About the RBOOM & Infrasound category

#1

Have you picked up any strange infrasound readings recently? Share your findings with the community and any other interesting RBOOM related experiences!

#2

We have several quarries in the area that give us regular events - I thought I would share a typical one (RS on top, RB on bottom):

The spectrum of the RS shows a very distinct pattern of a sudden burst in the 10-40 Hz range “smeared” out over 5-10 seconds with a second low-frequency surface wave component that is delayed a bit, due to the slower propagation speed. You can read about it in the literature: this is a classic buried-charge type of explosion. From the difference in arrival times of the two waves, you could guess the range to the explosion site. But that is a bit difficult, since the time difference is not much on the RS.

Fortunately the RBOOM provides a second data point. The infrasound from the explosion is usually just single pulse and arrives much later due to the slower propagation speed. In this event the range appears to be roughly 7 miles. Most of the energy in this sound pulse is below 2 Hz.

I have detected similar events at ranges up to 28 miles thus far.

#3

you can read about that low frequency component of the RS graph (designated Rg) in the paper found here:

the following shows how the time difference increases with travel time. The upper trace is from an RSHAKE about 10 km from the likely source of the explosion. The lower trace is from an RSHAKE 40 km further west:

#4

Adding one more. The estimated distance to the blast is about 50 km.