Simultaneous ionospheric E- and F-layer perturbations caused by some major earthquakes in India
- Singh, C.
- Singh, O. P.
DOIAbstract
The variation in nighttime ionospheric E- and F-region critical frequencies (foEs and foF2) is examined for the months of August 1988, September 1993 and May 1997 in which major earthquakes (6<M<6.6) occurred in Indian seismic zones of Bihar-Nepal border, Latur in West India, and Jabalpur in Central India. The ionospheric data are obtained from Ahmedabad (latitude 23.01°N, longitude 72.36°E). The percent deviations of foF2 and foEs from their monthly median are determined for pre-midnight (18:00-00:00 h LT) and post-midnight (00:00- 06:00 h LT) periods and studied over a span of 20 days before the occurrence of earthquakes. The results show that foF2 are reduced in both the time sectors prior to the occurrence of main shocks. In pre-midnigh...
Add to ORKG