A radiation dose survey map via probe cars in Fukushima

[As part of our mission, we’ve been giving equipment to outside volunteers with the understanding they will take readings and report back. We gave one of our mobile bGeigie units to a team from Keio University. This is a guest post written by Tomoyuki Furutani of Keio University about their findings.]

Keio team conducted a radiation dose survey via a probe car from 5/5 to 5/7 in Fukushima prefecture (Fukushima city, Kawamata town, Iidate village and Minami-Soma city). Survey methods and results have already been shown on the Safecast blog. A Google Earth kmz file is available from here.

Radiation dose survey results via probe cars

Radiation dose survey results via probe cars (5/1 to 5/7) (Keio team crossed Northern Fukushima)

Major destinations of Keio team are as followings;

Fukushima city: JR (Japan Rail) East Fukushima stn., Takayu Onsen spa, Tsuchiyu Onsen, spa, JA (Japan Agricalture) Shin-Fukushima
Kawamata town: Kawamata Minami elementary school, Usuishi elementary school, Kawamata town gymnasiums
Iidate village: Iidate village office.

Minami-Soma city: Minami-Soma city office, Ishigami Daiichi elementary school, JR Minami-Soma stn., JR Iwaki-Ohta stn., Haramachi Thermal Plant, Ouchi-Shinko-Kagaku (20km boundary), Drive-Inn Hanazono (20km boundary), Baji-Koen Equestrian Park, Tetsuzan Dum (20km boundary).

We know that Safecast and Keio team surveyed very limited places. But when we view the kmz file shown above on Google Earth, we can easily find not only global hot spots but also local hot spots. It seems that local hot spots are affected by terrain or wind in small areas. We can find that radiation doses differ by several hundred meters.

Center of Fukushima city

Center of Fukushima city

Center of Minami-Soma city

Center of Minami-Soma city

We acknowledge that people have various opinions regarding publishing this kind of data, but we believe that this kind of maps are useful when discussing local issues on radiation dose in detail.

We’d like to report ground-level measurement results in the next blog.

About the Author

Sean Bonner


Sean Bonner is a co-founder and Global Director of Safecast. Based in Los Angeles, he's an Associate Researcher at the Center For Civic Media at the MIT Media Lab and a Shuttleworth Fellow.