Identification of Ionospheric GPS TEC Anomalies Prior to Earthquake in Sumatra Between 2007-2012 Using Correlation Technique

摘要

The occurrence of great earthquake as natural disaster is unavoidable and resulting a great loss in economy and human lives. So earthquake mitigation is a must to avoid greater loss in future. Past studies showed that there was ionospheric perturbation due to earthquake occurrence. This study analyzed the ionospheric Total Electron Content (TEC) before earthquake using Global Positioning System (GPS) data from Sumatran GPS Array (SuGAR) within 27 days using correlation technique. Correlation technique with anomaly threshold value was conducted to identify ionospheric variation related with earthquake preparation. From September 2007 until September 2012, 12 earthquakes occurred with magnitude> 6.0 over Sumatra, Indonesia. In result, ten of them preceded by TEC anomaly 1 to 24 days before earthquakes hit. The anomaly of TEC value is considered as effect of earthquake preparation activity after geomagnetic data validation.