ISR to set up 50 new seismic stations for earthquake analysis

Gandhinagar-based Institute of Seismological Research (ISR) has planned to set up 50 new seismic stations in Gujarat at a cost of around Rs five crore to enhance their capacity to analyse possible risk of earthquake in the state.

These new seismic stations will have two major components-- Strong Motion Accelerograph (SMA) and another is Broadband Seismometer (BBS), said senior scientist of ISR Dr Santosh Kumar.

At present, there are 60 permanent stations having such sensors in Gujarat as part of the earthquake early warning system. Out of these 60 stations, 45 are directly connected with ISR while remaining are offline.

As many as 13,800 people had died and 1,67,000 were injured when a powerful earthquake had struck about 250 km west of Ahmedabad at a depth of 25 kilometre on January 26, 2001.

According to Kumar, the 50 new stations will collect and analyse various noises, seismic waves and signals coming from the crust of the earth, which will help the scientists to locate active fault-lines which are responsible for earthquakes.

"ISR has planned to set up 50 new seismic stations to study what is happening below the surface of Gujarat. The main purpose of this project is to find out what is going on in deep mantle or deep crust by analysing various noises coming out from the earth" said Kumar.

"Each station will have one SMA and one BBS. These equipments are very sensitive and state-of-the-art. The total cost of our project is around Rs five crore. This project is more about estimating long term seismic hazard, as very less information is available with us about earth below," said Kumar.

Broadband Seismometers are instruments that measure motion of the ground including those of seismic waves generated by earthquakes, volcanic eruptions and other seismic sources.

Records of seismic waves allow seismologists to map the interior of the Earth as well as to locate and measure the size of these different sources. Strong Motion Accelerographs are useful when the earthquake ground motion is so strong that it causes the more sensitive seismometers to go off-scale, said Kumar.

According to Kumar, the new 50 stations will not be scattered across Gujarat like the present network.

"This time, we will set up all these 50 stations in one particular city or district for six months and collect the data offline. This will give us accurate result about seismic activity of particular area. Then, we will take them to another place," said Kumar.

"In this way we will have every minute detail of each place. This exercise will continue until data of entire state is collected. Through this, we can locate active fault lines at micro level," said Kumar.

Describing the need for such a project, he said that Gujarat is very different from other regions in India, as minor earthquakes keep striking, which is a unique phenomena.

"There is very less information about what is lying beneath Gujarat's earth. Gujarat is different from others as we continuously get minor earthquakes even after the major earthquake of 2001. We have to probe why Gujarat's crust is so much active," said Kumar.

Giving an analogy, he said, "What we have done till date is just an X-Ray.

"This new project will work as an MRI scan of earth's crust. It will tell us where these faultlines are located and what they are capable of. In the long run, it will help us in estimating or predicting long term seismic hazard here," said Kumar.