That's right, double what Japanese authorities originally estimated. That's a lot of caesium-137 to miss, so where did it all disappear to?
Out to sea, apparently. A study recently completed by Andreas Stohl of the Norwegian Institute for Air Research pegs the total amount of caesium-137 released at 36,000 terabecquerels through April 20 compared to the 15,000 terabecquerels the Japanese government reported. Stohl's report asserts that the government only gathered data from terrestrial sensors and failed to account for the radiation blown off-shore.
The report also states that a mere 20 per cent of the emitted radiation actually landed on the Land of the Rising Sun, the vast majority settling in the Pacific with as much as two per cent making foreign landfall. However, while 36,000 terabecquerels is a massive dose of radiation, it's still less than half of what Chernobyl released during its meltdown. It should also be noted that while the Atmospheric Chemistry and Physics journal posted the report for comment, the study hasn't yet completed the peer-review process. [Washington Post]