Views of the Earth today Earth as a system. The earth is a spherical shape It supports a complex web of life. The earth’s system has 4 major parts: –

Views of the Earth today

Earth as a system

• The earth is a spherical shape• It supports a complex web of life.• The earth’s system has 4 major parts:– Atmosphere - air– Hydrosphere - water– Biosphere – living things– Geosphere – interior and rocks and soil

Atmosphere

• The mixture of gasses and particles that surround the surface of the earth

• Mostly nitrogen (78%) and oxygen (21%)• Also contains water vapor and carbon dioxide

• The atmosphere starts at the ground and extends into space!

Hydrosphere

• This is all of the water on earth• Oceans, lakes, glaciers, rivers, streams and

underground water• Water covers ¾ of the earth’s surface• Only about 3% of this water is fresh water

Biosphere

• The biosphere is all of life on earth.• Life on land, in the air, and in water.• Living organisms interact with the other parts

of Earth’s systems.• Trees and large forests breath with the earth

by absorbing carbon dioxide and releasing oxygen.

Geosphere

• Geosphere is everything from the Earth’s surface inward.

• Includes continents, islands, sea floor and everything below the surface of the Earth.

• The geosphere is made up of 3 layers– Crust– Mantle– Core

Geosphere: Crust

• Crust is the outermost layer.• This is where we walk on the land and the

floor of the oceans.• It is a thin rocky skin, much like the skin on an

apple.

Crust

• There are 2 types of crust:– Continental Crust• Makes up continents• Contains light colored rocks like granite• Floats high on the mantle

– Oceanic Crust• Makes up ocean floor• Contains dense rocks like basalt• Thinner than continental crust

Geosphere: Mantle

• Hotter and more dense than the crust.• The deeper you go inside the earth the more

temperature and pressure increases.• Made of solid rock.• The mantle has 2 zones:– Lithosphere– Asthenosphere

Geosphere: Core

• Deep within the earth is the core.• Made of mostly nickel and iron.• Very dense, twice the density of the mantle.• The core has 2 layers:– Outer is molten and responsible for

Earth’s magnetic field– Inner is sold