Name: _________________________________

Seafloor Topography Activiy

Your task is to figure out what the “topography” of the bottom of your box looks like. You will complete this by modeling two different types of ocean mapping techniques.

Goal: To understand how scientists create maps of the ocean floor. You will use skewers to pierce the aluminum covering in order to review the topography of your “ocean floor”.

Pre-Lab questions: 1. What does “topography” mean?

2.What do scientists use to study the topography of the ocean?

2. What is the difference between single beam & multibeam sonar?

Materials: Ocean Floor box Ruler Skewer

Pen or pencil Colored pencils Earth Science textbook

Activity #1: Single Beam Sonar:

1. Look at the top of your bathymetry box and notice that there is a 1cm grid drawn onto the aluminum foil. Choose one single, straight line of squares to make your measurements. This is called a Transect Line. You transect line can run left to right, top to bottom, or on a diagonal—just as long as it runs in one straight line. An example is below:

2. Once you and your partner have decided on a transect line, you may begin by GENTLY poking one bamboo skewer straight down into the first square. Stop depressing the skewer when you feel it hits a surface.

3. You now need to figure out how deep that surface is beneath the surface of the water (or aluminum foil cover). Please measure in centimeters. There are lots of ways to do this…use your brilliant brains and the tools you have at your disposal

4. Record the depth in the table below and repeat these steps for the rest of the squares along your transect line.

Transect Line Data:

5. Now, you will use those measurement to make a “side view” map of your ocean floor. Having trouble visualizing this? Imagine that you are looking at apple from above and you cut it straight down the middle—that is your transect line. Now you take the apple half and turn in toward you so you can see the inside with the flesh, core, and seeds—that is your “side view” map. Use the graph below to help you map our your ocean floor side view map.

Activity #2: Multi-beam Sonar

1. Now, to get a more complete look at your ocean floor, you will model multi-beam sonar techniques. To do this, you will need to poke a skewer into the remaining boxes on your aluminum foil grid. Remember, do this gently!

Box #1 Box #2 Box #3 Box #4 Box #5 Box #6 Box #7 Box #8 Box #9Depth (cm)1 2 3 4 5 6 7

Box #1 Box #2 Box #3 Box #4 Box #5 Box #6 Box #7 Box#8 Box #9Depth (in cm)

2. The grid to the left matches the grid on your aluminum foil. Record the depth of each surface in the appropriate square below. For example, if the square in the upper left corner of your box has a depth of 1 cm, you would record 1 cm in the square in the upper left corner of this grid. It might help to record the depths from your transect line from the last activity first. 3. Once you have measurements in all of your squares, use the key below to shade your squares in the

appropriate color. This will help you determine high points, low points and land forms on the seafloor!

Analysis Questions:

1. If you haven’t already…peel off the aluminum foil from your box. How accurate were your maps? Were you missing any features on your maps?

2. Using the diagram and descriptions on page of the Earth Science textbook, determine which kind of features are present on your ocean floor.

3. With the two modeling activities you did in this lab, which one seems to give you a more accurate view of the ocean floor? Defend your answer with evidence from your mapping activities.

4. Using the tools you were given, how could you improve the measurements you took to make your map even more accurate and detailed?

Red Orange Yellow Green Blue Purple0-1 cm 1.1-2cm 2.1-3 cm 3.1-4cm 4.1-5cm 5.1-6cm

5. Oceanographers do not push giant skewers into the ocean to measure its depth…obviously. Describe what scientists actually use map the ocean floor and explain how it relates to what you did in this lab. In other words, how is using skewers similar to how scientists actually map the ocean floor?