how do scientists track plate motion?

At a workshop in Italy last week, researchers explained how they are using this ability to monitor volcanoes and earthquake zones, aid oil and gas prospecting, observe urban subsidence and measure the slow flow of glaciers.

Data from Synthetic Aperture Radar (SAR) instruments like those flown aboard the ERS spacecraft and Envisat are the basis for a technique called SAR interferometry, or InSAR for short. InSAR involves combining two or more radar images of the same ground location in such a way that very precise measurements – down to a scale of a few millimetres – can be made of any ground motion taking place between image acquisitions.

Very small movements can potentially be detected across wide areas: tectonic plates grinding past one another, the slow ’breathing’ of active volcanoes, the slight sagging of a city street due to groundwater extraction, even the thermal expansion of a building on a sunny day.Scientists want to know the tracking of plate motion becuase they need info on the area so they bury an epicenter to see hot big the earthquake was or how the plates moved or how far they moved.they also need to put someinfo in a book or some other people want to find tracking of plate motion