Exploratour - Does Europa have an Ocean?

This is an image of Europa.
Click on image for full size

7.) From what geologists have been able to determine so far, the heights of surface features seem low. Since there is no wind or other means of erosion, the general low height of the topography suggests that the heights of features may be limited somehow. This phenomenon suggests that there might be a process at work whereby the strength of the underlying material is not sufficient to raise the topography up to large heights. Such a process would require a weak (possibly liquid) lower layer.

Mountains on Earth are able to rise when the "root" of the mountain is sufficiently supported by the rocky (Earths crust is made of rock, not water) but pliable (it is also warm and flexible) mantle beneath the surface. The process is somewhat akin to the way in which an iceberg floating in the open sea exposes only the upper third of its volume. If the material in which the root is floating is strong enough, it can allow more of the tip to be exposed above the surface.

You may leave the tour and read more about the process of erosion, the process of mountain building, or the qualities of the Earth's mantle by using the links found at the bottom of this page.

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