Things that go bump

A few minutes ago, there was something that shook our deck and rattled the windows.
I checked my shake-boom, starting with the boom:

Hmm… that was quite strong! If anyone has seen anything like this, please let me know.
It shows up on the seismometer too:

This is the area, my station is the SB:

I wondered if the station down in the town (1D) had caught it:

Well, yes. Not as strong there, but it’s there. How about the 3D the other side of the mountain:

Yes … about the same as I saw. How about further out? The 1D in Sherwood?

There, but not really strong.
Looks like it was more an air event that shook the ground rather than the other way around.

Does this look like a meteor, maybe??


G’day Philip,

Hard to tell if the Infrasound is driving the seismic or the other way around as the signals look coincidental to me. You may be able to time them more accurately in SWARM. Personally I think it is easier for a ~7Pa pressure wave to create a seismic signal than for a seismic signal to create a ~7Pa pressure wave, so I think you may be right.

Timing between the different stations should also help determine to source. If the seismic signal delays are of the order of 0.3 km/s then the infrasound is driving. If the delay is of the order of 4 to 6 km/s then seismic is driving. The time will vary with the direction of the waves of course.

The infrasound signal doesn’t look like a meteor type signal (i.e. classic N wave) but bolides and re-entering space junk have more complex signatures. The second pulse at 11:31:39 would have to be a second body if it is a bolide or space junk. The signal is quite short, so it can’t be a bolide or space junk of , say the size of a SpaceX Dragon Trunk which gave a decaying signal about 75s long at 370kms distance. For these reasons I’m a little inclined to think it’s not a bolide or space junk without more info.

Keep your ears and eyes on the News… enquiring minds want to know! ;o)



I agree about it being easier for the pressure wave to generate the seismic signal than the other way around.

I did a bit more exploring, the seismic signat was picked up by other stations, much further out (50 miles or so), although it was stronger in our location.

Nothing on the news, or Facebook, which is usually very quick to respond to noises with lots of questions (“What was that boom?”)


Interesting indeed, especially if it was instrumentally felt 50 miles out of your location. Has anyone on local groups/chats and similar asked, “What was that noise earlier today?”

As you said, usually, such questions are quite fast to pop out.

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Nothing on the news or in local chat groups - probably because I think it was more of a pressure pulse than an explosive noise, so no BOOM that people would notice. The short rattle of the windows and noise from walls/deck could easily be put down to passing trucks, people slamming doors etc.

Never seen anything like this on the infrasound channel before.

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Every once in a great while I see something like that. When a sound wave goes all the way down to fractional-hertz I associate that with weather phenomena. Perhaps some sort of downdraft of the sort that toss airplane passengers about. Up in the sky it is called clear air turbulence. I am not sure what you would call it when/if it reaches the ground. Perhaps a rogue atmospheric wave?

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You have me looking for this kind of wave now.
Here is one:

This was an absolutely calm/quiet night, with no wind.

Here is another one with an interesting profile and lasting quite a while:

Two hours earlier the same night.

What kind of atmospheric phenomenon does this?

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Not quite sure what that first one is. It was fairly “loud” whatever it was.
Most of the high amplitude events around here are helicopters, the sound envelope and spectrum are quite distinctive:

I did have a fairly large amplitude event yesterday:

No idea what that was. I initially put it down to Amazon driving their truck up to the barn (where the 'Shake is located) and turning there, they do that fairly often, but when I check the timing against security camera times, the Amazon visit was half an hour earlier.

Your second trace, the long duration one - when I see that leading sharp edge, most of the energy in the lower frequencies and longish duration, slowly trailing off, that looks suspiciously like an earthquake.

I just checked you device - infrasound only … checked a shake-boom south of you, he sees something on the infrasound channel, but nothing at all on the seismometer - so probably not an earthquake. Interresting.


OK - now I realize what this was:


That would do it! Probably would be more of an infrasound pulse than seismic if it was an above ground pipeline.


RBE98HDF heard it well

But I have been unable to find a third RBOOM to use the source locator program :frowning:

The closest RShake did see something at the time:


That’s a problem I have. Mine is the only RB in the area. There are a few shakes, some of which are actually useful, but not many. Just my Boom…