Ms. Drakoulis
Earth Science
Topic: Introduction to Earth Science
The Earth’s four spheres
Atmosphere, Geosphere, Hydrosphere & Biosphere
The Atmosphere
 A gaseous envelope surrounding Earth.
 Composed of a mixture of gases.
 Oxygen, carbon dioxide, ozone, sulfur, nitrogen…
 The atmosphere is composed of 5 layers
 The atmosphere has four major layers:
First Layer of Atmosphere: The Troposphere
 Here all weather occurs.
 The thickest part is closest to the surface.
 The higher in altitude, the thinner the air.
 If you are on a mountain the air will be much
thinner than if you on the ocean.
 The pressure is highest at sea level.
 The further up you go in elevation the lower the
pressure.
Second Layer of Atmosphere: Stratosphere
 If you look at you ESRT you will see that the
stratosphere the temperature at the bottom is
cold then it increases, this is because of the
presence of ozone.
 Ozone absorbs ultraviolet rays and releases it as
heat.
Third layer of atmosphere: Mesosphere
 The atmospheres third layer extends about 50-90
kilometers above Earth’s surface.
 Because very little ozone is present in the
mesosphere, temperatures again drop with
increasing altitude.
Fourth layer of atmosphere: Thermosphere
 Above 90 kilometers fourth layer the
thermosphere.
Ms. Drakoulis
Earth Science
Topic: Introduction to Earth Science
 Air is extremely thin, the few molecules and
atoms present receive such intense solar
radiation that temperatures can rise above 1000
degrees Celsius.
 The thermosphere is divided into two sections the
Fifth layer of atmosphere: ionosphere and the
exosphere.
 Ionosphere
 The portion of the thermosphere between about 90500 kilometers above Earth is also called the
ionosphere, because the air there is highly
ionized.
 Exosphere
 Exo - in Greek means to be outside.
 Do you remember any words in living environment
that included this prefix?
The Geosphere or lithosphere
 The earth itself -the rocks, the mountains, the
beaches and all the other physical features of
the planet, except water make up the Geosphere or
lithosphere.
 The Geosphere includes the ocean basins (bottom)
and the rock layers beneath your feet, including
those that you cannot see.
 Layers of the Geosphere
 The layers you cannot see are the mantle that is
the source of lava that pours form volcanoes, and
the core that forms the planets center and
generates Earth’s magnetic field.
 The core is divided into two sections the inner
and outer core.
 On the diagram provided write the proper name.
Use the ESRT to write the density, temperatures
and distances of each.
The Hydrosphere
Ms. Drakoulis
Earth Science
Topic: Introduction to Earth Science
 The hydrosphere contains all the water in the
Earth system including the water in the oceans,
lakes and rivers, and groundwater.
 The hydrosphere also includes the water locked up
in ice and snow at the poles and in high
mountains.
 A person that studies the troposphere is a:
Meteorologist
 A person that studies the crust of the earth is
a:
Geologist
 A person that studies the bodies of water is a
Hydrologist