Download Our Dynamic Earth

Our Dynamic Earth
By
StarShineSandy,
tbanana123 and
Spencerdog!
Introduction
We would like to share our knowledge
about our Dynamic Earth. In this Power
point there is lots of different information.
We hope you will learn lots of new
information about our Dynamic Earth. We
hope you enjoy!
Contents
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
What are Plate Tectonics?
Structure of the Earth
Earthquakes explained
Tsunamis explained
Volcanoes explained
Pacific Ring Of Fire
Diagrams
Glossary
Pictures
Thanks
What are Plate Tectonics?
• The Earth is moving beneath our feet.
• Its hard shell, lithosphere, is made up of continental crust
and mantle.
• It is divided into 17 plates, which drift on the upper
mantle.
• Plates beneath the oceans are thin but made up of
heavy material, but continental plates are made of light,
thicker material.
• Some plates move apart (divergent), overlap
(convergent) and rub against each other (transform).
• These all lead up to mountains, volcanoes, ocean
trenches and earthquakes.
The Structure of the Earth
• The earth is made up of 3 main layers:
Core
Mantle
Crust
• The crust is what we live on.
• There are 2 types of crust:
Continental crust
Oceanic crust
Earthquakes Explained
• Earthquakes occur on plate boundaries
where there are faults.
• Friction causes stress to the plates and
then when the stress becomes to much
and that causes an earthquake.
• There are three main faults: strike-slip,
normal and reverse or thrust faults.
Tsunami’s Explained
• A tsunami occurs when plates rub together
creating an underwater earthquakes.
• This creates massive waves that hurl
themselves towards the shore.
• When there is a lot of wind it can make a
larger wave.
• Tsunamis can travel at speeds of up to
590 mph.
Volcanoes Explained
• About four-fifths of the Earths surface is
volcanic rock.
• Some volcanic eruptions are violent
explosions of lava, gas and ash.
• Where two oceanic plates move apart,
gentle eruptions produce long volcanic
ridges on the seafloor.
Pacific Ring of Fire
• An area where a number of earthquakes
and volcanic eruptions occur in the basin
of the Pacific ocean.
• Roughly 90% of earthquakes occur along
the Ring of Fire and dotted with 75% of
volcanoes on Earth.
• There are 452 active volcanoes along the
Ring of Fire.
• The Ring is shaped like a horse-shoe.
Diagrams
Glossary
• Lithosphere – the outer part of the Earth.
• Oceanic Crust – the part of the earth we
live on but underwater.
• Continental Crust – the part we live on (not
underwater)
• Mantle – the layer of the Earth underneath
the crust.
Pictures
• The blue
Lagoon in
Iceland is
heated by a
volcano
Thanks For Watching