1. Bell Work: 10/13/09
10/27/11
If you journeyed to the center of the Earth, what do you think you would observe along the way? Draw an illustration of your journey.

2. Objectives
Differentiate among the characteristics of the earth’s three layers. (SPI )
Recognize that lithospheric plates on the scale of continents and oceans continually move at rates of centimeters per year. (SPI )

3. 1-minute Journal
Write a 1-minute journal on how a peach is like the earth’s layers.

4. Chemical Composition: 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!

5. The Crust The solid outermost layer of the Earth is the _________.
The Earth's Crust is like the skin of a peach. It is very thin in comparison to the other three layers.
The solid outermost layer of the Earth is the _________.
The crust is ____ to _____ km thick (3 to 62 miles) = less than ___ of Earth’s mass.
It is the _________ layer of the Earth.
There are two types of crust- ___________ and ___________.
The crust is made up of the elements ________, _________, and ____________.
crust 5
100 1%
thinnest
continental
oceanic
oxygen
silicon
aluminum
The most common rock in the crust is _________________.
basalt

6. The Mantle mantle 2,900 67% thicker rock magma oxygen silicon
The Earth's Mantle is like the thick, fleshy inside of a peach. It is the thickest of the three layers.
The layer of rock between the Earth’s crust and core is the _________.
The mantle is ______ km thick (1,802 miles) = ____ of Earth’s mass.
It is much _________ than the crust and contains most of the Earth’s mass.
The mantle is made up of hot, solid _______ that acts like an extremely viscous or sticky liquid- a solid that flows! It is almost like Silly Putty! When the rock melts it becomes _________.
The mantle is made up of the elements ________, ________, ____________, and ________.
mantle
2,900
67%
thicker
rock
magma
oxygen
silicon
magnesium
iron

7. The Earth's outer core is like the juice of the peach
The Earth's outer core is like the juice of the peach. It is so hot that the metals in the outer core are all in the liquid state. The inner core is like the pit of a peach. The insane pressures at the center cause the inner parts to stay solid.
The Core
The central part of the Earth below the mantle is the _________.
The core has a radius of _________ (2,131 miles) = ____ of Earth’s mass.
The core is made up of the elements _______ and ____________.
The core is made up of an _________ core and an ________ core.
The outer core is the ________ layer of the Earth’s core that surrounds the inner core.
The inner core is the ________, dense center of our planet.
core
3,430 km
33%
iron
nickel
outer
inner
liquid
solid

8. Physical Structure: L.A.M.
The physical structure of the Earth describes how the earth moves and responds to temperatures and pressure.
The three physical structures:
Lithosphere
Asthenosphere
Mesosphere

9. Lithosphere
The crust and the upper layer of the mantle together make up a zone of rigid, brittle rock called the Lithosphere.

10. Tectonic Plates are pieces of the lithosphere that move around on top of the asthenosphere.
Earth’s outer shell, or lithosphere, is not one solid piece. It’s broken up like a cracked eggshell into huge pieces (our continents) and many small pieces called __________ __________.
Tectonic plates are continually __________.
Let’s look at pg. 396!
tectonic
plates
moving
at centimeters per year.

11. Asthenosphere
The Asthenosphere is the plastic or viscous layer (solid that flows) of the mantle on which pieces of the lithosphere move.
This part of the 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.

12. 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, like the cork in this illustration.

13. Mesosphere
Beneath the asthenosphere is the strong, lower part of the mantle called the mesosphere.
The mesosphere extends from the bottom of the asthenosphere to the Earth's core.
At a depth of 660 km (410 miles), pressure becomes so great in the mesosphere that the mantle can no longer flow and becomes a solid.