Amreli (Saurashtra), Dec 20 (IANS): Villagers of Mityala experienced minor tremors four times in less than 24 hours on Monday. This is not the first time, since in the last two years they have witnessed tremors 4 to 5 times in a day because of which they sleep in the open even on winter nights.

The village sarpanch (village head) Mansukh Moladiya alleges that the district or the state administration is not doing anything, though the matter has been brought to their notice. Fearing major earthquakes at night, the villagers sleep in the open even in winter.

It is not true that the district administration is not doing anything. The Gujarat Disaster Management Authority and the Institute of Seismology Research have been informed about it and the institute's researchers have completed one study while one more team is coming on Wednesday, said Ravindra Vala, resident additional collector of Amreli district.

These are swarm earthquakes occurring in the area since the last two years. A total of 225 tremors have taken place, but 200 of them were of less than magnitude 2 on the Richter scale. Only one was of magnitude 3.2 on the Richter scale, said Sumer Chopra, officiating director general of the Institute of Seismology Research, Gandhinagar.

He told IANS that their team is constantly studying the geological development in the area. There are many fault lines -- North-East South, North-West South and a few others. Teams have studied upto 20 to 25 kilometres below the earth/s surface. The entire area of Amreli, Bhavnagar, Botad, Jamnagar, some parts of Junagadh and Navsari in South Gujarat are rocky areas, because of which swarm earthquakes are common here.

According to his study, swarm tremors are in fact good, because energy is released in small quantities. If this continues for a longer period, it averts the risk of major earthquakes.