Plate tectonics homework answers

LAB MODULE 13: PLATE TECTONICS

Note: Please refer to the GETTING STARTED module to learn how to maneuver through, and how to answer the lab questions, in the Google Earth (GE.gif) component.

KEY TERMS

You should know and understand the following terms:

Continental Drift

Pacific Ring of Fire

Reverse Fault

Earthquakes

Pangaea

Subduction

Hotspots

Plate Convergence

Transform Fault

Normal Fault

Plate Divergence

Overthrust fault

Plate tectonics

LAB MODULE LEARNING OBJECTIVES

After successfully completing this module, you should be able to do the following tasks:

· Explain the theory of plate tectonics

· Explain the theory of continental drift

· Identify and describe types of plate movement

· Identify and describe the three types of volcanoes

· Explain the concept of hotspots

· Compute the rates of plate movement

· Identify and describe the different types of faults

INTRODUCTION

This module examines plate tectonics. Topics include continental drift, tectonic landforms, plate boundaries, faults and hotspots. While these topics may appear to be disparate, you will learn how they are inherently related. The module starts with four opening topics, or vignettes, which are found in the accompanying Google Earth file. These vignettes introduce basic concepts of the internal structure of the Earth. Some of the vignettes have animations, videos, or short articles that will provide another perspective or visual explanation for the topic at hand. After reading the vignette and associated links, answer the following questions. Please note that some links might take a while to download based on your Internet speed.

GE.gif Expand the INTRODUCTION folder and then check Topic 1: Introduction.

GE.gif Read Topic 1: Introduction

Question 1: Based on this map, what is one continent in which there are two (or more) plates?

A. North America

B. Europe

C. Asia

D. Africa

GE.gif Read Topic 2: Continental Drift

Question 2: What was discovered in Antarctica that solidified Wegener’s theory of continental drift?

A. Snow and ice

B. Mineral deposits

C. Tropical plant fossils

D. Extinct volcanoes

GE.gif Read Topic 3: Tectonic Landforms

Question 3: Where do scientists think the next major ocean will be formed?

A. Gulf of Mexico

B. Iceland

C. Australia

D. East Africa

GE.gif Read Topic 4: Human Interaction

Question 4: Based on the article, which is not a reason why humans are drawn to plate boundaries.

A. Nice scenery

B. Geothermal energy

C. Fertile soil

D. Ore deposits

GE.gif Collapse and uncheck the Introduction folder. GLOBAL PERSPECTIVE

GE.gif Expand GLOBAL PERSPECTIVE. Double-click and select Tectonic Plate Boundaries and Names to display the names on the globe of the major tectonic plates.

Millions of humans live near the major tectonic plate boundaries. The potential dangers of living on or near a plate boundary include earthquakes, volcanoes, and tsunamis. However, these natural hazards do little to discourage people from settling in these cities, especially if the region has economic, religious, political or social importance.

GE.gif Expand and select Major Cities. Double-click and select Question 5. When you arrive at your destination, find the information to fill in the blanks below. Choose the two closest tectonic plates. Repeat this for Questions 5 to 8.

Question 5: City: San Francisco

Two closest tectonic plates

A. Pacific/North America

B. Pacific/Californian

C. North American/California

D. Pacific/Juan de Fuca

Question 6: City: Taipei, Taiwan

Two closest tectonic plates

A. Philippine/Taiwan

B. Taiwan/China

C. Philippine/China

D. Eurasian/Philippine

Question 7: City: Jerusalem, Israel

Two closest tectonic plates

A. Arabian/Eurasian

B. Mediterranean/Eurasian

C. African/Arabian

D. African/Eurasian

Question 8: City: Karachi, Pakistan

Two closest tectonic plates

A. Indian/Eurasian

B. Arabian/African

C. Pakistani/Indian

D. Burmese/Eurasian

GE.gif Collapse and uncheck the GLOBAL PERSPECTIVE folder.

PLATE BOUNDARIES AND MOVEMENTS

In general, tectonic plate boundaries are classified as converging, diverging, and transform, while tectonic plate types are classified as either oceanic or continental. The following descriptions of plate boundaries and movements will help you answer Questions 10 to 23.

Converging Boundaries

When an oceanic plate and a continental plate converge (Figure 1), the result is subduction, because the oceanic plate slides under the continental plate. Mountain ranges of volcanoes are created by magma from the melting oceanic plate rising to (and through) the continental crust. Deep oceanic trenches typically parallel the coast.

Description: GE.gif Expand the PLATE BOUNDARIES folder and then click Subduction Animation to view an animation of this type of convergence boundary.

Figure 1. Oceanic-continental convergence (USGS).

Figure 2. Continental-continental convergence (USGS).

When two continental plates converge (Figure 2), compression and uplift occur at the boundary to form mountain ranges. Continental-continental convergence mountains are not comprised of volcanoes and thus contrast the orogeny of mountain ranges produced by oceanic-continental convergence.

When two oceanic plates converge (Figure 3), one subducts under the other and the result is a deep ocean trench. In some cases, under sea volcanoes format these boundaries. Over millions of years, these oceanic-oceanic convergence boundaries produce volcanoes that reach the surface and form a chain of islands shaped in an arc.

Figure 3. Oceanic-oceanic convergence (USGS).

Diverging Boundaries

As the name implies, diverging boundaries occur where plates are moving away from each other. If the plates are oceanic, the result can be an underwater mountain range which follows the plate boundaries. If the plates are continental, the initial result is the creation of a valley or rift. Given enough time, these valleys or rifts might be submerged, forming long, narrow seas.

Transform Boundaries

Transform boundaries occur when two plates move horizontally past each other. The boundary, or fault, between the two plates can be several miles wide. Friction between the two plate boundaries can build up tectonic stress, which can be released instantaneously into the Earth’s crust in the form of an earthquake.

Description: GE.gif Expand the Boundaries folder, check the Plate Boundaries folder, and then doubleclick Boundary A.

Based on the descriptions of plate boundaries and movement provided, identify Boundaries A through G: