Download UNIT 5 – Earth`s Internal Structure

EARTH’S INTERNAL
STRUCTURE
1 - EARTH STRUCTURE & DIMENSIONS
2 - LAYERS OF THE EARTH
3 - ELEMENTS OF THE EARTH
EARTH STRUCTURE & DIMENSIONS
• Earth is a terrestrial planet
• Terrestrial planet : one of
the first four planets of the
solar system whose surface
is composed of solid rock.
• The radius of the Earth is
approximately 6400 km
LAYERS OF THE EARTH
• The Earth is composed of the following layers :
• 1) The Crust
• 2) The Mantle
- The upper mantle (or asthenosphere)
- The lower mantle
• 3) The Core
- The outer core
- The inner core
LAYERS OF THE EARTH
The Crust
Upper Mantle
Lower Mantle
Outer Core
Inner Core
LAYERS OF THE EARTH
•
LAYER
DISTANCE
TEMP.
CRUST
5 – 65 km
5˚ C
UPPER MANTLE
670 km
LOWER MANTLE
2885 km
1800˚ - 3700˚ C
OUTER CORE
2270 km
3700˚ - 4500˚ C
INNER CORE
1216 km
+4500˚ C
1000˚ -1800˚ C
LAYERS OF THE EARTH
LAYERS OF THE EARTH: THE CRUST
• The solid surface of the Earth is called the crust.
• The Terrestrial crust covers the other layers of the
Earth.
• It becomes warmer and warmer as it approaches
the center of the Earth
LAYERS OF THE EARTH: THE CRUST
• The Earth's crust is solid.
• Its thickness varies:
• between 5 and 10 km under the oceans
(oceanic crust)
• between 30 and 65 km under the continents
(continental crust)
LAYERS OF THE EARTH: THE MANTLE
• THE MANTLE is directly beneath the Earth's crust.
• Its temperature is much hotter than the Earth’s crust
and is hotter in the lower mantle than the upper
mantle (or asthenosphere).
• UPPER MANTLE - Asthenosphere
• Its thickness can reach 670 km. This layer is semifluid.
It consists of partially molten rock. It is believed that
this is the surface on which the tectonic plates
move (the movement of continents).
LAYERS OF THE EARTH: THE MANTLE
• LOWER MANTLE
• This layer is solid despite its high temperature
because the pressure is too strong.
• It consists mainly of silicon , oxygen , iron and
magnesium.
LAYERS OF THE EARTH: THE CORE
• THE CORE is located below the two layers of the
mantle.
• THE OUTER CORE is liquid. The metal elements in this
layer gave rise to Earth's magnetic field.
• Its thickness is about 2.270 km .
• THE INNER CORE Despite its very high temperature, it
is solid due to the pressure.
ELEMENTS OF THE EARTH
• During the birth of the Earth,
the heavier elements ,
like Iron (Fe) and Nickel (Ni),
were attracted towards the
center of the Earth and
formed the nucleus.
• The lighter elements , such
as Silicon (Si) , Oxygen (O)
and Aluminum (Al), have
come together on the surface of the Earth to form
the mantle and crust.
EARTH = THE EGG
• One can compare the internal structure of the Earth
to that of an egg.
• The shell is the crust
• The White is the mantle
• The core is yellow
EARTH = THE EGG
• CRUST
SHELL
• MANTLE
EGG WHITE
• CORE
YOKE