Earlier this month we received our first measurements from inside the evacuation zone and talked about how they illustrated the point that “closer to the plant” doesn’t automatically mean higher readings. To illustrate that point even furthers, Safecast volunteers Akira Sugiyama and Tatsuhiko Kodama were able to take a bGeigie all the way across the exclusion zone including almost right up to the front gates of the Daiichi plant. Here is the map of their drive which shows a few things. First of all, these are now the highest levels we’ve recorded reaching almost 12,000 CPM. Secondly, this shows just how much the levels can change, as only a few km away and approximately the same distance from the plant they drop to barely 100 CPM. A 11,900 fluctuation in just a few minutes drive is noteworthy to be sure.
These readings also point out the limitations of our color scheme and scale on the maps, something we’ll be addressing shortly.