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Fukushima Crisis update: Latest maps of spread of radiation plumes in Asia-Pacific

Austria’s weather service, the Central Institute for Meteorology and Geodynamics in Vienna, has posted an update today of its dispersion modelling of radiation from the troubled Fukushima nuclear power. The plume, having been blown West to the ocean yesterday, has turned inwards to the mainland today Sunday, as it will tomorrow and Tuesday, while transport across the ocean is stopping. Rain and snow will wash out radioactivity to the ground.

The centre explains the colour coding used in it’s maps as: "The colour scale shows a total of 5 colours. The area marked “E” shows an area with estimated current equivalent dose rate of 10 mSv/h (in a 25×25 km2 square). The violet colour on the outer edge of contaminated areas (Area A) represents 0,3 μSv/h, which corresponds to the amount of the natural background radiation dose."

Figure 1: Plume as of Sunday and Monday (12:00 UTC)

<IMG SRC=“https://www.zamg.ac.at/pict/aktuell/20110320_fuku_I-131-Bild1_bild2.jpg”

Figure 2: Plume as of Tuesday

<IMG SRC=“https://www.zamg.ac.at/pict/aktuell/20110320_fuku_I-131-Bild3.jpg”

It also provides other fresh data from the Comprehensive Test Ban Treaty Organization (CTBTO) (see the long article I published last week on CTBTO data for more details on its data).


It says radiation levels at the Takasaki station in Japan fell after peaking midweek, due to atmospheric transport condition. Iodine-131 levels at Milli-Bq/m3 at the Petropavlovsk station in Russia on 15/16 March. Unreviewed data suggest similar levels at the CTBT station in Sacramento, California on 17 March. Radiation in both Russia and California was four orders of magnitude lower than in the Takasak station in Japan, it says, adding that “there is no health risk whatsoever.”

Below are animations of the plume’s predicted path:

World map

For full coverage of the Fukushima disaster, go to Nature’s news special.

Images: Central Institute for Meteorology and Geodynamics

Comments

  1. Report this comment

    Grattan Woodson said:

    Dear Declan,

    Thank you for bring us this very interesting information.

    On 19Mar2011 at about 1300 both my NukAlert devices began to chirp virtually simultaneously near Monroe, GA U.S.A. These are personal radiation detection devices useful for monitoring exposure during nuclear accidents etc. I believe these devices to be reliable but I would appreciate the opinion of others given the event described in this post. It is of interest however that both devices activated and terminated within seconds of each other.

    The units indicated 0.2 Roentgen per hour was present in the area at the time of the measurement.

    The alarm lasted for one minute only and then ceased. The units then recycled and went back into there normal operating mode.

    I would be grateful for an interpretation of this event.

    G. Woodson, MD

  2. Report this comment

    Grattan Woodson said:

    Dear Declan.

    I am pleased to report that the alters given off by my personal radiation detectors were not an indication of the presence of radiation in Georgia, U.S.A but rather a built-in quality control check of the device that permits the user to check that the unit is still operating normally. This function is triggered when the unit is heated up by more than 30 degrees rapidly. Please see the note below provided by the kind folks from NukAlert.

    Grattan Woodson, MD

    Dr. Woodson,

    Your description sounds like the expected low level alarm caused by sudden warming of the instrument. This can be caused by a sudden change in the ambient temperature or direct sunlight falling on the device. The transition back to the ticking mode indicates the typical return to equilibrium of the NukAlert. If you have further concerns please share them with me. You are fortunate to have a simple way to test the units with actual radiation.

    Phil Smith

    Dear Mr. Smith,

    That explanation does fit both the circumstances and the timing of my event. The devices were in a box stored in a room at 65 degrees F. I had picked both up and were holding them in my hands listening to them close to my ears so I could hear them tick for about 10 minutes when the alarms occurred.

    Thank you for your rapid response to my inquiry. You no doubt have been following the events in Fukushima, Japan, which is why I decided to retrieve the devices from storage.

    Best regards,

    Grattan Woodson

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