<p>The 'Bama Boom ('Bama is short for the US state of Alabama) is a term for some audible "booms" heard by many people in Alabama and now in Colorado. See for example the Popular Mechanics article <a href="http://www.popularmechanics.com/military/aviation/a13728147/mysterious-powerful-boom-shakes-alabama/" rel="nofollow noreferrer">Mysterious, Powerful "Boom" Shakes Alabama</a> and the Tech Times' <a href="http://www.techtimes.com/articles/216026/20171124/mysterious-booms-heard-in-colorado-leave-residents-baffled.htm" rel="nofollow noreferrer">Mysterious Booms Heard In Colorado Leave Residents Baffled</a>.</p>

<p><em>In this question I'm just asking about the measurements shown below from the CBS Denver News item <a href="http://denver.cbslocal.com/2017/11/21/mysterious-booms-heard-in-colorado/" rel="nofollow noreferrer">Mysterious Booms Around World Now Heard In Colorado</a></em>, not about the "booms" themselves.</p>

<p>The second plot states it's a seismogram, but I can't tell what the first one likely represents. Could this be an <a href="https://en.wikipedia.org/wiki/Infrasound" rel="nofollow noreferrer">infrasound</a> measurement? The caption says that it's a "sound graph" but that's not necessarily a technical term.</p>

<p><img src="https://i.sstatic.net/4a8EH.png" alt="enter image description here"></p>

<p><strong>above:</strong> "A sound graph from the USGS Lakeview Retreat near Centreville, Ala., shows a loud boom heard over Alabama at about 1:39 p.m. CST on Nov. 14. The cause of the boom is still unknown. (credit: NASA)" From <a href="http://denver.cbslocal.com/2017/11/21/mysterious-booms-heard-in-colorado/" rel="nofollow noreferrer">here</a>.</p>

<p><img src="https://i.sstatic.net/EkLp3.jpg" alt="enter image description here"></p>

<p><strong>above:</strong> "(credit: USGS and CBS)" From <a href="http://denver.cbslocal.com/2017/11/21/mysterious-booms-heard-in-colorado/" rel="nofollow noreferrer">here</a>.</p>

CC BY-SA 3.0
2017-11-25T17:43:21.657Z
the first graph being infrasound seems to be a valid assumption. The sampling rate given in the header is 40 sps (40 Hz), which means the Nyquist frequency (the maximum frequency that can be properly recovered) is 20 Hz, which is the upper end of the infrasound range
ye-ti-800
CC BY-SA 3.0
2017-11-26T04:38:56.943Z
@ye-ti-800 I'm guessing that the high-frequency cut-off for seismic data might also be around there as well, so I don't really assume either way.
uhoh
CC BY-SA 3.0
2017-11-26T13:29:39.760Z
yea that's right of course. Seems like there is a seismometer station called US.LRAL in Alabama. Has the right frequency range, too... http://anf.ucsd.edu/stations/US/LRAL
ye-ti-800
CC BY-SA 3.0
2017-11-26T15:07:40.627Z
@ye-ti-800 typing "infrasound" into this search http://anf.ucsd.edu/search/ it looks like most/all seismic stations also have infrasound sensors as well. See for example http://www.usarray.org/researchers/obs/transportable/atmospheric Also found this https://ucsd.tv/search-details.aspx?showID=24911
uhoh
CC BY-SA 3.0
2017-11-26T15:27:36.620Z
right, but for this particular station the website only lists a seismic sensor. Since for other stations other sensors are listed as well, that might be a clue?
ye-ti-800
CC BY-SA 3.0
2017-11-26T15:31:43.757Z
also: for the infrasound measurements they seem to have different channel codes. BHZ only occurs with the seismic stations. Might be specific nomenclature for seismic data acquisition http://scedc.caltech.edu/station/seed.html
ye-ti-800
CC BY-SA 4.0
2021-03-12T14:39:10.593Z
I've just asked in Astronomy SE: [How do they know the TNT equivalent of the meteor explosion over Vermont?](https://astronomy.stackexchange.com/q/41919/7982)
uhoh
<atmosphere><measurements>
Was the "'Bama Boom" even recorded by infrasound or by seismic detectors?
uhoh
# Was the "'Bama Boom" even recorded by infrasound or by seismic detectors?

(Asked by: username_0 on 2017-11-24)

The 'Bama Boom ('Bama is short for the US state of Alabama) is a term for some audible "booms" heard by many people in Alabama and now in Colorado. See for example the Popular Mechanics article [Mysterious, Powerful "Boom" Shakes Alabama](http://www.popularmechanics.com/military/aviation/a13728147/mysterious-powerful-boom-shakes-alabama/) and the Tech Times' [Mysterious Booms Heard In Colorado Leave Residents Baffled](http://www.techtimes.com/articles/216026/20171124/mysterious-booms-heard-in-colorado-leave-residents-baffled.htm).

*In this question I'm just asking about the measurements shown below from the CBS Denver News item [Mysterious Booms Around World Now Heard In Colorado](http://denver.cbslocal.com/2017/11/21/mysterious-booms-heard-in-colorado/)*, not about the "booms" themselves.

The second plot states it's a seismogram, but I can't tell what the first one likely represents. Could this be an [infrasound](https://en.wikipedia.org/wiki/Infrasound) measurement? The caption says that it's a "sound graph" but that's not necessarily a technical term.

![enter image description here](https://i.sstatic.net/4a8EH.png)

**above:** "A sound graph from the USGS Lakeview Retreat near Centreville, Ala., shows a loud boom heard over Alabama at about 1:39 p.m. CST on Nov. 14. The cause of the boom is still unknown. (credit: NASA)" From [here](http://denver.cbslocal.com/2017/11/21/mysterious-booms-heard-in-colorado/).

![enter image description here](https://i.sstatic.net/EkLp3.jpg)

**above:** "(credit: USGS and CBS)" From [here](http://denver.cbslocal.com/2017/11/21/mysterious-booms-heard-in-colorado/).

**Tags:** atmosphere, measurements

> **Comments:**
> **username_1**: the first graph being infrasound seems to be a valid assumption. The sampling rate given in the header is 40 sps (40 Hz), which means the Nyquist frequency (the maximum frequency that can be properly recovered) is 20 Hz, which is the upper end of the infrasound range  
> **username_0**: @username_1 I'm guessing that the high-frequency cut-off for seismic data might also be around there as well, so I don't really assume either way.  
> **username_1**: yea that's right of course. Seems like there is a seismometer station called US.LRAL in Alabama. Has the right frequency range, too... http://anf.ucsd.edu/stations/US/LRAL  
> **username_0**: @username_1 typing "infrasound" into this search http://anf.ucsd.edu/search/ it looks like most/all seismic stations also have infrasound sensors as well. See for example http://www.usarray.org/researchers/obs/transportable/atmospheric Also found this https://ucsd.tv/search-details.aspx?showID=24911  
> **username_1**: right, but for this particular station the website only lists a seismic sensor. Since for other stations other sensors are listed as well, that might be a clue?  
> **username_1**: also: for the infrasound measurements they seem to have different channel codes. BHZ only occurs with the seismic stations. Might be specific nomenclature for seismic data acquisition http://scedc.caltech.edu/station/seed.html  
> **username_0**: I've just asked in Astronomy SE: [How do they know the TNT equivalent of the meteor explosion over Vermont?](https://astronomy.stackexchange.com/q/41919/7982)  

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## 0 answers

