Download Sea Floor Mapping Lesson Plan Part 2

What’s Really Under the Ocean?
Sea Floor Mapping, Part 2
Summary
The ocean has many topographical features on land and under the ocean.
Key Concepts
National Science Standards
 Lithospheric plates on the scales of continents and oceans constantly move at rates of centimeters per
year in response to movements in the mantle. Major geological events, such as earthquakes, volcanic
eruptions, and mountain building, result from these plate motions.

Land forms are the result of a combination of constructive and destructive forces. Constructive forces
include crustal deformation, volcanic eruption, and deposition of sediment, while destructive forces
include weathering and erosion
Background Information:
The Earth is made of solid land. Some of the land is located above Earth’s water and some is located below the
oceans. However, there are similarities and differences between the landforms found on the continents and
those found on the ocean floor.
Description
Low land between hills
or mountains
Deep valley with high
steep sides
An underwater volcano
Land which rises high
above the ground
Wide, flat areas of land
Continental and Oceanic Landforms
Continental
Valley
Oceanic
Rift
Canyon
Trench
Volcano
Mountain
Seamount
ridge
Plains
Abyssal plains
Resource: South Carolina Science Standards Support Documents,
http://ed.sc.gov/agency/pr/Standards-and-Curriculum/old/cso/standards/science/sd.html
Scientist use tools to map or survey the ocean floor. LIDAR is an aircraft-based sensor that uses a laser to
bounce light off land. LIDAR stands for LIght Detection And Ranging. LIDAR sends laser light from the
bottom of an airplane to the sea floor. The light reflects back to the airplane. LIDAR measures the time it takes
for the reflections to return to the airplane.
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Sonar systems send sound waves from the bottom of a ship to the bottom of the sea. These sound waves bounce
off the sea floor and back up to the ship. SONAR stands for SOund NAvigation and Ranging. Two types of
mapping the ocean floor are single-beam sonar and mult-beam sonar.
Single-beam sonar have with a transceiver (transducer/receiver) mounted to the hull, or sidemount, to the ship
and measures the water depth directly beneath the research vessel. The hull-mounted transceiver transmits a
high-frequency acoustic pulse in a beam directly downward into the water column. Acoustic energy is reflected
off the sea floor beneath the vessel and received at the transceiver
Multi-beam sonar uses a swath out to each side to get full coverage of the ocean floor, with much greater detail
than the lines of depth seen by a single-beam sonar.
Objectives
Observe, classify, and identify ocean floor features.
Materials
 Sonar image cards set (rift, trench, seamount, volcanic island , & ridge)

Classification data sheets 1-6

Classification data sheet (teacher version, answer sheet)

Vocabulary word cards (rift, trench, seamount, volcanic island , & ridge)

Ocean Floor Features Map Image
Procedure
1.
Review landforms features on land (continental) from previous learning (valley, canyon,
volcano, mountain, and plains).
2.
Divide your class into small groups. Photo copy enough sonar image card sets for each group.
3.
Have students observe and discuss the characteristics of each image.
4.
Classify images by oceanic features. Use one classification data sheet per group.
5.
After the students classify the images under the specific descriptions of the ocean floor features,
use the vocabulary word cards to label each column. Identify sonar image cards with vocabulary
cards.
Additional Activity: Ocean Floor Charades
Have a student select a sonar image card of ocean floor feature. Student will act out the ocean floor features.
Assessment
Ocean Floor Features Map Image….Have students observe the images of the ocean floor. Have students write
rift, trench, seamount, ridge, or abyssal plain by the ocean features.
Additional Resources
Please list any Web sites, books, publications, or other resources that would be helpful for teachers or students
preparing for this lesson.
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Got time?
If you have time before your presentation, it would be helpful for me for you to provide

Relevant content standards—National Science Education Standards:
http://www.nap.edu/readingroom/books/nses/html/6a.html

Science skills (using the Essential Science Skills grid on the EARTH Web site:
http://www.mbari.org/earth/skills.htm

Ocean Literacy Standards:
http://www.coexploration.org/oceanliteracy/documents/OceanLitChart.pdf
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