Grade:
11-12
Subject:
Marine Science
Topic:
Bathymetry
Simulated Seas: Bathymetry
Adam Fox
February 2010
Coastal Carolina University
NSF GK-12 Program
http://kingfish.coastal.edu/GK-12
Standards Addressed:
 SC Standard ES-1: The student will demonstrate an understanding of how scientific inquiry and
technological design, including mathematical analysis, can be used appropriately to pose
questions, seek answers, and develop solutions.
ES-1.2: Use appropriate laboratory apparatuses, technology, and techniques safely and accurately when conducting a
scientific investigation.
ES-1.3: Use scientific instruments to record measurement data in appropriate metric units that reflect the precision and
accuracy of each particular instrument.
ES-1.4
Design a scientific investigation with appropriate methods of control to test a hypothesis (including
independent and dependent variables), and evaluate the designs of sample investigations.
ES-1.5: Organize and interpret the data from a controlled scientific investigation by using mathematics (including
calculations in scientific notation, formulas, and dimensional analysis), graphs, tables, models, diagrams, and/or
technology.
 Ocean Literacy Standard 1: The Earth has one big ocean with many features.
A. An ocean basin’s size, shape and features (islands, trenches, mid-ocean ridges, rift valleys) vary due to the
movement of Earth’s lithospheric plates. Earth’s highest peaks, deepest valleys and flattest vast plains are all in
the ocean.
 Ocean Literacy Standard 1: The ocean supports a great diversity of life and ecosystems
E. The ocean is three-dimensional, offering vast living space and diverse habitats from the surface through the
water column to the seafloor. Most of the living space on Earth is in the ocean.
 Ocean Literacy Standard 1: The ocean is largely unexplored
A. The ocean is the last and largest unexplored place on Earth— less than 5% of it has been explored. This is the
great frontier for the next generation’s explorers and researchers, where they will find great opportunities for
inquiry and investigation.
B. Understanding the ocean is more than a matter of curiosity. Exploration, inquiry and study are required to
better understand ocean systems and processes.
D. New technologies, sensors and tools are expanding our ability to explore the ocean. Ocean scientists are relying
more and more on satellites, drifters, buoys, subsea observatories and unmanned submersibles.
Summary:

The purpose of this activity is to allow students to explore how the sea floor was originally
mapped. They will design and carry out an experiment to map the floor of a simulated ocean.
Experimental results will be analyzed and used to create a model (in this case, a bathymetric map
and a contour map).
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Performance Objectives:
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Students will demonstrate an understanding of the Scientific Method.
Students will design an experiment to answer a question.
Students will be able to model the seafloor based on experimental results.
Students will be able to draw connections between marine science and human history.
Materials (for each group)
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1 Simulated Sea Box (see attached instructions)
1 Simulated Sea Surface (blue construction paper
large enough to fit inside of boxtop.
1 “lead line” dowel, marked off in cm.
Rulers
Hook:
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The deep ocean is hard to reach. How do we know
what it looks like, or how deep it is?
Concept Exploration:
1. Ask students to come up with ways to determine ocean depth and what the bottom of the ocean looks
like. Ask students to explain their ideas. No ideas are wrong, but explain that divers can only
explore a tiny fraction of the ocean and submarines only show you a small area.
2. Re-introduce the scientific method. Have students list the steps as a class, then fill in Question 1 on
worksheet: Observation -> Question -> Hypothesis ->Experiment ->Analysis -> Conclusion
3. Go through Bathymetry Powerpoint to introduce vocabulary and to and explain how we have
historically explored the sea floor.
4. Show students some photos of a landlocked (or mostly land-locked) sea, or a large lake. It’s easier to
get the ideas across using this sort of example than using a large ocean.
5. Ask students to come up with some questions about the sea basins themselves (rather than about
animals or water in the sea). The questions you want someone to ask are:
 What is surface area of the sea?
 What is volume? (How much water is in the sea?)
 What does the bottom of the sea look like?
When the class comes to a consensus on these questions, students should write them in for
Question 2.
6. Have a class discussion about experimental methods.
A. Start by asking how you determine surface area and volume.
Surface Area
Volume
Square Sea
length*width
Length*width*depth
Round Sea
Π*radius2 or π*( ½ diameter)2
(π r2)*depth
B. Ask the class for ideas about how you would take these measurements and how you could
visualize the sea floor.
C. Let the students design the experiment themselves, but guide it towards the following design:
 Establish an appropriately-sized grid to determine sampling points
 Mark off the grid so you know where to sample.
 Take soundings with a lead line
o Our lead line will actually be a length of dowel, since it’s easier to use at this scale
 Measure length and width of the sea (assuming the sea is square or round makes
calculations easier, while still getting the point across.
 Note that the depth at all edges of the sea is 0.
D. Ask students what our “end product” will be for the third question
 Maps of “sea” floor
Concept Introduction:
1. Run experiment
A. Give each group a piece of paper representing the surface of the sea (cut to size to fit in your
box lid). Have them mark off their sampling grid. Cut small holes or slits at the points to be
sampled.
B. Attach the “sea surface” to the box top.
C. Have students measure the length and width of their sea.
D. Have students draw a scale map of their sea on graph paper.
E. Place the box top onto a sea-in-a-box setup. Do not let the students peek into the box.
F. Have students take soundings using their “lead line” dowel.
a. Students will record their depth measurements in the appropriate locations on their maps.
G. Calculate surface area.
H. Determine average depth of pond and use this number to calculate volume.
I. On their map of their sea, each student will draw contour lines (isobaths) to create a
bathymetric contour map.
J. Each student will draw a line through their contour map, and draw a bathymetric cross-section
of their sea along that line.
Additional Resources:
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How to construct a simulated seafloor in a box:
1. Start with a cardboard copy-paper box.
2. Cut an irregular hole in the top of the box, so that it
retains structural integrity.
3. Paint boxtop green. Edge the hole through the top with
sand-colored paint.
4. Use scraps of cardboard and hot glue to construct
mountains, ridges, valleys, canyons or slopes inside the
box. Paint the inside of the box dark blue or black.
5. Cut a large piece of paper (preferably blue) to fit inside
the boxtop. You should be able to tape it in from the
underside, so it looks like the surface of a land-locked
sea, surrounded by green land.
6. Use a dowel marked off in cm to poke through the
“surface” andmeasure depth at the locations selected by
the students. 1cm=15m of sea depth.
http://kingfish.coastal.edu/GK-12
http://www.nsfgk12.org
Name______________________________ Date_______________ Group________________
Bathymetry: Mapping the Sea Floor
Vocabulary:
 Bathymetry: the measurement of water depth. Multiple measurements of depth can used to
visualize the topography of the sea floor.
 Sounding: an early method used to measure water depth by dropping a weighted line into the
water. As the line was pulled aboard, the sailor would measure the length of the line in fathoms,
the distance between his out stretched hands.
 Contour Lines / Isobaths (iso = same, bath = depth): lines of equal depth.
 Profile / Cross-section: a two dimensional side view of bottom topography.
1. Steps of the Scientific Method:
2. What are our questions about our seas?
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3. Pick up a simulated sea box top and a sea surface (piece of paper).
Remember: The scale of our Simulated Sea is 1cm = 15m
4. Sea Surface Data:
Length of sea: ____________cm = ___________________m
Width of sea: _____________cm = ___________________m
5. Calculate surface area of your sea. Show your work.
Stop Here! We will discuss the next step as a class!
6. After we have discussed our experiment as a class, provide a detailed description of our methods.
Methods should be clearly stated so that a random person reading this paper would be able to
easily understand what we are going to do. Make sure you mention how we will measure depth
and where we will take our measurements (Use the back of this page if necessary).
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7. Draw our sampling grid on your simulated sea surface. Cut small holes in the sea surface where we
will be taking our depth readings. Tape the sea surface to the inside of the box top.
8. Use a piece of graph paper to create a map of your sea. We will use this to plot your depth readings.
A. The sea must be as large on your graph paper as possible.
B. Draw the sea to scale – use the length and width you have measured. Draw our sampling grid
on your graph paper so you will know where to write down your measurements. Be sure to
include a scale for your graph.
C. Use your “lead line” (dowel) to measure depths of your sea in the locations we determined.
Remember to convert your measurements using the scale above!
D. Accurately plot each depth sounding in the appropriate place on your graph paper map.
9. When all your soundings have been plotted, we will draw contour lines (isobaths) to group areas
of equal depth. Start with the deepest depths and work towards the edges. Use common sense to
help you determine where lines should be placed. You will end up with a Contour Map of the
pond.
4. Calculate volume of your sea. Use the average depth of your sea. Show your work.
5. Create a bathymetric profile of your sea.
A. Draw a straight line anywhere across your contour map of your sea. This will be the line
along which you draw your cross-sectional profile.
B. On another piece of graph paper, draw a set of axes. The x-axis will be the same scale as your
contour map. The y-axis will be exaggerated to better show depth. y-axis will be
exaggerated to better show depth. Indicate a scale on your paper. Your deepest depth will
be the lowest depth measurement on your y-axis.
Distance
How your graph should be set up
Depth
C. Using the data from your contour map, plot the depths as you travel along your cross-section
line. You will end up with a Bathymetric Profile of your ocean.
6. Once you complete your contour map and your bathymetric profile, take the lid off of your
simulated sea. What do you see? Does it look like you thought it did?
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7. What are some reasons (or potential reasons) why your contour map and bathymetric profile might
have looked different than the actual seafloor of your simulated sea?
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8. Carefully remove your paper sea surface from the inside of the box top. Put your simulated sea back
where it came from, and recycle your paper sea surface.
9. Each person in your group needs to turn in:
 This worksheet.
 A contour map of your group’s sea. It should include isobaths and a scale.
 A bathymetric profile.