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Listening Device Provides Landslide Early WarningA device that provides earlywarning of a landslide by monitoring vibrations in soil is being tested by UKresearchers. The device could save thousands of lives each year by warning whenan area should be evacuated, the scientists say. Such natural disasters arccommon in countries that experience sudden, heavy rainfall, and can also betriggered by earthquakes and even water erosion. Landslides start when afew particles of soil or rock within a slope start to move, but the early stagescan be hard to spot. Following this initial movement, slopes can becomeunstable in a matter of hours or minutes, says Nell Dixon at SouthboroughUniversity1, UK. He says a warning system that monitors this movement might beenough to evacuate a block of flats or clear a road, and save lives. Themost common way to monitor a slope for signs of an imminent landslide is towatch for changes in its shape. Surveyors can do this by measuring asidedirectly, or sensors sunk into boreholes or fixed above ground can be used tomonitor the shape of a slope. Slopes can. however, change shape withouttriggering a landslide, so either method is prone to causing false alarms. NowDixons team has developed a device that listens for the vibrations caused whenparticles begin moving within a slope. The device takes the form of a steelpipe dropped into a borehole in a slope. The borehole is filled in with gravelaround the pipe to help transmit high-frequency vibrations generated byparticles within the slope. These vibrations pass up the tube and are picked upby a sensor on the surface. Software analyses the vibration signal to determinewhether a landslide may be imminent. | 
