PSN-L Email List Message

Subject: Re: Background Noise Again
From: Steinar Midtskogen steinar@.............
Date: Tue, 07 Oct 2008 08:16:49 +0200

[Gary Lindgren]

> I observed a strange phenomenon this weekend with my 23 sec. Lehman. Normally
> the background noise level drops down at night and gets very quiet after 11PM
> and until around 6AM. However on Saturday and Sunday night this past weekend,
> the background noise did not subside. Also the noise seem to peak with a FFT
> scan at around .06 Hz/sec. or a 16 second period. This all changed at around
> 0100 UTC 10/7/08 and is now back the normal signature. Does this make sense at
> all. Surely the earth is not ringing is it?

I haven't checked the frequencies, but I sometimes see similar things
when there's a storm in the ocean within a few hundred km.


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