How do Scientists Determine the Boundaries of Earth’s Plates

How do Scientists Determine the Boundaries of Earth’s Plates?

Name: ______________________________________ Hour: _________

Background

Scientists discovered that when the locations of earthquakes were plotted on a world map, these locations occurred in a pattern, or variety of patterns. These patterns led scientists to believe that the earth’s crust is divided into different sections, or plates. The theory of plate tectonics states that the earth’s lithosphere is broken into moving plates. Six of the seven major continental plates are named for the continent where they are located. The seventh plate, the Nazca Plate, is located between the South American plate and Pacific plate. The three types of plate boundaries – divergent, convergent, and transform – describe how two plates move relative to one another. By plotting the locations of earthquakes, scientists have not only been able to locate plate boundaries but have also been able to determine plate characteristics and predict movement of the plates. In this investigation, you will plot the locations of earthquakes and determine the boundaries of the earth’s plates. You will also study the directions in which various plates move.

Objectives

After completing this investigation, you will be able to:

Explain how geologists have identified major plate boundaries.
Explain how knowledge of plate boundaries can help scientists predict the location of future earthquakes.
Identify different formations caused by various plate movements.

Procedure

A. Following is a list of geographic coordinates of earthquakes. Plot the location of each earthquake on the map by placing a dot where the longitude and latitude coordinates intersect.

Latitude	Longitude	Latitude	Longitude
75 N	0	30 S	20 W
70 N	15 W	40 S	28 W
60 N	29 W	45 S	30 W
55 N	30 W	55 S	40 W
45 N	40 W	60 S	60 W
35 N	40 W	40 S	90 W
20 N	40 W	35 S	120 W
15 N	30 W	45 S	135 W
0	20 W	50 S	150 W
15 S	20 W

After you have plotted the coordinates, connect them to form curved line.

C. Plot the following coordinates and then connect the dots.

Latitude	Longitude	Latitude	Longitude
35 N	30 W	5 N	60 E
35 N	10 W	10 S	70 E
35 N	0	30 S	45 E
35 N	15 E	48 S	30 E
30 N	30 E	50 S	0
25 N	40 E	47 S	20 W
10 N	45 E

D. Plot the following coordinates and then connect the dots.

Latitude	Longitude
15 N	55 W
15 N	65 W
15 N	75 W

E. Plot the following coordinates and then connect the dots.

Latitude	Longitude	Latitude	Longitude
50 N	170 W	15 N	90 W
55 N	150 W	5 N	75 W
45 N	125 W	15 S	70 W
30 N	115 W	30 S	75 W
20 N	105 W	45 S	75 W

F. Plot the following coordinates and then connect the dots.

Latitude	Longitude	Latitude	Longitude
60 N	180 E	30 S	165 E
55 N	150 E	50 S	160 E
45 N	130 E	55 S	135 E
30 N	125 E	50 S	110 E
15 N	120 E	40 S	80 E
0	120 E	20 S	75 E
10 S	135 E	15 S	65 E
15 S	160 E

G. Plot the following coordinates and then connect the dots.

Latitude	Longitude
30 N	45 E
30 N	60 E
30 N	75 E
20 N	90 E
15 N	95 E
0	105 E
5 S	120 E

Look at the map you just completed. What do the lines represent?
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H. Listed below are six of the seven major continental plates that scientists have identified. Write the names of the following continental plates in the proper places on your map. The seventh major plate, the Nazca plate, has been identified for you.
North American Plate South American Plate African Plate
Eurasian Plate Indo-Australian Plate Antarctic Plate

I. Plate boundaries move in different directions. The movement of two plates creates natural formations. Study the diagrams below. Note that three of the views are cross sections while one is an overhead view.
2. Study your map. What landform might be illustrated in diagram B?
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3. What space might be illustrated in diagram C? ___________________________

4. What deep part of the sea floor might be illustrated by diagram A? _____________

5. What type of boundary is illustrated in diagram D? __________________________

Conclusions

1. How have earthquakes helped geologists identify major plates on earth?

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2. Why is knowing the location of plate boundaries important?

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3. What might occur as a result of the sliding boundaries illustrated in diagram D?

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