Weathering

Weathering:

one way the Earth's surface is SLOWLY changed.

Earth's Surface

The Earth's surface is mostly made up of rock. Although rock is hard, wind and water can SLOWLY break it apart.

Weathering

is the breakdown of rock into smaller pieces at or near the Earth's surface.

Poll

Which things do you think can weather rocks?

• wind

• water

• ice

• chemicals

• a hammer

The truth is

all of these things can break down or weather rocks. Even you, with a hammer in your hand, could change the surface of the Earth.

Wind weathers rocks.

The first type of weathering we will learn about is wind.

Weathering by Wind

Wind and water can carry sand and other small pieces of rock. Blowing sand can act like sand paper on a rock.

Multiple Choice

Do you think weathering by wind happens slowly or quickly?

• slowly

• quickly

Wind carries sand

in a desert that weathers down rocks.

Ocean Waves Weather Rocks

Ocean waves also weather down rock cliffs because the waves carry sand and pebbles.

This sea arch was created over hundreds of years.

Multiple Choice

How long did it take the Azure Window Sea Arch to form?

• 10 years

• 100 years

• 500 years

Sea Stacks

These are sea stacks and are another example of weathering by ocean waves.

Rain and Cold Temperatures Can Weather Rock

Rain fills cracks in a rock and cold temperatures freeze the water, causing weathering of the rock.

Rain also causes weathering

1. Water seeps into the cracks of a rock.

2. As the water freezes into ice, the rock expands and breaks apart.

** Remember weathering is the breaking down of rock.

Multiple Choice

What happens to rocks when water freezes in the cracks?

• the rocks grow

• the rain drains out

• the rock cracks

Plants Weather Rocks

Plants can break down rocks, too!

Poll

How do you think plants can weather rocks?

• trees grow through rocks

• roots can crack rocks

• plants live on rocks

Plant roots grow into the cracks of a rock.

As the roots become larger, they pry the rocks apart.

Weathering also

breaks down human created objects like roads and buildings.

Multiple Choice

What most likely causes potholes in roads?

• roots cracking the road

• sand blowing on the road

• water freezing in cracks

Wind, water, ice, and plants weather rock.

• Weathering breaks rock into smaller and smaller pieces over a long time.

• These pieces become pebbles and sand.

• Small pieces of rock along with material from living things make up soil.

Multiple Choice

What caused the weathering in this picture?

• ice in the crack

• tree roots

• ocean waves

• sand in the wind

Multiple Choice

What caused the weathering in this picture?

• ice in the cracks

• sand in the wind

• ocean waves

• tree roots

Multiple Choice

What caused the weathering in this picture?

• ice in the cracks

• tree roots

• ocean waves

• sand in the wind

Multiple Choice

What caused the weathering in this picture?

• ice in the cracks

• ocean waves

• tree roots

• sand in the wind

Poll

Can you tell someone what weathering means now?

• What is weathering?

• I can if I have to.

• I hope someone asks me!

• Absolutely! I'm a weathering expert!

• I know more than the teacher.