Sensitive reactive targets

[Jerry]

Yeah, from the hole left behind probably a hundred tons of topsoil was blasted in the air. And it takes a serious explosive to set off ammonium nitrate that was probably just sitting in bags with nothing like diesel mixed in like it is normally used.

[Doug Coulter]

If you look at say, Wikipedia on ammonium nitrate disasters, it seems you can in fact get it going with a big enough fire that lasts a long time. Perhaps it helps if some fuel drops into the hot AN, I'd suspect so. Like nitroglycerin or a number of other explosives, all the right stuff is there in just one chemical, once things get going with a detonation wave. NH4NO3 - the N's get back together - that's highly exothermic and a significant energy contribution in pretty much all HE (that is N based), and you have O and H left over...which will do the usual thing they do. It's very hard to get started, even when you do have the fuel oil, or Al or other fuel, but in large enough volume, and hot enough...
There was an especially nasty one in a Texas harbor just post WWII....There is lots of footage on youtube on unintentional AN explosions.

Unlike deliberate explosive use of this stuff, these are always preceded by huge fires that get everyone's attention and get these on film/video.

The thing is, I've blown a lot of test things up here, and when the explosive is on top of the dirt - the dirt it throws goes sideways, not primarily straight up, like that cloud - that just about had to be stuff that was either in the mix, or on top of the explosive. And NO isn't opaque at all- it's more like a color filter than some suspension, and that's what I see in poor low order detonations of AN here. So that looked a bit weird. Nice pic of nitric oxide here -
(slow heating of AN gives nitrous oxide instead - chemical reactions usually have more than one pathway).
https://www.youtube.com/watch?v=CqzrTxshOXM

Somehow I see a difference in shade.
The army did some buried - and got that opaque look: (different color soil) https://www.youtube.com/watch?v=084GndZlew8


No one is mentioning the Beirut stuff was buried. Haven't checked the color of the dirt there myself, it's probalby in some post boom footage. Note in the army test that any NO isn't obvious, and other than the HE they used to set it off, it's just
AN in bags.

Maybe silly, but some attention to observational detail often leads to better knowledge of what really happened.