Should a temblor of the scale that hit Manipur on Monday strike Jharkhand, the result could be catastrophic as experts say just 20% of the buildings in the eastern state are earthquake resistant.
The 6.7-magnitude quake that jolted the Northeast also shook up Jharkhand and triggered panic among locals, though authorities in Ranchi said no major damage was reported in the state.
Experts say while no building can be entirely safe from earthquake, measures like seismic strengthening do ensure that they respond to tremors of moderate intensities without structural damage and of heavy intensities without total collapse.
“Specific guidelines for building structures have been provisioned in different seismic zones,” said Sujit Bhagat, joint secretary, Bihar-Jharkhand chapter of the Indian Institute of Architects (IIA). “But there are hardly any structures in the state that follow the norms. These houses might not endure a high-intensity tremor for two to three minutes.”
The quake struck at around 4.30am, forcing many people to run out their houses on a chilly 8°C morning in Ranchi.
“I was sleeping when the tremors woke me up. I scrambled out of my residence as it continued for almost a minute,” said Rajiv Pandey, a resident of Kokar area in the state capital.
This was the second major tremor to hit Jharkhand in a month. On December 15, a 4.2-magnitude quake that originated near the temple town of Deoghar had shaken up the state for a few seconds.
Bhagat also said many apartments and multi-storey buildings have come up without proper soil testing.
“Soil testing is mandatory for apartments. Builders avoid the testing only because of the cost, which is around Rs 15,000 per boring,” he said.
However, state project officer from the disaster management department Colonel Sanjay Srivastava said building bylaws had been amended to make earthquake-proof construction mandatory.
“Besides, roads and other big infrastructure constructions need earthquake- resistant certificate from concerned architects and engineers,” he said, adding that the department also regularly organises training-cum-awareness camps for locals.
Though most districts in Jharkhand fall under the relatively safe seismic zones II and III, architects say a high-intensity tremor lasting a few minutes may cause major damage.
“Several changes were made in the building code after Gujarat earthquake in 2001,” said Kumud Jha, Jharkhand president of the Confederation of Real Estate Development Association of India (CREDAI). “Therefore, the apartments and multistoried buildings that are coming up now in the state are earthquake resistant.”
The devastating quake that originated in Nepal last year had also triggered major damage in the state, with many buildings developing cracks.
State-based seismologists said incidents of earthquakes have gone up in Jharkhand in recent years.
The seismic observatory centre of the Indian School of Mines (ISM) in Dhanbad recorded 620 tremors between January 2011 and December 2014 within a 300km radius.
“A majority of the tremors were of low to moderate intensity (1-3 magnitude). This is why we do not feel them. The tremors are felt when they go above 4 in magnitude,” said Rajkumar Prasad, senior technical assistant at the observatory.