Analysis of ionospheric anomalies before the 2011 M-w 9.0 Japan earthquake

作者：Yao YiBin^*; Chen Peng; Wu Han; Zhang Shun; Peng WenFei

来源：Chinese Science Bulletin, 2012, 57(5): 500-510.

DOI：10.1007/s11434-011-4851-y

• earthquake
• vertical total electron content
• ionospheric anomaly
• ionospheric tomography
• global positioning system

On March 11, 2011, a large earthquake of M-w=9.0 occurred near the east coast of Honshu, Japan. This paper investigates pre-earthquake ionospheric anomalies during the earthquake period, using data from global navigation satellite systems and ionosonde stations near the epicenter. A clear anomaly that occurred on March 8 lasted 6 hours. Eliminating ionospheric anomalies that may have been caused by solar activities and magnetic storms, we believe that a positive anomaly on March 8 was very possibly an ionospheric precursor. The affected ionospheric area on March 8, which is evident on a vertical total electron content distribution map, extended to 50 degrees in longitude and 20 degrees in latitude, with length ratio approximately 3:1. The anomaly peak arose from 15:00-19:00 LT, and its location did not coincide with the vertical projection of the epicenter, but was instead to its south. Corresponding ionospheric anomalies are also observed in the magnetically conjugated region. There were no obvious ionospheric anomalies in other parts of the world. To analyze changes in the ionospheric anomaly, computerized ionospheric tomography technology was used to invert the spatial and temporal distribution of electron density in the ionosphere. The ionospheric anomaly on March 8, 2011 is suggested to be an ionospheric precursor of the March 11 earthquake in Japan.

• 出版日期2012-2
• 单位武汉大学