## Process

Part 1:  Earth's Interior

Earth is a unique planet.  It is also a system in which the amount of matter is relatively constant, but through which energy flows.  Earth's four spheres, which include its bodies of water, its land, its atmosphere, and its living organisms, all interact.  The transfer of energy and matter on Earth takes place through complex cycles.

We will concentrate today on the geosphere.  Earth is many thousand kilometers in depth. If you could travel deep into the earth's surface you would find that it contains three main layers; the crust, mantle and core. To learn more about the layers of Earth, click the following links and answer the questions that follow.

Go to The Earth's Interior

• How is Earth's interior like an apple?
• The lithosphere is divided into 2 parts (or crust).
• What are they called?
• What is the thickness of each part?
• What are these parts primarily made of?

Click on the Volcano World link.  After reading each slide click the "next" button and proceed to read the next slide. When you have examined all of the slides, complete the questions on the "questions" slide. These questions are also below.

• Name the five layers of the earth in order from the outside to the center of the earth.
• What causes the mantle to "flow"?
• What are the two main metals that make up the outer and inner core?
• Describe in your own words how the earth's layers were formed.   (Slide 2 will help you.)

Part 2:  Convection Currents and the Mantle

Heat transfer is the movement of heat from a warmer object to a cooler object. There are three ways in which heat can be transferred; conduction, convection and/or radiation. Click on the links below and answer the questions that follow.

• How is heat transferred by conduction?
• Explain the process of convection.
• How is heat transferred by radiation?
• If air is a fluid, why isn't convection responsible for transferring heat to Earth from the sun?

Test your knowledge! Scroll back to the top of the Heat Transfer Web page and take the "Mini Quiz".

As you already know, the earth's mantle contains two layers; the stratosphere (tough liquid part of the outer mantle) and the lithosphere (the stiffer outer mantle and the crust). Because of the intense pressure and temperature in the mantle convection currents occur. To learn about what influence these convection currents have on Earth, read the Web page below and answer the questions that follow.

The Mantle

• Describe how convection currents occur in Earth's mantle.
• What is a constructive force caused by the convection currents in the earth's mantle?
• What is a destructive force caused by the convection currents in the earth's mantle?

Part 3:  Drifting Continents

The theory of continental drift originated from a German scientist named Alfred Wegener who proposed that there was once a super continent called Pangaea ("all lands"). Wegener proposed that over time the continents drifted apart. Read through the following links to learn about Wegener's theory of continental drift.

Continental Drift

• What 5 factors did Wegener use to support his theory?
• List three of the arguments of geologists that disproved Wegener's theory.
• Arthur Holmes came up with his own theory of drifting continents in 1928. What was his theory?

Pangaea

More Pangaea info

Still more Pangaea info

• Discuss the Supercontinent Cycle.
• Describe the formation and breakup of Pangaea as well as the projected geography of the future.
• What is rifting?  Give an example.
• What consequences can result from continental change?

• What two Earth changing events can occur when the plates underneath the ocean spread?
• What is an ocean ridge?
• Why are two plates spreading considered to be 'constructive'?
• What is subduction?
• What is the Mid-Atlantic Ridge? How many miles does it stretch?

Magnetic Symmetry

More Magnetic Symmetry

• Harry Hess' contribution to the theory of sea-floor spreading.
• What is paleomagnetism and a magnetic reversal?
• Discuss magnetic symmetry and how it serves as evidence for sea-floor spreading.
• Where is the youngest rock on the ocean floor?

#### Part 5: The Theory of Plate Tectonics

The theory of plate tectonics was formulated in the 1960s and 1970s when new information was discovered about the inside of Earth. To learn more, click on the links below, read the Web page and answer the questions that follow.

Plate Tectonics

• What is the theory of plate tectonics?
• What new information led to the theory of plate tectonics?
• About how fast to the plates move in relation to each other each year?
• What is it called when two plates meet?

Convergent Boundaries

• What are convergent boundaries?
• What occurs when a continental and an oceanic plate collide?
• When an oceanic plate digs into Earth's hot interior, what occurs?
• How were the Andes Mountains in South America formed?

Divergent Boundaries

• What are divergent boundaries?
• Explain how volcanoes form in the central valley of a divergent boundary?
• How much does the Atlantic ocean widen per year due to divergent boundaries?

Transform Boundaries

• What are transform boundaries?
• What could happen to to a stream bed that is split by a transform boundary?
• Name one of Earth's most famous transform boundary? Where is it located?
• True or False?
• Due to transforming plates, Los Angeles will break away from California. Explain your answer.

Part 6:  Deformation of the Crust

The Himalayas, the Rockies, and the Andes are some of Earth's most majestic mountain ranges.  Mountain ranges are visible reminders that the shape of Earth's surface changes constantly.  These changes result from deformation, or the bending, tilting, and breaking of Earth's crust.  To learn more, click on the links below, read the Web page and answer the questions that follow.

How Rock Deforms

More on Deformation of Rock

• Deformation sometimes occurs because the weight of some part of Earth's crust changes.  Describe isostasy.
• As Earth's lithosphere moves, the rock in the crust is squeezed, stretched, and twisted.  Describe the three types of stress (compression, tension, and shear)
• Differentiate between Strain, Folds, and Faults.
• What are the types and factors that affect

How Mountains Form

• What is a mountain range and system?
• Discuss collisions between plates as they refer to mountians.
• collisions between continental and oceanic crust
• collisions between oceanic and oceanic crust
• collisions between continental and continental crust

Types of Mountains

• What are the four main types of mountains and describe each.
• How long does it take to build a mountain?

## Web Resources

The Earth's Interior

Volcano World

The Mantle

Conduction

Heat Transfer

Convection Currents: Currents in the Earth's System

Plate Tectonics

Earth's Continental Plates - ZoomSchool.com