Major earthquake alert again
Monday, 17 August 2009
The last Tuesday's (11 Aug 2009) earthquake, which had its epicentre 980 km south-south-east of The Andaman Islands in the Indian Ocean, was felt in Dhaka, Chittagong and other areas of the country around 3.00 in the morning. The Bangladesh Meteorological Department had kept the country's coastal areas on a high tsunami alert for a few hours after the tremor. Fortunately it did not strike. The following day, again in the early hours, another quake, measuring over 5.0 on the Richter scale, shook the country's north-north-east and its surrounding areas. The source, according to the Met office, was 22 km below the ground, in the environs of Myanmar and the Indian state of Monipur. According to the US Geological Survey the magnitude of the first quake was 7.8 on the Richter scale at the source. The tremors here could be between 3.0 and 4.0, being stronger in the port city and coastal areas. Although no harm has been recorded this time round, the frequency of such phenomena forebodes ill. A major one is most likely to be in the making, according to experts. During the last 150 years, seven major earthquakes had struck the Bangladesh area and the epicentre of only two of them was inside the area.
A study of the seismic stresses building up in the Himalayan region as a result of two shifting tectonic plates had reportedly led researchers at the University of Colorado in 2001 to arrive at the conclusion that a really nasty earthquake of more than 8.0 magnitude is imminent in the subcontinent, putting over 50 million people at risk in India, Nepal, Pakistan, Bangladesh and Bhutan. Though nothing can be done to prevent the plates from colliding -- today, tomorrow or a hundred years on -- earthquake preparedness could certainly keep casualties down. Dire warnings had better be heeded by the governments and public alike.
It needs no telling what strong earthquakes in ill-planned densely populated areas can do. India's Bhuj in February 2001 showed that most deaths were due to the collapse of poorly constructed buildings, high rises on shaky foundations, and dangerously dilapidated concrete structures. It is quite imaginable what the scenario would be if Dhaka, Chittagong and Sylhet were struck with a similar high magnitude quake. Many existing buildings here are said to be particularly vulnerable due to fundamental faults in construction. Experts also point out that the Bangladesh National Building Code is also urgently in need of revision in the light of the latest findings related to disaster preparedness, specially information on up to date earth earthquake vulnerability zones. According to the latest seismic zoning map prepared by the Bangladesh University of Engineering and Technology as much as 43 per cent of Bangladesh falls in the high risk zone one, 41 under moderate risk zone two and 16 under low risk zone three.
In geologic terms this region is quite young, with the mountain ranges still growing, and Bangladesh, being close to the Indian-Eurasian tectonic plates meeting here, is highly at risk, should major movement in the plates occur. Every century had seen on average one big quake in the region and frequent tremors in recent years are said to be a forewarning. Rivers have been known to change course overnight due to seismic activity. Property developers, the building authority and the government in Bangladesh need to wake up to the risks sooner rather than later.
A study of the seismic stresses building up in the Himalayan region as a result of two shifting tectonic plates had reportedly led researchers at the University of Colorado in 2001 to arrive at the conclusion that a really nasty earthquake of more than 8.0 magnitude is imminent in the subcontinent, putting over 50 million people at risk in India, Nepal, Pakistan, Bangladesh and Bhutan. Though nothing can be done to prevent the plates from colliding -- today, tomorrow or a hundred years on -- earthquake preparedness could certainly keep casualties down. Dire warnings had better be heeded by the governments and public alike.
It needs no telling what strong earthquakes in ill-planned densely populated areas can do. India's Bhuj in February 2001 showed that most deaths were due to the collapse of poorly constructed buildings, high rises on shaky foundations, and dangerously dilapidated concrete structures. It is quite imaginable what the scenario would be if Dhaka, Chittagong and Sylhet were struck with a similar high magnitude quake. Many existing buildings here are said to be particularly vulnerable due to fundamental faults in construction. Experts also point out that the Bangladesh National Building Code is also urgently in need of revision in the light of the latest findings related to disaster preparedness, specially information on up to date earth earthquake vulnerability zones. According to the latest seismic zoning map prepared by the Bangladesh University of Engineering and Technology as much as 43 per cent of Bangladesh falls in the high risk zone one, 41 under moderate risk zone two and 16 under low risk zone three.
In geologic terms this region is quite young, with the mountain ranges still growing, and Bangladesh, being close to the Indian-Eurasian tectonic plates meeting here, is highly at risk, should major movement in the plates occur. Every century had seen on average one big quake in the region and frequent tremors in recent years are said to be a forewarning. Rivers have been known to change course overnight due to seismic activity. Property developers, the building authority and the government in Bangladesh need to wake up to the risks sooner rather than later.