Dynamics of vertical ionospheric inhomogeneities over Irkutsk during 06:00-06:20UT 11/03/2011 caused by the Tohoku earthquake

摘要

According to the data of quasi-vertical sounding at Usolie-Tory path(midpoint - 52.3N, 103E, 120km distance), the dynamics of vertical structure ofthe midscale inhomogeneities of the plasma frequency was reconstructed. These irregularities are caused by Tohoku earthquake 11/03/2011 (38.3N,142.4E). Observed horizontal velocities of propagation in the ionosphere andthe spatial scales of the wave-like disturbance modes, generated byearthquakes, are calculated. As a result of numerical simulation involving the data from TALAYA seismicstation (TLY, 51.7N, 103.7E) and comparison with the experiment it is shownthat the vertical ionospheric irregularities of 5-40km range observed in first20 minutes after the beginning of observations of effects (from 06:00 to 06:20UT) are qualitatively explained by travelling of acoustic shock wave cone (Mach cone ) from supersonic ground source - seismic wave to the heights up to200km. It is shown that the most likely source of the shock wave were Z and Ecomponents of the seismic oscillations observed at TLY station. Irregularitiesobserved after 06:20UT were apparently linked with other mechanisms. It isshown that the existing temporary CHIRP ionosonde temporal resolution (60seconds) and the ionogram inversion technique used are not enough for detaileddiagnosis of fine spatial vertical structures of this process.