Download oceanic crust

DO NOW Tuesday, November 15th
• Study for Test
TODAY’S PLAN
•Demonstrate Mastery of Chemistry Unit
Learning Targets
TODAYS DO
•Chemistry Unit Test
DO NOW Wednesday, November 16th
• How many layers of the Earth are there? (If
you’re not sure, take a guess!)
• Name as many of them as you can.
TODAY’S PLAN
•I can list the layers of the Earth.
•I can describe the composition of the layers
of the Earth.
TODAYS DO
•We will complete guided notes and a coloring
activity about the layers of the Earth.
Instructions
1. PLAY the presentation.
2. Fill in ALL blanks on your sheet (front and back).
3. Label your layers of the Earth wedge (on the back
of the page) as you come to those slides on the
PowerPoint.
4. Write the information on your wedge in the same
place I have it on the slides.
5. Color the layers of the Earth wedge.
6. You may use the colors on this PowerPoint or
choose your own colors. Color lightly so you can
still read what you have written.
The Layers of the Earth
© Copyright 2006. M. J. Krech. All rights reserved.
The Four Layers
The Earth is composed of four
different layers. The crust is
the layer that you live on, and
it is the most widely studied
and understood. The mantle
is much hotter and has the
ability to flow. The outer
core and inner core are
even hotter with pressures so
great you would be squeezed
into a ball smaller than a
marble if you were able to go
to the center of the Earth!
The Crust
The Earth's Crust is like
the skin of an apple. It is
very thin in comparison to
the other three layers. The
crust is only about 3-5
miles (8 kilometers) thick
under the oceans (oceanic
crust) and about 25 miles
(32 kilometers) thick
under the continents
(continental crust).
The Crust
The crust is composed of two rocks. The continental
crust is mostly granite. The oceanic crust is basalt.
Basalt is much denser than the granite. Because of this
the less dense continents ride on the denser oceanic plates.
Ocean
Oceanic Crust
Continent
Continental Crust: thick; granite; less dense
= floats
Oceanic Crust: thin; basalt;
more dense = sinks
The Lithospheric Plates
The crust of the Earth is broken into many pieces called
plates. The plates "float" on the soft, semi-rigid
asthenosphere.
The Lithosphere
The crust and the upper layer of the
mantle together make up a zone of rigid,
brittle rock called the Lithosphere.
Ocean
Continental Crust
Oceanic Crust
Upper Mantle
Oceanic Crust
Lithosphere:
Crust and
Upper Mantle
Rigid, brittle rock
The Asthenosphere
The asthenosphere
is the semi-rigid
part of the middle
mantle that flows
like hot asphalt
under a heavy
weight.
Ocean
Continental Crust
Oceanic Crust
Upper Mantle
Middle
Mantle
Oceanic Crust
Lithosphere
Asthenosphere: semi-rigid
The Mantle
The Mantle is the
largest layer of the Earth.
The middle mantle is
composed of very hot
dense rock that flows like
asphalt under a heavy
weight. The movement of
the middle mantle
(asthenosphere) is the
reason that the crustal
plates of the Earth move.
Ocean
Continental Crust
Oceanic Crust
Largest Layer is
Mantle
Very hot Dense Middle
Rock that flows Mantle
Upper Mantle
Oceanic Crust
Lithosphere
Asthenosphere
Lower Mantle
Convection Currents
The middle mantle "flows"
because of convection
currents. Convection
currents are caused by the
very hot material at the
deepest part of the mantle
rising, then cooling and
sinking again --repeating
this cycle over and over.
Convection Currents
The next time you heat anything like
soup or water in a pan you can watch
the convection currents move in
the liquid. When the convection
currents flow in the asthenosphere
they also move the crust. The crust
gets a free ride with these currents, as
shown in the animation to the left.
Safety Caution: Don’t get your face
too close to the boiling water!
Ocean
Continental Crust
Oceanic Crust
Upper Mantle
Convection currents
Convection currents
(in middle mantle):
Hotter magma from bottom
Rises and cooler magma at
Top sinks
Lower Mantle
Oceanic Crust
Lithosphere
Asthenosphere
The Outer Core
The core of the Earth
is like a ball of very
hot metals. The
outer core
is so
hot that the metals in
it are all in the liquid
state. The outer core
is composed of the
melted metals of
nickel and iron.
Ocean
Continental Crust
Oceanic Crust
Upper Mantle
Middle
Mantle
Convection currents
Lower Mantle
Outer Core: made
Of liquid metals like
Nickel and iron
Oceanic Crust
Lithosphere
Asthenosphere
The Inner Core
The inner core of the
Earth has temperatures
and pressures so great
that the metals are
squeezed together and
are not able to move
about like a liquid, but
are forced to vibrate in
place like a solid.
Ocean
Continental Crust
Oceanic Crust
Oceanic Crust
Upper Mantle
Middle
Mantle
Lithosphere
Asthenosphere
Lower Mantle
Outer Core
Inner
Core
Great pressures;
Metal atoms squeezed
Together and vibrate in
Place as a solid
The End
BONUS:
Find a pair or trio and answer
this question:
Have we ever seen part
of the Mantle? Explain.
© Copyright 2006. M. J. Krech. All rights reserved.
THURSDAY DO NOW
• What are convection currents?
• Why are they important?
TODAY’S PLAN
•I can list the layers of the Earth.
•I can describe the composition of the layers
of the Earth.
•I can explain what causes movement of the
crustal plates.
TODAYS DO
•We will complete notes about the layers of the
Earth.