Cannikin was an underground nuclear weapons test performed on November 6, 1971, on Amchitka island, Alaska, by the United States Atomic Energy Commission. [1] The experiment, part of the Operation Grommet nuclear test series, tested the unique W71 warhead design for the LIM-49 Spartan anti-ballistic missile. [2] [3] With an explosive yield of almost 5 megatons of TNT (21 PJ), the test was the largest underground explosion ever detonated by the United States. [4]
Prior to the main five-megaton test in 1971, a 1 Mt (4.2 PJ) test took place on the island on October 2, 1969, for calibration purposes, and to ensure the subsequent Cannikin test could be contained. [4] This test, Milrow, was included in the Operation Mandrel nuclear test series.
The Cannikin test faced considerable opposition on environmental grounds. The campaigning environmental organization Greenpeace grew out of efforts to oppose the test.
The Cannikin test was too large to be conducted safely at Nevada Test Site. [4] Amchitka had been considered in the 1950s as a potential nuclear test site, but had been deemed unsuitable at that time. [5] In 1965, a single nuclear test, Long Shot, was carried out on the island for the purposes of seismic test detection development, under program Vela Uniform. The Amchitka site was again investigated as an atmospheric nuclear test site for intercontinental ballistic missile silo design under Project Rufus in the 1960s, but the atmospheric testing component was abandoned following the establishment of the Partial Nuclear Test Ban Treaty. [6]
Preparation for the test took place over five years and involved hundreds of staff from the Lawrence Radiation Laboratory, later the Lawrence Livermore National Laboratory. Drilling for the shaft for the Milrow test began in March 1967, with drilling for the Cannikin test commencing in August 1967. [7]
To perform the test, 400 tons of equipment was placed in a shaft 1,870 metres (6,150 ft) deep and 2.3 metres (90 in) wide. Test support equipment was designed to survive a ground upheaval of 4.6 metres (15 ft) at test time. [2]
The chairman of the Atomic Energy Commission, James R. Schlesinger, brought his wife and two daughters to Amchitka for the test to emphasize the safety of the test. [8]
Both the 1969 calibration test and Cannikin itself attracted protest. Because of the 1964 Alaska earthquake, the plans raised concerns that tests might trigger earthquakes and cause a tsunami. A 1969 demonstration of 7,000 [9] people blocked a major U.S.–Canada border crossing in British Columbia, carrying signs reading "Don't Make A Wave. It's Your Fault If Our Fault Goes". [10] Further demonstrations occurred at Canada–US border crossings in Ontario and Quebec. [11] The Canadian Don't Make a Wave Committee, founded that year in Vancouver, attempted to halt further nuclear testing on the Aleutian Islands chain. [12] With the intention of sailing to Amchitka to protest the 1971 test, the committee chartered a ship it renamed Greenpeace . During the voyage to Amchitka, the test was delayed a month. The ship was turned back by the U.S. Coast Guard, although a letter given to the Greenpeace crew showed support for the protest by some on the intervening Coast Guard ship. Under their own ship's name, the organization created for the protest continued to exist as the campaigning environmental organization Greenpeace.
In July 1971, the anti-nuclear Committee for Nuclear Responsibility filed suit against the Atomic Energy Commission, asking the court to stop the test. [13] The suit was unsuccessful, with the Supreme Court denying the injunction by 4 votes to 3. [14] The test was carried out but, although it triggered small earthquakes, did not cause a tsunami as feared.
Cannikin was detonated on November 6, 1971 51°28′13.20″N179°6′40.75″E / 51.4703333°N 179.1113194°E , as the thirteenth test of the Operation Grommet (1971–1972) underground nuclear test series. The announced yield was 5 megatons (21 PJ) – the largest underground nuclear test in U.S. history. [15] [16] [17] (Estimates for the precise yield range from 4.4 [18] to 5.2 [19] megatons or 18 to 22 PJ). The ground lifted 20 feet (6 m), caused by an explosive force almost 400 times the power of the Hiroshima bomb. [20] Subsidence and faulting at the site created a new lake, several hundred meters wide. [21] : 11 The explosion caused a seismic shock of 7.0 on the Richter scale, causing rockfalls and turf slides of a total of 35,000 square feet (3,300 m2). [17] Though earthquakes and tsunamis predicted by environmentalists did not occur, [14] a number of small tectonic events did occur in the following weeks, (some registering as high as 4.0 on the richter scale) thought to be due to the interaction of the explosion with local tectonic stresses. [22]
The Tsar Bomba, also known by the alphanumerical designation "AN602", was a thermonuclear aerial bomb, and the most powerful nuclear weapon ever created and tested. The Soviet physicist Andrei Sakharov oversaw the project at Arzamas-16, while the main work of design was by Sakharov, Viktor Adamsky, Yuri Babayev, Yuri Smirnov, and Yuri Trutnev. The project was ordered by Nikita Khrushchev in July 1961 as part of the Soviet resumption of nuclear testing after the Test Ban Moratorium, with the detonation timed to coincide with the 22nd Congress of the Communist Party of the Soviet Union.
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.
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.
Nuclear weapons tests are experiments carried out to determine the performance, yield, and effects of nuclear weapons. Testing nuclear weapons offers practical information about how the weapons function, how detonations are affected by different conditions, and how personnel, structures, and equipment are affected when subjected to nuclear explosions. However, nuclear testing has often been used as an indicator of scientific and military strength. Many tests have been overtly political in their intention; most nuclear weapons states publicly declared their nuclear status through a nuclear test.
Red Snow was a British thermonuclear weapon, based on the US W28 design used in the B28 thermonuclear bomb and AGM-28 Hound Dog missile. The US W28 had yields of 70, 350, 1,100 and 1,450 kilotonnes of TNT and while Red Snow yields are still classified, declassified British documents indicate the existence of "kiloton Red Snow" and "megaton Red Snow" variants of the weapon, suggesting similar yield options, while other sources have suggested a yield of approximately 1 megatonne of TNT (4.2 PJ).
Amchitka is a volcanic, tectonically unstable and uninhabited island in the Rat Islands group of the Aleutian Islands in southwest Alaska. It is part of the Alaska Maritime National Wildlife Refuge. The island, with a land area of roughly 116 square miles (300 km2), is about 42 miles (68 km) long and 1 to 4 miles wide. The area has a maritime climate, with many storms, and mostly overcast skies.
Storax Sedan was a shallow underground nuclear test conducted in Area 10 of Yucca Flat at the Nevada National Security Site on July 6, 1962, as part of Operation Plowshare, a program to investigate the use of nuclear weapons for mining, cratering, and other civilian purposes. The radioactive fallout from the test contaminated more US residents than any other nuclear test. The Sedan Crater is the largest human-made crater in the United States and is listed on the National Register of Historic Places.
In 1952, the United Kingdom became the third country to develop and test nuclear weapons, and is one of the five nuclear-weapon states under the Treaty on the Non-Proliferation of Nuclear Weapons.
Operation Fishbowl was a series of high-altitude nuclear tests in 1962 that were carried out by the United States as a part of the larger Operation Dominic nuclear test program.
The Don't Make a Wave Committee was the name of the anti-nuclear organization which later evolved into Greenpeace, a global environmental organization. The Don't Make a Wave Committee was founded in Vancouver, British Columbia, Canada to protest and attempt to halt further underground nuclear testing by the United States in the National Wildlife Refuge at Amchitka in the Aleutian Islands of Alaska. The Don't Make a Wave Committee was first formed in October 1969 and officially established in early 1970.
The W71 nuclear warhead was a US thermonuclear warhead developed at Lawrence Livermore National Laboratory in California and deployed on the LIM-49A Spartan missile, a component of the Safeguard Program, an anti-ballistic missile (ABM) defense system briefly deployed by the US in the 1970s.
Underground nuclear testing is the test detonation of nuclear weapons that is performed underground. When the device being tested is buried at sufficient depth, the nuclear explosion may be contained, with no release of radioactive materials to the atmosphere.
Operation Redwing was a United States series of 17 nuclear test detonations from May to July 1956. They were conducted at Bikini and Enewetak atolls by Joint Task Force 7 (JTF7). The entire operation followed Project 56 and preceded Project 57. The primary intention was to test new, second-generation thermonuclear weapons. Also tested were fission devices intended to be used as primaries for thermonuclear weapons, and small tactical weapons for air defense. Redwing demonstrated the first United States airdrop of a deliverable hydrogen bomb during test Cherokee. Because the yields for many tests at Operation Castle in 1954 were dramatically higher than predictions, Redwing was conducted using an "energy budget": There were limits to the total amount of energy released, and the amount of fission yield was also strictly controlled. Fission, primarily "fast" fission of the natural uranium tamper surrounding the fusion capsule, greatly increases the yield of thermonuclear devices, and constitutes the great majority of the fallout, as nuclear fusion is a relatively clean reaction.
Operation Fusileer was a series of 16 nuclear tests conducted by the United States in 1983–1984 at the Nevada Test Site. These tests followed the Operation Phalanx series and preceded the Operation Grenadier series.
Amchitka Air Force Base is an abandoned Air Force Base located on Amchitka, in the Rat Islands group of the Aleutian Islands in southwest Alaska.
The military history of the Aleutian Islands began almost immediately following the purchase of Alaska from the Russian Empire by the United States in 1867. Prior to the early 20th century, the Aleutian Islands were essentially ignored by the United States Armed Forces, although the islands played a small role in the Bering Sea Arbitration when a number of British and American vessels were stationed at Unalaska to enforce the arbitrators' decision. By the early 20th century, a number of war strategies examined the possibility of conflict breaking out between the Empire of Japan and the United States. While the Aleutian Islands were seen as a potential staging point for invasions by either side, this possibility was dismissed owing to the islands' dismal climate. In 1922, the Washington Naval Treaty was signed, after which the United States Navy began to take an interest in the islands. However, nothing of significance was to materialize until World War II.
Operation Dominic was a series of 31 nuclear test explosions ("shots") with a 38.1 Mt (159 PJ) total yield conducted in 1962 by the United States in the Pacific. This test series was scheduled quickly, in order to respond in kind to the Soviet resumption of testing after the tacit 1958–1961 test moratorium. Most of these shots were conducted with free fall bombs dropped from B-52 bomber aircraft. Twenty of these shots were to test new weapons designs; six to test weapons effects; and several shots to confirm the reliability of existing weapons. The Thor missile was also used to lift warheads into near-space to conduct high-altitude nuclear explosion tests; these shots were collectively called Operation Fishbowl.
Project Rufus was a United States nuclear weapons program aimed at investigation and selection of sites within the United States and its possessions that would be suitable for high-yield atmospheric nuclear testing programs. The project's primary purpose was to identify locations where a Minuteman missile silo could be tested under realistic conditions. The project operated under the umbrella of the Vela Uniform research program.
the AEC instituted an extensive bioenvironmental program on Amchitka, and within a few years had completed Project Milrow, Project Long Shot, and Project Cannikin
Pursuant to section 142d of the Atomic Energy Act of 1954, you determine that the following information can be published without undue risk to the common defense and security and can therefore be declassified and removed from the Formerly Restricted Data category: The fact that the Cannikin event was a proof test of the W71 warhead for the Spartan missile system.
This test, by far the highest-yield underground test ever conducted by the United States, was too large to be safely conducted in Nevada
For the Milrow detonation, drilling began March 9, 1967
James Schlesinger, then AEC chairman, brought his wife and two daughters to Amchitka for the Cannikin blast