Quake Escape

Geoscientist Harsh Gupta speaks to Dinsa Sachan on the need for an  early warning system for  earthquakes  

By Dinsa Sachan
Published: Tuesday 15 November 2011

Harsh GuptaGeoscientists say earthquakes cannot be predicted. How will the warning system then help?

Early warning is different from prediction. An early earthquake warning system locates and measures the magnitude of an earthquake soon after its occurrence. So let’s say an earthquake occurs 200km from NCR in the Himalayas. A warning system in the Himalaya will estimate the earthquake parameters within 10 to 15 seconds of its occurrence and determine whether the shear waves generated by it would be damaging for NCR. So if we have 60 seconds before the quake strikes, people can get to safer places and Metro can be stopped.

Are 60 seconds sufficient?

The Haiti earthquake of 2010 of magnitude 7 left around 300,000 people dead. The Japan earthquake of magnitude 9 took 30,000 lives. Japan and Haiti have the same population density. But Japan has an early warning system.

How will a warning system work?

We will identify three-four places where earthquakes occur frequently. Around 10 to 12 stations will need to be installed. Then we will set up an automatic system that will locate earthquakes, find their magnitude.

How useful will microzonation be for early warning?

Microzonation helps us identify high-risk zones within a city, areas which are likely to sustain more damage in the event of an earthquake. Early warning could be more beneficial if people know they are living in a high-risk zone.

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