IONOSPHERİC TOTAL ELECTRON CONTENT (TEC) ANOMALİES RELATED TO THE (MW=7.8), 25 APRİL 2015 NEPAL EARTHQUAKE

Two-dimensional principal component analysis (2DPCA) are used to examine the ionospheric total electron content (TEC) data during the time period from 00:00 on 20 April to 06: 10 on 25 April (UT) 2015, which are 5 days before the Mw=7.8 Nepal earthquake at 06:11:25 on 25 April 2015 (UT) with the epicenter (28.230°N, 84.731°E) and the depth of 8.2km. From the analysis result of 2DPCA, a TEC precursor of Nepal earthquake is found localized nearby the epicenter during the time period from 16:55 to 17:00 on 23 April 2015 (UT) with the duration time of at least 5 minutes. This work discusses potential reasons for the TEC anomaly related to this earthquake and possible reasons including radon gas release and P-type semiconductor effects.