Structure of the Earth Not so solid Earth. The Earth has three levels: Core, Mantle, Crust.

Structure of the Earth

Not so solid Earth

The Earth has three levels:

• Core,

• Mantle,

• Crust

• Is the center of the earth

• Consists of iron and nickel

Mantle• Surrounds the core

• Consists of the earth’s mass

• Contains molten rock called magma

Crust

• Thin layer of rock at the earth’s surface

On and above the earth

AtmosphereLithosphereHydrosphereBiosphere

Atmosphere• A layer of gases surrounding the

earth• Contains the oxygen we breathe• Protects earth from radiation and

space debris• Provides medium for weather and

climate

LithosphereThe outer shell of the earthIncludes the crust and uppermost mantle

Together, the hydrosphere, lithosphere, and atmosphere form the.

. .

biosphere

Continental Drift Theory

• Presented by Alfred Wegener

• Earth was once a supercontinent that divided and slowly drifted apart over millions of years

• Wegener called the supercontinent Pangea(all earth)

Do the continents continue to drift today?

How can the presence of seven continents on the

earth's surface be explained?