Exploratour - Does Europa have an Ocean?

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

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.

This is page 16 of 20

You might also be interested in:

Traveling Nitrogen Classroom Activity Kit

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

ExploraTour - Looking at the World in a Different Light

Even though the sleeping man is no longer on the bed, you can still see where he was lying down. The heat from his body warmed up the bed sheets which are now radiating infrared light toward your eyes....more

ExploraTour - Looking at the World in a Different Light

All warm objects radiate in the infrared. The warmer the object, the higher the frequency and intensity of the radiation. Very hot objects give off other types of radiation in addition to infrared. Click...more

ExploraTour - Looking at the World in a Different Light

Your eye is a wonderful detector of visible light. Different frequencies of light produce different sensations in the eye which we interpret as colors. Our eyes detect light by using light sensitive components...more

ExploraTour - Looking at the World in a Different Light

Imagine you found a pair of special glasses that not only gave you telescopic vision but gave you the ability to see all forms of radiant energy. The universe in visible light contains all the familiar...more

ExploraTour - Looking at the World in a Different Light

This is a volcano on the island of Miyake in Japan. It has erupted, sending hot lava and ash into the air, a total of ten times. The time after one eruption until the next occurred was about twenty years...more

ExploraTour - Looking at the World in a Different Light

The awesome power of a giant black hole was revealed by looking at this galaxy in three different types of light. The picture that you see is of Centaurus A, a very peculiar galaxy. A galaxy is just a...more

ExploraTour - Looking at the World in a Different Light

This is a plant in Gary, Indiana where power is made. We use power to run things like television sets, radios, lights, and microwave ovens. The picture looks very strange because it was taken in infrared....more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA