Distributed Strain, Temperature and Acoustic seNsing Suite (DiSTANS)

The DiSTANS project will use state-of-the-art technology to provide a brand-new method of monitoring changes underground. This offers the possibility of game-changing data capture to examine subsurface processes. This method uses fibre optic cables similar to those used in telecommunications, to get data from underground at a speed and density that far exceeds traditional monitoring technology.

The optical fibres in the cables have small imperfections in them. The new technology shoots a pulse of light along the fibres, which reflects off the imperfections and returns to the recorder. The tiny differences in the time that the light takes to return will tell us about very small vibrations, temperature changes and movements around the underground cable.

Because the cable is the sensor, we can monitor the underground conditions for up to 15 km and see differences along the cable as close together as 25 cm. These measurements are taken one hundred thousand times each second, which means that very quick changes can also be measured.

This new technology, called distributed strain, temperature and acoustic sensing suite, can be used in many different places. It can be used to monitor volcanoes and earthquakes, but can also be used to keep track of traffic and people walking. For the first project, we will be installing the DiSTANS system on the North Norfolk coast, where the sea erodes the coast at a rate of 10 cm per year, threatening people's houses and businesses, and posing a danger for people and wildlife who use the coast. We will monitor small cracking and slumping before landslides, and how these are affected by temperature changes each day and season.