Ionospheric Anomaly after the 11 April, 2012, Mw =8.6 Indonesia’ Sumatra Earthquake Using Two-Dimensional Principal Component Analysis (2DPCA)
Jyh-Woei Lin *
Department of Earth Science, National Cheng Kung University, No.1 University Road, Tainan City, Taiwan.
*Author to whom correspondence should be addressed.
Abstract
Two-dimensional Principal Component Analysis (2DPCA) and principal component analysis (PCA) were performed to determine two-dimensional ionospheric total electron content (TEC) anomaly after Indonesia’s Sumatra earthquake on 11 April, 2012 (UT) (Mw =8.6). The earthquake occurred at 08:38:37UT with vibrated duration time of 2 minutes and therefore the TEC data at the time 08:40 to 08: 50 (UT) after the earthquake were examined using both PCA and 2DPCA. The TEC anomaly was more intense localized at 08:40 to 08: 45 (UT) but the range was outside the epicenter. Potential cause of the TEC anomaly, which may be a density variance, was rising high speed slanted acoustic shock wave, which had small horizontal component, resulted by the mainshock of the earthquake. The duration time of this TEC anomaly was at least 5 minutes.
Keywords: Two-dimensional Principal Component Analysis (2DPCA), Principal Component analysis (PCA), two-dimensional Total Electron Content (TEC), Indonesia’s Sumatra earthquake, slanted acoustic shock waves, `