Editing Nuclear weapons testing (section)

==Types==
[[File:Types of nuclear testing.svg|thumb|Four major types of nuclear testing: 1. atmospheric, 2. [[underground nuclear testing|underground]], 3. exoatmospheric, and 4. underwater]]
Nuclear weapons tests have historically been divided into four categories reflecting the medium or location of the test.

*'''Atmospheric''' testing involves explosions that take place in the [[Atmosphere of Earth|atmosphere]]. Generally, these have occurred as devices detonated on [[Bomb tower|towers]], balloons, barges, or islands, or dropped from airplanes, and also those only buried far enough to intentionally create a surface-breaking crater. The United States, the Soviet Union, and China have all conducted tests involving explosions of missile-launched warheads (See [[List of nuclear weapons tests#Tests of live warheads on rockets]]). Nuclear explosions close enough to the ground to draw dirt and debris into their [[mushroom cloud]] can generate large amounts of [[nuclear fallout]] due to [[irradiation]] of the debris (particularly with [[neutron radiation]]) as well as [[radioactive contamination]] of otherwise non-radioactive material. This definition of atmospheric is used in the [[Limited Test Ban Treaty]], which banned this class of testing along with exoatmospheric and underwater.
*'''Underground''' testing is conducted under the surface of the earth, at varying depths. [[Underground nuclear testing]] made up the majority of nuclear tests by the United States and the Soviet Union during the [[Cold War]]; other forms of nuclear testing were banned by the [[Limited Test Ban Treaty]] in 1963. True underground tests are intended to be fully contained and emit a negligible amount of fallout. Unfortunately these nuclear tests do occasionally "vent" to the surface, producing from nearly none to considerable amounts of radioactive debris as a consequence. Underground testing, almost by definition, causes [[seismic]] activity of a magnitude that depends on the [[nuclear weapon yield|yield]] of the nuclear device and the composition of the medium in which it is detonated, and generally creates a [[subsidence crater]].<ref>For a longer and more technical discussion, see {{cite book|title=The Containment of Underground Nuclear Explosions|url=http://www.nv.doe.gov/library/publications/historical/OTA-ISC-414.pdf|publisher=US Government Printing Office|date=October 1989|location=Washington, D.C.|author=US Congress, Office of Technology Assessment|access-date=2018-12-24|archive-url=https://web.archive.org/web/20130227180158/http://www.nv.doe.gov/library/publications/historical/OTA-ISC-414.pdf|archive-date=2013-02-27|url-status=dead}}</ref> In 1976, the United States and the USSR agreed to limit the maximum yield of underground tests to 150 [[kiloton|kt]] with the [[Threshold Test Ban Treaty]].<br />Underground testing also falls into two physical categories: tunnel tests in generally horizontal tunnel ''drifts'', and shaft tests in vertically drilled holes.
*'''Exoatmospheric''' testing is conducted above the atmosphere. The test devices are lifted on rockets. These [[high-altitude nuclear explosion]]s can generate a [[nuclear electromagnetic pulse]] (NEMP) when they occur in the [[ionosphere]], and charged particles resulting from the blast can cross hemispheres following [[magnetosphere|geomagnetic lines of force]] to create an auroral display.
*'''Underwater''' testing involves nuclear devices being [[Underwater explosion|detonated underwater]], usually moored to a ship or a barge (which is subsequently destroyed by the explosion). Tests of this nature have usually been conducted to evaluate the effects of nuclear weapons against naval vessels (such as in [[Operation Crossroads]]), or to evaluate potential sea-based nuclear weapons (such as [[nuclear torpedo]]es or [[nuclear depth charge|depth charges]]). Underwater tests close to the surface can disperse large amounts of radioactive particles in water and steam, contaminating nearby ships or structures, though they generally do not create fallout other than very locally to the explosion.

===Salvo tests===
Another way to classify nuclear tests is by the number of explosions that constitute the test.  The treaty definition of a salvo test is:

<blockquote>In conformity with treaties between the United States and the Soviet Union, a salvo is defined, for multiple explosions for peaceful purposes, as two or more separate explosions where a period of time between successive individual explosions does not exceed 5 seconds and where the burial points of all explosive devices can be connected by segments of straight lines, each of them connecting two burial points, and the total length does not exceed 40 kilometers. For nuclear weapon tests, a salvo is defined as two or more underground nuclear explosions conducted at a test site within an area delineated by a circle having a diameter of two kilometers and conducted within a total period of time of 0.1 seconds.<ref>{{cite web|title=Worldwide Nuclear Explosions| first1=Xiaoping| last1=Yang| first2=Robert| last2=North |first3=Carl| last3=Romney| first4=Paul R.| last4=Richards| url=http://www.ldeo.columbia.edu/~richards/my_papers/WW_nuclear_tests_IASPEI_HB.pdf}}</ref></blockquote>

The USSR has exploded up to eight devices in a single salvo test; Pakistan's second and last official test exploded four different devices.  Almost all lists in the literature are lists of tests; in the lists in Wikipedia (for example, ''[[Operation Cresset]]'' has separate items for ''Cremino'' and ''Caerphilly'', which together constitute a single test), the lists are of explosions.