Bomb detonation detection

Hi. I am in the process of building an outdoor environmental sensor. One of the features I want to add, mostly for fun, is the capability to monitor for and report the incidence of explosives detonation. I happen to live near a military installation. Also one of the locations I plan to place one of my sensors is at my summer home which is also near a military installation. Generally the sounds of the explosions are pretty evident. I would like to put some type of sensor on my device that will report the incidence and intensity of the explosions.

My initial thought would be to find a sensor for detecting the sound waves and then doing some sort of Fourier transformation to seperate the frequencies and then through manual calibration pick out the frequencies that seem to coorespond to the activities. Another thought was around some type of vibration sensor. Or some combination of the two.

As mentioned this is basically just a "fun" piece of my project that does not have to be super accurate. However I would like it to be accurate enough to track things that I may not be able to hear easily.

Does anyone have suggestions on sensors or on projects that I may be able to reference that have done something similar ?

Seismic (ground vibrations) will be much better for detecting explosions. A loud noise nearby is very difficult to discriminate from an explosion at a distance. Plant the detector in a part of the garden that you (and your neighbours) don't usually walk and you should be able to detect many explosions.

Bury a cheap microphone a few feet down and see what you get.

MorganS:
Seismic (ground vibrations) will be much better for detecting explosions.

Are their any recommended sensors I might take a look at ? From searching around it looks like a 3-axis accelerometer might be a good starting point.