S An analysis of currents produced by waves proves that most of the net movement of sand is usually along the shore. This VHS program demonstrates that the beach is a river of sand which exists between land and breaking waves. This revised video emphasizes that mountains are always changing. Discusses volcanism, plate tectonics, and folding. Footage of Mt. St. Helens.
Studies show how a land mass is slowly shaped over billions of years.
I Explains why the land changes on earth. Geologic history determined. P, I While viewing very beautiful scenery, young students learn about the forces that change the earth - water, wind, plants, animals, temperature and the forces beneath the surface. This videotape explores the formation of sand dunes as a natural process in the Great Sand Dunes of Colorado. The ver changing dunes sometimes reach a height of 700 feet.