Transcript The Layer`s Of The Earth!

The Layers of the
Earth!
Earth Layers
• The Earth is divided into three
major zones that are defined by
their compositions.
*Core (Inner and Outer)
*Mantle
*Crust
The Crust
*The Earth’s crust is the
thin, rocky outer layer of
Earth
*It is composed of the
oceanic and continental
crust
*The crust makes up 1% of
the Earth.
* The crust of the Earth is
broken into many pieces
called plates.
Crust
• Oceanic crust is composed of basalt
• Continental crust is composed of
granite
• Temp of crust - up to 870◦C
• Approx. 30 miles deep
The Mantle
*. The mantle is the layer
below the crust
*The mantle is the largest
layer of the Earth; over
82% of the Earth’s
volume
*The mantle is divided into
two regions: the upper
and lower sections.
Mantle
• 1,800 miles thick
• Temp – up to 2700◦ C
• Composed of dense rock and semisolid
rock
Outer Core
* The core of the Earth is
like a ball of very hot
metals; it is composed
of an iron-nickel alloy.
* The outer core is liquid.
* The flow of metallic iron
within this zone
generates the Earth’s
magnetic field.
Inner Core
The inner core of the
Earth is compressed
into a solid state by the
immense pressure.
• The inner core is a solid.
• Temp - 7200◦C
• Depth of up to 2100 mi
Lithosphere
*The rigid outer layer of
Earth, including the
crust and upper mantle.
Asthenosphere
Is the hotter upper mantle below the
lithospheric plate;
Can flow like silly putty; and
Is a viscoelastic solid, NOT liquid!!
Seismic Waves
*Seismic waves are the
vibrations from
earthquakes that travel
through the Earth.
*They are the waves of
energy suddenly created by
the breaking up of rock
within the earth or an
explosion .They are the
energy that travels through
the earth and is recorded
on seismographs.
Types of Seismic Waves
• Surface
Waves
• Body Waves
P waves
S waves
Surface Waves
* Seismic waves that travel along the Earth’s
outer layer.
* They travel along the ground and cause the
ground and anything resting upon it to move.
*Surface waves are the most destructive
earthquake waves.
Primary or p-wave
* Compression wave
* The first kind of body wave is the P wave or primary
wave. This is the fastest kind of seismic wave. The P
wave can move through solid rock and fluids, like water
or the liquid layers of the earth. It pushes and pulls the
rock it moves through just like sound waves push and
pull the air.
Secondary or s-wave
* Transverse wave
The second type of body wave is the S wave or
secondary wave, which is the second wave you
feel in an earthquake. An S wave is slower than
a P wave and can only move through solid rock.
This wave moves rock up and down, or side-toside.
Review
1) What are the three layers of the Earth?
2) The Earth’s crust is very ______?
3) The mantle is the largest layer of the
Earth? True or False
4) Is the Outer Core a liquid or a solid?
5) What is the difference between p-waves
and s-waves?
6) What are surface waves?
Answers!
1) Crust, Mantle, Outer Core, Inner Core
2) Thin
3) True
4) Liquid
5) P waves are primary waves and S waves
are secondary waves
6) Waves that occur on the Earth’s crust.
Cause the most earthquake damage.