Presents an activity that is part of a unit on topography and land masses in the earth science curriculum. Involves students learning about scientific inquiry, comparing a model with what it represents, making and interpreting scale drawings, learning how to use new instruments, and learning about computation and estimation. (JRH)

Discussed are two techniques that can be used to directly test the theory that the plates which make up the crust of the earth are still moving. Described are the use of satellite laser ranging and very long baseline interferometry. Samples of data and their analysis are provided. (CW)