Download The Geosphere

The Geosphere
Changes occur on the Earth
constantly:
• Molten rock flows from volcanoes
• Hurricanes batter beaches and change
coastline
• Earthquakes shake the ground
The Earth is a system that consists of
air, water, rock and living things
All of the ‘parts’ interact with each other
Scientists use special terms to describe
the different parts of the Earth
• Geosphere – consists of all the rock, soils and
sediments on the Earth
• Atmosphere – consists of the air that surrounds the
Earth
• Hydrosphere – consists of all water, fresh or
saltwater
• Biosphere – all living things on the planet
Most of the geosphere is located in
the Earth’s interior
The average diameter of the Earth is 12,756km
Discovering the Earth’s Interior
The earth is like an onion
Its made of layers
The information we have concerning the
interior of the Earth comes to us from
studying seismic waves
Seismic waves travel through different material at
different rates. When seismic waves change direction
or speed, it means they have moved through different
layers
Scientists divide the Earth into three
layers based on composition
• Crust – the thinnest layer of the Earth (5-20km thick)
made entirely of light elements
• Mantle – makes up 64% of the earth’s mass, (2900km
thick) made of rocks of medium density
• Core – has a radius of 3400km and composed of the
densest elements
The Earth can also be divided into 5
layers based on physical properties
• Lithosphere
• Asthenosphere
• Mesosphere (mantle)
• Outer core
• Inner core
The lithosphere is the Earth’s outer
layer
It contains the crust and uppermost part of the
mantle and is divided into moving sections called
Tectonic Plates
The asthenosphere is the layer
beneath the lithosphere
The asthenosphere is the ‘plastic’ solid layer of the
Earth that the plates move on top of
The mesosphere consists of the
lower mantle between the
asthenosphere and outer core
The mesosphere contains molten rock which is
called ‘magma’
The outer core is 2200km thick
and made of nickel and iron
The outer core is mostly liquid
The inner core is a solid sphere of
iron, nickel and cobalt (radioactive)
The temperature of the inner core is thought to be
between 4000 and 5000 degrees Celsius
Scientists believe that cobalt in the
core decays producing heat
The heat from the core produces energy that
makes the magma move producing earthquakes,
volcanoes and plate movement