PLANET EARTH - The Incredible Visual Guide Part 3 ppt

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5 THIN AIR

For climbers, every mountain is a challenge. Climbing can

involve not only the dangers of ascending steep, icy rock faces,

but also the problem of surviving at high altitudes. It can be

freezing cold, and the air on the highest peaks is so thin that

there is barely enough oxygen to breathe. This makes climbing

almost impossible, so many mountaineers are forced to wear

breathing equipment.

Barren granite peaks are

separated by steep valleys

gouged out by ice

4 MOUNTAIN WILDLIFE

The higher you go, the colder it gets, so being near the top of a

high mountain on the equator is almost like being in the Arctic.

The plants that live there have to be tough to survive, and at

really high altitudes nothing can grow at all. Mountain animals

like the snow leopard have thick fur coats to keep out the cold,

and must be surefooted to move confidently through the

rugged and often frozen terrain.

2 ANCIENT RANGES

Many ancient mountain ranges mark geological events in the

distant past. The Caledonian mountains of Scotland were formed

by a collision of continents more than 400 million years ago, along

a tectonic plate boundary that no longer exists. The mountains

were once as high as the Himalayas, but they have been worn

down to form the heavily eroded landscape that now makes

up the Scottish Highlands.

3 ERODED STUMPS

Eventually all mountains are reduced to rounded stumps by

the relentless forces of erosion. The Bungle Bungle range in

northwestern Australia was once a high plateau formed from

horizontal layers of sandstone. Over some 350 million years, the

edge of the plateau has crumbled under the assault of torrential

rain, blistering summer heat, and winter frosts to create these

layered domes.

2

Iron oxide makes the layered

sandstone glow rust-red

Suilven in northwest

Scotland is the

remains of a much

bigger peak

3

The Torres del Paine

rise above the steppe

in southern Chile

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