I was notified by Francesco Berni about DMS warning about "high seismic noise on EDB" (Figure 1). As shown in the plot the EDB seismic noise had a slow rms increase starting from June 3 then, on top of it since June 9 afternoon there are transient seismic shakes with 2-4kHz frequency content. The first of thee shakes seems occurred on June 9 at 13:52 UTC. They seem local to the EDB since nothing is seen on SQZ bench, also there is little acoustic content (Figure 2). Beside this there are periodic (10min approx) acoustic (mainly) transients heard by the mic on the EDB bench (Figure 2 as well). I could find no correlation with HVAC signals for neither of them.
I wander if something has been added or switched on the bench (some piezo?) and if shakes can be associated with ITF operation?
While looked at it I noticed that both the accelerometer and microphone on the nearby SQZ bench see loud noise transients with 2min rate (in Figure 2). It must be some device on the bench.