This is the strongest earthquake in the known history of Japan[8] and the seventh[10], and according to other estimates, even the sixth[11], fifth[2] or fourth[12] in strength in the history of seismic observations in the world[13]. However, in terms of the number of victims and the scale of destruction, it is inferior to the earthquake in Japan in 1896 and 1923 (the most severe consequences).
The earthquake occurred at a distance of about 70 km from the nearest point on the coast of Japan. Initial calculations showed that the tsunami waves took 10 to 30 minutes to reach the first affected areas of Japan. 69 minutes (15: 55 JST) [14] after the earthquake, a tsunami flooded Sendai airport.
Immediately after the earthquake, scientists have predicted that within a month after the first strike in Japan, earthquakes of magnitude above 7 can occur[15].