Name ___________________________________________​​
Period _________
Comparing Seafloor Data
Like the surface of the continents, the elevation of the seafloor varies. The graph in Figure 11-4 shows
how much of Earth’s surface area lies at each elevation. The vertical axis shows elevation relative to
sea level. Positive elevation means height above sea level while negative elevation means depth
below sea level. The horizontal axis shows the basic breakdown of Earth's main topographic surfaces,
including the total area in millions of square kilometers and the percentage of Earth’s total surface at
each elevation.
Using the graph above, answer the following questions:
1.​ Roughly what percent, or about 150 million square kilometers, of Earth's surface lies above sea
level (Hint: see dashed line) _______________%
2.​ How does the total area of Earth’s surface (in square kilometers) above sea level compare with
the total area of Earth’s surface below sea level?
3.​ How does the average elevation of land above sea level compare to the average depth of
ocean basins?
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Does this surprise you? Why or why not?
4.​ How do Earth’s highest peaks compare to the deepest trenches in the oceans in terms of
elevation?
Use table 11-1 and plot the location of these features on the map. (you can use google:)
5.​ According to Table 11-1, where are most of the world’s deepest points located? What is the
name given to this region?
6.​ Based on what you know about the movement of Earth’s plates, why is this likely true? Be sure
to include what you know about the plate movement at these locations.