The Shape of the Ocean Floor Name __________________________

Interpreting Data


Imagine you are an oceanographer traveling across the Atlantic along the 45N latitude line marked on the map. You and your crew are using sonar to gather data on the depth of the ocean between Nova Scotia, Canada, and the town of Soulac on the coast of France. In this lab, you will interpret the data to create a profile of the ocean floor.


u Problem

How can you use data about ocean depths to determine the shape of the ocean floor?

u Materials

Ocean Depth Sonar Data


Ocean Depth (m)

1. 64W


2. 60W


3. 55W


4. 50W


5. 48W


6. 45W


7. 40W


8. 35W


9. 33W


10. 30W


11. 28W


12. 27W


13. 25W


14. 20W


15. 15W


16. 10W


17. 05W


18. 04W


19. 01W


Pencil graph paper

u Procedure

1. Draw the axes of a graph. Label the horizontal axis Longitude. Mark from 65W to 0 from left to right. Label the vertical axis Ocean Depth. Mark 0 meters at the top of the vertical axis to represent sea level. Mark 5000 meters at the bottom to represent the depth of 5000 meters below sea level. Mark depths at equal intervals along the vertical axis.

2. Examine the data in the table. The numbers in the Longitude column give the ships location at 19 points in the Atlantic Ocean. Location 1 is Nova Scotia, and Location 19 is Soulac. The numbers in the Ocean Depth column give the depth measurements recorded at each location. Plot each measurement on your graph. Remember that the depths are represented on your graph as numbers below 0, or sea level.

3. Connect the points you have plotted with a line to create a profile of the ocean floor.

u Analyze and Conclude

1. On your graph, identify and label the continental shelf and continental slope.

2. Label the abyssal plain on your graph. How would you expect the ocean floor to look there?

3. Label the mid-ocean ridge on your graph. Describe the process that is occurring there.

4. What might the feature at 10W be? Explain.

5. Think About It-How is it helpful to organize data into a data table or a graph?

More to Explore Use the depth measurements in the table to calculate the average depth of the Atlantic Ocean between Nova Scotia and France.