A July 4th 2011 Radiation Anomaly

After the Japan earthquake, there were (unsubstantiated) fears of radioactive clouds engulfing the west coast. Since I did have a SparkFun USB Geiger Counter laying about, I figured it would be a fun project to set up a monitoring station and post results to a web page with graphs. The Geiger counter is sitting on the table, indoors, facing the exterior corner of the house, perpendicular to the ground, with the Puget Sound about 1000 feet in that direction. There couldn’t be a worse location.

But some really, really boring data collection ensued. *yawn* 9 counts per minute, 7 counts per minute, 5 counts per minute. I’m glad to know the Ikea table wasn’t radioactive, but it was very boring to watch. Lacking any radioactive sources to play with, I just ended up leaving it on the desk collecting data continuously since March 25th 2011. Over the next few months, it was completely flat. No up trending. Nothing.

Fast forward to the end of September, I was investigating what I thought was an unusual cpm event between 30-50 CPM on late August, when I did this ‘grep’ command:

$ grep "] 40" radlog.txt
[Mon Jul 4 07:45:24 2011.1309790724.28] 400
[Mon Aug 1 15:46:59 2011.1312238819.67] 40
[Fri Aug 26 18:18:09 2011.1314407889.55] 40

Oh crap!? What the heck? 400 counts per minute? The warning threshold in Colorado on Radiation Network is 100 CPM, and mine is near sea level indoors in suburban Seattle!

Here is a dump of the log file:

[Mon Jul 4 06:53:32 2011.1309787612.03] 6
[Mon Jul 4 06:54:33 2011.1309787673.27] 14
[Mon Jul 4 06:55:34 2011.1309787734.47] 16
[Mon Jul 4 06:56:35 2011.1309787795.05] 7
[Mon Jul 4 06:57:36 2011.1309787856.5] 13
[Mon Jul 4 06:58:37 2011.1309787917.82] 12
[Mon Jul 4 06:59:38 2011.1309787978.8] 8
[Mon Jul 4 07:00:39 2011.1309788039.19] 7
[Mon Jul 4 07:01:40 2011.1309788100.16] 11
[Mon Jul 4 07:02:41 2011.1309788161.26] 11
[Mon Jul 4 07:03:42 2011.1309788222.31] 17
[Mon Jul 4 07:04:43 2011.1309788283.22] 13
[Mon Jul 4 07:05:44 2011.1309788344.34] 11
[Mon Jul 4 07:06:45 2011.1309788405.6] 17
[Mon Jul 4 07:07:46 2011.1309788466.7] 11
[Mon Jul 4 07:08:47 2011.1309788527.86] 13
[Mon Jul 4 07:09:48 2011.1309788589.0] 13
[Mon Jul 4 07:10:50 2011.1309788650.27] 9
[Mon Jul 4 07:11:51 2011.1309788711.27] 10
[Mon Jul 4 07:12:52 2011.1309788772.98] 17
[Mon Jul 4 07:13:53 2011.1309788833.7] 14
[Mon Jul 4 07:14:54 2011.1309788894.11] 14
[Mon Jul 4 07:15:55 2011.1309788955.3] 19
[Mon Jul 4 07:16:56 2011.1309789016.31] 16
[Mon Jul 4 07:17:57 2011.1309789077.85] 10
[Mon Jul 4 07:18:58 2011.1309789138.29] 10
[Mon Jul 4 07:19:59 2011.1309789199.2] 19
[Mon Jul 4 07:21:00 2011.1309789260.91] 15
[Mon Jul 4 07:22:01 2011.1309789321.99] 20
[Mon Jul 4 07:23:02 2011.1309789382.3] 21
[Mon Jul 4 07:24:03 2011.1309789443.33] 35
[Mon Jul 4 07:25:04 2011.1309789504.1] 27
[Mon Jul 4 07:26:05 2011.1309789565.37] 33
[Mon Jul 4 07:27:06 2011.1309789626.8] 23
[Mon Jul 4 07:28:07 2011.1309789687.42] 36
[Mon Jul 4 07:29:08 2011.1309789748.3] 45
[Mon Jul 4 07:30:09 2011.1309789809.0] 238
[Mon Jul 4 07:31:10 2011.1309789870.97] 212
[Mon Jul 4 07:32:11 2011.1309789931.35] 75
[Mon Jul 4 07:33:12 2011.1309789992.2] 81
[Mon Jul 4 07:34:13 2011.1309790053.93] 207
[Mon Jul 4 07:35:14 2011.1309790114.54] 205
[Mon Jul 4 07:36:15 2011.1309790175.05] 119
[Mon Jul 4 07:37:16 2011.1309790236.44] 229
[Mon Jul 4 07:38:17 2011.1309790297.45] 229
[Mon Jul 4 07:39:18 2011.1309790358.02] 322
[Mon Jul 4 07:40:19 2011.1309790419.33] 203
[Mon Jul 4 07:41:20 2011.1309790480.06] 92
[Mon Jul 4 07:42:21 2011.1309790541.24] 114
[Mon Jul 4 07:43:22 2011.1309790602.27] 258
[Mon Jul 4 07:44:23 2011.1309790663.04] 298
[Mon Jul 4 07:45:24 2011.1309790724.28] 400
[Mon Jul 4 07:46:25 2011.1309790785.02] 49
[Mon Jul 4 07:47:26 2011.1309790846.14] 229
[Mon Jul 4 07:48:27 2011.1309790907.77] 457
[Mon Jul 4 07:49:28 2011.1309790968.03] 192
[Mon Jul 4 07:50:29 2011.1309791029.48] 211
[Mon Jul 4 07:51:30 2011.1309791090.57] 384
[Mon Jul 4 07:52:31 2011.1309791151.94] 100
[Mon Jul 4 07:53:32 2011.1309791212.64] 175
[Mon Jul 4 07:54:33 2011.1309791273.01] 269
[Mon Jul 4 07:55:34 2011.1309791334.19] 150
[Mon Jul 4 07:56:35 2011.1309791395.37] 101
[Mon Jul 4 07:57:36 2011.1309791456.16] 118
[Mon Jul 4 07:58:37 2011.1309791517.03] 385
[Mon Jul 4 07:59:38 2011.1309791578.68] 705
[Mon Jul 4 08:00:39 2011.1309791639.44] 496
[Mon Jul 4 08:01:40 2011.1309791700.8] 89
[Mon Jul 4 08:02:41 2011.1309791761.26] 84
[Mon Jul 4 08:03:42 2011.1309791822.78] 20
[Mon Jul 4 08:04:43 2011.1309791883.46] 16
[Mon Jul 4 08:05:44 2011.1309791944.6] 13
[Mon Jul 4 08:06:45 2011.1309792005.46] 14
[Mon Jul 4 08:07:46 2011.1309792066.03] 16
[Mon Jul 4 08:08:47 2011.1309792127.57] 13
[Mon Jul 4 08:09:48 2011.1309792188.87] 26
[Mon Jul 4 08:10:49 2011.1309792249.96] 31
[Mon Jul 4 08:11:50 2011.1309792310.28] 33
[Mon Jul 4 08:12:51 2011.1309792371.12] 12
[Mon Jul 4 08:13:52 2011.1309792432.0] 25
[Mon Jul 4 08:14:53 2011.1309792493.3] 7
[Mon Jul 4 08:15:54 2011.1309792554.22] 16
[Mon Jul 4 08:16:55 2011.1309792615.91] 15
[Mon Jul 4 08:17:56 2011.1309792676.99] 19
[Mon Jul 4 08:18:57 2011.1309792737.47] 10
[Mon Jul 4 08:19:58 2011.1309792798.71] 7
[Mon Jul 4 08:20:59 2011.1309792859.04] 17
[Mon Jul 4 08:22:00 2011.1309792920.0] 13
[Mon Jul 4 08:23:01 2011.1309792981.52] 17
[Mon Jul 4 08:24:02 2011.1309793042.13] 16
[Mon Jul 4 08:25:03 2011.1309793103.18] 9
[Mon Jul 4 08:26:04 2011.1309793164.73] 21
[Mon Jul 4 08:27:05 2011.1309793225.54] 22
[Mon Jul 4 08:28:06 2011.1309793286.1] 10
[Mon Jul 4 08:29:07 2011.1309793347.07] 14
[Mon Jul 4 08:30:08 2011.1309793408.19] 9
[Mon Jul 4 08:31:09 2011.1309793469.99] 14
[Mon Jul 4 08:32:10 2011.1309793530.59] 14
[Mon Jul 4 08:33:11 2011.1309793591.35] 14
[Mon Jul 4 08:34:12 2011.1309793652.16] 13
[Mon Jul 4 08:35:13 2011.1309793713.18] 25
[Mon Jul 4 08:36:14 2011.1309793774.96] 31
[Mon Jul 4 08:37:15 2011.1309793835.77] 26
[Mon Jul 4 08:38:16 2011.1309793896.35] 14
[Mon Jul 4 08:39:17 2011.1309793957.17] 15
[Mon Jul 4 08:40:18 2011.1309794018.79] 9
[Mon Jul 4 08:41:19 2011.1309794079.26] 11
[Mon Jul 4 08:42:20 2011.1309794140.97] 19
[Mon Jul 4 08:43:21 2011.1309794201.17] 17
[Mon Jul 4 08:44:22 2011.1309794262.18] 48
[Mon Jul 4 08:45:23 2011.1309794323.23] 43
[Mon Jul 4 08:46:24 2011.1309794384.21] 28
[Mon Jul 4 08:47:25 2011.1309794445.2] 26
[Mon Jul 4 08:48:26 2011.1309794506.02] 19
[Mon Jul 4 08:49:27 2011.1309794567.07] 18
[Mon Jul 4 08:50:28 2011.1309794628.0] 24
[Mon Jul 4 08:51:29 2011.1309794689.08] 137
[Mon Jul 4 08:52:30 2011.1309794750.0] 93
[Mon Jul 4 08:53:31 2011.1309794811.71] 261
[Mon Jul 4 08:54:32 2011.1309794872.74] 210
[Mon Jul 4 08:55:33 2011.1309794933.04] 67
[Mon Jul 4 08:56:34 2011.1309794994.88] 106
[Mon Jul 4 08:57:35 2011.1309795055.44] 86
[Mon Jul 4 08:58:36 2011.1309795116.47] 48
[Mon Jul 4 08:59:37 2011.1309795177.51] 60
[Mon Jul 4 09:00:38 2011.1309795239.0] 14
[Mon Jul 4 09:01:39 2011.1309795299.71] 7
[Mon Jul 4 09:02:40 2011.1309795360.44] 13
[Mon Jul 4 09:03:41 2011.1309795421.72] 11
[Mon Jul 4 09:04:42 2011.1309795482.01] 13
[Mon Jul 4 09:05:43 2011.1309795543.8] 10
[Mon Jul 4 09:06:44 2011.1309795604.08] 16
[Mon Jul 4 09:07:45 2011.1309795665.94] 11
[Mon Jul 4 09:08:46 2011.1309795726.54] 11

Click here for my giant 2328×1280 graph.

That’s right! We hit a 705 CPM here, indoors, near sea level, with no circulating outdoor air, while everyone was sleeping, which is almost 100 times the normal level in my house. It was a beautiful day, no rain. All times are in PDT. Did I catch some cosmic burst from space? A radioactive bug? Some uranium dust? Sensor error? Can anyone guess what happened here?

2 Responses to “A July 4th 2011 Radiation Anomaly”

  1. Bo says:

    Sensor error (avalanche), se post on Sparkfun web site…

    Regards

    Bo

  2. Please contact me…I have similar results and some theoretical possibilities.
    peterfebbroriello@sbcglobal.net

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