An icy, floating threat
Science | Scientists study the impact a massive iceberg could have on South Georgia Island
by John Dawson
Posted 12/17/20, 11:31 am
British scientists will steam out of a Falkland Islands port in January on a mission to study the largest iceberg in the world. But it’s not just out of curiosity: Scientists are worried it could damage wildlife habitats in the British territory of South Georgia Island.
At nearly 2,200 square miles, the A-68 iceberg covers an area nearly the size of Delaware and is almost 62 percent larger than South Georgia. Scientists warn the iceberg is on a collision course with the island and its sparsely populated research station some 1,000 miles east southeast of the Falklands.
In late 2016, scientists discovered a crack developing in the Larsen C ice shelf in Antarctica, and the iceberg broke away in 2017. Ocean currents have pushed it north toward the shallower water around South Georgia Island.
Once the RRS James Cook reaches the iceberg, a team of researchers with the British Antarctic Survey will collect water samples and observe wildlife. Scientists can’t push the massive feature away, but they can get a jumpstart studying the effects A-68 might have if it lodges on the coast.
If the massive iceberg comes to rest on the continental shelf surrounding the island, researchers worry it would disrupt the delicate ecosystem. The waters around South Georgia teem with phytoplankton, microscopic algae that forms the basis of many aquatic food chains. Scientists fear an iceberg this size could lower water temperatures a few degrees below the normal 39 degrees.
Another concern: As the Delaware-sized iceberg melts, it could release enough freshwater to meaningfully alter the water salinity near the island, rendering the environment unsuitable to the type of microscopic life that presently exists there.
“Even though icebergs are common, we’ve never had anything this size before, so it’s a first for us. … It brings a wholesale change to the environment,” Geraint Tarling, a biological oceanographer at the British Antarctic Survey, told The Guardian. “If the iceberg does ground, we could be looking at this being there for up to 10 years because it’s so large. It’ll be a huge problem.”
While whales can find new feeding grounds if the food chain around South Georgia becomes disrupted, the large populations of seals and penguins are stuck. “They are fixed to their base and without being able to get out, feed and get back quickly, they have got a real problem,” Tarling said.