Possible ionospheric effects of two major earth quakes in Papua New Guinea

Abstract

Pre-seismic ionospheric F2 layer instabilities have been studied which could help in predicting earthquakes. Two major earthquakes in the western province of Papua New Guinea, one in Sissano in 1998 of magnitude 7.1 and the other in Aitape in 2002 of magnitude 6.7 were analyzed. An analysis of the perturbations in the electron content up to the ionospheric F₂ layer peak and F2 layer peak height (h_mF2) variations during earthquake time has been done using published ionosonde data. A decrease in peak electron density ranging from 20 to 30% was observed within 10 days during pre-seismic as well as post-seismic periods during both earthquakes. On these days, an increase in the height of the peak electron density was also observed. This could be because during seismic periods, a large amount of radon gas is emitted during earthquake preparation time, which ionize neutral atoms and molecules and the ions raise to ionospheric heights by electric fields created and produce ionospheric fluctuations. This helps in predicting the earthquake in advance.