Lesson 5: Axial Seamount (4)

Learning Activities

Diagramming the Ocean Floor (1 class period)

  1. Read aloud Solving the Puzzle Under the Sea: Marie Tharp Maps the Ocean Floor by Robert Burleigh and Raul Colon.
    1. Discuss trailblazing women in science and underrepresented groups in oceanography
    2. Discuss how science is always changing based on what we learn over time and it can very much be like solving puzzles
  2. Students should interact with the map found at OOI  as they label structures and depths and define ocean floor structures and how they compare to land features.Take screenshots of structures with “eye” (please add me to email of this screenshot, dwina@uw.edu)
    1. Continental shelf
    2. Continental slope
    3. Continental rise
    4. Trench
    5. Rift valley–forms where the seafloor spreads due to tectonic plates moving
    6. Guyot
    7. Seamount–When tectonic plates collide near subduction zones, oceanic crust is forced down toward Earth’s hot mantle. The crust melts, forming magma, that rises back to the surface and erupts to create seamounts
    8. Volcanic island
    9. Abyssal plain
    10. Mid-ocean ridge–Earth’s crust continuously forms at divergent plate boundaries when new seafloor is created. As the plates separate, lava rises to the seafloor, cools and hardens. The rocks that are formed here are mostly basalt

Sculpting the Ocean Floor  (2 class periods)

  1. Give students at least 3 colors of modeling clay (or damp sand), 10 rounded toothpicks, sticky address labels, and black flair pens, and 4.25” x 11” cardboard for sculpting the model on.
  2. Instruct students to sculpt ocean floor structures and make toothpick/address labels for each of the 10 structures listed above.

Graphing the Ocean Floor  (2 class periods)

  1. Give students a copy of the data collection sheet showing depths of the Northeast Pacific Ocean SONAR Coordinate Grid
  2. Have students plot ordered pairs on 8.5” x 14” grid paper and connect the points as a line graph. When students are finished, they will turn the graph upside down, and color the seafloor tan or gray and the ocean water blue so that they can visualize the seafloor structures.
  3. Instruct students to analyze the data and determine the ocean floor structures and label all that they see.**

 Check for Understanding (formative assessment)
**Label all the structures you see on the ocean floor graph you constructed.


Introduction (Images/Graphics & Animation)

Ask: What are the structures of the ocean floor? What are the geologic processes that shape the ocean floor?

Say: In this unit, we will learn about the structures of the ocean floor, the geologic processes that shape the landscape of the ocean floor, how scientists and engineers use data-collecting instruments to gather information on ocean floor structures, and finally all about one particular dynamic ocean floor structure, Axial Seamount.

Say: The Circum-Pacific Belt is nicknamed The Ring of Fire because most of Earth’s volcanoes and earthquakes take place along this circular path. In addition to underwater volcanoes, or seamounts, our ocean hosts several structures similar to what we see on land. For example, we see the Great Plains on land and the abyssal plains, which cover most of the ocean floor.

Give students several minutes to interact with the images, Ring of Fire, and Interactive map – have them list what they notice and what they wonder.


Solving the Puzzle Under the Sea
Images/Graphics: Explore
Interactive Map
Ring of Fire