23 ms·
USGS Data on the Lebanon Blast
- sandworm101 6y agoIf this involved 2700 tons of ammonium nitrate, does that mean it was the equivalent to 2700 tons of TNT? A 2.7 kiloton bomb? That would put it at the smaller end of nuclear weapon yields, but not at the bottom.
- throwaway0a5e 6y agoANFO is only ~3/4 as powerful as TNT per kilogram and this was just amonium nitrate, not much fuel for it to combust (hence the nice brown smoke). Additionally, "pile of junk in a warehouse" is second only to "pile of junk not in a building" when it comes to having the least efficient yield for a given amount of explosives. Doubtful this is over a kiloton. It's really hard to make big efficient explosions by accident.
- CLETMP 6y agoFurthermore, this wasn't ANFO, just ammonium nitrate. So, no fuel--only oxidizer. Some analysis has suggested that the efficiency of a detonation here would only be .15. Furthermore, probably a low-order detonation (only part of the material detonating). Even actual ANFO typically needs an intermediate booster explosive to achieve a good high-order detonation. For example, instead of just having a detonator on its own a blaster might add a PETN booster charge to make sure the ANFO all detonates. Without that you typically see pellets of undetonated ANFO scattering around the explosion. Hell, even with a booster you still tend to see ANFO pellets lying around the blast area. All that is to say, this was probably closer to 200 tons of TNT, very roughly speaking.
- sandworm101 6y agoEven 200, 0.2kt, is literally on par with the lowest tested nuke.
- penagwin 6y agoIt’s relatively small compared to similar incidents- https://en.m.wikipedia.org/wiki/Largest_artificial_non-nuclear_explosions https://en.m.wikipedia.org/wiki/Largest_artificial_non-nucle...
- ummonk 6y agoIt’s a little larger than the Galveston Bay explosion.
- deleted 6y ago[deleted]
- runarberg 6y agoAccording to Wikipedia the Texas City disaster had just over 2000 tonnes of ammonium nitrate explode (as opposed to 2700 in Beirut) which they claim to be “one of history's largest non-nuclear explosions”. Was there some other factor that caused the Texas City to have a bigger blast?
- Jtsummers 6y agoIf I'm reading it right, the Texas City disaster had 2300 tons on the Grandcamp, and 961 tons on a nearby ship, the High Flyer. That second ship exploded later in the day. There was also a chemical plant that was caught in the blast and a warehouse with fertilizer.
- deleted 6y ago[deleted]
- refurb 6y agoSo, no fuel--only oxidizer. Ammonium ion is the fuel when pure ammonium nitrate explodes. Adding fuel oil increases the power for a couple reasons - 1) fuel oil adds additional fuel 2) ammonium nitrate absorbs water from the atmosphere and makes it much less sensitive. The fuel oil “waterproofs” the ammonium nitrate.
- dragonwriter 6y ago> If this involved 2700 tons of ammonium nitrate, does that mean it was the equivalent to 2700 tons of TNT? No, because ammonium nitrate isn't equivalent to TNT. Various sources give the REF of Ammonium Nitrate as 0.42, so at most it should, by itself, be equivalent to 1134 tons of TNT, but the actual explosion could be less because of inefficient ignition, or more if it set off something else that added to the explosion.
- frickinLasers 6y agoI've seen estimates from 200 tons to 1 kT, still quite powerful. See: https://news.ycombinator.com/item?id=24053732 https://news.ycombinator.com/item?id=24053732 Nuclear weapons span a huge range of yields. The W54 yield was as low as 10 tons, about as energetic as a daisy cutter conventional bomb. https://en.wikipedia.org/wiki/W54 https://en.wikipedia.org/wiki/W54 https://en.wikipedia.org/wiki/BLU-82 https://en.wikipedia.org/wiki/BLU-82
- tempodox 6y agoThe article explicitly states: News reports state the explosion was caused by 2750 tons of ammonium nitrate which is roughly equivalent to 1100 tons of TNT.
- missedthecue 6y agoI doubt it exploded at full efficiency.
- deleted 6y ago[deleted]
- eCa 6y ago”The reported magnitude is not directly comparable to an earthquake of similar size because the explosion occurred at the surface where seismic waves are not as efficiently generated.” Should this be interpreted to mean that the blast had more force than a 3.3 earthquake?
- EarthIsHome 6y ago> Should this be interpreted to mean that the blast had more force than a 3.3 earthquake? Yes. While "force" might not be the right word, your intuition is correct.
- dredmorbius 6y agos/force/energy release/
- gpsx 6y agoWatching a video of the blast, you can see a very large shock wave in the air. A large amount of energy was dissipated this way which would not happen in a normal earthquake. I am sure the fraction could be estimated. In fact, in a fluids physics course I had the teacher said Russia was able to estimate the power of one of the first US test nuclear explosions by watching its video.
- infinite8s 6y agoEnrico Fermi was able to do perform a similar estimate, based on the distance traveled by pieces of paper he dropped from his hand during the blast - https://en.wikipedia.org/wiki/Fermi_problem https://en.wikipedia.org/wiki/Fermi_problem
- me_me_me 6y agoI think they mean its different. The seismic wave it way more devastating to the infrastructure. Leading to collapsing buildings, ripped gas pipes etc. Explosion like this one move most of the energy into the heat and air displacement. The immediate area is shattered but the building outside have only windows smashed. The explosion look terrifyingly massive but the number of victims seams small in comparison.
- 082349872349872 6y agoSomewhat related, the face when you solve for epicentre from seismic station data and get a location at negative depth: https://blogs.ei.columbia.edu/2016/02/04/the-earth-shook-but-it-wasnt-an-earthquake/ https://blogs.ei.columbia.edu/2016/02/04/the-earth-shook-but...
- refurb 6y agoI’m assuming that USGS picks up lots of ground movement, for example, large blasts from mining operations. They must filter those out based on characteristics? Do companies give advance warning? Just curious because those instruments must pick up a lot of things that aren’t earthquakes.
- LinuxBender 6y agoUSGS eventually learn of rock quarries, mines and other things that cause regular earth movements and they tune them out of their reporting. A rock quarry near me used to generated 3.4's a few times a week. I do not know if there is regular correspondence or schedules relayed however.
- giantrobot 6y agoI'm pretty sure blasting requires some permits. In a sane world I'd imagine blasting permits get automatically funneled into a "booms will be here" list at least at state levels. But then we don't necessarily live in a same world.
- LinuxBender 6y agoThey do require paperwork, a lot of it. One of the youtube channels I enjoy watching use every kind of demo material under the sun and they often talk about the paperwork required.
- ajsnigrutin 6y agoI'm not from usa, but EU. Here, mining operations, quarries, etc. get "booms will be here" licences, with limits (when (usually only daytime), where (quarry/mine limits and how strong the 'booms' are). So for those (rutine, standard blasts), our enviromental (earthquake) agencies don't get the data for each blast (they eg. get data, that company XYZ is allowed to do blasts up to ABC power (KJ or whatever) in location DEF, from 1. jan 2020 to 31. dec 2020 when they have to renew their licence). Source: friend works as an explosives expert at a quarry
- mattlondon 6y agoI was looking at the maps for this on the USGS site and thought that the location of the blast cant be that accurate surely? Image from the BBC showing the location of the blast on a satellite image: https://ichef.bbci.co.uk/live-experience/cps/624/cpsprodpb/vivo/live/images/2020/8/5/24402a28-1228-4d18-b373-3b3c7e6821d5.png https://ichef.bbci.co.uk/live-experience/cps/624/cpsprodpb/v... It looks like the crater (crater! wow this was huge) was almost exactly where USGS plotted it to be, like down to a couple of meters. Are the earthquake sensors that are in use really this so specifically accurate?
- deleted 6y ago[deleted]
- caymanjim 6y ago> To remove uncertainties in the location associated with seismic methods, we fix the location to the location seen in videos of the blast. Right at the top of the page.
- mytailorisrich 6y agoBBC is reporting that people in Eastern Cyprus, ~250km away, felt the blast and interpreted it as an earthquake. Quite a blast.
- refurb 6y agoWhat the videos capture well is the ground wave. You see the blast, then the building shakes within a second, then the atmospheric shockwave arrives a few seconds later. Gives you a sense of the power - to violently shake the ground from over 1km away.
- afvictory 6y agoRoscosmos has shared before & after satellite imagery for anyone interested: https://twitter.com/roscosmos/status/1291023063404994560/photo/1 https://twitter.com/roscosmos/status/1291023063404994560/pho...
- deadalus 6y agoRegarding the satellite image, a few questions : 1) Can nation-states spy like this on every location on the planet? 2) Can you view the live feed of any location and follow vehicles(for example)? 3) Is there anything a country can do to prevent other's from spying on your country from satellites?
- _jal 6y ago1) Yes. 2) Well, I can't, but the capability exists. 3) Dig.
- taejo 6y agoI don't think you can get a live feed of a location since the satellites generally aren't geostationary (geostationary orbit is too far away, and are always above the equator). But AFAIK even commercially you can get still photographs of any point on earth within a couple days (i.e. you don't have to be a nation state or have your own satellites)
- walrus01 6y agoa live feed to follow something would 99% of the time be implemented from a HALE (high altitude/long endurance) group 4 size UAS. RQ9 or in the same class, with a combination of a high end gimbaled camera system and satellite data uplink.
- savoytruffle 6y agoGeostationary is very very far away and useless for nighttime. Imaging satellites usually have a shorter polar orbit that precesses east to west along with sunshine. https://en.wikipedia.org/wiki/Sun-synchronous_orbit https://en.wikipedia.org/wiki/Sun-synchronous_orbit
- dreamcompiler 6y agoSo about 1/15 the energy of the Hiroshima nuclear bomb then.
- mrep 6y agoAnd about 1/270 the energy of a single w87 thermonuclear warhead and a single ICBM can carry up to 10 of those.
- runarberg 6y agoThat is insane... Makes you wonder why on earth people think its a good idea to have weapons that can cause 100s of times the damage then this horrible event.
- ISL 6y agoOnce one person has one, they can tell everyone else what to do unless other people have them, too. Until we find a way to alter that incentive structure, mutually-assured destruction remains one of our best-available options for tenuous stability and peace.
- deleted 6y ago[deleted]
- coronadisaster 6y agoWhy are people so evil...
- ISL 6y agoPerhaps some are, but most people are not. On the latter subject, I offer the advice of Gandalf: Gandalf: "You cannot offer me this Ring!" Frodo: "I'm giving it to you!" Gandalf: "Don't tempt me Frodo! I dare not take it. Not even to keep it safe. Understand Frodo, I would use this Ring from a desire to do good. But through me, it would wield a power too great and terrible to imagine."
- m0zg 6y agoThat's 25 times the yield of the largest conventional munition (Russia's FOAB, 44T yield). The videos look unreal.