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Listening Device Provides Landslide Early Warning A device that provides early warning of a landslide by monitoring vibrations in soil is being tested by UK researchers. Tile device could save thousands of lives each year by warning when an area should be evacuated，the scientists say. Such natural disasters are common in countries that experience sudden，heavy rainfall，and can also be triggered by earthquakes and even water erosion. Landslides start when a few particles of soil or rock within a slope start to move，but the early stages can be hard to spot. Following this initial movement，slopes can become. unstable in a matter of hours or minutes, says Nell Dixon at Loughborough University1,UK.He says a warning system that monitors this movement might be enough to evacuate a block of fiats or clear a road，and save lives. The most common way to monitor a slope for signs of an imminent landslide is to watch for changes in its shape.Surveyors can do this by measuring a site directly，or sensors sunk into boreholes or fixed above ground can be used to monitor the shape of a slope.Slopes can，however，change shape without triggering a landslide，so either method is prone to causing false alarms.Now Dixons team has developed a device that listens for the vibrations caused when particles begin moving within a slope. The device takes the form of a steel pipe dropped into a boreh01e in a slope.The borehole is filled in with gravel around the pipe to help transmit high-frequency vibrations generated by particles within the slope.These vibrations pass up the tube and are picked up by a sensor on the surface.Software analyses the vibration signal to determine whether a landslide may be imminent. | 
