The study of ionospheric anomalies in Japan area during 1998–2010 by Kon et al.: An inaccurate claim of earthquake-related signatures?

Brief communication "Further comments on the ionospheric precursor of the 1999 Hector Mine earthquake"

“…On the contrary, other studies document the observation of pre-earthquake ionospheric disturbances but no statistically significant correlation between these anomalies and the seismic events (see e.g. Dautermann et al, 2007;Rishbeth, 2006) showing that some ionospheric precursors are artefacts related to changes in solar and geomagnetic activity, which influences the ionospheric parameters such as the regional TEC variations (see Afraimovich and Astafyeva, 2008;Masci, 2012c). Thus, it is evident that the consideration of the geomagnetic activity level is a key parameter for the interpretation of the observed ionospheric disturbances.…”

Is there any difference in local time variation in ionospheric F2-layer disturbances between earthquake-induced and Q-disturbance events?

“…And why do the ionospheric anomalies before earthquakes exhibit distinct features of LT variation? In addition, Kon et al (2011) statistically analyzed TEC anomalies associated with M ≥ 6.0 earthquakes during the 12-year period of 1998-2010 in Japan, but the results were rebutted by Masci (2012), who attributed these disturbances to geomagnetic activity. Recently, Kamogawa and Kakinami (2013) claimed that the variation in slant TEC from 40 min before the Tohoku earthquake, reported by Heki (2011), was due to a tsunami rather than a precursory enhancement.…”

“…However, in a recent paper, Pulinets and Davidenko (2014) doubted the existence of charged aerosols, and proposed the concept of the global electric circuit (GEC), providing a reasonable explanation of the anomalous electric field in the ionosphere, due to the deAnn. Geophys., 33, 687-695, 2015 www.ann-geophys.net/33/687/2015/ 9 Japan, but the results was rebutted by Masci (2012) who attributed these disturbances to 11 geomagnetic activity. Recently, Kamogawa and Kakinami (2013) claimed that the variation of 12 slant TEC from 40 minutes before the Tohoku earthquake reported by Heki (2011) was due to 13 tsunami rather than the precursory enhancement.…”

Comment on "Fractal analysis of ULF electromagnetic emissions in possible association with earthquakes in China" by Ida et al. (2012)

“…In recent years, many studies (see, e.g., Campbell, 2009;Masci, 2010Masci, , 2012cMoldovan et al, 2012;Thomas et al, 2009aThomas et al, , b, 2012a have shown strong evidence that ionospheric and geomagnetic anomalies claimed to be earthquake precursors were normal magnetic disturbances driven by solar-terrestrial interaction. These papers have examined many controversial reports of earthquake-related signals demonstrating that several methodologies used in previous studies are not appropriate to detect the presence of earthquake precursors (see, e.g., Thomas et al, 2012b).…”