Fig. 1From: Ionospheric signatures of the April 25, 2015 Nepal earthquake and the relative role of compression and advection for Doppler sounding of infrasound in the ionosphereA scheme of the infrasound generation by seismic waves of observed horizontal velocity c G . The meaning of variables is as follows: c s0 is the initial speed of sound, α is the initial zenith angle of infrasound waves, ε is the initial elevation angle of infrasound wave vectorBack to article page