Planet Earth: The Surface of the Earth Flashcards
What do we call the hard, rocky layer on the surface of the earth?
The earth’s crust.
True or False. The earth’s crust stops at the sea.
False. The crust surrounds the whole earth, including under the sea and oceans.
What is the earth made from?
Rock. Even under the soil, water, sand there is always rock.
What four things things does life on earth need to survive?
Soil
Water
Air
Sunlight
What is the top layer of the earth called? Describe it.
Topsoil.
Dark in colour.
And it has the remains of dead plants and animals in it.
Must nutrient rich layer.
What is the second layer of the earth called? Describe it.
Subsoil.
Under the topsoil.
Not as nutrient rich as topsoil.
Nutrients go to this layer when it rains.
What is decompose?
When a plant or animal dies and it breaks down into smaller parts and the nutrients go into the soil.
What is below subsoil?
Broken pieces of rock mixed with some soil.
What are the layers of soil?
Topsoil
Subsoil
Pieces of rock and soil (sandy soil)
Solid rock/crust (bedrock)
Name two ways rocks are broken into tiny pieces of grain to make topsoil?
Root of plants growing in the cracks in the rock can split the rock.
Chemicals in the water and air cause the rock to weaken and crumble,
What is fertile soil?
Soil in which the plants can grow well.
Name three types of soil?
Sandy soil.
Clayey soil.
Loamy soil.
Does coarse grain have large or small grains?
Large.
What size are fine grains?
Very small.
What are soil grains?
Small pieces of broken rock.
What is humus?
Dark material in the soil made of fully decomposed remains of plants and animals.
Describe sandy soil:
More coarse grains than fine grains.
Feels gritty when you rub it between your fingers.
Describe clayey soil:
More fine grains than course grains.
If feels smooth when you rub it between your fingers.
Feel sticky when wet.
Describe loamy soil:
Equal amounts of a sandy and clayey soil.
Contain humus.
What is the difference between compost and humus?
In compost not all the vegetable and plant matter is fully decomposed. In humus it is full decomposed.
True or false. Can soil hold air and water?
True.
Why is loamy soil the best soil for growing plants?
It has a mixture of coarse and fine grains. It does not get too wet or too dry.
Name four kinds of mals that live in soil.
Earthworms
Termites
Crickets
Spiders
What do animals that live in soil help with?
Mixing the soil up so that it takes material on the top into the soil.
They make open spaces for more air and water so that it makes it easier for plants to grow.
What is soil erosion?
When the soil is washed away by water or blown away by wind.
How long does topsoil take to form?
Many thousands of years.
