Quake Prone Indian Cities

What is the issue?

According to the National Centre for Seismology (NCS), 29 Indian cities and towns, including Delhi and capitals of nine states, fall under "severe" to "very severe" seismic zones.

How zoning is done?

• The Bureau of Indian Standards (BIS) has classified different regions in the country into zones II to V, taking into consideration earthquake records, tectonic activities and damage caused,
• The NCS, which records earthquakes and carries out studies pertaining to micro-zonation of cities, comes under the India Meteorological Department (IMD).
• The NCS has also carried out micro-zonation of cities like Delhi and Kolkata to study the possible impact of earthquake in these mega cities.
• Seismic micro-zonation is the process of subdividing a region into smaller areas having different potential for hazardous earthquake effects.

What are the available zones?

• Zone II is considered the least seismically active, while Zone V is the most active.
• Zone IV and V fall under "severe" to "very severe" categories respectively.
• Zone V includes 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.
• The Himalayan arc, stretching from the upper Assam region to Jammu and Kashmir, is known to be a high seismic zone.
• Parts of Jammu and Kashmir, Delhi, Sikkim, northern Uttar Pradesh, West Bengal, Gujarat and a small part of Maharashtra fall under Zone IV.
• 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.
• The cities in the Indo-Gangetic belt fall within reasonable limits of the Himalayas. So repercussions are bound to be felt there

What is the way ahead?

• 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.

Source: Business Standard