Fractures To Antarctic Iceberg Reduce Risk to South Georgia Wildlife

by user | January 6, 2021 12:50 am

The island of South Georgia in the Atlantic Ocean has recently been threatened with a possible impact from a massive iceberg.

The iceberg, named A68a by researchers, was struck by strong currents around the middle of December causing it to splinter off into three additional chunks from the main mass of ice.

The fractures to the iceberg have greatly reduced the risk that it initially posed to South Georgia and its wildlife.

The origins of the iceberg are said to be linked to the Larsen C ice shelf[1] that is a part of the Antarctic Peninsula.

For a long time, the Antarctic Peninsula[2] has been identified as one of the fastest-warming regions of the world.

Due to this, icebergs have been breaking off of the peninsula as far back as 1995. The A68a iceberg is said to have formed somewhere in 2017.

When it first formed, researchers did notice that the iceberg was quite massive.

The size of the iceberg was captured via satellite imaging and measured somewhere around 4,200 square kilometres (or around 1,622 square miles) which made it the fourth largest iceberg ever recorded.

Due to the strong currents that it has recently experienced, A68a was able to fracture and change its course away from the island.

However, it is important to note that these currents would have to be incredibly strong to tackle such a large iceberg.

Not only was this iceberg impressive by what could be seen on the surface of the water, but these chunks of ice are also pretty deep as well.

When this fracture occurred, the subsequent icebergs that formed were also given names to help identify them.

They were labelled as A68d, A68e, and A68f. Labelling them in such a manner helps researchers track their paths.

Additionally, the currents that broke A68a into these pieces really reduced the icebergs overall size. It is estimated that the size shrunk from 4,200 square kilometres to about 2,600 square kilometres (or about 1004 square miles).

This drastic split in the iceberg has also shifted the trajectory path as well.

While the initial path has been disrupted by the currents, researchers say there is still a possibility that it could reach South Georgia, just on the eastern shelf as opposed to its original point of potential impact.

If the original iceberg, given its giant size, had hit the island it would have been completely devasting to South Georgia’s wildlife.

The original path would have meant that the iceberg could have severely disrupted the underwater shelves and ecosystem of the island.

This ultimately means the iceberg would have blocked the island’s penguin and seal populations from having access to key feeding spots.

The penguins and seals on South Georgia are heavily dependent upon having access to the underwater ecosystems surrounding the island for their meals.

It is really easy to see how an iceberg of the A68a’s size could have created a lot of issues with their ability to eat.

However, this isn’t the only iceberg to pass by the island (or near it. In past research, this particular section of the Atlantic has been named “iceberg alley” because icebergs travel past South Georgia all of the time.

So why was this one so concerning?

The enormous size of the iceberg certainly had a part in the concern but the speed of it was alarming as well.

When the iceberg first broke off of the Antarctica Peninsula, it was travelling at a normal slow-paced speed.

Within the past year, the speed became quite reasonable which started quite a buzz among researchers who were watching the iceberg’s path of travel.

The speed was said to have increased due to the currents of the ocean increasing as well. With the currents also contributing to iceberg’s fracture it goes to show just how unpredictable ocean currents can be.

In fact, other icebergs that have passed through the notorious iceberg alley near the island have also broken apart.

So perhaps the ocean currents in this particular region aren’t so unpredictable after all. While there are strong currents in the region, researchers weren’t quite prepared for the A68a’s fracture.

Considering the iceberg’s size, researchers weren’t expecting the currents to break it up very much, if at all.

Thankfully for the island and its wildlife, the iceberg’s decreased size has greatly reduced the risk it had posed to the island.

As the icebergs currently stand, the island is extremely lucky that it broke into multiple pieces and chances are they will not hit the island.

Even if the icebergs were to make contact, researchers now predict that the damage would be lessened.

Additionally. researchers also suggest that when and if the icebergs to circle back around to South Georgia that they will have more than likely experienced further breakage.

This is excellent news and truly brings relief to researchers who were formally thought South Georgia was in big danger.

If the currents in this specific area of iceberg alley are able to fracture such a large mass of ice, then researchers have no doubt that they will be able to continually break down the smaller icebergs that were created off of A68a.

This evidence has been supported through other icebergs in the alley also being broken up.

If the currents keep up their destruction of the icebergs that spawned off of the larger one, by the time it would reach South Georgia again, there might be very little to no risk at all to the island.

Geraint Tarling[3] with the British Antarctic Survey[4] stressed the relief that researchers are feeling about the possibility of the icebergs further being diminished in size.

However, while researchers certainly feel optimistic about the safety of the island at this point, the ocean, in general, is a constantly moving mass.

With this in mind, the icebergs could move direction again at any point and time.

Even with the larger iceberg broken up, researchers are still keeping a close eye on the fracture pieces in the event that they do make their way back to South Georgia.

For now, though, the penguins and seals can continue feeding as they normally do.

Endnotes:
  1. Larsen C ice shelf: https://en.wikipedia.org/wiki/Larsen_Ice_Shelf
  2. Antarctic Peninsula: https://en.wikipedia.org/wiki/Antarctic_Peninsula
  3. Geraint Tarling: https://www.bas.ac.uk/profile/gant/
  4. British Antarctic Survey: https://www.bas.ac.uk/

Source URL: http://www.newsinsider.org/546/fractures-to-antarctic-iceberg-reduce-risk-to-south-georgia-wildlife/