Scientists have been studying a vast ice sheet in Antarctica for months. Now, they warn that if it melts, the effects could be catastrophic . But what are glaciers? And why do they affect us?
What are glaciers?
Glaciers are huge masses of ice. They flow over land like water – but much more slowly. As a result, many people describe them as “rivers of ice”. They form over hundreds of years where fallen snow compresses and turns into ice. In many glaciers, the ice is so compacted that it is a bright, clear blue. Glaciers make up the largest store of water on the planet. In fact, they hold 75% of the world’s freshwater.
Are there different kinds?
Yes! They are usually divided into two groups. Alpine glaciers form on mountainsides and move downwards over land. Over millions of years, they change the way the ground looks by forcing dirt and debris out of their way, creating whole valleys.
The second kind is an ice sheet. These are not limited to mountainous areas. They spread out and cover much larger areas. As they grow, they cover everything around them including valleys, plains – even entire mountains. The largest ice sheets are known as continental glaciers and are found in Greenland and Antarctica.
Does anything live on them?
Temperatures may be too low for humans, but some creatures depend on these icy conditions. All sorts of microbes live on the surface of the ice – and under it. Many species of birds also visit the glaciers during the summer months. Whales, polar bears and seals are larger animals that roam the ice looking for food.
How big are they?
They are huge. To be considered an official glacier, the ice must cover 25 acres – or nearly 15 football pitches.
The world’s largest glacier is the Lambert Glacier in East Antarctica. It is nearly 100km wide and 2,500 metres deep. It is about 435km long — almost as wide as the UK. The Lambert Glacier is sometimes known as an ice stream because it moves faster than most glaciers. Its top speed is 1,200 metres per year.
What’s the problem?
Last week, scientists announced that the Thwaites Glacier in Antarctica is melting faster than they thought. This is because of warm seawater from the other side of the world. It usually doesn’t travel this far south. Now, it is arriving as a result of the unusually strong winds caused by the warming of the Pacific Ocean.
When glaciers melt, sea levels rise. Scientists estimate that if all the world’s glaciers melted, sea levels would rise by 65 metres — enough for London to be buried underwater.
Is there anything we can do?
Luckily, yes! Melting glaciers are just one example of how the world is being affected by global warming. We can all help by reducing our carbon footprint.
Some ways to do this are by wasting less electricity, finding alternatives to single-use plastic and eating food that is produced locally.
- Is it too late to prevent the climate crisis?
- Use the internet to find out about an animal that lives on an ice sheet. Make a poster about it, showing what it eats and how it survives in such extreme weather.
- Pressed down very tightly. In glaciers, layers of snow are pressed on top of one another, eventually turning into the clear blue ice you might see in pictures.
- The world's largest island, located between the Arctic and Atlantic oceans. It is very close to the North Pole, which actually sits in the middle of the Atlantic ocean.
- The southernmost continent and site of the South Pole. Few people live there, but it is home to hundreds of different kinds of animals.
- Tiny living creatures that are invisible to the human eye. To see them, we need to use a microscope.
- Thwaites Glacier
- One of the largest glaciers in the world. Scientists have made their recent discoveries there with the help of a remote-controlled yellow submarine.