Features of the Ionosphere around the Time of the 5th August, 2014 M5.5 Orkney Earthquake

摘要

In this paper, presentation of specific features of TEC behaviour as a possible precursor of Orkney earthquake of August 5th, 2014 (M5.5) was made. To achieve this, TEC data from Suth station and GIM TEC maps were used. The period understudied (prior to and after the earthquake) experienced quiet geomagnetic situation which made the analysis much easier. A characteristic anomaly was noticed from 4 days before the earthquake and it was found out that the day-time TEC increases significantly and consistently relative to the background condition up to the day before the earthquake. To reveal the spatial dimensions of seismo-ionospheric anomaly longitudinally, the maps from IONEX database were used. The ionosphere, experiencing a modification as an increase of electron concentration over a large area, was revealed.