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Entry  Tue Oct 8 08:08:18 2019, gautam, Update, PEM, PEM BLRMS anomaly PEManomaly.png
    Reply  Wed Oct 23 11:49:21 2019, gautam, Update, PEM, PEM BLRMS anomaly seisAll_20191021.pdfspecGrams.zip
       Reply  Thu Oct 24 18:37:15 2019, gautam, Update, PEM, T240 checkout 
          Reply  Tue Nov 5 12:37:50 2019, gautam, Update, PEM, T240 interface unit pulled out T240_recenter.pdfffPotential.pdf
             Reply  Wed Nov 13 19:34:45 2019, gautam, Update, PEM, Follow-up on seismometer discussion seisAll_20191111.pdfffPotential.pdf
                Reply  Wed Nov 13 20:15:56 2019, rana, Update, PEM, Follow-up on seismometer discussion 
                   Reply  Wed Nov 13 23:40:15 2019, gautam, Update, PEM, Follow-up on seismometer discussion seisAll_20191111_1Hz.pdf
                      Reply  Thu Nov 14 12:11:04 2019, rana, Update, PEM, Follow-up on seismometer discussion 
                      Reply  Fri Nov 15 00:18:41 2019, rana, Update, PEM, Follow-up on seismometer discussion MCshake.pdf
                         Reply  Fri Nov 15 12:16:48 2019, gautam, Update, PEM, Follow-up on seismometer discussion BS_ZspecGram.pdf.zip
                            Reply  Mon Nov 18 14:32:53 2019, gautam, Update, PEM, Follow-up on seismometer discussion 
                               Reply  Tue Nov 19 21:53:57 2019, gautam, Update, PEM, Follow-up on seismometer discussion seisxSpec.pdf
Message ID: 15024     Entry time: Wed Nov 13 23:40:15 2019     In reply to: 15023     Reply to this: 15025   15027
Author: gautam 
Type: Update 
Category: PEM 
Subject: Follow-up on seismometer discussion 

Here is some disturbance in the spacetime curvature, where the local gradient of the metric seems to have been modulated (in the "downward" as well as in the other two orthogonal Cartesian directions) at ~1 Hz - seems real as far as I can tell, all the suspensions were being shaken about and all the seismometers witnessed it, though the peak is pretty narrow. A broader, less prominent peak also shows up around 0.5 Hz. We couldn't identify any clear source (no LN2 fill-up / obvious CES activity). This event lasted for ~45 mins, and stopped around 2315 local time. Shortly (~5min) after the ~1 Hz peak died down, however, the 3-10 Hz BLRMS channel reports an increase by ~factor of 2. 

Onto trying some locking now that the suspensions have settled down somewhat.

Quote:

this is due to the Equivalence Principle: local accelerations are indistinguishable from spacetime curvature. On a spherical Earth, the local gradient of the metric points in the direction towards the center of the Earth, which is colloquially known as "down".

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