New Delhi: Last thursday an earthquake measuring 4.7 on the Richter scale jolted Gilgit in the Baltistan region of Pakistan Occupied Kashmir (POK) and its adjoining areas. People came out of their homes in panic, though luckily no loss of life or property was reported due to the earthquake.

 

According to Pakistan's National Seismic Monitoring Centre, the epicenter of the quake which struck on early Monday morning was located 35 kilometres southwest of Skardu at the depth of 15 kilometres. This is not the first earthquake in the Himlayas but for the past several years, quakes have caused major loss to life and property across the mighty mountain ranges. Be it Pakistan, China, Nepal, India or the other neigbouring countries, the threat is equal.

 

The threat to India, given its varied geographical features, is varied.According to the recent National Centre for Seismology (NCS), Twenty-nine Indian cities and towns, including Delhi and capitals of nine states, fall under "severe" to "very severe" seismic zones which mean they are highly vulnerable to earthquakes.

 

These regions includes Delhi, Patna (Bihar), Srinagar (Jammu and Kashmir), Kohima (Nagaland), Puducherry, Guwahati (Assam), Gangtok (Sikkim), Shimla (Himachal Pradesh), Dehradun (Uttarakhand), Imphal (Manipur) and Chandigarh fall under seismic zones IV and V.These cities have a combined population of over three crore.

 

The majority of these places are in the Himalayas, one of the most seismically active regions in the world but fortunately is scarcely populated.

An earthquake is the shaking of the ground cause by seismic waves. Almost all earthquakes occur when pent up stress in rocks along large, active faults (like the SAF) are suddenly released as the rock breaks.An earthquake (or quakes, tremors) is shaking of the surface of earth, caused by sudden movement in the Earth's crust. They can be extremely violent.

 

 

The Indian subcontinent has a history of earthquakes. The reason for the intensity and high frequency of earthquakes is the Indian plate driving into Asia at a rate of approximately 47 mm/year.

 

India has witnessed more than 20 earthquakes since 1990’s. 

 

India has suffered some of the greatest earthquakes in the world with magnitude exceeding 8.0. For instance, in a short span of about 50 years, four such earthquakes occurred with the highest mangnitude: Assam earthquake of 1897 (magnitude 8.7), Kangra earthquake of 1905 (magnitude 8.6), Bihar-Nepal earthquake of 1934 (magnitude 8.4) and the Assam-Tibet earthquake of 1950 (magnitude 8.7). 

 

But there were many earthquakes which had impacted lives of many in India be it 1950 Assam earthquake, 1991 Uttarkashi earthquake, 1993 Maharashtra earthquake,1934 Bihar earthquake, 2001 Gujarat earthquake.

 

Gujarat Earthquake 2001

 

The entire northeastern region, parts of Jammu and Kashmir, Himachal Pradesh, Uttarakhand, the Rann of Kutch in Gujarat, parts of north Bihar and the Andaman and Nicobar archipelago falls under Zone V category – most active seismically. Zone II is considered the least seismically active, Zone IV and V fall under “severe” to “very severe” categories respectively.

 

Parts of Jammu and Kashmir, Delhi, Sikkim, and northern Uttar Pradesh, West Bengal, Gujarat and a small part of Maharashtra fall under Zone IV.

Bhuj, which was struck by a massive earthquake in 2001 in which 20,000 people were killed, Chandigarh, Ambala, Amritsar, Ludhiana and Roorkee fall under zones IV and V.

 

Earthquakes are inevitable but surely the effects of the calamity can be curtailed to minimum. If one follows few things, one can survive the effects of an earthquake.

 

Things to Do During an Earthquake:

 

 

If you are indoors: “DROP, COVER AND HOLD ON”

• Stay inside.

• Drop under heavy furniture such as a table, desk, bed or any solid furniture.

• Cover your head and torso to prevent being hit by falling objects.

• Hold on to the object that you are under so that you remain covered. Be prepared to move with the object until the shaking has finished.

• If you can't get under something strong, or if you are in a hallway, flatten yourself or crouch against an interior wall and protect your head and neck with your arms.

• If you are in a shopping mall, go into the nearest store. Stay away from windows, and shelves with heavy objects.

• If you are at school, get under a desk or table and hold on. Face away from windows.

• If you are in a wheelchair, lock the wheels and protect the back of your head and neck.

 

If you are outdoors:

• Stay outside.

• Go to an open area away from buildings. The most dangerous place is near exterior walls.

• If you are in a crowded public place, take cover where you won't be trampled.

 

Ensure you do the following if you are trapped under debris during or after an earthquake:

• Do not light a match.

• Do not move around or kick up dust.

• Cover your mouth with a handkerchief or clothing.

• Tap on a pipe or wall so rescuers can locate you. Use a whistle if one is available. Shout only as a last resort. Shouting can cause you to inhale dangerous amounts of dust.

 

To reduce the effects of the earthquake on self and the property, many believe that people should invest in earthquake prone buildings. But is it really effective the answer is yes and no.

 

There are of course, engineering techniques that can be used to create a very sound structure that will endure a modest or even strong quake. However, during a very strong earthquake, even the best engineered building may suffer severe damage. Engineers design buildings to withstand as much sideways motion as possible in order to minimize damage to the structure and give the occupants time to get out safely.

 

Buildings are basically designed to support a vertical load in order to support the walls, roof and all the stuff inside to keep them standing. Earthquakes present a lateral, or sideways, load to the building structure that is a bit more complicated to account for. One way to make a simple structure more resistant to these lateral forces is to tie the walls, floor, roof, and foundations into a rigid box that holds together when shaken by a quake.

 

Construction techniques can have a huge impact on the death toll from earthquakes. An 8.8-magnitude earthquake in Chile in 2010 killed more than 700 people. On January 12, 2010, a less powerful earthquake, measuring 7.0, killed more than 200,000 in Haiti.The difference in those death tolls comes from building construction and technology. 

 

According to the National Disaster Management authority, Government of India, India's increasing population and extensive unscientific constructions mushrooming all over, including multistoried luxury apartments, huge factory buildings, gigantic malls, supermarkets as well as warehouses and masonry buildings keep - India at high risk. 

 

During the last 15 years, the country has experienced 10 major earthquakes that have resulted in over 20,000 deaths. As per the current seismic zone map of the country (IS 1893: 2002), over 59 per cent of India’s land area is under threat of moderate to severe seismic hazard-; that means it is prone to shaking of MSK Intensity VII and above (BMTPC, 2006).

 

The increase in earthquake risk is due to a spurt in developmental activities driven by urbanization, economic development and the globalization of India’s economy. The increase in use of high-technology equipment and tools in manufacturing and service industries has also made them susceptible to disruption due to relatively moderate ground shaking. As a result, loss of human life is not the only determinant of earthquake risk any more.

 

 Severe economic losses leading to the collapse of the local or regional economy after an earthquake may have long-term adverse consequences for the entire country. This effect would be further magnified if an earthquake affects a mega-city, such as Delhi or Mumbai.

 

As per the statement given to PTI after the recent report was released, M Rajeevan, Secretary, Ministry of Earth Sciences, said 31 new earthquake observatories will come up in the country by March next year. At present, there are 84 observatories. 

 

This is being done to detect and record earthquake parameters more accurately and identify possible precursors of tremors.