Anomalous behavior of D-layer formation time of the ionosphere due to earthquake

Abstract

The very low frequency (VLF) data for over three months (May to July 2008) using Gyrator II loop antenna has been analyzed in the present study. The significant anomalies of D-layer formation time of the ionosphere are observed during sunrise. These anomalies are observed only before, during and after the earthquakes, which took place in the neighboring region. The anomalies were also observed in sunrise terminator time during seismically active days. These abnormal behavior may be due to the lithosphere - ionosphere coupling. These anomalies may be a precursor of earthquake.