TOPOGRAPHY OF THE OCEAN FLOOR
Objective: Use sounding data to prepare a cross section of the ocean floor. Background:
The ocean floor is one of Earth’s last unexplored frontiers. Most of our knowledge about
this frontier comes from soundings, depth measurements made at many thousands of
points. From these soundings, it is possible to make a crude picture of the ocean floor. In
this investigation you will use sounding data to make a cross section map of a typical
ocean floor.
Materials: Dell Computer
Microsoft Office Excel Program
Procedure:
1. Open Excel.
2. In column A1 type DISTANCE. In column B1 type DEPTH
3. In columns B2 through B51 type in the depth data from the chart below. Make sure to
include the negative (-) sign with all negative numbers.
4. In column A1 type the data for distance .
5. Highlight all your data without the labels.
6. Go to Insert on the menu bar. Select Chart and choose the X Y Scatter plot from
the gallery. Choose the second one down with the connected points.
7. You should now see a list of options on the bottom, choose next, fill in the x axis and
the y axis. In the title box type “Topography of the Ocean Floor”.
8. Click Finish and you should see your graph.
9. Cut and paste your graph on a new Word Document.
10. Based on the class discussions of the ocean floor, label these features on your graph:
continental shelf, continental slope, continental rise, abyssal plain, mid-ocean ridge, rift
valley, trench, seamount, guyot, continents, island.
11.
12. Select the Text Tool to create a text box. Type the name of each label in a separate
text box.
13. Make your graph larger by dragging the box out.
15. Answer the questions below directly on the word document. Answers should be
below the graph.
16. When you finish with your labels and questions, make sure you save the file before
you quit. Save the file as “lastname_firstinitial_oceangraph”. Put the save file into my
virtual share drop box.
Questions:
1. What parts of your cross section show land that is not water-covered?
2. How does the continental shelf differ from the continental slope on your map?
3. Where is the deepest part of the ocean? How deep is it? What is the name for this
feature?
4. Mount Everest, the world’s highest mountain is 8,848 m high. If you sketched Mount
Everest in at the deepest part of your map, how high would its summit be compared to
sea level?
5. Name the types of plate boundaries that are found on your graph.
6. What is the evidence does the graph show that indicates these boundaries are present?
Cross Section Distances and Depths
Distance
(km)
Depth
(m)
Distance
(km)
Depth
(m)
Distance
(km)
Depth
(m)
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
1500
1600
1700
+800
+600
+250
0
-300
-450
-500
-1430
-2700
-3800
-4000
-4100
-4100
-150
-4250
-4300
-4250
-4200
1800
1900
2000
2100
2200
2300
2400
2500
2600
2700
2800
2900
3000
3100
3200
3300
3400
-4200
-4100
-4200
-4000
-4000
-3950
-3850
-3800
-3600
-3500
-3150
-1000
-650
-2100
-300
-2400
-3100
3500
3600
3700
3800
3900
4000
4100
4200
4300
4400
4500
4600
4700
4800
4900
5000
5100
-3550
-3800
-4000
-4100
-4100
-4000
-2500
-2500
-4100
-4000
-9800
+400
-1300
-700
-650
-250
+450
(+ = above sea level; - =below sea level)