Introduction Page

Visualization of the Seafloor (Mapping the Ocean Floor)

Objectives:

1.  Students will be able to graph the depth of the Atlanta Ocean at 45 degree north moving from the western side of the ocean to the coastline of France.

2.  Students will be able to visualize and label various features of the ocean floor.

3.  Students will be able to use GeoMapApp to collect data of the Atlantic Ocean’s depth at 32 degree north latitude and plot the data to create a profile of the ocean floor.

4.  Students will be able to compare and contrast the Mid-Atlanta ridge and its surrounding features at two distinct locations.

Background Information: (two paragraphs)

Students will use prior knowledge and research to write at least two paragraphs about the ocean floor.

Materials:

GeoMapApp Tape

Graph paper Ruler

Pencil computer

Coloring Pencils

Procedure:

Part I: Mapping the Ocean Floor at 45 Degrees North Latitude

Imagine you are an oceanographer traveling across the Atlantic along the 45 degree N latitude line. 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 activity, you will plot depth data to create a profile of the ocean floor.

1.  Draw the axes of a graph. Label the horizontal axis longitude. Mark from 65⁰W to O⁰ 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 500 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 ship’s location at 19 points in the Atlantic Ocean. Location 1 is Nova Scotia, and location 19 is Soulac.

3.  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.

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

Observation:

A.  (Chart)Ocean Depth Sonar Data

Longitude (⁰ W) / Ocean Depth (m)
1.  64 / 0
2.  60 / 91
3.  55 / 132
4.  50 / 73
5.  48 / 3512
6.  45 / 4024
7.  40 / 3805
8.  35 / 4171
9.  33 / 3439
10.  30 / 3073
11.  28 / 1756
12.  27 / 2195
13.  25 / 3146
14.  20 / 4244
15.  15 / 4610
16.  10 / 4976
17.  05 / 4317
18.  04 / 146
19.  01 / 0

B.  Attach a copy of the Graph.

  1. Label the points where the city of Nova Scotia , Canada and Soulac, France should be on the graph.
  2. Draw a research boat crossing the ocean mapping the ocean floor.
  3. Color the features (boat, water, and rock)
  4. Label the mid-ocean ridge.
  5. Place a vertical temperature scale along the right (y) axis. OR
  6. Describe the temperature change as the depth changes along the right axis.
  7. Don’t forget to label your graph with
  8. Equal intervals
  9. X and Y title with units
  10. Graph title

Conclusion: Restate the question into your answer using complete sentences.

1.  Label the mid-ocean ridge on your graph. Describe the process that is occurring there? (Explain the concept of sea-floor spreading)

2.  Explain how the temperature of the lithosphere changes with the ocean depth.

3.  Explain how the temperature changes near and away from the mid-ocean ridge.

4.  Explain how the density changes with the ocean depth.

Procedure:

Part I: Mapping the Ocean Floor at 32 Degrees North Latitude

Part II: Learning to use GeoMapApp

1.  Open a window with GeoMapApp, DO NOT TRY TO INSTALL THE SOFTWARE on the harddrive.

2.  GO to www.geomapapp.org and open to run ONLY.

3.  Click HERE to download the program onto the desktop.

4.  Click OK to open the default Mercator Base Map.

5.  Once GeoMapApp is running, you’ll see a map image of Earth.

6.  Start the activity with Step 2 – Examine a visualization of the seafloor.

7.  Under this section you will learn how to use some basic parts of “geomapapp” that will be needed to complete the activity.

8.  Follow the instructions step by step.

Part II: Take a Virtual Cruise across the Atlantic Ocean

1.  Prepare to gather data from the North Atlantic Ocean

  1. Follow the instructions (1-5) on the sheet to set up the activity.

2.  Collect depth data along a latitude line using the geomapapp program.

3.  Instead of positioning the image to measure every 200 km, you will collect depth data for the longitude coordinates in the table. They have been set up so that each point indicated is 200 km away from the previous one.

Observation:

A.  Chart: Using GeoMapApp complete the chart.

Longitude (⁰W) / Ocean Depth (meters)
80.0
77.7
75.5
73.3
71.2
69.1
66.7
64.7
62.5
60.3
58.1
55.0
53.0
50.9
49.0
46.5
44.4
42.3
40.1
38.0
36.0
34.0
31.4
29.3
27.2
25.0
23.0
20.8
18.5
16.3
14.2
9.9
8.1

B.  Graph:

C.  Use graph paper to create a graph (profile) of the ocean floor using the data collected.

Put sea level (0) at the top and increasing depth values down to the bottom.

Attach a copy of the Graph.

  1. Draw a research boat crossing the ocean mapping the ocean floor.
  2. Color the features (boat, water, and rock)
  3. Label the mid-ocean ridge.
  4. Try to identify and label various other features along the ocean floor.
  5. Convergent boundaries
  6. Divergent boundaries
  7. Subduction zones
  8. Volcanic ridges
  9. (see power point 9.3 diagram of the ocean floor)
  10. Don’t forget to label your graph with
  11. Equal intervals
  12. X and Y title with units
  13. Graph title

Conclusion: Restate the question into your answer using complete sentences.

Once you’ve created your graph, consider what the visual representation you’ve made actually means about the seafloor.

1.  What do the high and low points along your graph mean?

2.  Does your profile represent the actual shape of the seafloor? Explain why or why not.

3.  Discuss how the profile is similar to and different from the seafloor it represents.

I.  Reflection:

a.  Compare and contrast the Atlantic Ocean Floor at the two different locations. (45⁰N and 32⁰N latitude)

b.  If you were to do this activity again what would you change and why? If you decided to not change the activity, why?