In previous studies, observed STID signatures were usually induced by a single source: either Rayleigh waves [Calais and Minster, 1995; Ducic et al., 2003], seismo-AGWs in the ionosphere [Afraimovich et al., 2001; Heki and Ping, 2005; Otsuka et al., 2006; Liu et al., 2010], or tsunami [Artru et al., 2005; Liu et al., 2006b; Otsuka et al., 2006] disturbances were observed individually. Due to the powerful M9.0 Tohoku earthquake occurring near the two densest ground-based GPS networks in the world, numerous AGWs, including signatures of Rayleigh, tsunami waves, etc. appear simultaneously. It is found the STIDs reaching the ionosphere in about 7 min after the earthquake occurs. Since the ionosphere is assumed to be a thin spherical shell at a height of 350 km, the average speed of the STID traveling from the Earth's surface to the ionosphere is about 833 (=350 km/7 min/60 s) m/s which agree with those observed by Liu et al. [2006a, 2006b, 2010]. Meanwhile, the observed speeds of 2.3–3.3 km/s and 720–800 km/h are nearly identical to the speeds of Rayleigh waves and tsunami waves, which suggest that the two STIDs are locally induced by the two waves right under them [Liu et al., 2006a, 2006b]. It has been known that vertical motions of the solid surface near the epicenter and/or the sea surface around the tsunami origin trigger disturbances (i.e., acoustic gravity waves) in the neutral atmosphere. Artru et al.  and Heki and Ping  show that the acoustic speed is about 300 m/s from the Earth's surface to the mesosphere at about 90–100 km altitude, and speed up to 1000–1100 m/s at 300 km altitude in the ionosphere. Therefore, if the triggered disturbances (i.e., AGWs) depart with low elevation angles, they travel near horizontally between the troposphere and the mesosphere with speeds of about 300 m/s, and further locally/vertically perturb the ionospheric TEC (i.e., STID) [Liu et al., 2006a]. On the other hand, those AGWs depart with high elevation angles, travel near vertically into the thermosphere (ionosphere), and propagate horizontally interacting with the ionized gas. Thus, due to the AGWs (i.e., STIDs) traveling most of the time in the ionosphere, the speeds are of 600–1100 m/s [Afraimovich et al., 2001; Heki and Ping, 2005; Otsuka et al., 2006; Liu et al., 2010]. For those speeds greater than 1100 m/s, such as 1596.67 m/s (Satellite 15 in Figure 4), they might result from mode mixings of the STIDs induced by Rayleigh waves and acoustic waves near the epicenter right after the earthquake occurrence [Astafyeva et al., 2009].
 It was reported that STIDs propagations had strong north-south asymmetry. Scientists hypothesized that the northward propagating disturbances might be selectively attenuated by interaction between the movements of charged particles in STIDs and the Earth's magnetic fields [Heki and Ping, 2005; Otsuka et al., 2006]. For the event studied here, signatures of the Rayleigh waves travel away from the epicenter along the Japanese island in both the northeast and southwest directions with speeds of 2.1–3.0 km/s, while those of acoustic and tsunami waves propagate in all directions. The Tohoku earthquake is the 5th largest earthquake after 1900. The massive energy released by this event has an immense impact extending from the surface of the Earth up into the ionosphere, as observed by the two densest ground-based GPS networks of the world. The resulting data set illustrates the dynamics and physical mechanisms of ionospheric disturbances/waves triggered by the M9.0 Tohoku earthquake in unprecedented detail.