Jann-Yenq (Tiger) Liu (Institute of Space Science, National Central University, TAIWAN)
Title
Statistical Analyses on seismo-ionospheric disturbances and precursors of the 11 March 2011 M9.0 Tohoku Earthquake
Abstract
Ground-based observations of the GPS TEC (total electron content) and satellite probing of radio occultation (RO) of FORMOSAT-3/COSMIC (F3/C)
are employed to study the co-seismic disturbances and precursors of the 11 March 2011 M9.0 Tohoku earthquake. It is for the first time the tsunami origin observed.
The horizontal propagation of seismo-traveling ionospheric disturbances (STIDs) induced by tsunami and seismic waves of the Tohoku earthquake are observed by the GPS TEC,
while the associated vertical propagation is probed by multi ground-based observations and F3/C RO sounding.
The raytracing and beamforming techniques are used to find the propagation and origin of the STIDs triggered by the seismic and tsunami waves.
Meanwhile, z test and the Receiver Operating Characteristic (ROC) curve are employed to find the characteristic of the temporal SIPs (seismo-ionospheric precursor)
of the GIM (global ionosphere map) TEC associated with earthquakes in Japan during 1998-2014.
It is found that anomalies appearing 3 days before the Tohoku earthquake well agree with the characteristic, which suggests that the SIPs of the earthquake have been observed.
A global study on the distribution of anomalies shows that the SIPs specifically and continuously occur over the epicenter on 8 March 2011, 3 days prior to the Tohoku earthquake.
Finally, a physical model of the ionosphere is used to reproduce the observed anomalies and find possible causal of the Tohoku SIPs.
