By R A Whittle, J C Gutmanis and D T Shilston, Soil Mechanics
This paper was first publsihed in GE’s January 1983 issue
Between 1972 and 1978 NASA launched a series of “Landsat” earth satellites capable of sensing and recording electromagnetic radiation reflected from or emitted by the earth’s surface. The data was transmitted in digital form to receiving stations where it was transformed into images of the earth. The advantages of being able to obtain “photographs” of whole regions or even continents were rapidly recognised by geologists, but, as with many new technologies, extravagant claims soon followed. These led to a polarisation of views amongst geologists, those who believed satellite imagery to be the answer to all geological problems, and those who thought that imagery merely provided pretty pictures from space. Both opinions are extremes and equally incorrect; it is now widely recognised that imagery is an invaluable geological tool, in the right hands.
This paper illustrates by means of two case histories the use of satellite imagery to locate geological faults. It will be seen that imagery must be interpreted with care and that the results must be verified by use of reliable “ground data” obtainedby more conventional survey methods.