At only 213 Miles away I had a good point from which to capture the NJ 4.8 quake on my RS&Boom today. I was not surprised to capture the quake, but very surprised that my boom also picked up something at the same time. The Infrasound appears to be absolutely correlated with the quake, but is it really possible I picked up the sound of the tremors from 200 miles away?
Hello K2PI,
That’s an amazingly clean trace, indeed; thanks for sharing it!
Since they are coincident in time (the sound and seismic waves), I think the most plausible explanation is that the same ground motion that set the geophone moving also set the BOOM sensor moving, which generated its own pressure waves!
This topic from some years ago covers very similar detections: Boom detects EQ 271 km away
Another very interesting case!
Thanks Stormchaser. Slapping my head! Seems the most logical explanation, although the sound appears to start prior to the largest part of the quake.
Nothing was felt here. The boom sensor is connected to a tube which terminates on an exterior wall about 5 feet away. It is a garage, which is normally quiet, and sits on the foundation slab. There is a 55-gallon emergency water barrel nearby, and I wonder if the movement of the ground was turned into sound by that?
Always welcome K2PI!
It is possible that it’s a combination of things close to the Shake (in addition to the original ground motion) contributed to what you have seen on the BOOM microbarometer.
Looking at the two plots and zooming in a bit, I think what’s recorded in the HDF channel matches pretty well the arrival of the P and S waves seen via the geophone. The first increase in amplitude starts around 14:24:15UTC, while the second, with larger amplitudes, occurs around 10:24:45UTC.
