For all who have been looking for realtime radiation data from Japan, you are in luck. Or maybe not, as the data unfortunately indicates nothing good. The System for Prediction of Environment Emergency Dose Information (SPEEDI) releases gamma radiation data online. The site is jittery and apparently not suited for major traffic which is why we represent several screen captures of the data. While it is not surprising that according to the website both Miyagi and Fukushima prefectures are entirely “Under Survey” as it makes sense that the government does not want to generate panic, SPEEDI has disclosed some tell-tale data about cities in Ibaraki prefecture, which is just a hundred or so miles north of Tokyo, and is just south of the ill-fated Fukushima prefecture. And the data is stunning: based on a N, NE and NNE wind direction (where it originates), meaning all coming from Fukushima, with a normal reading in the 80 nGy/h range, the city of Kounosu Naka is at 3,024, Kadobe Naka is at 2,416, Isobe Hitachioota is at 1,213 and many others are in the mid to upper triple digit range! Again, this is based on wind coming out of Fukushima and ultimately headed toward the capital. Indicatively, normal terrestrial plus cosmic gamma radiation is about 80 nGy/h.
Below we present screencaptures as of moments ago, as apparently the Japanese government seems to believe that abnormal gamma radiation levels are perfectly notmal:
A map of all prefectures, showing maximum gamma radation readings. Note Ibaraki at 3,024 nGy/h, and Kanagawa right below it (and downwind) at 224 nGy/h compared to low double digts for all other prefecture.
(more at link)
Ooh...3000 nanogreys per hour!
So, basically, about the same rate of radiation exposure as you get from cosmic rays while you're on an airline flight....or a few orders of magnitude less than that, perhaps.