One for the building geologist

Now you can enjoy a trip to the seaside without leaving your armchair. But don't be fooled, Sea Cliff Erosion (Cambridge) is purely an educational program for budding geologists.

One can talk about and show pictures of the results of natural erosion processes but it is sometimes difficult to relate geographical features we see today with the processes said to have formed them - the Grand Canyon being a case in point.

This program is an attempt to bridge this difficulty in under standing by showing the steady effects of sea and weather action on a cliff face.

It is a clever program but only a limited number of variables can be taken into account when setting up each simulation, and this is its weakness.

In reality a large number of variables affect the shape of any landscape but this program only allows the user to alter three parameters: the rock dip (slope of bedding), severity of cliff top erosion by weather and severity of wave action.

Perhaps the major omission is an option to vary rock type at different levels, important when one considers the structure of many of the cliff faces in Britain.

However, the program succeeds in illustrating the stages of weathering, deposition and scouring which take place over the lifetime of a typical cliff face.

It centres on the animation of a single screen display which can be altered by changing numerical values in the option boxes at the bottom of the screen, these being rock dip, cliff top attack and wave action. The process can be stopped and restarted at any stage so that the variables can be altered.

I would have liked to have seen a larger range of rock dip angles, but on the whole there is enough variation to obtain some idea of the effects different dip angles have on the formation of a shoreline.

A well-written manual gives suggestions for work sheets and, although the program is aimed at 13 to 16 year olds, I feel it would be more appropriate for sixth form classes.

John Daddy