With 30 aftershocks within 24 hours of the massive 7.8 tremblor that rocked Nepal around noon on Saturday, the ‘unsteady’ Earth in the region continues to pose fear among people and challenge to seismologists.
A couple of the aftershocks touched a magnitude of 6, which most often results in damage and was felt in large areas. “We expect the activity to go on for a few weeks. Our scientists (geologists) will go in the next few days to assess the damage and understand the mechanism of the large earthquake,” N Purnachander Rao, Principal Seismologist at the CSIR- National Geophysical Research Institute (NGRI), here said.
An aftershock in simple terms is the adjustment of the earthquake zone. The energy released by the big jolt gets settled over a period. The NGRI will also study the expression of the quake on the surface of the earth and collect data from the Indian side of the Himalayan region, where it has established an extensive network of seismic centres that have collected valuable data, Rao told
For seismologists, who have been expecting a big earthquake in the region, especially after the 2004 tsunami triggered by the Sumatra-Andaman earthquake measuring 9.1, the Saturday’s earthquake offered a rare chance to thoroughly analyse and study the earthquake mechanism, especially with advancement in technology.
The Nepal-Bihar earthquake of 8 magnitude in 1934 and Arunachal Pradesh earth quake of 8.5 magnitude completely caught people and earth scientists off guard with the latter equipped least in scientific capability to study the nature’s fury. There is scarce scientific recording of the events.
The NGRI plans to deploy GPS (Global Positioning Systems) instruments along the fault zones of the earthquake-hit region to understand the movement of the blocks. The millimetre accuracy devices have proved very useful in the study in the Andaman region after the 2004 earthquake. The NGRI gathered crucial data which helped in piecing together some of the movements and mechanisms of the earthquake, Purnachander Rao said.