Shifting of tectonic plates cause for tremors

by Lakshmi DE SILVA

The earth tremors like the one experienced last Wednesday (15) at several places including Kandy, Kataragama, Tissamaharama, Hambantota, Weerawila, Galle, Panama, Ampara, Badulla, Monaragala and Lunugala, were caused by seismic movements of tectonic plates. However, since we are placed in the centre of the Indian tectonic plate it was very unlikely that extensive damages from a direct impact of an earthquake could occur in our country Geo Physicist, Geological Survey and Mines Bureau, Nilmini Thaldena told Sunday Observer Friday (17).

In the recent past, Sri Lanka had experienced a number of earth tremors. A tremor felt around Monaragala on July 07, 2007 was due to an earth quake that occurred in the Bay of Bengal at a magnitude of 5.0 on the Richter scale some 400 kilometres away from Batticaloa. Exact sources of several tremors felt in Beralihela, Tissamaharama area (September 2007) was not known. Also these tremors were not stronger than 3 measured on the Richter scale she said.

During 2008 tremors were reported from Sigiriya on April 4, Tangalle on August 6, Diyatalawa on October 23 she said.

Though several other moderate earthquakes took place in the Indian Ocean region south of Sri Lanka and it was believed there was a defused plate boundary in the making some 500 km south of the southern tip of Sri Lanka as the cause of those tremors or minor quakes. But any damage that could be caused to us from this regional setting is minimal as most earthquakes that occurred were below or around the magnitude of 5.0 on the Richter scale.

People should not panic unless the Meteorological department announces any major disaster.

Though we at the National Seismic Data and Tsunami Alert Centre of the Geological Survey and Mines Bureau monitors such occurrences all 24 hours of the day we inform the Met Department in case of an emergency situation which could be very remote at present Deputy Director I.M. Mudunkotuwa noted.