ITIC Tsunami Bulletin Board
Dear all,

On Wikipedia page Fukushima I nuclear accidents in section Earthquake
and Tsunami
(http://en.wikipedia.org/wiki/Fukushima_I_nuclear_accidents#cite_note-nytimesWilson-28)
there is a passage that may relate to the travel time of tsunami wave to
this coastal ocation (37.421389N, 141.0325E).

An earthquake categorised as 9.0MW on the moment magnitude scale occurred
on 11 March 2011, at 14:46 Japan Standard Time (JST) off the northeast
coast of Japan. On that day, reactor units 1, 2, and 3 were operating, but
units 4, 5, and 6 had already been shut down for periodic inspection. When
the earthquake was detected, units 1, 2 and 3 underwent an automatic
shutdown.

After the reactors shut down, electricity generation stopped. Normally
the plant could use the external electrical supply to power cooling and
control systems, but the earthquake had caused major damage to the power
grid. Emergency diesel generators started correctly but stopped abruptly
at 15:41, ending all AC power supply to the reactors. The plant was
protected by a sea wall, but tsunami water which followed after the
earthquake easily topped this sea wall, flooding the low lying generator
building.

Thus, travel time to the plant was 55 min. The remaining question is which
wave (first, second or third) flooded  the diesels? Computed waveform near
the plant can shed light on this.

Slava Gusiakov