Transcript The Earth’s movement - Thomas Tallis Science Department

Structure of the Earth
The Earth’s layers
• The Earth consists of a core, mantle and crust.
Complete the table using previous slide
Thickness
Crust
Mantle
Inner core
Outer core
Temperature Properties
The Earth’s movement
• The Earth’s crust and the upper part of the mantle are
cracked into a number of large pieces (tectonic plates)
Continental drift
Convection currents
•
Convection currents within the Earth’s mantle, driven by heat
released by natural radioactive processes, cause the plates to move
at relative speeds of a few centimetres per year.
Effects of tectonic plate movements
• The movements can be sudden and disastrous. Earthquakes and/or
volcanic eruptions occur at the boundaries between tectonic plates
Why is the atmosphere
important?
The Earth is different to the
other planets in our solar system
because it has an atmosphere that
can support life.
The atmosphere is an envelope of
different gases (air) surrounding
Earth.
80% of atmospheric gases are in
the 15 km closest to Earth. This is
a very thin layer compared to the
Earth’s diameter, which is 12,756
kilometres.
What is the atmosphere made of?
The gases that make up the atmosphere have been the same for about
200 million years:
about 21% is
oxygen
about 78% is
nitrogen
The remaining 1% is mostly
argon (0.93%) with some
carbon dioxide (0.035%),
varying amounts of water
vapour and trace amounts
of other gases
How was our atmosphere formed?
•
•
•
•
During the first billion years of the Earth’s existence there was intense volcanic activity.
This activity released the gases that formed the early atmosphere and water vapour that
condensed to form the oceans.
There may also have been water vapour and small proportions of methane and ammonia.
Plants and algae produced the oxygen that is now in the atmosphere
Formation of plants and animals
•
There are many theories as to how life was formed billions of years ago
•
One theory as to how life was formed involves the interaction between
hydrocarbons, ammonia and lightning
Put into correct order
•
•
•
•
Most of the carbon from the carbon dioxide in the early atmosphere gradually became locked up
in sedimentary rocks as carbonates and fossil fuels
The oceans also act as a reservoir for carbon dioxide, though increased amounts impact on
marine life
Nowadays, burning fossil fuels is releasing carbon dioxide back into the atmosphere
Air is a mixture of gases with different boiling points an can be fractionally distilled to provide
a source of raw materials used in a variety of industrial processes