Inside earth
By Owen Hoffman
Seismographs and
seismograms
•
Scientists study earthquakes to
find out what the earth is like
under the crust.
•
To find out the intensity of a
earthquake scientists use
seismographs.
•
Seismographs are used to
make seismograms.
Fault lines and tectonic
plates
•
The Earth outer layer is a
broken up shell.These pieces
are tectonic plates.
•
When the mantle is heated up
by the core it the hot mantle
rises and then it cools down
and lowers,and the tectonic
plates go with the movement of
the mantle.
•
When the plates rub together
they can create mountains,
volcanos, or earthquakes
Earthquakes
•
Earthquakes happen when a
tremendous amount of energy
is released from the Earth's
crust.
•
There are hundreds of tiny
earthquakes happen a year,
but we can't feel them.
•
But the earthquakes we talk
about cause massive
destruction and are really
dangerous.
Seismic waves
•
A seismic wave is a wave of
energy that is generated by an
earthquake of other earth
vibration that travels within the
earth or along its surface.
Primary waves
•
Primary waves also called (P
waves are the fastest type of
wave.
•
P waves arrive at a distant
point first and is usually the
first type of wave to be
detected on a seismograph.
•
They travel in a ripple motion.
Secondary waves
•
Secondary waves are the
second fastest waves so that
makes them slower than P
waves.
•
Secondary waves can also be
called (S waves) and travel
through solids only.
Surface waves
•
Surface waves are the fastest
waves and are the most
dangerous.
•
Surface waves or (L waves)
slowly go up then down like a
wave.
•
Surface waves are the slowest
waves.
The layers of the Earth
•
Earlier in the presentation I
wrote about scientists using
Earthquakes to find out more
about the Earth and this is
what the next four slides are
about.
•
The Earth has four layers the
crust, mantle, inner core, and
outer core.
Earth's crust
•
The earth's crust is the thinnest
and the most outer layer.
•
There is oxygen so we can
breathe and there are plants
and animals to eat on the
earth's crust to survive.
•
The crust is made of sand, dirt,
and solid rock,but mostly rock.
Mantle
•
The mantle lies below the
crust. In the mantle rocks move
of flow due to pressure and
high temperature.
•
The mantle allows the tectonic
plates to move very very very
slowly.
The core
•
The core is split into two
parts,the inner core and the
outer core.
•
The outer core is made if
melted iron and it is totally
liquid. The inner core floats in
the outer core.
•
The inner core spins at a
different rate than the rest of
the planet. The inner core is a
solid sphere, and it is the
center of the Earth.