20 ms·

Order of magnitude estimate of Beirut explosion at 3 kilotons of TNT

258 points by sinab 6y ago

deleted 6y ago
[deleted]
animal_spirits 6y ago
I am awestruck. What an awful event. I will be keeping up to date with this and looking for ways I can help... All I know to do right now is pray for those that have suffered from this. My breath has been taken away...
sio8ohPi 6y ago
Similar in size to the Halifax explosion, then. https://en.wikipedia.org/wiki/Halifax_Explosion https://en.wikipedia.org/wiki/Halifax_Explosion
- skim_milk 6y ago
  Wow, and for comparison the viral 2015 Tianjin explosions in total released 28 tonnes of TNT of energy, or 100GJ.
  - sparker72678 6y ago
    https://en.wikipedia.org/wiki/2015_Tianjin_explosions https://en.wikipedia.org/wiki/2015_Tianjin_explosions notes "336 tons TNT equivalent."
    - mrep 6y ago
      A single m87 thermonuclear warhead has a detonation yeild of 300 tons of tnt, and a single ICBM can carry up to 10 of those. Absolutely terrifying.
      - sparker72678 6y ago
        Yes, utterly horrifying on those points alone, to say nothing of the added destruction that air blast and supersonic shockwaves will do, even before you get to radiation.
- eddytrex_ 6y ago
  Sixty Symbols video: https://youtu.be/u5uTAt_A8BY https://youtu.be/u5uTAt_A8BY Very sad indeed.
- t-writescode 6y ago
  So .... some discussion in this thread suggests that the Halifax explosion was still 10x the size of this one... ish. just in case you don't end up seeing that part of the post from other people.
- Nimitz14 6y ago
  It should be obvious that it's more like 10 times smaller than Halifax, otherwise we wouldn't have gotten half the footage we are seeing right now, those people would be dead.
aaron695 6y ago
The media doesn't seem to understand how big this is yet in short and long term damage and loss of life. I guess that doesn't matter? They are more for political bickering now? Running theory Ammonium Nitrate stored at port for many years - https://mobile.twitter.com/HachemYassin/status/1290702640930791424 https://mobile.twitter.com/HachemYassin/status/1290702640930... [Edit] Skipping the loss of grain and produce in port and the actual port in a country on the brink during a pandemic this isn't just 50 dead short term https://mobile.twitter.com/asharfouch/status/1290714104575848448 https://mobile.twitter.com/asharfouch/status/129071410457584...
- netsharc 6y ago
  What's with "Media"-blaming nowadays, it seems every Tom and Dick expects them to say/do in-depth analysis of everything Tom or Dick wants... At least the main media I read gets it, e.g.: https://www.theguardian.com/world/live/2020/aug/04/beirut-explosion-huge-blast-port-lebanon-capital?page=with:block-5f29c1b58f089d9b758a6bb4#block-5f29c1b58f089d9b758a6bb4 https://www.theguardian.com/world/live/2020/aug/04/beirut-ex... On a slight positive side, at least this explosion will mean the rulers of that country can now ask for help without losing face/admitting their failures/corruption...
  - aaron695 6y ago
    It's buried when I go to the Guardians homepage. Might be localised though. This is real news. I expect it to be easy to see. Not a doomscrolling meaningless repeat of the C19 countdown for the day.
    - netsharc 6y ago
      See, again with the expectations. If every big event requires a link to in-depth analysis on the front page of a news site, they'd need to have a small font size and a 16K monitor... And you'd complain that it's not in the corner you looked.
      - aaron695 6y ago
contravariant 6y ago
Unless I'm missing something they forgot to account for the fact that dimensional analysis will only give you a result up to a constant. This should be somewhat obvious as otherwise you'd get a different result with different units (and no SI units won't save you here, those just work for several common equations in physics not ones you came up with yourself).
- johnbcoughlin 6y ago
  it's not really dimensional analysis. the same methodology was used to estimate the Trinity blast.
  - vladTheInhaler 6y ago
    IIRC dimensional analysis lets you put constraints on the form of the equation, by requiring that the variables form dimensionless groups. But you still have to include the right variables, and then measure the values of those dimensionless quantities under different conditions (for instance the Reynolds number for different velocities or length scales) to figure out how the groups scale relative to one another. But I'm sure that data already exists for the situation in question. It would just be a matter of estimating the values from the video and dropping them into the equation.
  - contravariant 6y ago
    It is dimensional analysis provided you can justify that the constant should approximately be 1. This is what G. I. Taylor did for the fireball of the trinity test. And apparently it does end up being close to 1. I do worry about the accuracy of this a bit, but looks like it could in theory work.
- sinab 6y ago
  The underlying assumption in this analysis is that the constant is 1. Maybe I should have clarified that in the thread.. Thank you for pointing it out!
  - contravariant 6y ago
privateuser1981 6y ago
At max 0.2K TNT
- AnimalMuppet 6y ago
  What is your evidence or logic for claiming so? Just a bare claim is not very convincing.
  - privateuser1981 6y ago
    This was the aftermath of 15 kilotons: https://upload.wikimedia.org/wikipedia/commons/a/a0/Hiroshima_aftermath.jpg https://upload.wikimedia.org/wikipedia/commons/a/a0/Hiroshim... Despite 2750T of ammonium nitrate the yield of explosion was around 0.2-0.3KT TNT
credit_guy 6y ago
Wikipedia's page of the largest non-nuclear explosions [1] was already updated and states "It generated a shock-waves equivalent to 13 tonnes TNT". Not sure who made this estimation and how, but various photos on that page can give you an idea what a large explosion looks like. For example take a look at the Yamato explosion [2]. Yamato was a 70000 ton Japanese battleship; the large explosion was due to its magazines being hit by bombs (this happened quite frequently when battleships were hit as they were fundamentally stacks and stacks of gun ammunition surrounded by a hull); it's likely that Yamato was carrying a few thousand tons of explosives, so that's how you get a few kt TNT non-nuclear explosion. Now in that photo you can see for reference another ship in the lower left. It looks quite puny. So, it appears to me the Yamato mushroom cloud was much, much bigger than today's mushroom cloud in Beirut. Edit: The wikipedia page was updated and now states 1kt TNT. [1] https://en.wikipedia.org/wiki/Largest_artificial_non-nuclear_explosions https://en.wikipedia.org/wiki/Largest_artificial_non-nuclear... [2] https://en.wikipedia.org/wiki/Largest_artificial_non-nuclear_explosions#/media/File:Explosion_of_the_Japanese_battleship_Yamato,_on_7_April_1945_(NH_62582).jpg https://en.wikipedia.org/wiki/Largest_artificial_non-nuclear...
- Aerroon 6y ago
  The ship you can see in the bottom left of the Yamato's explosion (link [2]) is a Japanese destroyer. I'm not sure which ship it is specifically, but she is likely 100-130 meters in length (those were the only ones around at the time Yamato sank). And she's closer than the actual cloud.
  - jcranmer 6y ago
    Another fun note about Yamato's explosion is that it appears to have been responsible for more plane losses than all of the AA fire during the battle. For a battleship with well over 100 AA guns, that's a pretty damning indictment of their quality.
    - forgot_account 6y ago
      One of my favorite YT naval historians, Drachinifel, constantly derides the Japanese 25mm AA gun, which was based on a French design. One of his longer podcasts (in the Drydock series) has a segment explaining the technical details of why.
einarfd 6y ago
Al Jazeera is reporting that according to the president in Lebanon, it was almost three thousand tons of ammonium nitrate that blew up https://www.aljazeera.com/news/2020/08/huge-explosion-rocks-lebanon-capital-beirut-live-updates-200804163620414.html https://www.aljazeera.com/news/2020/08/huge-explosion-rocks-... .
- nodesocket 6y ago
  It's hard to imagine, but that would mean this explosion was nearly 3.5x larger than 2015 Tianjin[1] which was 800 tonnes of ammonium nitrate (336 tons TNT equivalent). The video[2] from Tianjin looked way bigger and apocalyptic, but perhaps just because of the the fireball. [1] https://en.wikipedia.org/wiki/2015_Tianjin_explosions https://en.wikipedia.org/wiki/2015_Tianjin_explosions [2] https://www.youtube.com/watch?v=ONsmJAyFAAw https://www.youtube.com/watch?v=ONsmJAyFAAw
  - hn_throwaway_99 6y ago
    Yeah, honestly, the Beirut explosion looked bigger/scarier to me, like how they show nuclear explosions in the movies. The Tianjin explosion was an enormous fireball but didn't seem to have the same magnitude of shockwave from the videos I've seen of it.
    - actuator 6y ago
      From the videos I have seen the Tianjin fireball seemed to rage even for a longer duration. In the Beirut one maybe because of daylight, fire is not visible after the big blast. I wonder what would cause that difference, the Beirut one supposedly had more material as well.
      - aaomidi 6y ago
        Longer fire = less energy for explosion?
        6y ago
Leherenn 6y ago
A comparable explosion happened in Toulouse, France, in 2001, estimated at 20-40 tons of TNT. It was also some nitrate storage that blew up. Similar end result, pretty much everything window in the city was blown away, and most of the injuries were caused by broken glass.
- cm2187 6y ago
  Was watching some reporting from that explosion, and it starts with teachers being on strike when the explosion occurred. So French... https://www.youtube.com/watch?v=TioM7N0y8Co https://www.youtube.com/watch?v=TioM7N0y8Co
jungletime 6y ago
Lebanon has its share of enemies, internal and external. All it would take is a mavic inspire drone to fly over and drop the initial explosive. Trump said "it looks like a terrible attack" at his news conference. Which is probably what his intelligence officers/advisors speculated when they briefed him.
- ClumsyPilot 6y ago
  This speculation is silly, uninformed and unhelpfull. There was a primary fire of fireworks, you dont need to invent conspiracy. Besides one does not need a drone to start a fire in an unattended warehouse.
- Chris2048 6y ago
  > Which is probably what his intelligence officers/advisors speculated when they briefed him because Trump would never go off-script and speculate on his own?..
  - jungletime 6y ago
    That's possible for sure. But why do you assume that Trump made it up? Have you ever gone to hairdresser, asked for a haircut, and the hairdresser only took one snip, and asked for money? No, it doesn't happen. You know why, because people tend to justify their jobs. I'm betting at least one of his Intel officers, would be suspicious of almost nuclear level yield blast.
emeraldd 6y ago
When they started talking about ammonium nitrate, my first thought was of this: https://en.wikipedia.org/wiki/West_Fertilizer_Company_explosion https://en.wikipedia.org/wiki/West_Fertilizer_Company_explos... and the possibility of a shipment of fertilizer somehow getting caught in a fire ...
- azepoi 6y ago
  Toulouse AZF comes to mind List of Ammonium nitrate disasters https://en.m.wikipedia.org/wiki/Ammonium_nitrate_disasters https://en.m.wikipedia.org/wiki/Ammonium_nitrate_disasters
- coldcode 6y ago
  When I first saw the initial video, I immediately assumed a nitrate explosion. A bomb that large would be too hard to place or even deliver (if a plane), and fireworks would not explode with a such a perfect shockwave. The red color of the original smoke is rather telling as well and that it occurred in a dockyard.
aaron695 6y ago
I should just pre-flag this comment, so feel free. But Hezbollah use Ammonium Nitrate and could use the other small explosives stored near by. I think under current rules being actioned if there was intel people were stealing from the factory it would be considered a legitimate target. The question would be, would the analysis of intel be good enough to know exactly what was stored there and if it is clearly not an appropriate target. And I think their analysis would suck. If you want a source, the President of the United States said it was an attack. So we either believe official statements or we should learn to think for ourselves. Equally arson or a fire due to lack of security and maintenance due to coronavirus stress.
- rsynnott 6y ago
  > So we either believe official statements The closest to an official statement (US dept of defence officials to media) is that it is not thought to be an attack, Donald’s ex-cathedra ramblings notwithstanding. Nasty accidents at fertiliser plants are unfortunately somewhat common; they dominate the list of largest non-nuclear explosions. Also, why would you steal fertiliser from a fertiliser factory? Traditionally, I’m fairly sure people just BUY it if they want to make a bomb.
  - lazyjones 6y ago
    > The closest to an official statement (US dept of defence officials to media) Where is this press release from the US Dept. of Defence? Or are you talking about the mysterious "three unnamed defence officials" CNN wrote about in an article?
- fanatic2pope 6y ago
  > the President of the United States said it was an attack Meaningless. If Trump said the sky was blue, you'd be well advised to go outside and make sure.
  - vimy 6y ago
    He does have a habit of revealing highly sensitive national security information. https://www.youtube.com/watch?v=IYX9nyr7rng https://www.youtube.com/watch?v=IYX9nyr7rng
shadowprofile77 6y ago
Nitpicking here maybe but this does not look like a 3 kiloton blast to me. Neither the size of the core explosion or the apparent shock wave damage correspond to that magnitude from a surface blast. Guessing here but I'd say closer to 2 kilotons at most. Amazingly, the massive, hollow grain silo right next to the detonation itself remained standing afterwards.
- dfee 6y ago
  Uh, who are you? I don’t have the eye for the difference between 2 and 3 kiloton blasts. Maybe I’m the exception to the rule, but I don’t think so.
- IAmGraydon 6y ago
  It’s not a 3kt blast. Not even close.
  - shadowprofile77 6y ago
    I posit that it's definitely above 1 kiloton though. I base this on the radius of damage it caused (from photos compared to Google satellite images of the area around the explosion site) and by comparing the explosion's apparent magnitude with that of the PEPCON blast, which was fairly carefully estimated to have been roughly 1 kiloton. This blast looks bigger and spread its impact further than the PEPCON blast..
- flywheel 6y ago
  Amazing how nerds can be so focused on if it was 1 kiloton, 2 kilotons, or 3 kilotons - and they are arguing about it like it really matters.
  - shadowprofile77 6y ago
    This whole thread is full of debate about diverse details about this event and things related to it, so yeah, it's perfectly normal to debate claims like a headline's subject, Nobody thinks it literally matters too much, They do it out of intellectual curiosity.. It's not just a "nerd" thing.
kgm 6y ago
I am seeing other analyses that put the size of the explosion at about one tenth of this size. The analysis in this Twitter thread correlates the observed degree of damage with the distance from the explosion. It comes up with an estimated 240 tons TNT-equivalent, though naturally this comes with a considerable margin of error. https://twitter.com/GeorgeWHerbert/status/1290719719545159680 https://twitter.com/GeorgeWHerbert/status/129071971954515968... This Twitter thread is making the point that the explosiveness of ammonium nitrate can vary significantly depending on how it is stored. 2750 tons of AN at 20% efficiency gives 550 tons TNT. https://twitter.com/ArmsControlWonk/status/1290795532701425664 https://twitter.com/ArmsControlWonk/status/12907955327014256... This range is also apparently consistent with the explosion registering as a 3.5 seismic magnitude. https://twitter.com/ArmsControlWonk/status/1290734850769526784 https://twitter.com/ArmsControlWonk/status/12907348507695267... There are still a great many unknowns, and none of this should be mistaken for the real analysis which will come later, but these disparate sources of information all seem to agree with each other, to a first approximation.
- WalterBright 6y ago
  My fluid mechanics prof told the class that a scientist in the 1940's published the yield of the Hiroshima bomb. Since this was top secret, he got investigated. But he showed how the yield could be calculated from the film of the explosion - how fast the blast radius expanded. So I imagine the yield of the Beirut explosion could be calculated the same way from the video.
  - selimthegrim 6y ago
    It was G.I. Taylor.
    - tigerlily 6y ago
      Using the Buckingham Pi theorem.
      - hanche 6y ago
guerrilla 6y ago
> The cause of the explosion was not immediately clear. Officials linked the explosion to some 2,700 tonnes of confiscated ammonium nitrate that were being stored in a warehouse at the port for six years. https://www.aljazeera.com/news/2020/08/huge-explosion-rocks-lebanon-capital-beirut-live-updates-200804163620414.html https://www.aljazeera.com/news/2020/08/huge-explosion-rocks-...
stevespang 6y ago
Remember tannerite, the stuff you can buy at Academy or any gun shop to shoot as an explosive target ? It's ammonium nitrate fertilizer - - hopped up by mixing it with a little aluminum powder This guy loaded up his old rider lawn mower with it and shot it from only 43 feet away, see what happened . . . https://youtu.be/S6V0S1m5a7U?t=26 https://youtu.be/S6V0S1m5a7U?t=26
golemiprague 6y ago
what was the white ball during the explosion? it looks like some liquid spraying up in the shape of a ball, was it sea water? other liquid? or was it just looking to me like a liquid but actually was gas of something?
- zaarn 6y ago
  The white ball is water vapor that condenses into a cloud around the explosion as the shockwave passes through the air. Specifically it's the low-pressure area that comes after the initial shockwave, the rapid decrease in pressure causes water (and any other volatiles) to condense out.
- a_e_k 6y ago
  A Wilson cloud: https://en.wikipedia.org/wiki/Wilson_cloud https://en.wikipedia.org/wiki/Wilson_cloud
tzs 6y ago
This video [1] from The Guardian include the same video in that tweet, but also has a few other angles which gives a better appreciation of how big that thing was. [1] https://www.youtube.com/watch?v=93tV6-0Ugwk https://www.youtube.com/watch?v=93tV6-0Ugwk
- dylan604 6y ago
  I had only seen the headlines about this, but had not investigated anything until seeing this video. That's a much larger explosion than I was expecting.
  - zimpenfish 6y ago
    Yeah, I was taken aback when I saw the video because I thought the initial smoke plume was the aftermath of the explosion. Then it went off and bloody hell.
- look_lookatme 6y ago
  This video is the one that made me gasp the hardest: https://twitter.com/FadyRoumieh/status/1290670721488900096 https://twitter.com/FadyRoumieh/status/1290670721488900096 Something about the distance and the fact that it's on water puts everything into stark relief.
  - mmerlin 6y ago
    also the 2nd video here: https://t.co/BRezMWT5IV https://t.co/BRezMWT5IV
  - 9nGQluzmnq3M 6y ago
    The interesting part about the explosion in the video is that there's two clouds: first the rapidly expanding almost perfectly spherical white puff, and then the slower dark black mushroom cloud. I vaguely recall the first is mostly water vapor that suddenly condenses out of the air because of the massive shockwave, while the second is the 'actual' explosion and its byproducts being shot up into the air. Any physicists out there care to set me straight?
KMag 6y ago
Note that the distinctive orange color is probably a large volume of nitrogen dioxide at pretty high concentration. If it was an ammonium nitrate explosion, the orange cloud supports the idea it was accidental. The explosion would have been easier to set off and more powerful had there been a fuel (or more fuel) mixed with the ammonium nitrate.
- IAmGraydon 6y ago
  Why do you think that the release of NO2 makes it an accident? Nitrate based high explosives only release NO2 during an actual high-order detonation. Ammonium nitrate does this with or without sensitizers such as fuel oil.
  - KMag 6y ago
    A mixture close to a neutral oxygen balance (stochiometric mixture) would consume much of the N02 and have a much less brilliantly orange plume. Though, point taken that sensitization happens much before reaching a neutral oxygen balance.
  - jandrewrogers 6y ago
    This is definitely not the case. NO2 release is characteristic of spontaneous decomposition of nitrates, which can happen under a wide variety of conditions that have nothing to do with detonation. I’ve had the misfortune of seeing this happen once in a lab, due to a rookie mistake. It usually is the harbinger of a runaway exothermic reaction. There is nothing surprising here if ammonium nitrate is the primary suspect. In the specific case of bulk ammonium nitrate, it has a low melting point (relative to a fire) and it starts to become quite unstable in that phase. The low risk of AN is premised on it being stored in a relatively clean, non-reactive environment. Fuel oil generally isn’t considered a sensitizer for AN, you still need a booster, it compensates for the oxygen richness which improves efficiency. There are a bunch of nitrogen organics and metals, which I won’t list here, that will sensitize AN quite effectively but those aren’t implicated here. Most fires with AN are caused by its reactivity. It will readily combine with other chemicals in the environment to produce compounds that are far more unstable than AN. These byproducts often act as the ignition point that ultimately causes the AN to detonate.
sytelus 6y ago
Just in case people are wondering reason this explosion: there was 2,750 tonnes of ammonium nitrate stored without safety measures in a warehouse that went off.
sillysaurusx 6y ago
@quantian1 correctly determined that this was an ammonium nitrate blast by analyzing the footage: https://twitter.com/quantian1/status/1290695231910875136 https://twitter.com/quantian1/status/1290695231910875136 CHEMISTRY FACT: Explosives have characteristic "detonation velocities" at which shockwaves expand. Smartphone video records at 30 FPS, so the adjacent frames here suggest the front expands at ~100 m/(1/30 sec), or 3,000 m/sec. Consistent with ammonium nitrate, not black powder. This was confirmed a few hours later: https://twitter.com/BBCBreaking/status/1290758551737192455 https://twitter.com/BBCBreaking/status/1290758551737192455 Lebanese president blames 2,750 tonnes of ammonium nitrate left in warehouse unchecked for six years for devastating Beirut blast EDIT: By the way, one of my friends was almost killed by the explosion. Thankfully they're ok. But they said: https://twitter.com/cyrilzakka/status/1290766217989500928 https://twitter.com/cyrilzakka/status/1290766217989500928 This was terrifying to experience. Hospitals are being overrun with injured people. We need blood donations and disaster relief. Help however you can. As a US citizen, is there any way I can help directly? Is there any organization that ships blood donations directly to a disaster site? I suppose that would be very difficult, so the answer is probably no; it's frustrating not being able to assist.
- chmod775 6y ago
  Some chemist acquaintances of mine suggested the same from just looking at the footage immediately after. Along with some scary explanations of what fast shockwaves like that do to human blood vessels. I was convinced this stuff should be outlawed for most uses pretty fast. https://en.wikipedia.org/wiki/Ammonium_nitrate_disasters https://en.wikipedia.org/wiki/Ammonium_nitrate_disasters Though on the other hand, the number of incidents and deaths aren't that high considering how prevalent it is. It's just that a critical failure of handling that stuff is quite spectacularly bad.
  - 082349872349872 6y ago
    What do you recommend using for fertiliser in its place? (I'm sure someone's thought about this idea before. Timothy McVeigh did his mad bombing with typical rural materiel. Not so fun fact: the VBIED predates the internal combustion engine.)
supernova87a 6y ago
The amount of material must have been ridiculous to store in such a place. The blast is staggering in size, almost like the Tianjin explosion a few years ago. Collected videos: Angle #1 https://streamable.com/xmmoa7 https://streamable.com/xmmoa7 Angle #2 https://streamable.com/nscx9m https://streamable.com/nscx9m Angle #3 https://streamable.com/zbjj5f https://streamable.com/zbjj5f Angle #4 https://streamable.com/saoafz https://streamable.com/saoafz Angle #5 https://streamable.com/4ga1vb https://streamable.com/4ga1vb Angle #6 https://streamable.com/lmivb2 https://streamable.com/lmivb2 Angle #7 https://streamable.com/mcy82f https://streamable.com/mcy82f Angle #8 https://streamable.com/zg9oal https://streamable.com/zg9oal Angle #9 https://streamable.com/zykkj6 https://streamable.com/zykkj6 Angle #10 https://streamable.com/22e152 https://streamable.com/22e152
- sozy777 6y ago
  http://washingtonindependent.com/large-explosion-in-beirut-lebanon-2020-08-04/ http://washingtonindependent.com/large-explosion-in-beirut-l... Many angles here as well
- 5m17h 6y ago
  The Tianjin explosion has been in the impression that many Chinese people have forgotten
- markdown 6y ago
  > The amount of material must have been ridiculous to store in such a place. This is a photo supposedly of the warehouse: https://imgbb.com/r4Q64xc https://imgbb.com/r4Q64xc
- yxhuvud 6y ago
  Roughly twice the amount exploded compared to Tianjin, actually. 2750 tonnes of ammonium nitrate compared to 800 tonnes of ammonium nitrates and 600 tonnes of potassium nitrate in Tianjin. So yes, quite ridiculous.
  - velox_io 6y ago
    What strikes me as odd (aside from the massive shockwave), is how there were no fireballs, all other fertilizer fires have bright explosions. It's burnt rather than detonated. Here, all of the fertilizer ignited faster than the speed of sound (resulting in a virtually perfect spherical shockwave). Although the shockwave could have doused any flames, so that idea is plausible.. The other anomaly is the deep red smoke, that's something that seems unusual too (aside from storing so much fertilizer in such a built up area for so long). This is a disaster on so many levels, but then when is a disaster only caused by a single issue?
jonplackett 6y ago
This is insane, this is tactical nuclear weapon size explosion right? I think they start at under 1kt up to about 10kt (not saying it is one, just for comparison of how insanely massive this explosion is)
ashtonkem 6y ago
This seems unlikely. Officially, they had 2750 tones of ammonium nitrate on that dock. Even if it were properly mixed with fuel oil to make ANFO, that would give you 2200 tones of tnt equivalent. It is quite unlikely that it was mixed to the perfect proportions, so we’d expect actual yield to be below theoretical max So unless if something else was involved (or the official amount of ammonium nitrate was wrong) I would expect the final blast to be under 2kt.
- totalZero 6y ago
  There are plenty of petroleum distillates in a dockyard. Diesel, bunker fuel, kerosene, gasoline....not to mention other flammable hydrocarbons and powders. You're assuming an 80% ratio ANFO/TNT but you're neglecting the mass of the FO, as well as the possibility of other oxidizers being stored near the blast site. I guess you could make some assumptions about the fuel based on detonation velocity as observed on video.
  - ashtonkem 6y ago
    Properly mixed ANFO doesn't contain a huge amount of FO; ideally it's supposed to be 6% by mass. Good enough for a quick HN estimate, although I'd hope an actual after action report does better. A better calculation is that 2750 tonnes of AN would yield 2864 tonnes of ANFO, which is 2,291 tonnes of TNT equivalent. However, we know that the explosion wasn't stoichiometrically perfect, because of the brown NO2 clouds that were hanging over Beirut. Properly mixed ANFO should release only H2O, CO2, and N2. So we know that there was some level of explosive power that wasn't fully consumed. This is why I put the ANFO yield as the absolute theoretical max, I think in reality the actual yield was much much lower. Some other people have speculated that the fireworks like mini explosions between the first and second big explosions was actually ammonium nitrate decomposing, which would imply that this was a pure ammonium nitrate explosion and not one accelerated by some sort of oil or other fuel. If that's true, various manufacturers give the AN to TNT equivalent of poorly handled AN at 15-40% of TNT, giving a yield somewhere in the 412-1,100 tonne range.
    - 6y ago
aunetx 6y ago
This reminds me a lot about AZF, a chemical explosion that happened in Toulouse, France back in 2001 [1]... And it was hundred of tons of ammonium nitrate here too. [1] https://en.wikipedia.org/wiki/Toulouse_chemical_factory_explosion https://en.wikipedia.org/wiki/Toulouse_chemical_factory_expl...
SDJ100 6y ago
According to my estimate the Beirut explosion was about one quarter the explosive force of the Hiroshima bomb. Does anyone concur with this?
SDJ100 6y ago
I estimate the Beirut explosion was one quarter the explosive force of the Hiroshima bomb. Does anyone concur?
agumonkey 6y ago
What are the pollution consequences of this (if any) ?
- est31 6y ago
  Dust pollution has turned out to be quite significant in the 9/11 aftermath, causing cancer in thousands of people. > As of August 2013, medical authorities concluded that 1,140 people who worked, lived, or studied in Lower Manhattan at the time of the attack have been diagnosed with cancer as a result of "exposure to toxins at Ground Zero". It has been reported that over 1,400 9/11 rescue workers who responded to the scene in the days and months after the attacks have since died. https://en.wikipedia.org/wiki/Casualties_of_the_September_11_attacks https://en.wikipedia.org/wiki/Casualties_of_the_September_11... The pictures of Beirut seemed quite dusty, reminiscent of the 9/11 pictures. Beirut 2020: https://streamable.com/22e152 https://streamable.com/22e152 NYC 2001: https://i.imgur.com/jfLUAiK.jpeg https://i.imgur.com/jfLUAiK.jpeg
  - agumonkey 6y ago
    good point but beirut is not the same dust, for better or worse
J0_k3r 6y ago
you're being downvoted because hn is filled with silicon valley cucks and orange man bad
lma21 6y ago
I have family and friends living in Lebanon. The explosion destroyed the windows of most homes in Beirut. Apartments of my family, friends, and colleagues have been shattered. Even the ones living dozens of kilometers away from Beirut. It's horrible, what pure incompetence can do to a people already living in poverty and under the covid-stress. I hope something good comes out of this...
- mekster 6y ago
  What good do you expect out of this mess? Like, some other location fixed their storage strategy to avoid same fate?
  - lma21 6y ago
    Change the whole governmental bodies. Build a new constitution. Hold new elections. Create a government that acts and builds, not one that talks and promises. Something that can lift this poor, small, desperate country out of its misery. I'm hoping for such changes...
    - WaxedLekku 6y ago
      Tear down and build a new state? Sounds like the recipe for a war
bluenose69 6y ago
The following is a citation for the seminal paper on this matter. G. I. Taylor was a god of fluid mechanics, and quite a lot of his work is available online for free. Taylor, Geoffrey. “The Formation of a Blast Wave by a Very Intense Explosion. - II. The Atomic Explosion of 1945.” Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences 201, no. 1065 (March 22, 1950): 175. https://doi.org/10.1098/rspa.1950.0050 https://doi.org/10.1098/rspa.1950.0050
worldpeacenow 6y ago
Ammonium nitrate is 1.35 less potent than TNT. So this was just over 2,000 tons of TNT blast. The first nuclear bomb ever dropped was 15,000 tons of TNT of force. So this was 13.3% of the force of what Hiroshima experienced. About 70,000 people died from Hiroshima. So 13.3% of Hiroshima force is still devastating. It's probably not going to be nearly as bad as 13.3% of 70,000 deaths because Hiroshima was more densely packed and there wasn't the electromagnetic pulse wave that vaporizes people and long lingering radiation associated with a nuclear bomb. ... Still what happened in Beirut is immensely devastating.
- DreamScatter 6y ago
  An electromagnetic pulse doesn't vaporize people, it mainly affects electronics.
RantyDave 6y ago
No. Because that would imply that ammonium nitrate has a higher specific energy than TNT. Which it doesn't. https://en.wikipedia.org/wiki/Energy_density_Extended_Reference_Table https://en.wikipedia.org/wiki/Energy_density_Extended_Refere...
totalZero 6y ago
I wonder if the shape of the storage receptacle and the geometry of surrounding buildings could have resulted in an elliptical fireball shape. If so, that could be one drawback of this method. Depending on viewing angle, you could overestimate or underestimate the R figure versus a same-energy spherical fireball.

258 points by sinab 6y ago

deleted 6y ago

[deleted]

I am awestruck. What an awful event. I will be keeping up to date with this and looking for ways I can help... All I know to do right now is pray for those that have suffered from this. My breath has been taken away...

sio8ohPi 6y ago

Similar in size to the Halifax explosion, then. https://en.wikipedia.org/wiki/Halifax_Explosion https://en.wikipedia.org/wiki/Halifax_Explosion

skim_milk 6y ago
Wow, and for comparison the viral 2015 Tianjin explosions in total released 28 tonnes of TNT of energy, or 100GJ.
- sparker72678 6y ago
  https://en.wikipedia.org/wiki/2015_Tianjin_explosions https://en.wikipedia.org/wiki/2015_Tianjin_explosions notes "336 tons TNT equivalent."
  - mrep 6y ago
    A single m87 thermonuclear warhead has a detonation yeild of 300 tons of tnt, and a single ICBM can carry up to 10 of those. Absolutely terrifying.
    - sparker72678 6y ago
      Yes, utterly horrifying on those points alone, to say nothing of the added destruction that air blast and supersonic shockwaves will do, even before you get to radiation.
eddytrex_ 6y ago
Sixty Symbols video: https://youtu.be/u5uTAt_A8BY https://youtu.be/u5uTAt_A8BY Very sad indeed.
t-writescode 6y ago
So .... some discussion in this thread suggests that the Halifax explosion was still 10x the size of this one... ish. just in case you don't end up seeing that part of the post from other people.
Nimitz14 6y ago
It should be obvious that it's more like 10 times smaller than Halifax, otherwise we wouldn't have gotten half the footage we are seeing right now, those people would be dead.

aaron695 6y ago

The media doesn't seem to understand how big this is yet in short and long term damage and loss of life. I guess that doesn't matter? They are more for political bickering now? Running theory Ammonium Nitrate stored at port for many years - https://mobile.twitter.com/HachemYassin/status/1290702640930791424 https://mobile.twitter.com/HachemYassin/status/1290702640930... [Edit] Skipping the loss of grain and produce in port and the actual port in a country on the brink during a pandemic this isn't just 50 dead short term https://mobile.twitter.com/asharfouch/status/1290714104575848448 https://mobile.twitter.com/asharfouch/status/129071410457584...

netsharc 6y ago
What's with "Media"-blaming nowadays, it seems every Tom and Dick expects them to say/do in-depth analysis of everything Tom or Dick wants... At least the main media I read gets it, e.g.: https://www.theguardian.com/world/live/2020/aug/04/beirut-explosion-huge-blast-port-lebanon-capital?page=with:block-5f29c1b58f089d9b758a6bb4#block-5f29c1b58f089d9b758a6bb4 https://www.theguardian.com/world/live/2020/aug/04/beirut-ex... On a slight positive side, at least this explosion will mean the rulers of that country can now ask for help without losing face/admitting their failures/corruption...
- aaron695 6y ago
  It's buried when I go to the Guardians homepage. Might be localised though. This is real news. I expect it to be easy to see. Not a doomscrolling meaningless repeat of the C19 countdown for the day.
  - netsharc 6y ago
    See, again with the expectations. If every big event requires a link to in-depth analysis on the front page of a news site, they'd need to have a small font size and a 16K monitor... And you'd complain that it's not in the corner you looked.
    - aaron695 6y ago

contravariant 6y ago

Unless I'm missing something they forgot to account for the fact that dimensional analysis will only give you a result up to a constant. This should be somewhat obvious as otherwise you'd get a different result with different units (and no SI units won't save you here, those just work for several common equations in physics not ones you came up with yourself).

johnbcoughlin 6y ago
it's not really dimensional analysis. the same methodology was used to estimate the Trinity blast.
- vladTheInhaler 6y ago
  IIRC dimensional analysis lets you put constraints on the form of the equation, by requiring that the variables form dimensionless groups. But you still have to include the right variables, and then measure the values of those dimensionless quantities under different conditions (for instance the Reynolds number for different velocities or length scales) to figure out how the groups scale relative to one another. But I'm sure that data already exists for the situation in question. It would just be a matter of estimating the values from the video and dropping them into the equation.
- contravariant 6y ago
  It is dimensional analysis provided you can justify that the constant should approximately be 1. This is what G. I. Taylor did for the fireball of the trinity test. And apparently it does end up being close to 1. I do worry about the accuracy of this a bit, but looks like it could in theory work.
sinab 6y ago
The underlying assumption in this analysis is that the constant is 1. Maybe I should have clarified that in the thread.. Thank you for pointing it out!
- contravariant 6y ago

privateuser1981 6y ago

At max 0.2K TNT

AnimalMuppet 6y ago
What is your evidence or logic for claiming so? Just a bare claim is not very convincing.
- privateuser1981 6y ago
  This was the aftermath of 15 kilotons: https://upload.wikimedia.org/wikipedia/commons/a/a0/Hiroshima_aftermath.jpg https://upload.wikimedia.org/wikipedia/commons/a/a0/Hiroshim... Despite 2750T of ammonium nitrate the yield of explosion was around 0.2-0.3KT TNT

credit_guy 6y ago

Wikipedia's page of the largest non-nuclear explosions [1] was already updated and states "It generated a shock-waves equivalent to 13 tonnes TNT". Not sure who made this estimation and how, but various photos on that page can give you an idea what a large explosion looks like. For example take a look at the Yamato explosion [2]. Yamato was a 70000 ton Japanese battleship; the large explosion was due to its magazines being hit by bombs (this happened quite frequently when battleships were hit as they were fundamentally stacks and stacks of gun ammunition surrounded by a hull); it's likely that Yamato was carrying a few thousand tons of explosives, so that's how you get a few kt TNT non-nuclear explosion. Now in that photo you can see for reference another ship in the lower left. It looks quite puny. So, it appears to me the Yamato mushroom cloud was much, much bigger than today's mushroom cloud in Beirut. Edit: The wikipedia page was updated and now states 1kt TNT. [1] https://en.wikipedia.org/wiki/Largest_artificial_non-nuclear_explosions https://en.wikipedia.org/wiki/Largest_artificial_non-nuclear... [2] https://en.wikipedia.org/wiki/Largest_artificial_non-nuclear_explosions#/media/File:Explosion_of_the_Japanese_battleship_Yamato,_on_7_April_1945_(NH_62582).jpg https://en.wikipedia.org/wiki/Largest_artificial_non-nuclear...

Aerroon 6y ago
The ship you can see in the bottom left of the Yamato's explosion (link [2]) is a Japanese destroyer. I'm not sure which ship it is specifically, but she is likely 100-130 meters in length (those were the only ones around at the time Yamato sank). And she's closer than the actual cloud.
- jcranmer 6y ago
  Another fun note about Yamato's explosion is that it appears to have been responsible for more plane losses than all of the AA fire during the battle. For a battleship with well over 100 AA guns, that's a pretty damning indictment of their quality.
  - forgot_account 6y ago
    One of my favorite YT naval historians, Drachinifel, constantly derides the Japanese 25mm AA gun, which was based on a French design. One of his longer podcasts (in the Drydock series) has a segment explaining the technical details of why.

einarfd 6y ago

Al Jazeera is reporting that according to the president in Lebanon, it was almost three thousand tons of ammonium nitrate that blew up https://www.aljazeera.com/news/2020/08/huge-explosion-rocks-lebanon-capital-beirut-live-updates-200804163620414.html https://www.aljazeera.com/news/2020/08/huge-explosion-rocks-... .

nodesocket 6y ago
It's hard to imagine, but that would mean this explosion was nearly 3.5x larger than 2015 Tianjin[1] which was 800 tonnes of ammonium nitrate (336 tons TNT equivalent). The video[2] from Tianjin looked way bigger and apocalyptic, but perhaps just because of the the fireball. [1] https://en.wikipedia.org/wiki/2015_Tianjin_explosions https://en.wikipedia.org/wiki/2015_Tianjin_explosions [2] https://www.youtube.com/watch?v=ONsmJAyFAAw https://www.youtube.com/watch?v=ONsmJAyFAAw
- hn_throwaway_99 6y ago
  Yeah, honestly, the Beirut explosion looked bigger/scarier to me, like how they show nuclear explosions in the movies. The Tianjin explosion was an enormous fireball but didn't seem to have the same magnitude of shockwave from the videos I've seen of it.
  - actuator 6y ago
    From the videos I have seen the Tianjin fireball seemed to rage even for a longer duration. In the Beirut one maybe because of daylight, fire is not visible after the big blast. I wonder what would cause that difference, the Beirut one supposedly had more material as well.
    - aaomidi 6y ago
      Longer fire = less energy for explosion?
      - 6y ago

Leherenn 6y ago

A comparable explosion happened in Toulouse, France, in 2001, estimated at 20-40 tons of TNT. It was also some nitrate storage that blew up. Similar end result, pretty much everything window in the city was blown away, and most of the injuries were caused by broken glass.

cm2187 6y ago
Was watching some reporting from that explosion, and it starts with teachers being on strike when the explosion occurred. So French... https://www.youtube.com/watch?v=TioM7N0y8Co https://www.youtube.com/watch?v=TioM7N0y8Co

jungletime 6y ago

Lebanon has its share of enemies, internal and external. All it would take is a mavic inspire drone to fly over and drop the initial explosive. Trump said "it looks like a terrible attack" at his news conference. Which is probably what his intelligence officers/advisors speculated when they briefed him.

ClumsyPilot 6y ago
This speculation is silly, uninformed and unhelpfull. There was a primary fire of fireworks, you dont need to invent conspiracy. Besides one does not need a drone to start a fire in an unattended warehouse.
Chris2048 6y ago
> Which is probably what his intelligence officers/advisors speculated when they briefed him because Trump would never go off-script and speculate on his own?..
- jungletime 6y ago
  That's possible for sure. But why do you assume that Trump made it up? Have you ever gone to hairdresser, asked for a haircut, and the hairdresser only took one snip, and asked for money? No, it doesn't happen. You know why, because people tend to justify their jobs. I'm betting at least one of his Intel officers, would be suspicious of almost nuclear level yield blast.

emeraldd 6y ago

When they started talking about ammonium nitrate, my first thought was of this: https://en.wikipedia.org/wiki/West_Fertilizer_Company_explosion https://en.wikipedia.org/wiki/West_Fertilizer_Company_explos... and the possibility of a shipment of fertilizer somehow getting caught in a fire ...

azepoi 6y ago
Toulouse AZF comes to mind List of Ammonium nitrate disasters https://en.m.wikipedia.org/wiki/Ammonium_nitrate_disasters https://en.m.wikipedia.org/wiki/Ammonium_nitrate_disasters
coldcode 6y ago
When I first saw the initial video, I immediately assumed a nitrate explosion. A bomb that large would be too hard to place or even deliver (if a plane), and fireworks would not explode with a such a perfect shockwave. The red color of the original smoke is rather telling as well and that it occurred in a dockyard.

aaron695 6y ago

I should just pre-flag this comment, so feel free. But Hezbollah use Ammonium Nitrate and could use the other small explosives stored near by. I think under current rules being actioned if there was intel people were stealing from the factory it would be considered a legitimate target. The question would be, would the analysis of intel be good enough to know exactly what was stored there and if it is clearly not an appropriate target. And I think their analysis would suck. If you want a source, the President of the United States said it was an attack. So we either believe official statements or we should learn to think for ourselves. Equally arson or a fire due to lack of security and maintenance due to coronavirus stress.

rsynnott 6y ago
> So we either believe official statements The closest to an official statement (US dept of defence officials to media) is that it is not thought to be an attack, Donald’s ex-cathedra ramblings notwithstanding. Nasty accidents at fertiliser plants are unfortunately somewhat common; they dominate the list of largest non-nuclear explosions. Also, why would you steal fertiliser from a fertiliser factory? Traditionally, I’m fairly sure people just BUY it if they want to make a bomb.
- lazyjones 6y ago
  > The closest to an official statement (US dept of defence officials to media) Where is this press release from the US Dept. of Defence? Or are you talking about the mysterious "three unnamed defence officials" CNN wrote about in an article?
fanatic2pope 6y ago
> the President of the United States said it was an attack Meaningless. If Trump said the sky was blue, you'd be well advised to go outside and make sure.
- vimy 6y ago
  He does have a habit of revealing highly sensitive national security information. https://www.youtube.com/watch?v=IYX9nyr7rng https://www.youtube.com/watch?v=IYX9nyr7rng

shadowprofile77 6y ago

Nitpicking here maybe but this does not look like a 3 kiloton blast to me. Neither the size of the core explosion or the apparent shock wave damage correspond to that magnitude from a surface blast. Guessing here but I'd say closer to 2 kilotons at most. Amazingly, the massive, hollow grain silo right next to the detonation itself remained standing afterwards.

dfee 6y ago
Uh, who are you? I don’t have the eye for the difference between 2 and 3 kiloton blasts. Maybe I’m the exception to the rule, but I don’t think so.
IAmGraydon 6y ago
It’s not a 3kt blast. Not even close.
- shadowprofile77 6y ago
  I posit that it's definitely above 1 kiloton though. I base this on the radius of damage it caused (from photos compared to Google satellite images of the area around the explosion site) and by comparing the explosion's apparent magnitude with that of the PEPCON blast, which was fairly carefully estimated to have been roughly 1 kiloton. This blast looks bigger and spread its impact further than the PEPCON blast..
flywheel 6y ago
Amazing how nerds can be so focused on if it was 1 kiloton, 2 kilotons, or 3 kilotons - and they are arguing about it like it really matters.
- shadowprofile77 6y ago
  This whole thread is full of debate about diverse details about this event and things related to it, so yeah, it's perfectly normal to debate claims like a headline's subject, Nobody thinks it literally matters too much, They do it out of intellectual curiosity.. It's not just a "nerd" thing.

kgm 6y ago

I am seeing other analyses that put the size of the explosion at about one tenth of this size. The analysis in this Twitter thread correlates the observed degree of damage with the distance from the explosion. It comes up with an estimated 240 tons TNT-equivalent, though naturally this comes with a considerable margin of error. https://twitter.com/GeorgeWHerbert/status/1290719719545159680 https://twitter.com/GeorgeWHerbert/status/129071971954515968... This Twitter thread is making the point that the explosiveness of ammonium nitrate can vary significantly depending on how it is stored. 2750 tons of AN at 20% efficiency gives 550 tons TNT. https://twitter.com/ArmsControlWonk/status/1290795532701425664 https://twitter.com/ArmsControlWonk/status/12907955327014256... This range is also apparently consistent with the explosion registering as a 3.5 seismic magnitude. https://twitter.com/ArmsControlWonk/status/1290734850769526784 https://twitter.com/ArmsControlWonk/status/12907348507695267... There are still a great many unknowns, and none of this should be mistaken for the real analysis which will come later, but these disparate sources of information all seem to agree with each other, to a first approximation.

WalterBright 6y ago
My fluid mechanics prof told the class that a scientist in the 1940's published the yield of the Hiroshima bomb. Since this was top secret, he got investigated. But he showed how the yield could be calculated from the film of the explosion - how fast the blast radius expanded. So I imagine the yield of the Beirut explosion could be calculated the same way from the video.
- selimthegrim 6y ago
  It was G.I. Taylor.
  - tigerlily 6y ago
    Using the Buckingham Pi theorem.
    - hanche 6y ago

guerrilla 6y ago

> The cause of the explosion was not immediately clear. Officials linked the explosion to some 2,700 tonnes of confiscated ammonium nitrate that were being stored in a warehouse at the port for six years. https://www.aljazeera.com/news/2020/08/huge-explosion-rocks-lebanon-capital-beirut-live-updates-200804163620414.html https://www.aljazeera.com/news/2020/08/huge-explosion-rocks-...

stevespang 6y ago

Remember tannerite, the stuff you can buy at Academy or any gun shop to shoot as an explosive target ? It's ammonium nitrate fertilizer - - hopped up by mixing it with a little aluminum powder This guy loaded up his old rider lawn mower with it and shot it from only 43 feet away, see what happened . . . https://youtu.be/S6V0S1m5a7U?t=26 https://youtu.be/S6V0S1m5a7U?t=26

golemiprague 6y ago

what was the white ball during the explosion? it looks like some liquid spraying up in the shape of a ball, was it sea water? other liquid? or was it just looking to me like a liquid but actually was gas of something?

zaarn 6y ago
The white ball is water vapor that condenses into a cloud around the explosion as the shockwave passes through the air. Specifically it's the low-pressure area that comes after the initial shockwave, the rapid decrease in pressure causes water (and any other volatiles) to condense out.
a_e_k 6y ago
A Wilson cloud: https://en.wikipedia.org/wiki/Wilson_cloud https://en.wikipedia.org/wiki/Wilson_cloud

tzs 6y ago

This video [1] from The Guardian include the same video in that tweet, but also has a few other angles which gives a better appreciation of how big that thing was. [1] https://www.youtube.com/watch?v=93tV6-0Ugwk https://www.youtube.com/watch?v=93tV6-0Ugwk

dylan604 6y ago
I had only seen the headlines about this, but had not investigated anything until seeing this video. That's a much larger explosion than I was expecting.
- zimpenfish 6y ago
  Yeah, I was taken aback when I saw the video because I thought the initial smoke plume was the aftermath of the explosion. Then it went off and bloody hell.
look_lookatme 6y ago
This video is the one that made me gasp the hardest: https://twitter.com/FadyRoumieh/status/1290670721488900096 https://twitter.com/FadyRoumieh/status/1290670721488900096 Something about the distance and the fact that it's on water puts everything into stark relief.
- mmerlin 6y ago
  also the 2nd video here: https://t.co/BRezMWT5IV https://t.co/BRezMWT5IV
- 9nGQluzmnq3M 6y ago
  The interesting part about the explosion in the video is that there's two clouds: first the rapidly expanding almost perfectly spherical white puff, and then the slower dark black mushroom cloud. I vaguely recall the first is mostly water vapor that suddenly condenses out of the air because of the massive shockwave, while the second is the 'actual' explosion and its byproducts being shot up into the air. Any physicists out there care to set me straight?

KMag 6y ago

Note that the distinctive orange color is probably a large volume of nitrogen dioxide at pretty high concentration. If it was an ammonium nitrate explosion, the orange cloud supports the idea it was accidental. The explosion would have been easier to set off and more powerful had there been a fuel (or more fuel) mixed with the ammonium nitrate.

IAmGraydon 6y ago
Why do you think that the release of NO2 makes it an accident? Nitrate based high explosives only release NO2 during an actual high-order detonation. Ammonium nitrate does this with or without sensitizers such as fuel oil.
- KMag 6y ago
  A mixture close to a neutral oxygen balance (stochiometric mixture) would consume much of the N02 and have a much less brilliantly orange plume. Though, point taken that sensitization happens much before reaching a neutral oxygen balance.
- jandrewrogers 6y ago
  This is definitely not the case. NO2 release is characteristic of spontaneous decomposition of nitrates, which can happen under a wide variety of conditions that have nothing to do with detonation. I’ve had the misfortune of seeing this happen once in a lab, due to a rookie mistake. It usually is the harbinger of a runaway exothermic reaction. There is nothing surprising here if ammonium nitrate is the primary suspect. In the specific case of bulk ammonium nitrate, it has a low melting point (relative to a fire) and it starts to become quite unstable in that phase. The low risk of AN is premised on it being stored in a relatively clean, non-reactive environment. Fuel oil generally isn’t considered a sensitizer for AN, you still need a booster, it compensates for the oxygen richness which improves efficiency. There are a bunch of nitrogen organics and metals, which I won’t list here, that will sensitize AN quite effectively but those aren’t implicated here. Most fires with AN are caused by its reactivity. It will readily combine with other chemicals in the environment to produce compounds that are far more unstable than AN. These byproducts often act as the ignition point that ultimately causes the AN to detonate.

sytelus 6y ago

Just in case people are wondering reason this explosion: there was 2,750 tonnes of ammonium nitrate stored without safety measures in a warehouse that went off.

sillysaurusx 6y ago

@quantian1 correctly determined that this was an ammonium nitrate blast by analyzing the footage: https://twitter.com/quantian1/status/1290695231910875136 https://twitter.com/quantian1/status/1290695231910875136 CHEMISTRY FACT: Explosives have characteristic "detonation velocities" at which shockwaves expand. Smartphone video records at 30 FPS, so the adjacent frames here suggest the front expands at ~100 m/(1/30 sec), or 3,000 m/sec. Consistent with ammonium nitrate, not black powder. This was confirmed a few hours later: https://twitter.com/BBCBreaking/status/1290758551737192455 https://twitter.com/BBCBreaking/status/1290758551737192455 Lebanese president blames 2,750 tonnes of ammonium nitrate left in warehouse unchecked for six years for devastating Beirut blast EDIT: By the way, one of my friends was almost killed by the explosion. Thankfully they're ok. But they said: https://twitter.com/cyrilzakka/status/1290766217989500928 https://twitter.com/cyrilzakka/status/1290766217989500928 This was terrifying to experience. Hospitals are being overrun with injured people. We need blood donations and disaster relief. Help however you can. As a US citizen, is there any way I can help directly? Is there any organization that ships blood donations directly to a disaster site? I suppose that would be very difficult, so the answer is probably no; it's frustrating not being able to assist.

chmod775 6y ago
Some chemist acquaintances of mine suggested the same from just looking at the footage immediately after. Along with some scary explanations of what fast shockwaves like that do to human blood vessels. I was convinced this stuff should be outlawed for most uses pretty fast. https://en.wikipedia.org/wiki/Ammonium_nitrate_disasters https://en.wikipedia.org/wiki/Ammonium_nitrate_disasters Though on the other hand, the number of incidents and deaths aren't that high considering how prevalent it is. It's just that a critical failure of handling that stuff is quite spectacularly bad.
- 082349872349872 6y ago
  What do you recommend using for fertiliser in its place? (I'm sure someone's thought about this idea before. Timothy McVeigh did his mad bombing with typical rural materiel. Not so fun fact: the VBIED predates the internal combustion engine.)

supernova87a 6y ago

The amount of material must have been ridiculous to store in such a place. The blast is staggering in size, almost like the Tianjin explosion a few years ago. Collected videos: Angle #1 https://streamable.com/xmmoa7 https://streamable.com/xmmoa7 Angle #2 https://streamable.com/nscx9m https://streamable.com/nscx9m Angle #3 https://streamable.com/zbjj5f https://streamable.com/zbjj5f Angle #4 https://streamable.com/saoafz https://streamable.com/saoafz Angle #5 https://streamable.com/4ga1vb https://streamable.com/4ga1vb Angle #6 https://streamable.com/lmivb2 https://streamable.com/lmivb2 Angle #7 https://streamable.com/mcy82f https://streamable.com/mcy82f Angle #8 https://streamable.com/zg9oal https://streamable.com/zg9oal Angle #9 https://streamable.com/zykkj6 https://streamable.com/zykkj6 Angle #10 https://streamable.com/22e152 https://streamable.com/22e152

sozy777 6y ago
http://washingtonindependent.com/large-explosion-in-beirut-lebanon-2020-08-04/ http://washingtonindependent.com/large-explosion-in-beirut-l... Many angles here as well
5m17h 6y ago
The Tianjin explosion has been in the impression that many Chinese people have forgotten
markdown 6y ago
> The amount of material must have been ridiculous to store in such a place. This is a photo supposedly of the warehouse: https://imgbb.com/r4Q64xc https://imgbb.com/r4Q64xc
yxhuvud 6y ago
Roughly twice the amount exploded compared to Tianjin, actually. 2750 tonnes of ammonium nitrate compared to 800 tonnes of ammonium nitrates and 600 tonnes of potassium nitrate in Tianjin. So yes, quite ridiculous.
- velox_io 6y ago
  What strikes me as odd (aside from the massive shockwave), is how there were no fireballs, all other fertilizer fires have bright explosions. It's burnt rather than detonated. Here, all of the fertilizer ignited faster than the speed of sound (resulting in a virtually perfect spherical shockwave). Although the shockwave could have doused any flames, so that idea is plausible.. The other anomaly is the deep red smoke, that's something that seems unusual too (aside from storing so much fertilizer in such a built up area for so long). This is a disaster on so many levels, but then when is a disaster only caused by a single issue?

jonplackett 6y ago

This is insane, this is tactical nuclear weapon size explosion right? I think they start at under 1kt up to about 10kt (not saying it is one, just for comparison of how insanely massive this explosion is)

ashtonkem 6y ago

This seems unlikely. Officially, they had 2750 tones of ammonium nitrate on that dock. Even if it were properly mixed with fuel oil to make ANFO, that would give you 2200 tones of tnt equivalent. It is quite unlikely that it was mixed to the perfect proportions, so we’d expect actual yield to be below theoretical max So unless if something else was involved (or the official amount of ammonium nitrate was wrong) I would expect the final blast to be under 2kt.

totalZero 6y ago
There are plenty of petroleum distillates in a dockyard. Diesel, bunker fuel, kerosene, gasoline....not to mention other flammable hydrocarbons and powders. You're assuming an 80% ratio ANFO/TNT but you're neglecting the mass of the FO, as well as the possibility of other oxidizers being stored near the blast site. I guess you could make some assumptions about the fuel based on detonation velocity as observed on video.
- ashtonkem 6y ago
  Properly mixed ANFO doesn't contain a huge amount of FO; ideally it's supposed to be 6% by mass. Good enough for a quick HN estimate, although I'd hope an actual after action report does better. A better calculation is that 2750 tonnes of AN would yield 2864 tonnes of ANFO, which is 2,291 tonnes of TNT equivalent. However, we know that the explosion wasn't stoichiometrically perfect, because of the brown NO2 clouds that were hanging over Beirut. Properly mixed ANFO should release only H2O, CO2, and N2. So we know that there was some level of explosive power that wasn't fully consumed. This is why I put the ANFO yield as the absolute theoretical max, I think in reality the actual yield was much much lower. Some other people have speculated that the fireworks like mini explosions between the first and second big explosions was actually ammonium nitrate decomposing, which would imply that this was a pure ammonium nitrate explosion and not one accelerated by some sort of oil or other fuel. If that's true, various manufacturers give the AN to TNT equivalent of poorly handled AN at 15-40% of TNT, giving a yield somewhere in the 412-1,100 tonne range.
  - 6y ago

aunetx 6y ago

This reminds me a lot about AZF, a chemical explosion that happened in Toulouse, France back in 2001 [1]... And it was hundred of tons of ammonium nitrate here too. [1] https://en.wikipedia.org/wiki/Toulouse_chemical_factory_explosion https://en.wikipedia.org/wiki/Toulouse_chemical_factory_expl...

SDJ100 6y ago

According to my estimate the Beirut explosion was about one quarter the explosive force of the Hiroshima bomb. Does anyone concur with this?

SDJ100 6y ago

I estimate the Beirut explosion was one quarter the explosive force of the Hiroshima bomb. Does anyone concur?

agumonkey 6y ago

What are the pollution consequences of this (if any) ?

est31 6y ago
Dust pollution has turned out to be quite significant in the 9/11 aftermath, causing cancer in thousands of people. > As of August 2013, medical authorities concluded that 1,140 people who worked, lived, or studied in Lower Manhattan at the time of the attack have been diagnosed with cancer as a result of "exposure to toxins at Ground Zero". It has been reported that over 1,400 9/11 rescue workers who responded to the scene in the days and months after the attacks have since died. https://en.wikipedia.org/wiki/Casualties_of_the_September_11_attacks https://en.wikipedia.org/wiki/Casualties_of_the_September_11... The pictures of Beirut seemed quite dusty, reminiscent of the 9/11 pictures. Beirut 2020: https://streamable.com/22e152 https://streamable.com/22e152 NYC 2001: https://i.imgur.com/jfLUAiK.jpeg https://i.imgur.com/jfLUAiK.jpeg
- agumonkey 6y ago
  good point but beirut is not the same dust, for better or worse

J0_k3r 6y ago

you're being downvoted because hn is filled with silicon valley cucks and orange man bad

lma21 6y ago

I have family and friends living in Lebanon. The explosion destroyed the windows of most homes in Beirut. Apartments of my family, friends, and colleagues have been shattered. Even the ones living dozens of kilometers away from Beirut. It's horrible, what pure incompetence can do to a people already living in poverty and under the covid-stress. I hope something good comes out of this...

mekster 6y ago
What good do you expect out of this mess? Like, some other location fixed their storage strategy to avoid same fate?
- lma21 6y ago
  Change the whole governmental bodies. Build a new constitution. Hold new elections. Create a government that acts and builds, not one that talks and promises. Something that can lift this poor, small, desperate country out of its misery. I'm hoping for such changes...
  - WaxedLekku 6y ago
    Tear down and build a new state? Sounds like the recipe for a war

bluenose69 6y ago

The following is a citation for the seminal paper on this matter. G. I. Taylor was a god of fluid mechanics, and quite a lot of his work is available online for free. Taylor, Geoffrey. “The Formation of a Blast Wave by a Very Intense Explosion. - II. The Atomic Explosion of 1945.” Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences 201, no. 1065 (March 22, 1950): 175. https://doi.org/10.1098/rspa.1950.0050 https://doi.org/10.1098/rspa.1950.0050

worldpeacenow 6y ago

Ammonium nitrate is 1.35 less potent than TNT. So this was just over 2,000 tons of TNT blast. The first nuclear bomb ever dropped was 15,000 tons of TNT of force. So this was 13.3% of the force of what Hiroshima experienced. About 70,000 people died from Hiroshima. So 13.3% of Hiroshima force is still devastating. It's probably not going to be nearly as bad as 13.3% of 70,000 deaths because Hiroshima was more densely packed and there wasn't the electromagnetic pulse wave that vaporizes people and long lingering radiation associated with a nuclear bomb. ... Still what happened in Beirut is immensely devastating.

DreamScatter 6y ago
An electromagnetic pulse doesn't vaporize people, it mainly affects electronics.

RantyDave 6y ago

No. Because that would imply that ammonium nitrate has a higher specific energy than TNT. Which it doesn't. https://en.wikipedia.org/wiki/Energy_density_Extended_Reference_Table https://en.wikipedia.org/wiki/Energy_density_Extended_Refere...

totalZero 6y ago

I wonder if the shape of the storage receptacle and the geometry of surrounding buildings could have resulted in an elliptical fireball shape. If so, that could be one drawback of this method. Depending on viewing angle, you could overestimate or underestimate the R figure versus a same-energy spherical fireball.