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Message ID: 8752     Entry time: Wed Jun 26 01:30:31 2013
Author: rana 
Type: Summary 
Category: PEM 
Subject: Variation in 10-30 Hz seismic RMS 

For quite a while (no one knows how long), we've seen fluctuations in the 10-30 Hz seismic motion. This shows up as the purple trace on the seismic BLRMS on the wall projector.

The second plot shows that this is not only a periodic increase in the usual 29.5 Hz HVAC peak, but also an anomolous 32.2 Hz peak. Probably some malfunctioning machinery - maybe in the 40m or maybe on the roof.

Attachment 1: gur1z_rms.pdf  22 kB  | Hide | Hide all | Show all
Attachment 2: gur1z.pdf  12 kB  | Show | Hide all | Show all
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