Small pieces of earth material can be rolled along the ground surface by wind.

Frost can form because the ground surface is cold enough.

The project shows higher grade portions located close to the ground surface.

Consider an arbitrary point five meters below the ground surface.

Its top reached to just below the ground surface.

Their camp sites are many feet below the present ground surface,.

It can be difficult to appreciate the amount by which the ground surface has been raised in this way.

For example, you could ensure that the ground surface is flat and well maintained.

Most of the mounds rise more than three feet above the ground surface.

The building is currently 160 by 150 meters, and has a total built ground surface of 26,000 m2.