A team of seismologists and scientists led by Dr. D. Srinagesh, chief scientist of the Hyderabad-based National Geophysical Research Institute (NGRI), made a field visit to the micro tremors-hit villages like Varikuntapadu and Vinjamur in the upland areas of Nellore district here on Tuesday.
During their interactions with the fear-stricken local people, the scientists sought to allay the public concerns saying the majority of the micro tremors were actually mere low intensity after-shocks and there would be no damage or harm because of either of these happenings.
The seismologists also said that in the past six months or so in Nellore district, nearly two tremors occurred with a very low intensity of 3 to 3.4 on the Richter scale while 29 after-shocks took place with 2 to 2.9 intensity and another 25 shocks occurred with 1 to 1.9 intensity.
After listening to the concerns of the locals, Dr. Srinagesh said that all the tremors recorded on the seismographs in Nellore district lasted three to four seconds and even lesser. Similar harmless happenings were recorded at Nanded in Maharashtra and Jubilee Hills and Vanasthalipuram in Hyderabad.
Dr. Srinagesh said it was true that such micro tremors did not take place in Varikuntapadu area in the past 50 years but there were other places in the district such quakes were recorded where they eventually disappeared.
Seismic zone 3
Stating that there was no mechanism so far to predict the quakes beforehand with accuracy, Dr. Srinagesh said that the coastal region including Nellore fell in the seismic zone 3 which was classified keeping in view of the seismic activity in Bhadrachalam and Ongole areas. In this zone, tremors measuring only between 4.5 to 5.5 intensity may occur, which did not pose any danger to the people like in the case of quakes of 6 and above magnitude.
District Collector M. Janaki, who interacted with the scientists, said that needless fears and rumours were being fuelled every time there were after-shocks and the people should not be worried about them considering the very low intensity.
Stating that the NGRI scientists installed seismic instruments in Varikuntapadu just to monitor the quake activity, Ms. Janaki appealed to the public to cooperate with the district administration and the scientists by maintaining restraint in times of rumours. She said that false rumours led to people not to send their children to a school in Chakalikonda.
The scientists installed a new velocity metre at Chakalikonda to measure the tremor intensity accurately. Nearly 4 types of seismic instruments were being used to study the pattern of the tremors and after-shocks.
As part of the confidence building measures, the authorities and the scientists had decided to retain these seismic instruments for the next one year to continuously monitor the seismic activity in the affected villages.
