Investigation of the Possible GPS-TEC Anomalies before the 2005 Northern Peru Earthquake

Recently, Total Electron Content (TEC) data, obtained from Global Navigation Satellites Systems (GNSS) receivers, are increasingly being used to detect seismo-ionospheric anomalies. In this study, Global Positioning System – Total Electron Content (GPS-TEC) data were used to investigate ionospheric abnormal behaviours prior to the 2005 Northern Peru earthquake (5.674 S, 76.409 W, September 26, 2005, 01:55:37 UT, Mw:7.5). The data obtained from three International GNSS Service (IGS) stations near the epicentre of the earthquake were used to detect ionospheric anomalies before the earthquake. Solar activity (F10.7), geomagnetic storm (Kp) and geomagnetic activity (Dst) index values which are both related to space weather conditions, were used to analyze these pre-earthquake ionospheric anomalies. Analysis results revealed that anomalies occurred and the possible ionospheric VTEC anomalies associated with the earthquake obtained four to nine days before the Northern Peru earthquake. This study is supported by TUBITAK, Environment, Atmosphere, Earth and Marine Science Research Support Group (CAYDAG) grant no. 116Y109