Sensors to detect tsunamis, quakes
London: The Comprehensive Nuclear Test-Ban Treaty Organization monitoring centre in Vienna, Austria, spotted yesterday’s Japanese quake.
It also alerted Indonesia and other governments to the quake off Sumatra that caused the 2004 Boxing Day tsunami, reports new Scientist.
Its ability has led experts to think that the worldwide network of seismographs and other sensors designed to detect nuclear blasts could also listen to impending earthquakes and tsunamis.
The Comprehensive Nuclear Test-Ban Treaty was signed in 1996 but has not yet come into effect, mostly because the US has not yet ratified it - though US President Obama wants to.
The system includes arrays of sensors at 60 sites across the world that listens for the low boom of atmospheric blasts. They are tuned to infrasound - frequencies under 20 hertz (cycles per second).
They also pick up volcanoes, and even rogue waves in the north Atlantic.
In 2009 the CTBT's scientists reported that their station on the Indian Ocean island of Diego Garcia had picked up infrasound from big quakes in Sumatra in 2004, and Mantawi and Nias Island in 2005.
According to Milton Garces of the University of Hawaii at Manoa, this could be made into a tsunami warning system.
The infrasound signals generated by the tsunami-making quakes travel at up to 330 metres per second, while the tsunamis themselves propagate at about 260 metres per second. So the sound signal should arrive at a monitoring station before the wave hits.
Although more research is underway, the infrasound network being used to do it is under threat: the longer the CTBT remains unratified, the less enthusiastic governments are to keep funding it.