It was previously theorized that ionosphere disturbances can only be detected for earthquakes which happened closer than 6,000 kilometers.
KFU employees Kamil Yusupov and Adel Akchurin, together with Takashi Maruyama and Hiroyuki Shinagawa, published a paper titled «Sensitivity of ionosonde detection of atmospheric disturbances induced by seismic Rayleigh waves at different latitudes» in Earth, Planets and Space.
The Cyclone ionosonde (creatied by Dr. Akchurin, Head of the Near Space Studies Lab of SAU AstroChallenge) can detect earthquakes at distances as big as 15,000 kilometers. The paper also states that earthquake signatures for mid-latitude KFU ionosonde can be up to 3 times more prominent than on a low-latitude ionosonde in Japan.
The furthest earthquake detected by Cyclone was that in Chile on 27th February 2010. It was one of the strongest in the last 50 years, with a magnitude of 8.8. Over 500 people died in the disaster, and 220 thousand buildings were damaged or destroyed.
Dr. Akchurin explains, "Ionospheric disturbances are caused by infrasound waves caused by seismic Rayleigh waves. The Chilean earthquake was so powerful that its seismic waves spread across 15,000 kilometers of the earth surface. Such disturbances have been studied before in Japan, but they have only been detected from as far as 6,000 kilometers. Thanks to this research with our Japanese colleagues, we found out that ionosondes' sensitivity to atmospheric disturbances in infrasound differs in various places of Earth. In Kazan this sensitivity is about 3 times that of Tokyo. The reason is the difference in geomagnetic inclination. It affects the ionosphere-atmosphere dynamical coupling and radio propagation of vertical incidence ionosonde sounding."
Research of ionosphere has been ongoing at KFU since the 1980s. Dr. Akchurin's sonde is situated at the University's radio polygon and works in one-minute intervals. There is only one similar device in Finland.