“Science tells us where an earthquake can strike, and with what magnitude, but ‘when’ it will strike is a bad question to ask”. It is analogous to a statement that “We are living on a time bomb and time is unknown”.
Kashmir lies in one of the most seismically vulnerable areas of Zone IV & Zone V. Based on historical records, the region had experienced quite a few devastating earthquakes in the past. A massive earthquake struck the Jammu & Kashmir on the morning of 8 October 2005 having a magnitude of 7.6 and tremors were felt strongly in Pakistan, India and Afghanistan. This earthquake resulted in more than 80,000 deaths across Indian and Pakistan administrated Kashmir.
In the past innumerous smaller intensity earthquakes have struck the Himalayas and studies have suggested that a large strain have buildup. It has been estimated that magnitude 7.6 Muzaffarabad earthquake that struck in 2005 at the far western end of the Kashmir have released only 10 per cent of the accumulated stress
An International conference on “Climate Change and Extreme events in Himalayan Region” was recently held at the Indian Institute of Technology (IIT) Mandi attended by top earth scientists and seismologists. The conference concluded with a consensus among all scientists and scholars who are studying The Himalayas that a great earthquake is imminent anytime in future. Apart from that, the imagery maps of ISRO’s satellite, alongwith Google Earth suggests grim prediction for North Indian regions. The research suggests,” An earthquake of magnitude 8.5 or more is overdue in Himalayas and some parts of Northern India “. It also indicates towards poor preparation by authorities to deal with some natural calamity which is only likely to increase the level of destruction.
When an earthquake does hit an area and it causes unmentionable destruction and loss of life, there is nothing but repentance over the unpreparedness. Despite the enough warnings by many Scientists and agencies including international ones, the administration is not taking steps to understate the damage. The onus lies with both at individual and administrative level to reduce damage to minimum level if steps are taken on a time.
At individual level at the time of planning of building a structure, seismic consideration should be given a proper importance as this region is highly vulnerable to earthquakes. Before finalizing a building plan proper discussion should be held with engineers and experts for making a structure seismic resistant that can protect our lives. The architects and Engineers should properly investigate the site where a structure is coming up and follow Standard Building codes to analyse and design a structure that will resist natural forces.
As conditions and techniques to make structure seismic proof vary from site to site few general techniques or guidelines can be followed to reduce or mitigate the damage. The first and the primary thing that a planner/ builder must do is to Compact the soil to maximum possible level on which structure is to be constructed. All the built up area should have same level. The superstructure and substructure should be properly tied up and should resist sliding forces of seismic waves. If the structure is made on columns then light weight concrete/material should be used in walls.
Also studies have shown that houses constructed with traditional Kashmiri methods can resist seismic forces better. The Taq (timber-laced masonry) and Dhajji-Dewari (timber frame with infill walls) methods of house construction are earthquake-safe construction practice. “Tak” is a load bearing pier with in-filled walls in it. Timber runners at each level are tied in the walls. The infill walls have timber embedded in them which increases their elasticity.
The other safe construction technique that was prevalent in Kashmir is using ‘dajji dewar’ walls These will have greater ductility and damping as compared to commonly used masonry or brick walls. In these walls the horizontal and vertical mesh is formed by the timber are braced diagonally to resist shear stress. The timber studs prevent propagation of shear cracks. This construction technique results in breaking up of masonry walls into smaller multiple panels, each of which are independent. The collapse of any one panel will not result in the complete collapse of the wall, and therefore the structure.
Also at administrative level there is a need to divide the cities into zones and identify the each zone according to level of possible potential damage. The steps to mitigate effects can be taken in each zone according to possible potential damage at that zone. The Building permission authorities should also permit the construction only after proper approval of site plans that are in compliance with Building bylaws and structural codes.
It is impossible to predict when the great Himalayan earthquake is going to hit, but primary importance should be given to strengthening of schools, hospitals and densely populated structures and to develop emergency response plans.
(Shaief Manzoor is a Research Scholar at National Institute of Technology, Srinagar)