UPDATE 13 April 2011: All links work in Part 1. Added a Part 2 for U.S, European radiation levels
Part One: Radiation levels in Japan
The source for this chart is Ryugo Hayano, Ph.D. Professor Hayano is the Physics Department Chair at The University of Tokyo. Click on the image to view a larger version, with higher resolution. It links directly to the Professor’s user page on image-sharing site Plixi. You’ll find many other charts and graphs there. Some charts are localized at a prefecture level.
I offer my thanks to @hayano and Daniel Garcia. Daniel R. Garcia Ph.D. is a nuclear scientist from France, doing a post-doc at TEPCO, in Fukushima. He was there prior to the earthquake and tsunami. Daniel frequently sends updates via Twitter as @daniel_garcia_r. He works at the reactor site every day, takes photos, and makes them available via Twitter.
Both Daniel and Professor Hayano are reliable, because they never confuse Becquerel with Sievert with Roentgen, they know radio-isotopes and their half-lives better than nearly anyone. Daniel had to assisted the press a few weeks ago when there was confusion between Cesium 137 versus Iodine 137 versus Iodine 131 versus Uranium 137.
PART II: Other locales, other radiation levels
The Radiation Network is an excellent resource for radiation information in the U.S.A. and other parts of the world. It is a network of civilian volunteers using a protocol to report radiation readings, 24 hours a day, 7 days a week. Sensor stations are located throughout the contiguous 48 states, Hawaii, Alaska and Norway. There was one in Northern Japan. Sadly, it went off-line last month.
The Radiation Network is non-profit, all volunteer and headquartered in Arizona. Tim is the public face of the Radiation Network. Using software developed for this purpose, Tim collects and aggregates the real-time data from the sensor stations, then updates the map online with the readings at one-minute intervals. The Radiation Network has went online nearly a decade, ago. Thus they offer very reliable baseline measures for comparison and detection of any incident. Their criteria for elevated radiation include
- Rule out protocol for false positives e.g. spikes due to sensors malfunctioning,
- Level of radiation that is significant: Higher than the threshold AND sustained, and how long “sustained” is,
- Exogenous causes such as geography. Readings in Colorado are always higher due to the higher elevation.
In addition to the embedded links above, you can read a little more about the Radiation Network in this little piece I wrote on Amplify on April 7.