When the tragic earthquake hit Japan back in March of 2011,
mobile communications were severely disrupted in the affected
regions, even in metropolitan Tokyo. The University of Tokyo’s
Center for Spatial Information Science has put together an
incredible visualization which dramatically illustrates how
mobile activity almost completely stops in the minutes after the
earthquake hit at 14:46PM on that afternoon. In the video below,
anonymized geo-speatial data from Zenrin DataCom shows the
movement of people in the city throughout the day 1. Time is
shown progressing in the bottom right corner. As you can see,
mobile movement is most intense during the morning rush hour
between 8AM and 9AM, with the majority of movement concentrated
on major train lines. But just after the earthquake hits in the
afternoon, mobile activity ‘goes dark’ so to speak. Train
service was also interrupted, and you can see that people don’t
really resume movement until late in the evening, and even then
it was at just a fraction of its