World’s biggest iceberg breaks free and could leave Antarctic waters
An iceberg that’s twice the size of London and two thirds the height of the world’s tallest skyscraper has started drifting away from Antarctica and could wind up in British waters
READING LEVEL: GREEN
The world’s biggest iceberg is on the move for the first time after being stuck to the ocean floor for 30 years.
The iceberg, called A23a, is 3884 km sq in size, which is twice the size of London.
It is also 399m thick, which is about two-thirds as high as the world’s tallest skyscraper, the Burj Khalifa in Dubai.
The iceberg split from the Antarctic coastline in 1986 but got stuck to the ocean floor and became an ice island.
It started drifting again in 2020 but picked up speed this year as wind and currents pushed it along faster.
The iceberg has started heading past the northern tip of the Antarctic Peninsula and could soon leave Antarctic waters altogether.
British Antarctic Survey remote sensing expert Dr Andrew Fleming told the BBC that scientists had been expecting the iceberg to start moving again once it had melted enough to lose its grip on the ocean floor.
The iceberg will most likely end up in the Antarctic “Circumpolar Current” before being pushed into a path known as “iceberg alley”.
Icebergs like A23a that end up in the Weddell sector usually follow the same path because of the movements of the Circumpolar Current, which is the strongest current in the Earth’s oceans.
From there, the huge iceberg might drift towards South Georgia island, which often has big tabular icebergs sitting off its coast.
The ice blocks usually get pinned on the shallow continental shelf of the island, which is considered British territory.
If A23a gets stuck near South Georgia, it might pose a problem for the millions of seals, penguins and other seabirds that live on the island.
The mega berg could get in the way of the animals’ normal foraging routes, stopping them from feeding their young properly.
But all icebergs eventually melt and wither away, releasing mineral dust.
And this dust is an important part of oceanic food chains.
“In many ways these icebergs are life-giving; they are the origin point for a lot of biological activity,” said Dr Catherine Walker, from the Woods Hole Oceanographic Institution.
The scientists will observe the movement of A23a closely.
This story originally appeared in The Sun and is reproduced here with permission
POLL
GLOSSARY
- Circumpolar current: an ocean current that flows clockwise around Antarctica from west to east
- Weddell sector: part of the Weddell Sea, off the north of Antarctica
- tabular icebergs: icebergs with flat tops that have broken off an ice shelf or glacier
- continental shelf: the edge of the continent that is covered by water
- British territory: under British rule
- foraging routes: places to look for food
- oceanic: things that have something to do with the ocean
- origin point: starting point
- biological: related to life and living things
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QUICK QUIZ
1. What is the name of the iceberg that is floating away from Antarctica?
2. How thick is its ice?
3. What year did it break away from Antarctica?
4. What year did it start to drift away?
5. What is the name of the island it is heading towards?
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CLASSROOM ACTIVITIES
1. Ice issues
If the A23a iceberg does move and get pushed to a different part of the ocean, what are some of the possible ramifications, apart from those listed in the Kids News article (disrupting food sources for marine life)?
Work with a partner and list some of the issues it might cause to people who use the ocean or live where it might next get submerged.
Time: allow 20 minutes to complete this activity
Curriculum Links: English, Geography, Science, Personal and Social, Critical and Creative Thinking
2. Extension
How do you think icebergs form?
Write a KWL (Know, Want to know and Learnt) chart on this topic and use your research skills to answer your own wonderings.
| KNOW: | WANT TO KNOW: |
LEARNT: |
Time: allow 45 minutes to complete this activity
Curriculum Links: English, Science, Personal and Social, Critical and Creative Thinking
VCOP ACTIVITY
BAB it!
Show you have read and understood the article by writing three sentences using the connectives “because’’, “and”, and “but” (BAB). Your sentences can share different facts or opinions, or the same ones but written about in different ways.