Tokyo Magnitude 8.0 reach her own daughter and mother in Sangenjaya. Together, the three of them brave the partly ruined city and try their best to make it home safely. The series was first announced at the 2009 Tokyo Anime Fair, denoting that it would replace "Eden of the East" in Fuji TV's noitamina well-rated anime timeblock and would be co-produced by Bones and Kinema Citrus. The series' setting is based upon the prediction that there is 70% or higher chance of an earthquake measuring 7.0 magnitude on the Richter scale hitting Tokyo in the next 30 years, with the series illustrating the
Richter magnitude scale used by astronomers. Second, he wanted a magnitude of zero to be around the limit of human perceptibility. Third, he specified the Wood-Anderson seismograph as the standard instrument for producing seismograms. Magnitude was then defined as "the logarithm of the maximum trace amplitude, expressed in microns", measured at a distance of 100 km. The scale was calibrated by defining a magnitude 3 shock as one that produces (at a distance of 100 km) a maximum amplitude of 1 micron (1 µm, or 0.001 millimeters) on a seismogram recorded by a Wood-Anderson torsion seismograph. Finally, Richter calculated a table of distance