Figure2.6: ThisimagewasmadefromdataoftheLandsatsatelliteandshowsthetopography
of the San Francisco Mountain and surrounding areas in northern Arizona. You can see the
differences in elevation of the mountain and surrounding lava flows. ( 25 )
Landforms
If you look at the Earth’s surface and take away the water in the oceans (Figure2.7), you
will see that the surface has two distinctive features, continents and the ocean basins. The
continentsare large land areas extending from high elevations to sea level. Theocean
basinsextend from the edges of the continents down steep slopes to the ocean floor and
into deep trenches.
Figure 2.7: This image shows examples of some of the main features found on the ocean floor,
as well as their above-water continuations. The red areas are high elevations (mountains).
Yellow and green areas are lower elevations and blue areas are the lowest on the ocean floor.
(i.e., the image below is a slice through a relief map of world. ( 32 )
Both the continents and the ocean floor have many features with different elevations. Some
areas of the continents are high. These are the mountains we have already talked about.