Earth's Layers

Earth's Layers Webquest

Directions:  Answer the questions given to you by your teacher by clicking on the links below. 

Part 1: Earth's Interior

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.

Convection, Conduction and Radiation & Heat Transfer

  • 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 link 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?

Part 4: Sea-Floor Spreading

The movement of plates caused by convection currents causes both constructive and destructive forces beneath the ocean floor. To learn more about this topic click on the link below and answer the questions that follow.

Sea-Floor Spreading

  • 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?

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?