%0 Journal Article
%T Capability of TEC correlation Analysis and Deceleration at Propagation Velocities of Medium-Scale Traveling Ionospheric Disturbances: Preseismic Anomalies before the Large Earthquakes
%A Ken Umeno
%A Ryo Nakabayashi
%A Takuya Iwata
%A Minghui Kao
%J Open Journal of Earthquake Research
%P 105-137
%@ 2169-9631
%D 2021
%I Scientific Research Publishing
%R 10.4236/ojer.2021.104008
%X Data analysis method (CRA, hereafter) to correlate
multiple TEC anomaly signals has detected pre-seismic anomalies before the 2011
Tohoku-Oki earthquake (Iwata & Umeno 2016), the 2016 Kumamoto earthquake
(Iwata &amp; Umeno 2017) and the 2016 Tainan earthquake (Goto <i><span style=\"font-family:Verdana;\">et al</span></i><span style=\"font-family:Verdana;\">. 2019). However, a critical argument
said that those anomalies detected by CRA would not </span><span style=\"font-family:Verdana;\">be pre-seismic anomalies published by Journal of Geophysical Re</span><span style=\"font-family:Verdana;\">search-Space
Physics (126), 2021 (JGR-SP (126), hereafter). In this paper, we would point
out its incorrect use of statistical anomalies in evaluating CRA as the
following points: CRA is shown to increase the signal-to-noise ratio (SNR) to
amplify pre-seismic TEC¡¯s small anomaly signals with synchronizing and
correlating multiple GNSS receivers¡¯ data. We proved again that pre-seismic anomalies
certainly exist before the 2011 Tohoku-Oki earthquake and the 2016 Kumamoto
earthquake with additional data analysis. In particular, </span><span style=\"font-family:Verdana;\">a</span><span style=\"font-family:Verdana;\">s </span><span style=\"font-family:Verdana;\">a</span><span style=\"font-family:Verdana;\"> temporal anomaly, deceleration at propagation
velocities of medium-scale traveling ionospheric disturbances (MSTID,
hereafter) before the 2016 Kumamoto earthquake captured by CRA (Iwata &amp; Umeno
2017) is elucidated as pre-seismic anomalies. Furthermore, we proposed a
physical model to predict that 35 m/s change at MSTID propagation velocities
estimated by TEC¡¯s CRA requires 0.58</span><span style=\"font-family:;\" \"=\"\"> </span><span style=\"font-family:Verdana;\">¡Á</span><span style=\"font-family:;\" \"=\"\"> </span><span style=\"font-family:Verdana;\">10</span><sup><span style=\"font-family:Verdana;\"><span style=\"white-space:nowrap;\">-</span>3</span></sup><span style=\"font-family:Verdana;\"> V/m electric field in the F Layer ionosphere. Contrary to the claim with
the incorrect use of statistical anomalies in JGR-SP (126), TEC¡¯s correlation
anomalies detected by CRA (Iwata &amp; Umeno 2016 and Iwata &amp; Umeno 2017)
clearly provided supporting evidence that physical pre-seismic anomalies really
exist.</span>
%K CRA
%K TEC
%K MSTID
%K Preseismic Ionospheric Anomaly
%K The 2016 Kumamoto Earthquake
%K The 2011 Tohoku-Oki Earthquake
%U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=112968