Geologists allay fears over tremors, say Deccan Plateau is safe zone

Bengaluru: A series of seismic activities in parts of Karnataka are not major ones, hence there was no need to worry because the Deccan Plateau is a safe zone, geologists have said.

The tremors in Kodagu district and adjoining districts of Hassan, Shivamogga, Chikkamagaluru and Dakshina Kannada besides Vijayapura and neighbouring regions in north Karnataka have been felt since June 26.

On Saturday, the quake measured 4.4 on the Richter scale in Vijayapura bordering Maharashtra, and there was another tremor of 1.8 this morning in south Karnataka.

Kodagu reported several incidents of landslide and in one incident three days ago, three labourers were killed.

Incidentally, the seismic activities became more visible soon after a major earthquake in Afghanistan, which killed several people and left many injured. But, the geologists in Karnataka were unanimous in saying there was no need to panic as the Deccan Plateau is a safe zone seismically.

They were also of the opinion that these tremors were essential as the pressure caused by the disturbance is coming out in the form of mild tremor.

Earthquake is not a regional phenomenon. The Indian subcontinent is always moving. Each year, the subcontinent is moving 0.5 centimetre. So, there would always be some internal disturbance, Dr Lakshmamma, Joint Director in the Department of Mines and Geology, said.

What we had studied in school that the Deccan Plateau is safe is true even now, but there are some internal disturbance at the crust. So the pressure caused due to disturbance should come out, otherwise, if the pressure remains forever, it can cause major disturbance, she said. These disturbances coming out through small tremors is good. We are still in the safe zone. We will be safe even if there is an earthquake of 5 on the Richter scale, the geologist said.

According to her, the river valleys themselves are the fault zones. The valley region of major rivers are the lineaments, which are fault zones where weak areas and fissures are formed in hard rock terrain, Lakshmamma said.

Whenever there are rains, water percolates into the fault zones and gets filled up in empty places, the geologist added. Another geologist Professor Renuka Prasad also said these are too minor a phenomenon to worry. Earthquakes have been happening across the world and at many places, but we are coming to know about the tremors because we are in an information era. Further, more devices have been installed at various places to study the seismic activities, due to which we get information in real time and we panic, he said. Hydro-geologist Dr Kumar C, who is a professor at the Nrupathunga University, pointed out that the intensity of seismic activities was increasing from two on Richter scale to 4.4 on Saturday in Vijayapura in north Karnataka.

But, there is no need to panic as of now but these seismic activities give us some indications that we should be on the alert and avoid using substandard materials for constructing buildings, he said.