Tag Archives: Oceanic

Update: Tracking the arrival of Fukushima derived contamination in the Pacific off North America

By Jay T. Cullen

Previously unpublished data results from research expeditions in 2014 and 2015 are summarized here.  Overall the data indicate that:

  1. Fukushima derived radiocesium was first detected 1500 km west of British Columbia Canada in June 2012
  2. Contamination was detected on the continental shelf (near coastal waters) in June 2013
  3. By February 2014 Fukushima radiocesium was present at levels similar to preexisting weapons testing derived 137Cs
  4. The timing of the arrival and levels of radiocesium in the contaminated plume are in reasonable agreement with existing ocean circulation model predictions
  5. 134Cs, a unique indicator of Fukushima impact given its ~ 2 year half life, increased in 2014 and 2015 relative to previous years indicating that peak concentrations are likely to arrive in 2016
  6. Maximum combined radiocesium activities (137Cs + 134Cs) offshore as of summer 2015 are 11 Bq m-3 of seawater are about 8-10 fold less than maximum activities measured in the 1960’s due to weapons testing fallout. Current levels do not represent a significant risk to ecosystem or public health

Continue reading Update: Tracking the arrival of Fukushima derived contamination in the Pacific off North America

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Dramatic Decrease of Fukushima Derived Radionuclides in the Northwest Pacific Ocean 2011-2012

By Jay T. Cullen

A schematic view of the formation and subduction of mode waters in the North Pacific

The purpose of this diary is to report on a recently published (Jan 2015) open-access, peer reviewed study which examined the activities of 137Cs (half life 30.2 yr), 134Cs (half life ~2.1 yr) and 90Sr (half life ~28.8 yr) in the northwest Pacific off the coasts of Japan and China. The diary is part of a ongoing effort to communicate the results of scientific research into the impact of the Fukushima Dai-ichi nuclear disaster on environmental and public health. Men and colleagues report on how activities of these fission produced isotopes changed between three research expeditions in June 2011, December 2011 and June 2012. Activities in seawater decreased dramatically through time for all three isotopes consistent with very high release rates measured from the Fukushima site in March-April 2011 followed by ongoing but many orders of magnitude (10,000 – 100,000 fold) lower releases from the site thereafter. By 2012 the impact of the Fukushima releases could be still be detected in most samples for Cs isotopes however 90Sr distributions were much more uniform with the highest measured activity only slightly above the pre-Fukushima background. These results are consistent with:

  1. the relatively small source term for 90Sr from compared with the Cs isotopes from Fukushima as determined by measurements of air, soil and water after the disaster
  2. the much lower Fukushima derived activities for these isotopes in the eastern Pacific off of North America being measured given decay and mixing of the contamination as it is transported by ocean currents

Continue reading Dramatic Decrease of Fukushima Derived Radionuclides in the Northwest Pacific Ocean 2011-2012

B.C.’s citizen scientists on alert for radiation from Japan

 Amy Smart

Originally Published in the Times Colonist January 24, 2015 10:22 PM

Surfriders collect samples.jpg
Citizen scientists with environmental group Surfriders collect seawater samples off a dock in Port Renfrew. The samples will be analyzed for traces of radiation from the 2011 Fukushima nuclear meltdown. Photo courtesy Craig Wardle

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Canadian scientists track Pacific Ocean currents… using Fukushima radiation

Scott Sutherland
Meteorologist, theweathernetwork.com

Originally published by The Weather Network

Wednesday, January 7, 2015, 8:09 PM – Radioactive isotopes originating from the Fukushima nuclear power plant in Japan have been slowly drifting across the Pacific Ocean since March 2011, and Canadian scientists have been using this to test some of their most basic ideas of how ocean currents work. Continue reading Canadian scientists track Pacific Ocean currents… using Fukushima radiation