More tremors likely in Mahaweli Reservoir region: Prof. Dissanayake

By Shane Senevirathne  

There is more likelihood of minor earth tremors taking place in the buffer zones of the  Mahaweli Reservoir in the near future, Professor C. B. Dissanayake of the Geological Faculty of the Peradeniya University  said.   

He stressed that  such  earth tremors were significant with the pressure in the reservoirs or the impact caused by the  blasting of limestone in the vicinities of the reservoirs  and  when the water levels increased or decreased in the reservoirs.  

 The Professor said further that on  the night of the 29th August  as well as on later occasions,  tremors measuring less than 2 in the Richter had been experienced and those tremors had been limited to the areas of the Victoria Reservoir and the rock surfaces close to the reservoir were mainly of complex limestone ridges.

He opined that the pressure increasing and decreasing on those stone surface would have had their effects on the tremors and that the particular hypothesis  should not be  dismissed as minor issues and it should be noted that the occurrence of the tremors during the immediate past had been recorded by the sensitive equipment fixed at Victora, Randenigala and Rantembe Reservoirs.   

• pressure increasing and decreasing on those stone surface would have had their effects on the tremors and that the particular hypothesis  should not be  dismissed as minor issues

Meanwhile, The Mahaweli Authority  had pointed out that the breaches visible on the bund of the Victoria Reservoir had not shown any increase or decrease resulting from the impact of the tremors experienced lately.