Shiela, Arnaud, Timesh

The lockloss at 17:16:32 UTC appears to have been caused by ground motion at the Y end. We see that in the H1:ISI-GND_STS_ETMX_Y_BLRMS_1_3 seismometer, there are multiple peaks in the time series amplitude indicating increased ground motion at the Y end. As a result, H1:IMC-F_OUT16 became unstable and the lockloss occurred. We think this could be attributed to the wind fence installation that is currently being undertaken at the Y end. 

It appears that during periods where there are spikes in the 1_3 BLRMS, the IMC-F responds i.e there is some correlation between loud events at the end station seismometers and the IMC-F.

The NDSCOPE attachment shows the timeseries of the IMC, Lockstate, 10_30 STS BLRMS and the 1-10 STS BLRMS around the time of the lockloss.The y axis units are nanometres per second.