# How big is a one kiloton explosion? \[edited title\]
**URL:** https://boards.straightdope.com/t/how-big-is-a-one-kiloton-explosion-edited-title/819092
**Category:** Factual Questions
**Created:** [August 4, 2018, 3:12pm UTC](https://boards.straightdope.com/t/how-big-is-a-one-kiloton-explosion-edited-title/819092 "2018-08-04T15:12:42Z")
**Posts on this page:** 17
**Page:** 1
### Author:  [@A\_Dodgy\_Dude](https://boards.straightdope.com/u/A_Dodgy_Dude)
#### Post date: [August 4, 2018, 3:12pm UTC](https://boards.straightdope.com/t/how-big-is-a-one-kiloton-explosion-edited-title/819092/1 "2018-08-04T15:12:42Z")
I was just reading about the meteor that hit Greenland the other day; it exploded with 2.1 kilotons of force.
Nobody gave a simple explanation for what 2.1 kilotons of force means, only that a kiloton is the equivalent of a thousand tons. I don’t know how big an explosion 2100 tons of TNT produces; I only know I want to be far away from it.
Since Google failed to produce an answer I’m turning to the folks at Straight Dope.
One kiloton of TNT is sitting on the ground in front of me. What is the minimum safe distance?
And, as they say on the internet, please explain like I’m five.
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### Author:  [@Ravenman](https://boards.straightdope.com/u/Ravenman)
#### Post date: [August 4, 2018, 3:16pm UTC](https://boards.straightdope.com/t/how-big-is-a-one-kiloton-explosion-edited-title/819092/2 "2018-08-04T15:16:17Z")
How about a picture? Just pop your desired numbers into the calculator:
> **[NUKEMAP by Alex Wellerstein](https://nuclearsecrecy.com/nukemap/)**
>
> NUKEMAP is a mapping mash-up that calculates the effects of the detonation of a nuclear bomb.
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### Author:  [@beowulff](https://boards.straightdope.com/u/beowulff)
#### Post date: [August 4, 2018, 3:19pm UTC](https://boards.straightdope.com/t/how-big-is-a-one-kiloton-explosion-edited-title/819092/3 "2018-08-04T15:19:42Z")
You can play with a simulator [here](http://nuclearsecrecy.com/nukemap/classic/).
For a meteor, ignore the radiation. A 2.1 kt explosion would destroy several blocks in a city.
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### Author:  [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)
#### Post date: [August 4, 2018, 4:06pm UTC](https://boards.straightdope.com/t/how-big-is-a-one-kiloton-explosion-edited-title/819092/4 "2018-08-04T16:06:55Z")
**Moderator Note**
Thread title changed from “I’m starting to think no one knows the answer to this question” to “How big is a one kiloton explosion?” Please use descriptive thread titles.
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### Author:  [@Isilder](https://boards.straightdope.com/u/Isilder)
#### Post date: [August 4, 2018, 4:07pm UTC](https://boards.straightdope.com/t/how-big-is-a-one-kiloton-explosion-edited-title/819092/5 "2018-08-04T16:07:47Z")
A 1 Kiloton detonation.
[http://www.military.com/video/nuclear-bombs/nuclear-weapons/1-kiloton-nuclear-bomb-detonated/3067132402001](http://www.military.com/video/nuclear-bombs/nuclear-weapons/1-kiloton-nuclear-bomb-detonated/3067132402001)
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### Author:  [@Riemann](https://boards.straightdope.com/u/Riemann)
#### Post date: [August 4, 2018, 4:31pm UTC](https://boards.straightdope.com/t/how-big-is-a-one-kiloton-explosion-edited-title/819092/6 "2018-08-04T16:31:42Z")
Hiroshima & Nagasaki were 15 and 20 kilotons. Some pictures of the aftermath here:
[https://www.history.com/topics/world-war-ii/world-war-ii-history/pictures/hiroshima-and-nagasaki/bomb-damaged-facade-hiroshima](https://www.history.com/topics/world-war-ii/world-war-ii-history/pictures/hiroshima-and-nagasaki/bomb-damaged-facade-hiroshima)
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### Author:  [@ftg](https://boards.straightdope.com/u/ftg)
#### Post date: [August 4, 2018, 5:56pm UTC](https://boards.straightdope.com/t/how-big-is-a-one-kiloton-explosion-edited-title/819092/7 "2018-08-04T17:56:51Z")
The [PEPCON disaster](https://en.wikipedia.org/wiki/PEPCON_disaster) near Las Vega in 1988 is estimated to have been ~1Kt equivalent. [Video](https://youtu.be/_KuGizBjDXo?t=52).
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### Author:  [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)
#### Post date: [August 4, 2018, 6:05pm UTC](https://boards.straightdope.com/t/how-big-is-a-one-kiloton-explosion-edited-title/819092/8 "2018-08-04T18:05:56Z")
[Here’s a good video.](https://www.youtube.com/watch?v=hkoBwFYitlU) It’s actually a half-kiloton explosion. But it’s detonated near some ships so it gives you a good sense of the scale.
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### Author:  [@A\_Dodgy\_Dude](https://boards.straightdope.com/u/A_Dodgy_Dude)
#### Post date: [August 4, 2018, 8:29pm UTC](https://boards.straightdope.com/t/how-big-is-a-one-kiloton-explosion-edited-title/819092/9 "2018-08-04T20:29:09Z")
> [@Ravenman](#):
>
> How about a picture? Just pop your desired numbers into the calculator:
>
> [NUKEMAP by Alex Wellerstein](https://nuclearsecrecy.com/nukemap/)
Very good! Excellent! That’s pretty much everything I wanted to know.
Thanks, Ravenman.
I figured Straight Dope would be more useful than Google.
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### Author:  [@Tim\_T-Bonham.net](https://boards.straightdope.com/u/Tim_T-Bonham.net)
#### Post date: [August 4, 2018, 10:46pm UTC](https://boards.straightdope.com/t/how-big-is-a-one-kiloton-explosion-edited-title/819092/10 "2018-08-04T22:46:01Z")
So is a ‘kilo-ton’ an actual metric (SI) unit of measure?
I’d think it would actually be a conversion equivalent to X Joules, maybe?
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### Author:  [@Chronos](https://boards.straightdope.com/u/Chronos)
#### Post date: [August 4, 2018, 10:56pm UTC](https://boards.straightdope.com/t/how-big-is-a-one-kiloton-explosion-edited-title/819092/11 "2018-08-04T22:56:28Z")
A kiloton is a perfectly valid metric unit of mass. But it’s most often used as a shorthand for “kiloton of TNT equivalent”, which is a unit of energy.
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### Author:  [@smithsb](https://boards.straightdope.com/u/smithsb)
#### Post date: [August 4, 2018, 11:53pm UTC](https://boards.straightdope.com/t/how-big-is-a-one-kiloton-explosion-edited-title/819092/12 "2018-08-04T23:53:53Z")
For a person in the open, no glass breakage like standing behind a window; the standard for a non-purposeful explosion is:
D=40\*(W^1/3)
D=distance, W=net explosive weight in lbs., 1/3 is superscript=cube root
1 kiloton of TNT = 1000\*2000 lbs. 2,000,000 lbs.
D=40\*(2,000,000^1/3)
Somewhere around 5,040 ft. back and you should be just fine.
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### Author:  [@smithsb](https://boards.straightdope.com/u/smithsb)
#### Post date: [August 5, 2018, 12:15am UTC](https://boards.straightdope.com/t/how-big-is-a-one-kiloton-explosion-edited-title/819092/13 "2018-08-05T00:15:09Z")
For intentional detonations, things got a bit (a really big bit) more stringent.
d = 328\*(W^1/3)
Around 7.8 miles
[http://www.esd.whs.mil/Portals/54/Documents/DD/issuances/dodm/605509v5\_dodm\_2008.pdf?ver=2017-12-18-131901-623](http://www.esd.whs.mil/Portals/54/Documents/DD/issuances/dodm/605509v5_dodm_2008.pdf?ver=2017-12-18-131901-623) just up from the bottom of page 8. (pdf)
Anecdote: We were in Iraq at Objective Arlington (Iraqi Army Depot) destroying unsafe munitions. Each day (6/7 with Friday a religious observance for the locals) we would detonate 4 pits with a maximum of 20,000 lbs. NEW per pit. The detonations were not simultaneous but had enough delay so the shock fronts would not merge and reinforce each other. The pits had fragmenting munitions which is far more complicated if you were to read page 9 above. We started out 3.4 miles back:D to observe the blasts. One day with the majority of munitions being 155mm HE projectiles (nasty fragments from ogive and baseplate), some fragments were noted passing over our heads. :eek: We adjusted back to 4.7 miles; still a good show.
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### Author:  [@smithsb](https://boards.straightdope.com/u/smithsb)
#### Post date: [August 5, 2018, 12:17am UTC](https://boards.straightdope.com/t/how-big-is-a-one-kiloton-explosion-edited-title/819092/14 "2018-08-05T00:17:29Z")
Scale up to the 2.1 kilotons and recalculate.
6453 feet for that figure.
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### Author:  [@Gray\_Ghost](https://boards.straightdope.com/u/Gray_Ghost)
#### Post date: [August 5, 2018, 5:29am UTC](https://boards.straightdope.com/t/how-big-is-a-one-kiloton-explosion-edited-title/819092/15 "2018-08-05T05:29:30Z")
> [@Chronos](#):
>
> A kiloton is a perfectly valid metric unit of mass. But it’s most often used as a shorthand for “kiloton of TNT equivalent”, which is a unit of energy.
Thank You! And Tim just above, for pointing out that “kiloton” the way the OP used it, is a unit of energy, not force. Reading phrases like, “a kiloton of force,” makes my teeth itch.
Even if it is technically correct in an English unit system as pounds are units of force.
One kiloton of TNT is stated to have the chemical energy of 4.184 x 10^12 joules.
‘Ouch’ when reading smithsb’s story of having shrapnel and debris still sailing over his head, 3 and a half miles away from the det. I literally can’t imagine, unless I’m seeing something like vulcanology photos from watching something like St. Helens blow up.
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### Author:  [@DPRK](https://boards.straightdope.com/u/DPRK)
#### Post date: [August 5, 2018, 10:16am UTC](https://boards.straightdope.com/t/how-big-is-a-one-kiloton-explosion-edited-title/819092/16 "2018-08-05T10:16:10Z")
What this reminds me of is the electron-volt. This is a unit of energy used by particle physicists. To note is that if one multiplies the unit by a convenient factor, say a billion, and uses universal physical constants via E = mc[sup]2[/sup], one gets 1 GeV/c[sup]2[/sup] = 1.783 × 10[sup]−27[/sup] kg which is a convenient unit of mass, again for particle physicists.
Similarly “kilotons” form a convenient unit of energy for the Dr Strangelove types (cf. “World Targets in Megadeaths”).
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### Author:  [@DesertDog](https://boards.straightdope.com/u/DesertDog)
#### Post date: [August 5, 2018, 1:34pm UTC](https://boards.straightdope.com/t/how-big-is-a-one-kiloton-explosion-edited-title/819092/17 "2018-08-05T13:34:59Z")
> [@smithsb](#):
>
> For intentional detonations, things got a bit (a really big bit) more stringent.
>
> d = 328\*(W^1/3)
>
> Around 7.8 miles
>
> [http://www.esd.whs.mil/Portals/54/Documents/DD/issuances/dodm/605509v5\_dodm\_2008.pdf?ver=2017-12-18-131901-623](http://www.esd.whs.mil/Portals/54/Documents/DD/issuances/dodm/605509v5_dodm_2008.pdf?ver=2017-12-18-131901-623) just up from the bottom of page 8. (pdf)
>
> Anecdote: We were in Iraq at Objective Arlington (Iraqi Army Depot) destroying unsafe munitions. Each day (6/7 with Friday a religious observance for the locals) we would detonate 4 pits with a maximum of 20,000 lbs. NEW per pit. The detonations were not simultaneous but had enough delay so the shock fronts would not merge and reinforce each other. The pits had fragmenting munitions which is far more complicated if you were to read page 9 above. We started out 3.4 miles back:D to observe the blasts. One day with the majority of munitions being 155mm HE projectiles (nasty fragments from ogive and baseplate), some fragments were noted passing over our heads. :eek: We adjusted back to 4.7 miles; still a good show.
Dodged a bullet, eh?
When I was at Keflavik the Air Force decided to destroy some out of date bombs. Since our direction-finding station was in a remote part of the base they set up shop in the vicinity, a couple miles away I think. The 100-pound bombs you had to be outside when they were touched off to hear them. You could feel the concussion of the 250-pounders inside but not hear them inside.