Yearly Report for 2017, Multiple Records Broken!
Some of these background increases were not Fukushima related.
This short animation of Northern and Southern Hemisphere air circulation, shows why we can get detections so far south.
2017 was a record breaking year. Contributing factors to this year's background increases were, Radon from earthquake activity in the Pacific, the Sun going into a quiet period, and from Northern to Southern equatorial air flow break through. These were in addition to the recorded Fukushima increases since 2011. Detailed 2017 monthly reports can be found here, https://sccc.org.au/daily-local-background-radiation-levels-and-advisories-for-2017
1. March 30th saw the highest day average background ever recorded here, at 0.215 uSv/hr.
On March 29th, the day average was 51% above average. On the 30th, the low pressure system left over from cyclone Debbie came through, and the local background 24 hour day average spiked even more. Background peaked at 0.215 uSv/hr which is ~115% above average for this location. Yes, there was a spike in Radon levels on that day, but it wasn't significant enough to account for this amount of increase in local background. At the time Cyclone Debbie had turned into a low pressure system but was drawing in tropical air.
March 30th day average chart.
March 30th 24 hour 60 chart.
2. February, June, July, August, September and December had the highest recorded background month averages since Fukushima. June water tank filter testing detected mainly Lead-210, the a decay daughter of Radon, and Beryllium-7. Beryllium-7 is created by cosmic ray spallation in the upper atmosphere. Although Pb-210 and Be-7 may have contributed to the background increases the amounts detected where not significant enough to account for this significant increase in local background.
Water tank filter test.
This detailed rain water report provides a possible explanation for the significant Berryllium-7 detection in the June 2017 water tank filter test.
3. On the 3rd December 2017 a massive radon spike was detected that reached up to 8 pCi/L. At the time of the event it was very humid but not raining. The local live Radon monitor was in a wooden building with the door, and some windows open. Under these environmental monitoring conditions, this is a very large spike in local Radon levels. The wind direction during the Radon spike was easterly off the Pacific Ocean.
4. 2017 had the highest year average background level ever recorded here at 27% above the 4 year pre-Fukushima average. Some of the local background increases in October, November, and early December occurred during Easterly air flows. These Easterly air flows brought Radon gas releases to this location from a massive earthquake swarm and volcanic activity that appeared in the New Caledonia, Vanuatu, Soloman Islands and Fiji regions of the Pacific Ocean, at that time.
2007 to 2017 year average background level comparison.
5. The Monitoring GammaScout Geiger counter alarmed numerous times on the mornings of the 30th and the 31st December. These alarms were for short duration spikes in background, as wind direction changed to a Northern tropical direction. The last time we saw spikes like this was after Fukushima. These where very short duration events, less than 60 seconds, which suggest hot particles were passing through the monitoring Geiger counter environment.
Background spike detected on the 30th December 2017. (Visual observation at the time saw the GammaScout Geiger counter spike at 0.650 uSv/hr.)
Caloundra December month average, year comparisons.
2017 45% above pre-Fukushima average
2016 36% above pre-Fukushima average
2015 35% above pre-Fukushima average
2014 32% above pre-Fukushima average
2013 36% above pre-Fukushima average
2012 43% above pre-Fukushima average
December day average chart, (What the bar chart colour codes mean.)
Year and month average local background radiation levels from 2007 to 2017.
Disclaimer: This is an amateur volunteer run service. Human error can provide incorrect information, and equipment malfunction can produce false readings. Do not rely on, or take action upon information presented on this web site, without further research.