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By Greg Bartlett

Earthquakes. Destructive, frightening and unpredictable. In some parts of the world earthquakes occur far too frequently and have destructive and devastating consequences to buildings and lives. Traditional methods of trying to predict them have involved digging trenches along the fault lines themselves and analyzing past earthquake signals and lines to try to discover how fast the Earth‘s plates move in relation to each other and trying to extrapolate this data to predict the next earthquakes.

Can a satellite tracking device be used to track the actual Earth itself? Well, the way GPS actually works lends itself quite easily to this. Satellites in orbit around the planet have equipment which routinely sends signals down to receivers below. These satellites are positioned at equidistant locations around the Earth, but send signals at exactly the same time, every five seconds. Something receiving these signals would receive them at different times. By extrapolating this data it is possible to construct an algorithm which can allow the receiving system to discover its exact position on Earth with pin-point accuracy.

At these earthquake fault lines, GPS receivers are embedded into the shifting geological plates. They are actually firmly positioned into the bedrock itself. The plate shift is not so important as how quickly the plates are shifting away from each other. Scientists can measure the exact distance moved by working out the end position of each receiving station in relation to the original position.

Now scientists are able to measure this shift to within a millimeter. Several of these measurements taken over time can allow the pattern of seismic shift to be determined which eventually leads to an earthquake. It has been found that the distance moved is related to the magnitude of the earthquake itself. This research is in its early stages still, but it has the potential to save hundreds of lives and hundreds of thousands of dollars worth of damage.

The uses of GPS satellite tracking are extraordinary and seemingly unlimited. Using this technology the movements of the Earth itself can be tracked and in California there is now a network of two hundred and fifty GPS stations. These are now poised to give as early a warning as possible about any earthquakes likely to occur in the region.