How much freshwater is stored in Antarctic ice?

Thanks Bea (age 8) for this great question!

Let’s start with some basic info about the Antarctic ice sheet, and then we’ll go into exactly how much freshwater is stored there.

Freezing facts about Antarctic ice

The Antarctic ice sheet is the biggest reservoir of freshwater on Earth. It is a huge, thick blanket of ice that flows slowly over and around mountains, filling the valleys and canyons underneath.

This is part of the Antarctic ice sheet. You can see the tops of mountains sticking out of the ice in some places, and the flow of the ice like a river down the middle.

The Antarctic ice sheet covers around 14 million square kilometres – almost twice the size of Australia! Almost all of Antarctica (98 percent) is completely covered in ice.

Australia and Antarctica compared on a map. The grey parts you can see around the edges are ice shelves, massive plates of ice that flow out over the ocean. We can talk more about them another time.

Around 70 percent of all the freshwater on Earth is frozen in the Antarctic ice sheet. That’s much more than half! The other 30 percent is made up by all the other freshwater on earth, from rivers and lakes to glaciers and stores underground.

One way to help visualise this is to ask your parents to get a 1 litre bottle and pour 30 percent (300 millilitres) into a cup. What’s left in the bottle is the percentage of water on earth that is stored as ice in Antarctica. The part they poured out is ALL the other freshwater on earth!

This enormous iceberg broke off the edge of the Antarctic ice sheet in 1987. It was  154 kilometres (96 mi) long and 35 kilometres (22 mi) wide. Since then it has been breaking into smaller pieces and drifting around the continent. We sailed past it in the December, 2018. It was amazing!

Almost all the ice on earth (around 90 percent) is in Antarctica. All the ice in every other glacier, from Greenland to the Himalayas and the Alps, from to the Rockies to the Andes, makes up only 10 percent of the ice on the planet.

The pink sections are glaciers (like rivers of ice). The white sections are ice sheets, which are huge glaciers that cover areas over 50,000 square kilometres. Ninety percent of the world’s freshwater ice is in Antarctica.

The Antarctic ice sheet is deep

How can Antarctica hold 90 percent of the world’s ice, when there are so many glaciers (marked in pink above)?

Part of the reason is that the Antarctic ice sheet is more than just a thin layer of ice spread across the continent like vegemite on toast.

It is deep. Very deep.

It can be helpful to think of the Antarctic ice sheet as a three dimensional thing, like the ocean.

In some areas near the coast it may only be a few metres deep, but that changes as you move away from the ocean.

The deepest part of the ice sheet is 4776 metres deep. That’s nearly 5 kilometres – twice the height of Mt Kosciuszko in the Australian Snowy Mountains!

Here you can see the ice is particularly deep in East Antarctica. The white part is ice, and the grey shading is land beneath the ice. DiscoveringAntarctica.

If all of Australia was covered in ice 2km thick, this would still only be around half the amount of ice in Antarctica.

The Antarctic ice sheet is so deep that even the longest, strongest drills can’t drill all the way through. In 2019, a group of scientists drilled a hole over 2 kilometres (2152 metres) into the ice. They drilled non-stop for 63 hours to get there!

So how much freshwater is stored in Antarctic ice?

Ok, it’s time to answer your question. Get ready to hear one of the biggest numbers around.

Drumroll please . . .

The answer is: the Antarctic ice sheet contains around 30 million cubic kilometres of ice.

Let’s try to put that in perspective.

ONE cubic kilometre is about the same as:

• 400 Great Pyramids of Giza

Great Pyramid of Giza, Egypt

• 600 Melbourne Cricket Grounds

Melbourne Cricket Ground, Melbourne

• One and four fifths Sydney Harbours (so – almost twice as big ;))

A cubic kilometre is 1.78 times the size of Sydney Harbour

So, multiply that by 30 million, and that’s how much ice there is in the Antarctic ice sheet.

Around 53.4 million Sydney Harbours.

Or 18 billion Melbourne Cricket Grounds.

But how much freshwater is in 30 million cubic metres of ice?

The answer is 27.6 million cubic metres! _{(You can find out why the volume of water is lower than ice here).}

One way to imagine this is: if you melted the entire Antarctic ice cap and spread it across the sea, the sea would rise around 60 metres!

It can be hard to wrap your head around a number that big. But isn’t it marvellous to think that there’s a continent on our planet covered in so much ice it’s hard to even imagine it?

Antarctica is different from all the other continents on our planet. In fact, it has so much in common with Mars and the Moon that NASA sends its astronauts there for training!

One thing’s for sure: there’s a whole lot of ice in Antarctica!

Thanks again for your question Bea! What do you think about Antarctic ice, now that you know how much of it there is? Let me know on Facebook or leave a reply below!

Want to learn more?

• You can find out more about ice and the water cycle here.

• You can read about how to calculate volumes of ice and water (and convert them) here and here.

This post is part of my Antarctic Q&A series. If you have a question about Antarctica you can submit it here or send it to asktheantarcticshop@gmail.com, and I’ll write you a personalised response!

Subscribe to Blog via Email

Enter your email address to subscribe to this blog and receive notifications of new posts by email.

Email Address:

Subscribe

_{This blog post was written by Nina, an Antarctic guide based in Australia. If you have an Antarctic question for Nina, you can submit it here or send it to asktheantarcticshop@gmail.com.}

Thanks to Blue Bulb Projects for helping me conceptualise the mass of the Antarctic ice sheet!

Australia and Antarctica from space
Antarctic Climate and Ecosystems CRC

You can support Nina’s work by shopping below or at The Antarctic Shop.

Protect Antarctica Pillow

Shop Now

Ice Paradise Tote Bag

Shop Now

Mist on the Glacier Poster

Shop Now

Advertisement