Listening device provides landslide early warning
A device that provides early warning of landslide by monitoring vibrations in soil is being tested by UK researchers. The 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.
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 monitoring a site directly, or sensors sunk into boreholes or fixed above ground can be sued 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 Nixons team has developed a device that listens for the vibrations caused when particles begin moving within a slope.
The device is currently being tested in a 6-metre-tall artificial clay embankment in Newcastle, UK. Early results suggest it should provide fewer false positives than existing systems. Once it has been carefully and thoroughly tested, the device could be used to create a complete early-warning system for dangerous slopes.
1. What does Such natural disasters in the first paragraph refer to?
B. Earthquakes
D. Landslides
A. The initial movement is hard to spot
C. They can be destructive in a matter of hours or minutes
3. Why do researchers develop a new device to monitor signs of landslides?
B. because the new device can be sunk into boreholes or fixed above ground
D. because the common methods are useless
A. it is filled in with gravel
C. It is dropped into a borehole filled with gravel
5. According to the context, what does the word positives in the fifth paragraph mean?
B. evidences
D. predictions