Electron and ion density variations before strong earthquakes (M>6.0) using DEMETER and GPS data

Abstract. Using IAP (plasma analyzer) and ISL (Langmuir probe) experiments onboard DEMETER (Detection of Electromagnetic Emissions Transmitted from Earthquake Regions) satellite and GPS (Global Positioning System) measurements, we have statistically analyzed the variations of the electron and ion densities to search for disturbances in the vicinity of four large earthquakes prior to events. The indices Dst and Kp were used to distinguish pre-earthquake anomalies from the other anomalies related to the geomagnetic activities. For each studied case, a very good agreement was found between the different parameters estimated by DEMETER and GPS data in the detection of pre-seismic anomalies. Our statistics results show that the anomalous deviations prior to earthquakes have different sign from case to case, and that their amplitude depends on the magnitude of the earthquake. It has also been found that the electron density measured by the ISL experiment at night detects anomalous variations significantly before the earthquakes. The appearance of positive and negative anomalies in both of DEMETER and TEC (Total Electron Content) data during 1 to 5 days before all studied earthquakes during quiet geomagnetic conditions indicates that these anomalous behaviors are highly regarded as seismo-ionospheric precursors.

[1]  Bodo W. Reinisch,et al.  International Reference Ionosphere 2000 , 2001 .

[2]  Jean-Pierre Lebreton,et al.  Examples of unusual ionospheric observations made by the DEMETER satellite over seismic regions , 2006 .

[3]  Sergey Pulinets,et al.  Main phenomenological features of ionospheric precursors of strong earthquakes , 2003 .

[4]  I. P. Dobrovolsky,et al.  Estimation of the size of earthquake preparation zones , 1979 .

[5]  P. Mayaud,et al.  Derivation, Meaning, and Use of Geomagnetic Indices , 1980 .

[6]  A. Rius,et al.  Estimation of the transmitter and receiver differential biases and the ionospheric total electron content from Global Positioning System observations , 1994 .

[7]  S. C. Garg,et al.  Ionospheric precursors observed at low latitudes around the time of koyna earthquake , 2008 .

[8]  S. Pulinets,et al.  Ionospheric precursors of earthquakes , 2004 .

[9]  M. Devi,et al.  Preliminary results of TEC measurements in Guwahati, India , 2008 .

[10]  P. Fagundes,et al.  Statistical analysis of the total electron content observed at 23°S in the Brazilian sector , 2009 .

[11]  早川 正士,et al.  Seismo electromagnetics : lithosphere-atmosphere-ionosphere coupling , 2002 .

[12]  V. Klimenko,et al.  Physical mechanism and mathematical modeling of earthquake ionospheric precursors registered in total electron content , 2009 .

[13]  A. K. Gwal,et al.  Ionospheric variations observed by the DEMETER satellite in the mid-latitude region during strong earthquakes , 2007 .

[14]  Sergey Pulinets,et al.  Physical mechanism of the vertical electric field generation over active tectonic faults , 2009 .

[15]  T. Zelenova,et al.  Electron density profile changes in a pre-earthquake period , 1996 .

[16]  Sergey Pulinets,et al.  Quasielectrostatic Model of Atmosphere-Thermosphere-Ionosphere Coupling , 2000 .

[17]  Dieter Bilitza,et al.  International reference ionosphere , 1978 .

[18]  Yi-Ben Tsai,et al.  Pre-earthquake ionospheric anomalies registered by continuous GPS TEC measurements , 2004 .

[19]  Henry Rishbeth,et al.  Patterns of F2-layer variability , 2001 .

[20]  Masashi Hayakawa,et al.  Thermal IR satellite data application for earthquake research in Japan and China , 2002 .

[21]  T. Ondoh.  Investigation of precursory phenomena in the ionosphere, atmosphere and groundwater before large earthquakes of M > 6.5 , 2009 .

[22]  C. Park,et al.  Penetration of thundercloud electric fields into the ionosphere and magnetosphere: 1. Middle and subauroral latitudes , 1973 .

[23]  P. Gilbert,et al.  IAP, the thermal plasma analyzer on DEMETER , 2006 .

[24]  Libo Liu,et al.  Is an unusual large enhancement of ionospheric electron density linked with the 2008 great Wenchuan earthquake , 2008 .

[25]  Anthony J. Mannucci,et al.  A global mapping technique for GPS‐derived ionospheric total electron content measurements , 1998 .