GUWAHATI, May 22 � The Gauhati University (GU) Physics Department is making big strides towards predicting earthquakes. For the purpose, the Department has been engaging itself in the study of the coupling process of ionosphere, troposphere and lithosphere since 2005.
Moreover, the Department, at the behest of the University, is also developing an ST Radar global facility to monitor other natural hazards and phenomena like global warming and climate change, along with the earthquake precursors, said Professor Emeritus Ananda Kumar Barbara and Senior Prof Minakshi Devi of the Department.
They also apprised this correspondent that their study of the coupling process of ionosphere, troposphere and lithosphere had led them to a point where they were able to foresee the possibilities of the May12, 2008 Great Sichuan earthquake of 8 in magnitude that killed 69,197 people and left 18,222 missing as per reports.
The two other devastating earthquakes � March 11, 2011, Japan earthquake of 9 in magnitude and the April 25, 2015 Nepal earthquake of 7.9 in magnitude, were also foreseen by the Department.
In all these cases, the scholars and researchers of the Department could see the anomalies in the ionosphere and troposphere one day ahead of the seismic events at their latitudinal and longitudinal points, said the physicists, attributing this success to their round-the-clock monitoring of the signals emanating from the Global Positioning Satellites (GPS), which they have been practising since 2006.
But, they admitted that they could foresee the events only a day or two ahead of their happening and hence they are now concentrating on advancing the prediction period. For the purpose, the Department is now trying to take the help of nano satellites and with this aim in view it has entered into an agreement with an international group of earthquake scientists, said the physicists.
In recognition to its performance, the Union Government has started treating the GU Department as a leading research hub. It has installed an ST Radar facility at the GU campus and this will be used for the entire NE region. The ST Radar facility in GU will be able to provide support in predicting earthquake, other natural hazards, impacts of climate change etc. The facility is expected to be operative by the end of the current year.
The GU Department is now concentrating mainly on West Pacific Zone so far as earthquake and other natural hazards are concerned. The location of GU at latitude 15 degree geometric North is very important so far as ionosphere equatorial anomalies are concerned. This location is providing GU with scopes to identify properly the earthquake precursors in the ionosphere. Besides, its location in a very high seismic vulnerable zone is also providing it an advantage in studying earthquake, said the physicists.
The GU scientists apprised that in 1984, when they were studying the long-distance anomalous propagation of very high frequency (television) signals, they received some anomalous signals from Thailand, China and even from Iran. Then they were quite in the dark as to the factors responsible for such anomalous propagations.
In 2005, the study on earthquake precursor was undertaken by the Department and initially it was confined to the study of anomalies in the ionosphere. In 2006, the integrated long-term project for earthquake precursor study was undertaken in collaboration with the Izmiran - the Russian Academy of Science. At this stage, troposphere (lower atmosphere) was taken into consideration for the purpose.
Now, when the GU physicists started re-examining their 1984 observations, co-relating them with the occurrence of earthquake, they found that such anomalies were associated with earthquakes and the epicentres were located at the site from where the signals originated.
However, TV signals coming via satellites remain unchanged, as, to undergo modifications, signals should pass through the ionosphere or troposhphere. Considering the changes in the technological environment with the coming of satellite, it is found that terrestrial TV links are not available for continuing earthquake precursor studies. Therefore, the GU physicists have now started monitoring the FM signals transmitted by the FM transmitters situated beyond the Line Site Path (LOS), besides the GPS signals.
However, the FM signals are yet to help the GU physicists to determine the epicentres of the earthquakes, said the scientist.