The Earth System: Lithosphere, Biosphere Hydrosphere,

and Atmosphere

This Island Earth

As far as life is

concerned:

“Goldilocks of the

Solar System”

(relative to Sun, not

too far, not too close,

just right !)

About 4.5 billion

years old

Earth’s Four Spheres

1.Lithosphere

2.Atmosphere

3.Hydrosphere

4.Biosphere

The Earth’s Four Spheres

Geosphere

1.Geosphere: comprises the solid

Earth and includes both Earth’s

surface and the various layers of

the Earth's interior.

94 % percent of the earth is

composed of the elements oxygen,

iron, silicon, and magnesium

Earth’s Layers: Composition and Mechanical Characteristics

ATMOSPHERE

• This is the gaseous envelope that

surrounds the Earth and is the

transition between its surface and

the vacuum of space

• consists of a mixture of gases

composed primarily of nitrogen,

oxygen, carbon dioxide, and water

vapour

Majority of atmospheric

mass here

Atmospheric structure

exosphere

Many meteors burn up here

Auroras in lower troposphere

Satellites and space shuttle

orbit in the upper themosphere

HYDROSPHERE

This includes all water on Earth (including surface water and groundwater)

Liquid water on Earth makes it distinct from other bodies in the solar system

Subcomponents of hydrosphere are

connected via the hydrologic cycle

BIOSPHERE

This includes all living organisms, and all organic matter that has not yet decomposed.

Plants, animals, bacteria, viruses, fungi, everything that is or was alive.

BIOSPHERE

Life began at least 3.5billion years ago and

The biosphere makes our planet different from all others (as far as we know)

It is structured into a system known as the food chain whereby all life is dependent upon the plants that are capable of photosynthesis.

Food chain is more realistically viewed as a web

Food Web

Note that interactions within even a single ecosystem are

very complex !