ZAM distribution analysis of radiowave ionospheric propagation interference measurements

This work investigates the occurrence of radiowave propagation disturbances across a wide range of VLF and LF frequencies received prior to a seismic event (Mw=4), that took place on May 12th 2012, the epicenter of which was very close (14Km) to the receiver. The signals analysed were from 4 VLF and 6 LF European transmitters. This seismic event produced precursory ionospheric disturbances, identified as spectral distortion, before its occurrence, providing a distinct pattern. Although the basis of the ionosphere interaction with seismic phenomena has been well documented in previous studies, the close proximity of the receiver to the seismic event provides a new perspective to this study. The received signals have undergone normalisation and then they have been processed by the application of the Zhao-Atlas-Marks Distribution (ZAMD). Diagrams of the signals relevant to the phenomena are presented as well as the the result of the application of the ZAMD.