Dimensions of the Earth

Shape and Composition of the Earth

POLES: slightly flattened

EQUATOR: slightly bulging

The Earth is composed of a series of spheres. Each sphere has a different composition of materials and is held together by gravity. The spheres of Earth are arranged from least dense (atmosphere)

to most dense (geosphere) depending on how close they are found to the Earth’s center.

Atmosphere

The atmosphere is the least

dense of all the spheres

The atmosphere is composed of 78%

nitrogen,21% oxygen and 1% other gases

and aerosols – suspended solids and

liquids in the atmosphere.

Earth’s atmosphere is broken known into

smaller spheres (zones) with distinct

differences in air temperature and composition. The interface between these zones are called pauses.

RT = Pg. 14

Hydrosphere

The hydrosphere consists of bodies of freshwater and saltwater found on

Earth’s surface including: oceans, lakes, rivers and

streams.

Mostof the hydrosphere(~

70%) is composed of

water (hydrogen/oxyg

en).

Lithosphere

The lithosphere lies

beneath the atmosphere

and hydrosphere.

The uppermost section of the lithosphere is

the crust which is broken up into sections

known as lithospheric or tectonic plates.

RT = Pg. 1

Geosphere

The geosphere is the most

dense of all the spheres

RT = Pg. 10

The geosphere is broken into zones

based on changes in density, pressure and temperature.