File:Newton2011 7 27b.jpg

Map of contamination after the Fukushima disaster.

Colors represent the density $D(\alpha,\delta)$ of ionizing radiation measured from the aircrafts (airplanes helicopters) and recalculated for April 29, altitude one meter above the ground.

The view covers the range approximately $140.0<\delta<141.1$, $36.8<\alpha<38.0~$.

The intermediate blue represents the Pacific Ocean, that does not show its contamination at the aerial view.

The dark blue indicates the region with $D<1\mu \mathrm {Sv/h}$. The following levels are shown:

$1\mu$Sv/h, between dark blue and light blue.

$1.9\mu$Sv/h, between light blue and green.

$3.8\mu$Sv/h, between green and yellow

$9.5\mu$Sv/h, between yellow and orange

$19\mu$Sv/h, between orange and red

Maximal estimate for the red region is 91$\mu$Sv/h.

The high resolution image appeared 2011 May 26 at the Newton Graphic Science Magazine, 2011, issue 7, page27. ^[1]

Similar image recalculated for levels of the concentration of rarioactivity in Becquerel/meter$^2$ is available at the MEXT cite ^[2] indicating that the recalculation uses the approximation that the surface density of contaminants $q= 1 $MegaBequerel/square meter causes corresponds to the density if ionizing radiation $D\approx 3.1$ microSievert per hour.

References

Red corresponds to den