Editing Effects of nuclear explosions (section)

{{short description|Type and severity of damage caused by nuclear weapons}}
[[File:NuclearTestUS.gif|thumb|300px|A [[Nevada Test Site|Nevada-series]] of nuclear weapons effects tests by the United States, displaying initial thermal flash-burns followed by blast and shock-front against various types of vehicles and infrastructures.]]
{{nuclear weapons}}

The '''effects of a nuclear explosion''' on its immediate vicinity are typically much more destructive and multifaceted than those caused by conventional [[explosives]]. In most cases, the energy released from a [[nuclear weapon]] detonated within the [[troposphere|lower atmosphere]] can be approximately divided into four basic categories:<ref name="remmNucExpl">{{cite web |url=http://www.remm.nlm.gov/nuclearexplosion.htm |title=Nuclear Explosions: Weapons, Improvised Nuclear Devices |publisher=U.S. Department of Health and Human Services |date=16 February 2008 |access-date=3 July 2008}}</ref>
*the [[Blast wave|blast]] and [[shock wave]]: 50% of total energy<ref>{{Cite web |title=Nuclear Radiation Protection Guide Civil Defense|url=https://www.atomicarchive.com/science/effects/energy.html |access-date=2022-04-10 |website=www.atomicarchive.com}}</ref>
*[[thermal radiation]]: 35% of total energy
*[[ionizing radiation]]: 5% of total energy (more in a [[neutron bomb]])
*[[Nuclear fallout|residual radiation]]: 5–10% of total energy with the mass of the explosion.

Depending on the design of the weapon and the location in which it is detonated, the energy distributed to any one of these categories may be significantly higher or lower. The physical blast effect is created by the coupling of immense amounts of energy, spanning the [[electromagnetic spectrum]], with the surroundings. The environment of the explosion (e.g. submarine, [[ground burst]], [[air burst]], or exo-atmospheric) determines how much energy is distributed to the blast and how much to radiation. In general, surrounding a bomb with denser media, such as water, absorbs more energy and creates more powerful shock waves while at the same time limiting the area of its effect. When a nuclear weapon is surrounded only by air, lethal blast and thermal effects proportionally scale much more rapidly than lethal radiation effects as [[Nuclear weapon yield|explosive yield]] increases. This bubble is faster than the [[speed of sound]].<ref name="remm.nlm.gov">{{Cite web |url=http://www.remm.nlm.gov/RemmMockup_files/radiationlethality.jpg |title=Yield (kilotons) |access-date=2012-04-27 |archive-date=2013-06-07 |archive-url=https://web.archive.org/web/20130607091341/http://www.remm.nlm.gov/RemmMockup_files/radiationlethality.jpg |url-status=dead }}</ref> The physical damage mechanisms of a nuclear weapon (blast and thermal radiation) are identical to those of conventional explosives, but the energy produced by a nuclear explosion is usually millions of times more powerful per unit mass, and temperatures may briefly reach the tens of millions of degrees.

Energy from a nuclear explosion is initially released in several forms of penetrating radiation. When there is surrounding material such as air, rock, or water, this radiation interacts with and rapidly heats the material to an equilibrium temperature (i.e. so that the matter is at the same temperature as the fuel powering the explosion). This causes [[vaporization]] of the surrounding material, resulting in its rapid expansion. [[Kinetic energy]] created by this expansion contributes to the formation of a shock wave which expands spherically from the center. Intense thermal radiation at the [[hypocenter]] forms a nuclear fireball which, if the explosion is low enough in altitude, is often associated with a [[mushroom cloud]]. In a high-altitude burst where the density of the atmosphere is low, more energy is released as ionizing [[gamma radiation]] and [[X-ray]]s than as an atmosphere-displacing shockwave.