No accurate prediction of disaster, says expert

No accurate prediction of disaster, says expert
Tue, Feb 02, 2010
New Straits Times
   
Earthquakes cannot be predicted with accuracy and certainty. Geophysics and Tsunami Department director Dr Mohd Rosaidi Che Abas says, however, that seismic agencies around the world are able to compile statistical estimates and probabilities of an earthquakes based on past records.

"But such forecast is very general covering a long period and a large area. It is arrived at by analysing the stress that builds along the fault lines of subduction zones."

This involves an oceanic plate sliding beneath either a continental plate or another oceanic plate. These areas are often noted for their high rates of volcanism, earthquakes and mountain-building.

"These are the areas where most of the earthquakes occur," he says.

The Malaysian National Tsunami Early Warning System (MNTEWS), which was established in 2005, monitors earthquakes and tsunamis in the region.

The centre within the Malaysian Meteorological Department monitors the phenomenon and issues alerts and advisories.

To monitor earthquakes in the region, a network of 17 seismic stations: seven in the peninsula, four in Sarawak and six in Sabah have been set up.

Rosaidi says through the network, MMD maintains a real-time monitoring of earthquake and tsunami occurrence in the region on a daily basis .

"The system also receives earthquake monitoring data from 34 stations overseas."

Sharing the ways MMD disseminate earthquake information to other government agencies, the mass media and the public, Rosaidi says it is done via SMS, a hotline, the Internet, phone and telefax within 15 minutes of an occurrence.

As for the implications of earthquakes, he said these range in intensity from slight tremors to great shocks which may last from a few seconds to as a long as several minutes.

"There may also be fore-shocks, which are usually small, and there may be many aftershocks which vary in intensity and last for days and sometimes even a month .

"Also, the impact of an earthquake depends on both the distance to the epicentre and the type of soil at the site. Hence the damage caused by an earthquake varies from one area to another depending on the factors.

"In a major earthquake, the energy released can be devastating and cause damage hundreds of kilometres away from the epicentre itself," he adds.

He says major earthquakes in the region usually occur in Indonesia and the Philippines, while tremors felt along the west coast of peninsular Malaysia originate from large earthquakes in the active seismic areas of Sumatra and the Andaman Sea.

Sumber: http://news.asiaone.com/News/AsiaOne%2BNews/Malaysia/Story/A1Story201002...