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corey.gray@LIGO.ORG - posted 21:23, Tuesday 07 November 2023 - last comment - 23:59, Tuesday 07 November 2023(74081)

M6.8 Earthquake north of Australia Takes H1 (and later L1) Down

H1 taken to Earthquake mode at 0509utc; started seeing seismic signal on Picket Fence and seismic blrms. Squeezer unlocked taking H1 out of Observing and then lockloss 1-min later. It's been about 15min since the EQ waves hit us and seismic is still increasing (ISC LOCK has x&y arms at INCREASE FLASHES). Marking time as EARTHQUAKE.

Comments related to this report

corey.gray@LIGO.ORG - 21:32, Tuesday 07 November 2023 (74082)

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Since earthquake motion is still increasing, I'm going to take ISC_LOCK to DOWN and wait 30min.

corey.gray@LIGO.ORG - 22:11, Tuesday 07 November 2023 (74083)

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UPDATE After An Hour Since The Earthquake Arrived: Picket Fence is still orange (or more) and BLRMS hasn't quite started to turn downward yet....assess in another 30min (I tried to lock a green arm, but they are wobbling all over the place anyways.)

corey.gray@LIGO.ORG - 23:59, Tuesday 07 November 2023 (74084)

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With 30min left in the shift and seismic elevated 2.5orders of magnitude due to the earthquake (for almost 2.5hrs!), going to run an Initial Alignment. Mainly because Y-arm has OK flashes, but now it won't attempt to lock its green arm.

At the moment,

X-arm is finally locked and waiting for (5) ALS signals to converge (first time in 2.5hrs!)
Y-arm wouldn't align and so it is going through a round of Increase Flashes during this Alignment.

Seismically, the "Earthquake Band" is finally touching the 1um/s mark after being above that for the last 2.5hrs.

X-Arm currently waiting for (2) ALS signals to converge.
Y-arm has a note about "Camera centering too far off. Need to turn on slowly" while ALS Y node in the ENABLE WFS stage.