Download Pattern of Crustal Activity

Name__________________________ Lab # ____________ date____________per_____
Pattern of Crustal Activity
INTRODUCTION: Studies of diastrophism have shown that crustal activities are occurring world-wide.
Earthquakes, volcanoes, and mountain ranges do not occur randomly. There are special zones in which
they occur. In this lab you will look for the relationships between the locations of these crustal activities.
OBJECTIVE: You will plot the areas in which earthquakes occur most frequently, the depths at which
they happen, and identify other crustal activities that appear related to these zones.
VOCABULARY:
Mid-Atlantic Ridge:
shallow-focus earthquake:
intermediate-focus earthquake:
deep-focus earthquake:
continental drift:
plate tectonics:
Andes Mountains:
PROCEDURE A: HORIZONTAL PATTERNS
1. Referring to the Earthquake Location Map provided by your instructor, mark the epicenters on your
world map by placing an X in each area where earthquakes have occurred.
2. Referring to a textbook, mark the areas with active volcanoes by placing small circles in regions where
they occur.
3. Referring to the World Map and globes supplied by your instructor, indicate on your map the regions
where mountain ranges occur by placing small triangles in the appropriate areas. Be sure to include
mountain ranges that are located under the oceans.
Using the data that your teacher supplied for the most recent earthquakes, plot 30 epicenters with
an x on the world map
4. Find the chart, “Active and Extinct Volcanoes Around the World” in the Appendix. On your world map,
plot and label the locations of the following volcanoes:
Mauna Loa, Krakatau, Vesuvius, Mt. Rainer, Paricutin, Fuji, and Mt. St. Helens
5. Find the chart, “Earthquakes Around the World” in the Appendix. On your world map, plot, in red, the
locations of the following earthquakes:
January 18, 1985; June 6, 1985; November 17, 1985; April 26, 1986; May 7, 1986
PROCEDURE B: VERTICAL PATTERNS
1. On the graph provided, draw a cross-section along line AB on your map of South America to show the
depth of earthquake foci.
2. After plotting the depth of earthquake foci connect them with a smooth line.
3. On your cross-section, copy the arrows that show the directions the crustal plates are moving.
4. On the cross-section, draw arrows to show the direction of any movement you predict where these two
crustal plates meet.
DISCUSSION QUESTIONS: (Answer in Complete Sentences)
1. Your world map should show that earthquakes do not occur at random locations. Describe the pattern of
earthquakes on your map.
2. How are the locations of earthquakes, mountain ranges, and volcanic activity related?
3. What regions of North and South America show the greatest crustal activity?
4. According to your map, what is the probability of having either a major earthquake shake your house or
of having a volcano pop up in your backyard?
5. Why is the perimeter around the Pacific Ocean referred to as the “Ring of Fire”?
6. Using your cross-section of South America, describe the pattern of earthquake depth from west to east
along line AB.
7. Based on your answer to question 6, what appears to happen as the ocean plate to the west collides with
the continental plate to the east?
8. What surface feature on the west coast of South America has apparently formed as a result of the
collision of the two crustal plates?
CONCLUSION: Compare the pattern of earthquakes, volcanoes, and mountain ranges on the
earth.