Abstract：By use of the technology of ionospheric tomography，threedimension ionospheric electronic density in a time length of 21 days prior to Japan March 11,2011 earthquake were reconstructed over the epicenter area, and the electron density anomaly detection was conducted at all ionosphere grid network points for a specific time period. After excluding the effect of solar and geomagnetic activity，the computational results indicate that the abnormal ionospheric electron density decreased at the Universal Time (UT) of 14:00-16:00 on February 28 and increased at 08:00-14:00 on March 2, 00:00-06:00 on March 3, and 12:00-20:00 on March 4. The occurrence of these anomalies is likely a precursor of the Japan Ms9.0 earthquake.
Chen Biyan,Dai Wujiao,Cai Changsheng et al. IONOSPHERIC ANOMALY DETECTION BEFORE JAPAN Ms9.0 EARTHQUAKE BY USE OF IONOSPHERIC TOMOGRAPHY TECHNOLOGY[J]. jgg, 2011, 31(6): 11-14.
