and nearly 1,000 feet thick — one of the largest single icebergs ever known. Since then, pieces have cracked off as it moves ponderously in the currents of the Ross Sea. Another scientific mission has placed radio markers on the berg so its exact movements can be tracked by satellite.
Researchers are not sure whether the calving of B-15 from the main ice shelf is a consequence of global warming or, as one research project has suggested, part of a natural sequence in which massive icebergs break off the main shelf on a 50-year cycle.
The Braveheart was unable initially to reach B-15 because of thick pack ice in the region. Crew members were diving along other icebergs, and some had landed on B-15 using the ship’s Hughes 300 two-man helicopter.
Communication from the Ice Island mission has been spotty since its satellite phone failed. Some communication has been made using single sideband radio.
"The iceberg gives us a reference to understand global changes. There have been a lot of studies regarding ocean warming on tropical reefs. Now we need to look at the extreme cold regions," Turnbull said before leaving Honolulu.
[back to top] |
