A68 ON ROUTE TO COLLIDE AND GROUND NEAR SOUTH GEORGIA
The A68a Antarctic ice giant, the world's biggest iceberg, is on its way to ground and anchor itself offshore of the wildlife haven island of South Georgia.
Scientists believe that, if the collision happens, it poses a grave threat to local penguins and seals. The animal's normal foraging routes could be blocked, which will prevent them from feeding their young.
The collision will also cause all the creatures on the seafloor to be crushed on the site where the A68a will ground itself. BAS remote-sensing and mapping specialist, Dr Peter Fretwell, stated that, even though the satellite imagery suggests that A68a is on a direct path for South Georgia, the island might still escape capture.
Fretwell said "The currents should take it on what looks like a strange loop around the south end of South Georgia, before then spinning it along the edge of the continental shelf and back off to the northwest. But it's very difficult to say precisely what will happen."
The British Overseas Territory (BOT) of South Georgia is known as something of a graveyard for the Antarctica's greatest icebergs. When the A38 grounded at South Georgia in 2004, countless dead penguin chicks and seal pups were found on local beaches.
These icebergs get drawn up from the White Continent on the strong currents, where their keels then catch in the shallows of the continental shelf that surrounds the remote island, which leads to these huge ice sculptures slowly withering in sight of the land.
Proffessor Geraint Tarling from the British Antarctic Survey (BAS) said that; "Ecosystems can and will bounce back of course, but there's a danger here that if this iceberg gets stuck, it could be there for 10 years. And that would make a very big difference, not just to the ecosystem of South Georgia but its economy as well."
A68a has a shape similar to a hand with a pointing finger. The A68a has been riding this "iceberg alley" since it broke free from Antarctica in mid-2017, and it has now found itself a few hundred kilometers to the southwest of the the island.
Scientists revealed that A68a is the size of the English county of Somerset, which reaches 4,200 sq km, which is a similar size to the South Atlantic island lying in its path. The A68a weighs hundreds of billions of tonnes, however its relative thinness which is only a depth of perhaps 200m means it has the potential to drift right up to South Georgia's coast before anchoring itself.
Tarling further added that "A close-in iceberg has massive implications for where land-based predators might be able to forage. When you're talking about penguins and seals during the period that's really crucial to them – during pup- and chick-rearing – the actual distance they have to travel to find food (fish and krill) really matters. If they have to do a big detour, it means they're not going to get back to their young in time to prevent them starving to death in the interim."
Research is being conducted to further study the A68a route should it ground in one of the key productive areas for wildlife and the local fishing industry. However, researchers point out that not all the effects could be negative seeing that icebergs bring with them enormous quantities of dust which fertilises the ocean plankton around them which will then cascade up the food chain.
Researchers from BAS is currently in the process of trying to organise the resources to study A68a at South Georgia.
BAS colleague, Dr Andrew Fleming, confirmed that a request was going into the European Space Agency for more satellite imagery that will allow them to see through cloud, which mean they will be able to track the iceberg no matter what the weather conditions are like.
"The idea that it is still in one large piece is actually remarkable, particularly given the huge fractures you see running through it in the radar imagery. I'd fully expected it to have broken apart by now. If it spins around South Georgia and heads on northwards, it should start breaking up. It will very quickly get into warmer waters, and wave action especially will start killing it off," Fleming added.