Topic: Plate Tectonics

Pre-assessment

1. Earth’s mantle plays an important role in plate tectonics. Why is the mantle so important to thisprocess?

  1. Earthquakes occur constantly in the mantle, which causes the plates to move.
  2. The mantle is made up entirely of liquid rock, on which Earth’s crustal plates can float.
  3. Heavy metals in the mantle set up strong magnetic fields that attract and repel Earth’splates.
  4. Temperature differences in the mantle set upconvection currents that help to drive themovement of the plates.

2. Two tectonic plates collide and one sinks beneath the other. What do you predict will form?

  1. volcanoes
  2. hurricanes
  3. abyssal plains
  4. mid-ocean ridges

Student Exploration: Dance of the Plates

Overview

In this Exploration you will discover how the tectonic plates that make up the Earth's outer layer interact at their boundaries.

Questions

  1. What are plates?
  1. What combination of boundary type and crust type creates enormous mountains?

3. How did the San Andreas fault system form?

4. What landform is created when convergent plates met along oceanic crusts?

How to Use This Exploration
1. / Read the Introduction and click the Continue button.
2. / Identify the Exploration components.
3. / Select the Type of Boundary and the Crust Type and press the Play button.
4. / Read the text as you watch the animation. Fill out the Data Chart below. Press Replay
as necessary.
5. / Continue with all combinations.

Extension:Student Exploration: Plate Tectonics

Vocabulary:collisional boundary, convergent boundary, crust, divergent boundary, earthquake, lithosphere, mantle, plate, plate tectonics, transform boundary, volcano

Prior Knowledge Questions (Do these BEFORE using the Gizmo.)

  1. Volcanoes are openings in Earth’s crust where lava, gas, and ash can erupt. Where are active volcanoes located? ______

______

  1. An earthquake is a violent shaking of Earth’s surface. Where are earthquakes common? ______

______

Gizmo Warm-up

Volcanoes, earthquakes, mountains, and other features of Earth’s surface owe their origin to the movements of plates: enormous, slowly-moving sections of Earth’s crust. At plate boundaries, plates collide, move apart, move under or over each other, or slide past one another. The theory of plate tectonics describes how the plates move, interact, and change the physical landscape.

The Plate Tectonics Gizmo™ shows a cross-section, or side view, of Earth. (Not to scale.) Above the cross section is a bird’s-eye view of the same location.

3.Turn on Show labels. What are the layers of Earth that you can see? ______

______

4.Turn on Boundary name, and click on each boundary. What four boundaries do you see? ______

Activity A:
Sliding plates / Get the Gizmo ready:
  • Select BOUNDARY A.
/

Question: What happens when plates slide past one another?

  1. Observe: Boundary A is a transform boundary. The arrows below the BOUNDARY A label will move the plates. Click the left arrow once to see how the plate moves.

How would you describe the motion of plates in a transform boundary? ______

______

  1. Sketch: Draw a bird’s-eye view of the plate boundary before and after the plate motion. Draw an arrow to show which way the plate moved.

Before movementAfter movement

  1. Locate: Turn on Show location. Where on Earth can you find this type of boundary? (Note: You can refer to a world map or atlas for location names.)

______

Highlight these locations on the map below.

Activity B:
Colliding continents / Get the Gizmo ready:
  • Turn off Boundary name and Show location.
  • Select BOUNDARY B.
/

Question: What happens when two continents collide?

  1. Observe: Boundary B is a collisional boundary. Click the left arrow four times to see how the plate moves.

How would you describe the motion of plates in a collisional boundary? ______

______

  1. Sketch: Draw a side view of the plate boundary before and after the plate motion. Draw an arrow to show which way the plate moved.

Before movementAfter movement

  1. Locate: Turn on Show location. Where on Earth can you find this type of boundary? (Note: You can refer to a world map or atlas for location names.)

______

Highlight these locations on the map below.

Activity C:
Oceanic crust meets continental crust / Get the Gizmo ready:
  • Turn off Boundary name and Show location.
  • Select BOUNDARY C.
/

Question: What happens when ocean crust collides with continental crust?

  1. Observe: Boundary C is a convergent boundary. Click the left arrow four times to see how the plate moves.

How would you describe the motion of plates in a convergent boundary? ______

______

  1. Sketch: Draw a side view of the plate boundary before and after the plate motion. Draw an arrow to show which way the plate moved.

Before movementAfter movement

  1. Locate: Turn on Show location. Where on Earth can you find this type of boundary? (Note: You can refer to a world map or atlas for location names.)

______

Highlight these locations on the map below.

Activity D:
Spreading plates / Get the Gizmo ready:
  • Turn off Boundary name and Show location.
  • Select BOUNDARY D.
/

Question: How is new crust formed?

  1. Observe: Boundary D is a divergent boundary. Click the right arrow four times to see how the plate moves.

How would you describe the motion of plates in a divergent boundary? ______

______

  1. Sketch: Draw a side view of the plate boundary before and after the plate motion. Draw an arrow to show which way the plate moved.

Before movementAfter movement

  1. Locate: Turn on Show location. Where on Earth can you find this type of boundary? (Note: You can refer to a world map or atlas for location names.)

______

Highlight these locations on the map below.

Post-Assessment

1. The diagram below shows a cross-section of the lithosphere. Point C represents a boundary between twotectonic plates. The plates shifted in opposite directions.

CROSS-SECTION OF LITHOSPHERE

What occurred at Point A as a result of this movement?

  1. a release of energy that caused an earthquake
  2. the formation of a tsunami, or underwater seismic wave
  3. the formation of a hot spot
  4. the sinking of one plate under another

2. A region known as the Ring of Fire follows theborder of the Pacific Ocean basin. Why do somany earthquakes and volcanoes occur in thisregion?

  1. Tidal action around the Pacific Ocean is very strong.
  2. Two plates are diverging in the Pacific Oceanbasin.
  3. It is a region of numerous tectonic plate boundaries.
  4. Many transform boundaries are locatedaround the basin.

The movement of tectonic plates can produce landforms on Earth’s surface. Along what type ofplate boundary might a mountain range form?

  1. convergent
  2. divergent
  3. fault
  4. transform

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