Investigation of precursory phenomena in the ionosphere, atmosphere and groundwater before large earthquakes of M>6.5

Electron and ion density variations before strong earthquakes (<i>M</i>>6.0) using DEMETER and GPS data

“…Accordingly, the measured parameters may display variations in absence of seismic activity. Therefore, it is difficult to separate pre-seismic ionospheric phenomena from the ionospheric disturbances due to the solar-terrestrial activities (Ondoh, 2008). Consequently, to discriminate the seismo-ionospheric perturbations from geomagnetic disturbances, the geomagnetic indices D st and K p (http://spider.…”

Ionospheric anomalies detected by ionosonde and possibly related to crustal earthquakes in Greece

“…Ondoh (2009) and Ondoh and Hayakawa (2006) observed an anomalous foEs increase on some Japanese ionosonde stations close in time to a strong earthquake with M = 7.2.…”

“…Ground-based facilities, such as ionosonde stations, magnetic observatories and GPS receivers can monitor various parameters used to detect ionospheric anomalies, such as F2-layer critical frequency (foF2), total electron content (TEC), electron temperature (Te) at F2-layer heights, magnetic pulsations and low-frequency radio signals (see, e.g., Hayakawa et al, 1999;Strakhov and Liperovsky, 1999;Bortnik et al, 2008;Ondoh, 2009;Trigunait et al, 2004;Hobara and Parrot, 2005;Liu et al, 2006;Maekawa et al, 2006;Sharma et al, 2006;Ondoh and Hayakawa, 2006;Dabas et al, 2007;Oikonomou et al, 2016).…”

Giant disturbance in the ionospheric F2 region prior to the <i>M</i>8.0 Wenchuan earthquake on 12 May 2008

“…Since the phenomenon related to ionospheric perturbation caused by the earthquake at Alaska 1964 was firstly reported (Barnes and Leonard, 1965), many researchers have devoted themselves to seismo-ionospheric research and there have been numerous observational studies of ionospheric anomalies prior to strong earthquakes (Pulinets, 1998;Silina et al, 2001;Liu et al, , 2006Liu et al, , 2009Rios et al, 2004;Dabas et al, 2007;Sarka et al, 2007;Chmyrev et al, 2008;Za-Correspondence to: T. Xu (xutong1104@126.com) kharenkova et al, 2008Sharma et al, 2008;Hsiao et al, 2009;Ondon, 2009;Zhao et al, 2009). An excellent review of ionospheric precursors has been presented by Pulinets et al (2003).…”