Operation Ivy was the eighth series of American nuclear tests, coming after Tumbler-Snapper and before Upshot–Knothole. The two explosions were staged in late 1952 at Enewetak Atoll in the Pacific Proving Ground in the Marshall Islands.
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 lower atmosphere can be approximately divided into four basic categories:
Operation Crosstie was a series of 48 nuclear tests conducted by the United States in 1967–1968 at the Nevada Test Site. These tests followed the Operation Latchkey series and preceded the Operation Bowline series.
Ivy Mike was the codename given to the first full-scale test of a thermonuclear device, in which part of the explosive yield comes from nuclear fusion. Ivy Mike was detonated on November 1, 1952, by the United States on the island of Elugelab in Enewetak Atoll, in the now independent island nation of the Marshall Islands, as part of Operation Ivy. It was the first full test of the Teller–Ulam design, a staged fusion device.
Operation Wigwam involved a single test of the Mark 90 "Betty" nuclear bomb. It was conducted between Operation Teapot and Project 56 on May 14, 1955, about 500 miles (800 km) southwest of San Diego, California. 6,800 personnel aboard 30 ships were involved in Wigwam. The purpose of Wigwam was to determine the vulnerability of submarines to deeply detonated nuclear weapons, and to evaluate the feasibility of using such weapons in a combat situation. The task force commander, Admiral John Sylvester, was embarked on the task force flagship USS Mount McKinley. Wigwam was the first atomic test in the deep ocean, and it remains the only test that has been conducted in water deeper than 1,000 ft (300 m).
Operation Buster–Jangle was a series of seven nuclear weapons tests conducted by the United States in late 1951 at the Nevada Test Site. Buster–Jangle was the first joint test program between the DOD and Los Alamos National Laboratories. As part of Operation Buster, 6,500 troops were involved in the Operation Desert Rock I, II, and III exercises in conjunction with the tests. The last two tests, Operation Jangle, evaluated the cratering effects of low-yield nuclear devices. This series preceded Operation Tumbler–Snapper and followed Operation Greenhouse.
Operation Plumbbob was a series of nuclear tests that were conducted between May 28 and October 7, 1957, at the Nevada Test Site, following Project 57, and preceding Project 58/58A.
Operation Hardtack I was a series of 35 nuclear tests conducted by the United States from April 28 to August 18 in 1958 at the Pacific Proving Grounds. At the time of testing, the Operation Hardtack I test series included more nuclear detonations than the total of prior nuclear explosions in the Pacific Ocean. These tests followed the Project 58/58A series, which occurred from 1957 December 6 to 1958, March 14, and preceded the Operation Argus series, which took place in 1958 from August 27 to September 6.
Elugelab, or Elugelap, was an island, part of the Enewetak Atoll in the Marshall Islands. It was destroyed by the world's first true hydrogen bomb test on 1 November 1952, a test which was codenamed shot "Mike" of Operation Ivy. Prior to being destroyed, the island was described as "just another small naked island of the atoll".
There have been many extremely large explosions, accidental and intentional, caused by modern high explosives, boiling liquid expanding vapour explosions (BLEVEs), older explosives such as gunpowder, volatile petroleum-based fuels such as gasoline, and other chemical reactions. This list contains the largest known examples, sorted by date. An unambiguous ranking in order of severity is not possible; a 1994 study by historian Jay White of 130 large explosions suggested that they need to be ranked by an overall effect of power, quantity, radius, loss of life and property destruction, but concluded that such rankings are difficult to assess.
The explosive yield of a nuclear weapon is the amount of energy released when that particular nuclear weapon is detonated, usually expressed as a TNT equivalent (the standardized equivalent mass of trinitrotoluene which, if detonated, would produce the same energy discharge), either in kilotons (kt—thousands of tons of TNT), in megatons (Mt—millions of tons of TNT), or sometimes in terajoules (TJ). An explosive yield of one terajoule is equal to 0.239 kilotonnes of TNT. Because the accuracy of any measurement of the energy released by TNT has always been problematic, the conventional definition is that one kiloton of TNT is held simply to be equivalent to 1012 calories.
Operation Sailor Hat was a series of explosives effects tests, conducted by the United States Navy Bureau of Ships under the sponsorship of the Defense Atomic Support Agency. The tests consisted of two underwater explosions at San Clemente Island, California in 1964 and three surface explosions at Kahoʻolawe, Hawaii in 1965. They were non-nuclear tests employing large quantities of conventional explosives to determine the effects of a nuclear weapon blast on naval vessels, and the first major test of this kind since Operation Crossroads in July 1946.
Operation Julin was a group of 7 nuclear tests conducted by the United States in 1991–1992. These tests followed the Operation Sculpin series, and were the last before negotiations began for the Comprehensive Test Ban Treaty.
Bomb Power Indicator known by the acronym BPI was a detection instrument, located at the twenty five British Royal Observer Corps controls and nearly 1,500 ROC underground monitoring posts, across the United Kingdom, during the Cold War that would have detected any nuclear explosions and measured the peak-overpressure of the blast waves.
Misty Picture was a test conducted on May 14, 1987 by the United States Defense Nuclear Agency involving the detonation of several thousand tons of conventional explosives to simulate the explosion of a small nuclear bomb.
Operation Distant Plain was a series of non-nuclear explosive and detonable gas tests performed on test sites in Alberta, Canada, during the course of 1966 and 1967. Their purpose was to provide airblast, cratering, and ground shock data in summer and winter conditions for testing new prototype equipment, military targets and coniferous forest blowdown, and defoliation.
Operation Project 56 was a series of 4 nuclear tests conducted by the United States in 1955–1956 at the Nevada Test Site. These tests followed the Operation Wigwam series and preceded the Operation Redwing series.
Project 57 was an open-air nuclear test conducted by the United States at the Nellis Air Force Range in 1957, following Operation Redwing, and preceding Operation Plumbbob. The test area, also known as Area 13, was a 10 miles (16 km) by 16 miles (26 km) block of land abutting the northeast boundary of the Nevada National Security Site.
Operation Snowball was a conventional explosive test to obtain information on nuclear weapon detonations run by the Defence Research Board with participation from the United Kingdom and United States. A detonation of 500 short tons (454 t) of TNT was used to study the resulting phenomena. The test was held at the Suffield Experimental Station in Alberta and was the largest ever man-made, non-accidental explosion in Canada. The test was also the first of its kind using a stacked TNT block hemisphere of such magnitude, a method repeated in six subsequent tests such as Operation Sailor Hat and Prairie Flat. The test allowed verifying predicted properties of shock and blast and determining its effect on a variety of military targets at varied distances from ground zero.
Operation Prairie Flat was a test involving the detonation of a 500-short-ton (450 t) spherical surface charge of TNT to evaluate airblast, ground shock and thermal effects of nuclear weapons.
