Possible reason of ionospheric anomaly post the April 20, 2013, Mw=6.6 China' Lushan earthquake: Applying two-dimensional principal component analysis (2DPCA) to two-dimensional total electron content (TEC)

In this study, two-dimensional principal component analysis (2DPCA) was used to determine the reason for the ionospheric two-dimensional total electron content (TEC) anomaly after China's Lushan earthquake at 00: 02: 47 UT on April 20, 2013 (M-w = 6.6). TEC data from 00: 00 to 00: 15 (UT) on April 20, 2013 were examined. The TEC anomaly was very intense 00: 05 to 00: 10 (UT) after the earthquake. One potential cause of the TEC anomaly, which might have been a density variance, is a rising acoustic shock wave, with speed of at least 1127.82 ms(-1), resulting from the mainshock. The duration of the TEC anomaly was at least 5 min.