Preparedness, best defence against quakes

by Mai Phuong

Haiti and Chile broken and then Turkey wounded – could this be a year of devastation?

No, earthquakes are an act of nature.

Not so, climate change: As we argued earlier this year, weather disruption is more likely Mother Nature's revenge for human irresponsibility and neglect.
Humanity has long ignored the task of healing the environment to ensure the planet's survival; perhaps the calamities of early 2010 will persuade the world's people that they must look beyond economic development to make their lives rich and beautiful.
Earthquakes – despite the best efforts of scientists – are unpredictable but their consequences – water contamination, hunger, disease and crime – are not. If we prepare, these can be limited.

It's not the number of quakes, but their devastating impact that captures attention. High death tolls are mostly the result of poor construction and over crowding as the Haitian capital, Port-au-Prince shows.

Viet Nam?

Viet Nam Information and Tsunami Warning Centre deputy director Dr Nguyen Hong Phuong warns the country could fall victim to quakes that could generate level eight or nine shaking intensity.

The scientist, whose organisation is part of the Institute of Geophysics, first issued his caution at a seminar titled, "Earthquake Danger in Viet Nam", in Ha Noi about this time last year.

He repeated it yesterday and emphasised the need to be prepared to respond to any damage.

A series of studies that included magnitude 6.8 earthquakes in north-western Viet Nam prompted his warning.

The scientist said the country was located in a region where various tectonic movement, particulary in the northwest, were possible so this region was most vulnerable to quakes of more than magnitude 7.

"Some major urban areas of Viet Nam, particularly those in northwestern region would be very sensitive to tectonic movement and tremors," he said.

Although possibility of a major quake in HCM City was far less than in the capital, the southern hub would be more vulnerable to smaller tremors.

Earthquakes with shaking intensity at level 8 in Ha Noi was possible.

Vulnerable

A Institute of Geophysics research shows that many apartments, hospitals and schools built on weak foundations in the 1960s and 1970s would be particularly vulnerable to earthquakes.

The research was done in HCM City's districts 1 and 3 and in Ha Noi's Ba Dinh, Hoan Kiem and Hai Ba Trung districts.

The hypotheses is based on the weak soil structure of these areas.

The Geophysics Institute research models for the capital's Hoan Kiem District show that about 30 per cent of construction would be destroyed in a distant quake.

And a 6.5 magnitude quake at Hoan Kiem Lake would destroy between 80-100 per cent of structures.

The Agriculture and Rural Development Ministry has proposed a project to raise the community awareness to mitigate the consequences of natural calamities.

Phuong said the Infornation and Tsunami Warning Centre has provided the ministry with evidence which shows the need to increase the people's awareness of earthquakes.

The project would ensure that all people, especially the young in quake-prone-zones had knowledge about earthquakes.

While many old buildings have deteriorated and residents have changed their structure, more are being constructed without attention to anti- seismic design.

Experts said new high-rise buildings incorporate the highest levels of anti-seismic design because criteria for buildings of nine stories and above were issued in 2006.

The past

Viet Nam suffered two major earthquakes in the 20th century, both in what is now Dien Bien Province.

The first, a magnitude 6.8 earthquake, struck in 1935; the second magnitude 6.7, struck in 1983. Both cracked the walls of houses in Ha Noi, about 470km away.

Ha Noi felt the tremors of a magnitude 6.1 earthquake in northern Laos in May 2008.

Although no casualties were recorded, residents and occupants of the city's few high-rise buildings were terrified.

Light tremors scared many in HCM City in 2005.

These were caused by a minor earthquake in the sea off Ba Ria-Vung Tau Province.

In 2001, an earthquake damaged thousands of residences in Dien Bien Province. — VNS