aLIGO LHO Logbook

H1 General

ryan.crouch@LIGO.ORG - posted 15:59, Tuesday 21 October 2025 - last comment - 16:49, Tuesday 21 October 2025(87621)

OPS Tuesday EVE shift start

TITLE: 10/21 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Preventive Maintenance
OUTGOING OPERATOR: Oli
CURRENT ENVIRONMENT:
SEI_ENV state: USEISM
Wind: 4mph Gusts, 1mph 3min avg
Primary useism: 0.07 μm/s
Secondary useism: 0.49 μm/s
QUICK SUMMARY:

We are still trying to recover lock post maintenance
2ndary microseism is still high, right around the 90th percentile, but the wind is low
- Primary also seems elevated
BRS-Y's velocity is high, Jim's looking into it, this happened about a month ago as well alog86985

Comments related to this report

ryan.crouch@LIGO.ORG - 16:49, Tuesday 21 October 2025 (87627)PEM

Link

Looking at the high 2ndary microseism it seems to be from the storm off west coast with wave swells of 10m and a swell period of 7.6sec ( ~0.13Hz). Something weird is that the MY seismometer had a big sudden jump in motion at ~23:10 UTC.

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