The response of the ionosphere to the earthquake in Japan on March 11, 2011 as estimated by different GPS-based methods

Abstract

The results of detecting ionospheric disturbances by different methods based on GPS observations during the mega earthquake in Japan (March 11, 2011) are analyzed. It is shown that different methods of analysis and data processing technologies provide generally similar results and suggest quite a complex mor phology of the ionospheric response to this seismic event. We distinguish three types of wave disturbances that appeared in the ionosphere in response to the earthquake: slow gravity waves, acoustic-gravity oscillations, and fast disturbances corresponding to the Rayleigh waves. Such an analysis of the wave phenomena and the comparison between the results provided by different methods has been carried out for the first time.

Middle-Scale Ionospheric Disturbances Observed by the Oblique-Incidence Ionosonde Detection Network in North China after the 2011 Tohoku Tsunamigenic Earthquake

“…These suggested that the horizontal wavelength of the gravity waves following the 2011 Tohoku tsunamigenic earthquake ranged from 200 to 400 km. Yasyukevich et al [ 12 ] also indicated that the wavelength of the gravity waves induced by the 2011 Tohoku earthquake was ~200 km.…”

“…It is well known that three kinds of ionospheric disturbances were observed after the 2011 Tohoku tsunamigenic earthquake related to the source displacement, the Rayleigh waves, and the tsunami waves. The three kinds of ionospheric disturbances have different propagating speeds, which are associated with seismic Rayleigh waves (2.0–3.0 km/s), acoustic waves (0.3–1.5 km/s), and gravity waves (0.1–0.3 km/s) [ 5 , 9 , 11 , 12 , 30 , 33 ]. As studied by Galvan et al [ 30 ] and Jin et al [ 11 ], the most disturbed region after the 2011 tsunamigenic earthquake was located in the northwest part of the epicenter.…”

“…Liu et al [ 4 ] also suggested that the ionosphere could have been disturbed by the 2011 Tohoku tsunami for several hours with much slower horizontal velocity (60–180 m/s) because the sea surface was continuously disturbed for more than 10 h after the tsunami occurrence. However, vertical displacement of the ocean surface induced by several aftershocks, as well as the additional turbulization in the upper atmosphere induced by a series of weaker temblors, can also generate significant gravity waves in the northwestward direction [ 12 , 22 , 30 , 32 ]. Future studies are needed to further investigate the source mechanism for the STIDs following the 2011 Tohoku tsunamigenic earthquake.…”

“…The horizontal and vertical propagation of STIDs triggered by the 11 March 2011 Tohoku earthquake and the subsequent tsunami near the east coast of Japan have been observed by various atmospheric and ionospheric observation instruments, including ionosonde [ 5 , 6 , 7 , 8 ], global positioning system (GPS) network [ 9 , 10 , 11 , 12 ], all-sky airglow imager [ 13 , 14 , 15 ], high-frequency (HF) Doppler measurements [ 16 , 17 ], and satellite/occultation observations [ 4 , 18 , 19 , 20 , 21 ]. The STIDs associated with the 2011 Tohoku tsunamigenic earthquake along the open sea (Pacific Ocean) have been widely reported using GPS network and all-sky airglow observations.…”

First results of registering ionospheric disturbances obtained with SibNet network of GNSS receivers in active space experiments

“…The method of mapping ionospheric disturbances, which has been repeatedly used for detecting TIDs [Perevalova et al, 2008;Tsugawa et al, 2011;Kunitsyn et al, 2011;Perevalova et al, 2012;Afraimovich et al, 2013;Astafyeva et al, 2013;Yasyukevich et al, 2015;Zakharov et al, 2016], has demonstrated its effectiveness in detection of local disturbances. We have identified relatively weak and vertically localized disturb-ances caused by the effect of the Progress spacecraft engine in the April 16, 2014 experiment.…”