Radiation
On West Coast of North America Could End Up Being 10 Times HIGHER
than in Japan
16
July, 2012
We've
extensively documented the fact that ocean currents bring Japanese
radiation to the West Coast of North America, and that - rather than
adequate ocean dilution - there could be “pockets” and “streams”of highly-concentrated radiation.
Joke
F Lübbecke of the National Oceanic and Atmospheric Administration's
(NOAA) Pacific Marine Environmental Laboratory and 3 scientists from
the GEOMAR Research Center for Marine Geosciences poured tracer dye
into coastal waters off of Fukushima, and monitored its progress as
it traveled to the West Coast of North America, to find out what
might really happen.
They
have revealed their results in a new paper published by journal
Environmental Research Letters.
The
paper shows that the West Coast of North American could end up with
10 times more radioactive cesium 137 than the coastal waters off of
Japan itself.
How
could radiation levels be lower closer to the source of
contamination: Fukushima?
Because
the currents are swift off of the Eastern coast of Japan, and quickly
move the contaminated water away.
The
paper explains:
In
the following years, the tracer cloud continuously expands laterally,
with maximum concentrations in its central part heading east. While
the northern portion is gradually invading the Bering Sea, the main
tracer patch reaches the coastal waters of North America after 5–6
years, with maximum relative concentrations ( > 1 × 10−4)
covering a broad swath of the eastern North Pacific between Vancouver
Island and Baja California. Simultaneously some fraction of the
southern rim of the tracer cloud becomes entrained in the North
Equatorial Current (NEC), resulting in a westward extending wedge
around 20°N that skirts the northern shores of the Hawaiian
Archipelago. After 10 years the concentrations become nearly
homogeneous over the whole Pacific, with higher values in the east,
extending along the North American coast with a maximum (~1 × 10−4)
off Baja California. The southern portion of the tracer cloud is
carried westward by the NEC across the subtropical Pacific, leading
to increasing concentrations in the Kuroshio regime again.
***
With
caution given to the various idealizations (unknown actual oceanic
state during release, unknown release area, no biological effects
included, see section 3.4), the following conclusions may be drawn.
(i) Dilution due to swift horizontal and vertical dispersion in the
vicinity of the energetic Kuroshio regime leads to a rapid decrease
of radioactivity levels during the first 2 years, with a decline of
near-surface peak concentrations to values around 10 Bq m−3 (based
on a total input of 10 PBq). The strong lateral dispersion, related
to the vigorous eddy fields in the mid-latitude western Pacific,
appears significantly under-estimated in the non-eddying (0.5°)
model version. (ii) The subsequent pace of dilution is strongly
reduced, owing to the eastward advection of the main tracer cloud
towards the much less energetic areas of the central and eastern
North Pacific. (iii) The magnitude of additional peak radioactivity
should drop to values comparable to the pre-Fukushima levels after
6–9 years (i.e. total peak concentrations would then have declined
below twice pre-Fukushima levels). (iv) By then the tracer cloud will
span almost the entire North Pacific, with peak concentrations off
the North American coast an order-of-magnitude higher than in the
western Pacific.
"Order-of-magnitude"
is a scientific term which means 10 times higher. The "Western
Pacific" means Japan's East Coast.
Here
are the important graphics from the paper:
Figure
4. Decadal evolution of relative surface tracer concentration in the
0.1°-model simulation; boxes in (d) indicate regions for which the
temporal evolution is computed in figure 7; contour lines mark power
of 10 intervals.
Postscript:
Prussian Blue may be used to treat cesium poisoning. But don't take
any Prussian Blue before consulting with a qualified healthcare
professional. Antioxidants may also help reduce damage from
low-level radiation.
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