Earth+Rocks!

Since its creation, Earth has been a dynamic planet. In this unit, we will explore Earth's geologic history, with particular emphasis on what materials make up the Earth, how Earth is constructed, and how its surface moves and shifts over time. Find out about the layers of the Earth on [|this site].
 * What is the outermost layer of the Earth called?
 * What is the innermost layer of the Earth called?
 * What exists between these two layers?
 * Draw a diagram of the Earth with a section removed; label the layers of the Earth.

The Earth is also divided into regions.
 * Describe the region of the Earth called the [|lithosphere.]
 * Describe the region of the Earth called the [|asthenosphere.]

Using what you have learned, copy the diagram below into your notes and label it using the terms below.



**Lithosphere** - the crust plus the rigid, upper mantle. **Lower Mantle (semi-rigid)** - the deepest parts of the mantle, just above the core. **Mohorovicic discontinuity** - separates the crust and the upper mantle. **Ocean** - large bodies of water sitting atop oceanic crust. **Oceanic Crust** - thin parts of the Earth's crust located under the oceans. **Upper Mantle (rigid)** - the uppermost part of the mantle, part of the Lithosphere. **Upper Mantle (flowing) = Asthenosphere** - the lower part of the upper mantle that exhibits plastic (flowing) properties. It is located below the lithosphere (the crust and upper mantle). ||
 * **Continental Crust** - the thick parts of the Earth's crust, not located under the ocean.
 * What are the two types of crust?
 * What are the two types of mantle?
 * What is the Mohorovicic Discontinuity (better known as the Moho)?
 * How does oceanic crust differ from oceans?

 Review your understanding of Earth's interior on this [|interactive site].



Plate Tectonics

Plate tectonics is the theory that Earth's crust is subdivided into movable sections that have changed Earth's surface continually over time. [|Find out how this happens] and answer the questions that follow. 
 * 1) Of what are the plates constructed?
 * 2) How does Earth's structure allow the plates to move?
 * 3) What causes movement of the plates?
 * 4) What part does gravity play in the movement of the plates?
 * 5) On which plate do you live? How fast is it moving? In which direction is it moving?
 * 6) Describe what happens at each of the following boundaries:
 * convergent boundary
 * divergent boundary
 * transform boundary
 * spreading ridges

7. Explain the difference between oceanic crust and continental crust. 8. How does the composition of the crust cause the continents to rise above the ocean floor?



In 1912, Alfred Wegener proposed a [|revolutionary theory] to explain Earth's history.
 * What was it?
 * How did Wegener come up with this theory?
 * How was Wegener's theory regarded by scientists of his day?
 * What is current scientific opinion regarding Wegener's theory?

In 1960, Harry Hess suggested that [|sea floor spreading] was the method by which the plates moved.
 * Explain Hess's thinking.

Give three examples of [|scientific evidence] in favor of plate tectonics:
 * 1915
 * 1960s
 * 1980s

Take a look at the [|ancient continents].
 * How old is the oldest ocean floor?
 * What are [|cratons]? What is their importance to plate tectonics?

Where can [|craton] be observed in North America?
 * How was the North American craton formed? How old is it believed to be?

Cratons give evidence that Earth was [|once very different] from the way we know it today.
 * What are two conditions that prevailed on Earth long ago?

Rocks give us clues about the [|composition of the inner Earth.]
 * What are peridotites?
 * What information do peridotites provide?
 * Where is water found in Earth's mantle?
 * What information does a diamond provide?
 * How do diamonds get to the surface?
 * Where are diamonds found? Why are they found there?
 * How can earthquakes provide information about the Earth's temperature?
 * How do p-waves differ from s-waves?
 * What causes the Earth's magnetic field?
 * Every half million years, what happens to Earth's magnetic field?

See if you can [|locate the continents] as they were 250 million years ago.

Play these [|interactive games] to test your knowledge of earth science. 

<span style="font-family: 'Arial Black',Gadget,sans-serif;">View the UnitedStreaming video <span style="font-size: 120%; font-family: Impact,Charcoal,sans-serif;">//Our Changing Earth//. <span style="font-family: 'Arial Black',Gadget,sans-serif;">Answer the following questions :
 * 1) How do scientists think the solar system was formed?
 * 2) What are the main layers of the Earth?
 * 3) What is weathering?
 * 4) Name three things that can cause weathering.
 * 5) How have the Appalachian Mountains changed over millions of years?
 * 6) What is erosion?
 * 7) What are some forces that cause erosion?
 * 8) What is a delta?
 * 9) What is a glacier?
 * 10) Have the continents always had the positions they occupy on Earth's surface today? Explain.
 * 11) What is the theory of continental drift?
 * 12) What evidence is there to support continental drift?
 * 13) What is the theory of plate tectonics?
 * 14) What is a mid-ocean ridge, and what do mid-ocean ridges have to do with the theory of plate tectonics?
 * 15) How does the theory of plate tectonics explain how many mountains were formed?
 * 16) What are volcanoes?
 * 17) What are earthquakes?
 * 18) Where do most earthquakes occur? Why?
 * 19) What is the atmosphere?
 * 20) How might humans be changing the atmosphere?

Visit the [|Science Spot] and find the answers to the worksheet your teacher will give you.

Find interactive [|javagames] at this site.

See how easy it is to [|become a millionaire]!!



<span style="font-size: 120%; font-family: 'Arial Black',Gadget,sans-serif;">Log onto this website and learn [|why tectonic plates move].

<span style="font-size: 120%; font-family: Impact,Charcoal,sans-serif;">On your own paper, write the answers to this Layers of the Earth matching quiz.


 * || Inner Core || 1) crust that is covered with water ||
 * _ || Outer Core || 2) the hottest layer of the Earth and this is in liquid form. ||
 * _ || Mantle || 3) melted rocks inside the volcano ||
 * _ || Crust || 4) are continental crust and oceanic crust ||
 * _ || Continental Crust || 5) the hottest layer of the Earth and this layer is solid. ||
 * _ || Oceanic crust || 6) the surface of the Earth ||
 * _ || Magma || 7) land ||
 * _ || Lava || 8) "chimney of the Earth" It is one way the Earth releases its energy ||
 * _ || Plate || 9) this is the region between the outer core and the lower mantle. ||
 * _ || Volcano || 10) melted rocks that came out from the volcano - outside ||
 * _ || Earthquake || 11) this is the region between the crust and the upper mantle ||
 * _ || Moho || 12) the thickest layer of the Earth ||
 * _ || Gutenberg || 13) movement of the ground caused by plate tension. It is also one of the causes when Earth releases its energy. ||
 * _ || Lava || 8) "chimney of the Earth" It is one way the Earth releases its energy ||
 * _ || Plate || 9) this is the region between the outer core and the lower mantle. ||
 * _ || Volcano || 10) melted rocks that came out from the volcano - outside ||
 * _ || Earthquake || 11) this is the region between the crust and the upper mantle ||
 * _ || Moho || 12) the thickest layer of the Earth ||
 * _ || Gutenberg || 13) movement of the ground caused by plate tension. It is also one of the causes when Earth releases its energy. ||
 * _ || Earthquake || 11) this is the region between the crust and the upper mantle ||
 * _ || Moho || 12) the thickest layer of the Earth ||
 * _ || Gutenberg || 13) movement of the ground caused by plate tension. It is also one of the causes when Earth releases its energy. ||
 * _ || Moho || 12) the thickest layer of the Earth ||
 * _ || Gutenberg || 13) movement of the ground caused by plate tension. It is also one of the causes when Earth releases its energy. ||
 * _ || Gutenberg || 13) movement of the ground caused by plate tension. It is also one of the causes when Earth releases its energy. ||