Some more observations that I can’t explain. If anyone has any random guesses, they are probably at least as valid as my random guesses.
It began when I noticed this, this morning:
I have no clue what it might be. It doesn’t appear on a nearby station, well, there is a hint, but it could just be imagination…
I checked on the BOOM side to see if it shows up there. Well, there is something, but the timing doesn’t exactly match:
While looking at the BOOM data, I also noticed this:
That also shows up on the EHZ side:
The first event is quite unusual indeed, I personally don’t have a precise clue on what it could be, only that it seems something slightly visible on the higher frequencies by looking at the spectrogram. Very curious if anyone else has some insight!
The second appears to be some kind of medium to mainly low-frequency pressure displacement. It could have been a distant thunder event (maybe even two distinct ones), if you had any thunderstorms around.
Those are very nice little details that you have noticed, there’s lot to explore in the data from a Shake!
Yes - high frequency of the first is really odd. Of course you see a lot of HF transient things, but they never seem (except in this case) to have really measurable movement associated with them.
For the second - no, no thunderstorms. The interesting thing to me was that it looks a little the same form (yes … I know …) but minute earlier. Probably just coincidence, you can often find stuff like that if you look hard enough
The second set, to me, looks similar to what mine would look like whenever we had wind gusts shaking the building.
Yes, it does look a little like storm/wind. The only reason it stands out is that it was a quiet night.