# Would an air burst nuclear weapon make a crater? [closed]

In specific it would be a 300kt warhead detonated around 3000ft above the ground.

• Sounds like a real world question better suited to physics or some other stack exchange // a lot of air blast tests with much larger yields at much lower elevations have been carried out the results of which are in the public domain, so have you looked for reports on any of those? Jun 15 at 11:17

Depends on the material of the ground, but yes

Some quick calculations - a 300kt nuke (airburst) peaks at 1.6 kilometers from the detonations site at 20 psi, enough to destroy buildings and certainly enough to create a shockwave to displace the ground beneath it. You're not going to be destroying the ground as much as condensing and moving it to generate this crater.

The nature of the creature will depend on the nature of the ground, for the most part. If it's solid rock, not much of a crater. Loose earth (or sand), a lot more of a crate. But it's most likely going to end up being rather shalllow.

300 kt = $$1.2\times 10^{15}$$ Joules.

The blast is 3,000 ft (~ 1 kilometer = 1,000 meters) above the ground. So, the energy hitting the ground is $${1.2\times 10^{15}} \over {4 \pi r^2}$$ $$=$$ $${1.2\times 10^{15}} \over {4 \pi (1,000)^2}$$ $$\approx 1 \times 10^9$$ Joules per square meter

The amount of heat required to evaporate rock is $$790 ({{J}\over{g \cdot K}}) \cdot 1260 (deg) + 209 ({{J} \over {g}}) + 790 ({{J}\over{g \cdot K}}) \cdot (2600 - 1260) + 6090 ({{J} \over {g}}) = 2,107,699 ({{J} \over {g}})$$

With $$1 \times 10^9$$ Joules being applied to each square meter of dirt, roughly $${{1 \times 10^9} \over {2,107,699}} = 500 g$$. 500 grams of dirt per square meter of blast on the ground will be blasted into vapor.

With the density of granite at 2,691 kilograms per cubic meter, the depth of the crater will be 0.1 millimeters.

The crater depth varies with the square of distance, so if you want a 1 meter deep crater, detonating at 10 meters above the ground would do it.

• Why do you need to "vaporize" the dirt to blast it away? Isn't mechanical force enough? Jun 15 at 19:18
• "so if you want a 1 meter deep crater, detonating at 10 meters above the ground would do it" meaning that at 3,000 feet you'll realistically get no crater of course 👍 Jun 15 at 20:56

Yes, you could.

Data: 300kt, 3000 ft above ground.

Page used: https://nuclearsecrecy.com/nukemap/

Edit: In response to the comments about the size of the crater.

In the 2nd image on the right there are actual numbers of the sizes of the crater.

Here is a more detailed image moving the position to the border of Central Park: And a dedicated link to those presets here

• This answer is very vulnerable to link rot. I can't open the links, and I learned nothing from it. Please consider adding the data shown in the pictures to the answer. Jun 15 at 19:19
• It''s just the link, the web and the link are the same (has been the same at least from 2015). You will need JS activated. To input the options just input: 1) new york (and press Go), 2) 300, 3) Airburst, Adv Opts: Burst Height 3000 ft, 4) Detonate. It's as easy as that. Jun 15 at 21:07
• The crater are the grey and dark grey little circles. The question wanted numbers. There is a little diagram on the right of the photo giving those numbers. Jun 15 at 21:11
• I'm not sure that is really an accurate calculator, I just plugged in the appropriate stats for little boy (15 kt and 1900 ft) and got a result of a 20 m deep 50 m radius crater, little boy is reported as leaving no crater due to being an airburst in articles I found on it? Jun 15 at 21:24