Reports until 10:46, Friday 18 July 2025
H1 AOS (DetChar)
preeti.sharma@LIGO.ORG - posted 10:46, Friday 18 July 2025 - last comment - 15:57, Tuesday 29 July 2025(85848)
Investigation of Lock losses due to Earthquakes

Preeti, Gaby

With the help of Ashley Patron's Eqlock script, we calculated the locklosses caused due to EQs for each observing runs. This is a part of the study of investigating the correlation between the microseism and duty-cycle (alog), so we chose winter months (Nov, Dec, Jan and Feb) of each observing run and calculated the vertical velocity of the ground from z-channel and horizontal velocity which is the quadrature sum of x and y channels at the time of locklost due to an EQ. We also did the same study for LLO (alog). 

Conclusion:

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preeti.sharma@LIGO.ORG - 12:04, Thursday 24 July 2025 (85964)

After removing EQ events which happend during the locklosses, the probability of surviving lock during an EQ in O2 winter was found to be 54%, O3b winter was 64%, O4a winter was 73% and O4b winter was 41%. 

preeti.sharma@LIGO.ORG - 15:57, Tuesday 29 July 2025 (86082)

Some corrections have been done in the script after getting Derek's feedback and have attached the updated scatter plot between peak horizontal ground motion and peak vertical ground motion of Earthquake events, also data table including total number of EQs and lock probability in each observing runs' winters. Although, the number of surviving EQ events are still lower in O4 than O3. 

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