"Under the Sea" With Geological Oceanography
Undersea Topography
Level: Middle/High School
Subject: Science
Objective: Students will demonstrate knowledge of major underwater topographical structures and common undersea terrain features.
Background: Soviet submariners spent a tremendous amount of time and effort in the surveying and precise mapping of underwater topography in an attempt to use underwater terrain features to mask the presence of their submarines from American (and NATO) tracking devices and techniques.
Materials: None
Task: Students will learn the definitions of underwater terrain features.
Students will draw a cross-section of underwater topography, labeling major topographic features.
Activity: Students will complete the accompanying vocabulary sheet of terms commonly used to describe topographic features in geological oceanography.
Students will draw a cross-section of underwater topography from shore to shore showing the following topographic features:
a. Continental Shelf
b. Continental Slope
c. Abyssal Plain
d. Seamount
e. Guyot
f. Rift Valley
g. Canyon
h. Trench
i. Oceanic Ridge
Circumstances of performance: This student work is to be produced under the following work conditions:
__ alone __ in a group
__ in class __ as homework
__ with teacher feedback __ timed
__ with peer feedback __ opportunity for revision
Standards addressed:
S3a. Earth and Space Sciences Concepts: Motions and Forces. The student produces evidence that demonstrates understanding of:
a. Structure of the Earth system such as crustal plates and land forms, water and rock cycles; oceans, weather and climate.
Boy Scout Advancement Requirements:
Oceanography Merit Badge
4. Draw a cross-section of underwater topography. Show what is meant
By:
(a) Continental Shelf
(b) Continental Slope
(c) Abyssal Plain
Name and put on your drawing the following: seamount, guyot, rift valley, canyon, trench and oceanic ridge. Compare the depths in the oceans with the heights of mountains on land.
Undersea Topography
Vocabulary Quiz
1. ____________________ 1. The shallow part of the seafloor next to land. They are usually relatively smooth platforms that stretch seaward until a sudden change appears in the slope, known as the shelf break or continental edge.
2. ____________________ 2. Solitary, generally cone-shaped underwater mountains that may rise thousands of feet from the seafloor.
3. ____________________ 3. The greatest mountain range in the world, this distinct S-shaped ridge runs down the center of the Atlantic seafloor and circles the earth like the seam of a baseball. It can be traced for 40,000 miles through the Atlantic, Indian, Antarctic, and Pacific Oceans.
4. ____________________ 4. A flat-topped seamount
5. ____________________ 5. Undersea valleys found amidst mountains in the Mid-Oceanic Ridge system. The central rift valley can be as much as 2,000 meters below the peaks of the surrounding mountains.
6. ____________________ 6. Cuts in the continental shelf or slope that appear to be much like canyons on land. These features may cross the continental rise and reach even the deep ocean basins.
7. ____________________ 7. The largest single feature of the earth's surface, covering 46 percent of the planet. Smooth flat plains covered with sediments at about 12,300 feet in depth under the oceans.
8. ____________________ 8. The deepest points in the ocean are found in these commonly V-shaped topographical features with a narrow and sometimes flat floor.
9. ____________________ 9. This major ocean terrain feature stretches downward from the outer part of continental shelves to the deep sea floor.
10. ____________________ 10. Sand and gravel deposits that cover most of the shore.
11. ____________________ 11. Where land and water meet.
12. ____________________ 12. Places on the coast where fresh and salt waters mix. These locations serve as important nursery grounds for fish, shrimp, crabs, and other animals.
Undersea Topography
Vocabulary Quiz
ANSWER KEY
1. Continental Shelf 1. The shallow part of the seafloor next to land. They are usually relatively smooth platforms that stretch seaward until a sudden change appears in the slope, known as the shelf break or continental edge.
2. Seamounts 2. Solitary, generally cone-shaped underwater mountains that may rise thousands of feet from the seafloor.
3. Mid-Oceanic Ridge 3. The greatest mountain range in the world, this distinct S-shaped ridge runs down the center of the Atlantic seafloor and circles the earth like the seam of a baseball. It can be traced for 40,000 miles through the Atlantic, Indian, Antarctic, and Pacific Oceans.
4. Guyot 4. A flat-topped seamount
5. Rift valley 5. Undersea valleys found amidst mountains in the Mid-Oceanic Ridge system. The central rift valley can be as much as 2,000 meters below the peaks of the surrounding mountains.
6. Submarine canyon 6. Cuts in the continental shelf or slope that appear to be much like canyons on land. These features may cross the continental rise and reach even the deep ocean basins.
7. Abyssal plains 7. The largest single feature of the earth's surface, covering 46 percent of the planet. Smooth flat plains covered with sediments at about 12,300 feet in depth under the oceans.
8. Deep-sea trenches 8. The deepest points in the ocean are found in these commonly V-shaped topographical features with a narrow and sometimes flat floor.
9. Continental Slope 9. This major ocean terrain feature stretches downward from the outer part of continental shelves to the deep sea floor.
10. Beaches 10. Sand and gravel deposits that cover most of the shore.
11. Shoreline 11. Where land and water meet.
12. Estuaries. 12. Places on the coast where fresh and salt waters mix. These locations serve as important nursery grounds for fish, shrimp, crabs, and other animals.
