The Pacific Proving Grounds was the name given by the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

government to a number of sites in the

Marshall Islands The Marshall Islands ( mh, Ṃajeḷ), officially the Republic of the Marshall Islands ( mh, Aolepān Aorōkin Ṃajeḷ),'' () is an independent island country and microstate near the Equator in the Pacific Ocean, slightly west of the Intern ...

and a few other sites in the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contin ...

at which it conducted nuclear testing between 1946 and 1962. The U.S.

tested ''Tested'' is a live album by punk rock band Bad Religion. It was recorded in the USA, Canada, Germany, Estonia, Denmark, Italy and Austria, in 1996, and released in 1997. It is Bad Religion's second live album. Instead of using crowd microphon ...

a nuclear weapon (codenamed Able) on

Bikini Atoll Bikini Atoll ( or ; Marshallese: , , meaning "coconut place"), sometimes known as Eschscholtz Atoll between the 1800s and 1946 is a coral reef in the Marshall Islands consisting of 23 islands surrounding a central lagoon. After the Seco ...

on June 30, 1946. This was followed by Baker on July 24, 1946 (dates are

Universal Time Universal Time (UT or UT1) is a time standard based on Earth's rotation. While originally it was mean solar time at 0° longitude, precise measurements of the Sun are difficult. Therefore, UT1 is computed from a measure of the Earth's angle wit ...

, local dates were July 1 and 25, respectively). On July 18, 1947, the United States secured an agreement with the

United Nations The United Nations (UN) is an intergovernmental organization whose stated purposes are to maintain international peace and security, develop friendly relations among nations, achieve international cooperation, and be a centre for harmoniz ...

to govern the islands of Micronesia as the

Trust Territory of the Pacific Islands The Trust Territory of the Pacific Islands (TTPI) was a United Nations trust territory in Micronesia administered by the United States from 1947 to 1994. History Spain initially claimed the islands that later composed the territory of the Trus ...

, a strategic trusteeship territory. This is the only such trusteeship ever granted by the United Nations to the United States. The Trust Territory comprised about 2,000 islands spread over of the

North Pacific Ocean North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating direction or geography. Etymology The word ''north'' i ...

. Five days later, the

United States Atomic Energy Commission The United States Atomic Energy Commission (AEC) was an agency of the United States government established after World War II by U.S. Congress to foster and control the peacetime development of atomic science and technology. President ...

established the Pacific Proving Grounds. The United States conducted 105 atmospheric and underwater (i.e., not

underground Underground most commonly refers to: * Subterranea (geography), the regions beneath the surface of the Earth Underground may also refer to: Places * The Underground (Boston), a music club in the Allston neighborhood of Boston * The Underground ...

)

nuclear test Nuclear weapons tests are experiments carried out to determine nuclear weapons' effectiveness, Nuclear weapon yield, yield, and explosive capability. Testing nuclear weapons offers practical information about how the weapons function, how detona ...

s in the Pacific, many with extremely high yields. While the Marshall Islands testing composed 14% of all U.S. tests, it composed nearly 80% of the total yields of those detonated by the U.S., with an estimated total yield of around 210

megatons TNT equivalent is a convention for expressing energy, typically used to describe the energy released in an explosion. The is a unit of energy defined by that convention to be , which is the approximate energy released in the detonation of a m ...

, with the largest being the 15 Mt

Castle Bravo Castle Bravo was the first in a series of high-yield thermonuclear weapon design tests conducted by the United States at Bikini Atoll, Marshall Islands, as part of '' Operation Castle''. Detonated on March 1, 1954, the device was the most powerful ...

shot of 1954 which spread considerable

nuclear fallout Nuclear fallout is the residual radioactive material propelled into the upper atmosphere following a nuclear blast, so called because it "falls out" of the sky after the explosion and the shock wave has passed. It commonly refers to the radioac ...

on many of the islands, including several that were inhabited and some that had not been evacuated. Many of the islands which were part of the Pacific Proving Grounds are still contaminated from the

, and many of those who were living on the islands at the time of testing have suffered from an increased incidence of various health problems. Through the

Radiation Exposure Compensation Act The United States Radiation Exposure Compensation Act (RECA) is a federal statute providing for the monetary compensation of people, including atomic veterans, who contracted cancer and a number of other specified diseases as a direct result of t ...

of 1990, at least $759 million has been paid to Marshall Islanders as compensation for their exposure to U.S. nuclear testing. Following the Castle Bravo accident, the U.S. paid $15.3 million to Japan. Scientists have calculated that the residents of the

during their lifetimes will be diagnosed with an added 1.6% (with 90% uncertainty range 0.4% to 3.4%) cancers attributable to fallout-related radiation exposures. The cancers are the consequence of exposure to ionizing radiation from weapons test fallout deposited during the testing period (1948–1958) and from residual radioactive sources during the subsequent 12 years (1959–1970).

Strategic Trust Territory

On July 18, 1947, the United States convinced the United Nations to designate the islands of Micronesia as the Strategic Trust Territory. This was the only trust ever granted by the U.N. The directive stated that the United States should "promote the economic advancement and self-sufficiency of the inhabitants, and to this end shall... protect the inhabitants against the loss of their lands and resources..." The

United States Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...

controlled the Trust from a headquarters in

Guam Guam (; ch, Guåhan ) is an organized, unincorporated territory of the United States in the Micronesia subregion of the western Pacific Ocean. It is the westernmost point and territory of the United States (reckoned from the geographic cent ...

until 1951, when the

United States Department of the Interior The United States Department of the Interior (DOI) is one of the executive departments of the U.S. federal government headquartered at the Main Interior Building, located at 1849 C Street NW in Washington, D.C. It is responsible for the ma ...

took over control, administering the territory from a base in Saipan. Despite the promise to "protect the inhabitants", from July 1946 through July 1947, the residents of Bikini Atoll who had been relocated to Rongerik Atoll were starving for lack of food. A team of U.S. investigators concluded in late 1947 that the islanders must be moved immediately. Press from around the world harshly criticized the U.S. Navy for ignoring the people. Harold Ickes, a syndicated columnist, wrote "The natives are actually and literally starving to death." The islanders were later moved again to

Kili Island Kili Island or Kili Atoll ( Marshallese: , ) is a small, () island located in the Marshall Islands in the Pacific Ocean. It is the temporary home of 548 inhabitants who are descended from islanders who originally lived on Bikini Atoll. They were ...

, which is not surrounded by a reef. The island does not support the inhabitants' traditional way of life.

Radiation exposure

Because of the large amount of atmospheric testing, and especially the

accident of 1954, many of the islands which were part of the Pacific Proving Grounds are still contaminated by

. Scientists calculated in 2010 that during the lifetimes of members of the

population, potentially exposed to ionizing radiation from weapons test fallout deposited during the testing period (1948-1958) and from residual radioactive sources during the subsequent 12 years (1959-1970), perhaps 1.6% (with 90% uncertainty range 0.4% to 3.4%) of all cancers might be attributable to fallout-related radiation exposures. By sub-population, the projected proportion of cancers attributable to radiation from fallout from all nuclear tests conducted in the Marshall Islands is 55% (with a 28% to 69% uncertainty range) among 82 persons exposed in 1954 on

Rongelap Atoll Rongelap Atoll ( Marshallese: , ) is a coral atoll of 61 islands (or motus) in the Pacific Ocean, and forms a legislative district of the Ralik Chain of the Marshall Islands. Its total land area is . It encloses a lagoon with an area of . ...

and

Ailinginae Atoll Ailinginae Atoll ( Marshallese: , ) is an uninhabited (due to Castle Bravo nuclear testing) coral atoll of 25 islands in the Pacific Ocean, on the northern end of the Ralik Chain of the Marshall Islands. Its total land area is only , but it en ...

, 10% (2.4% to 22%) for 157 persons exposed on

Utirik Atoll Utirik Atoll or Utrik Atoll ( Marshallese: , ) is a coral atoll of 10 islands in the Pacific Ocean, and forms a legislative district of the Ratak Chain of the Marshall Islands. Its total land area is only , but it encloses a lagoon with an area ...

, and 2.2% (0.5% to 4.8%) and 0.8% (0.2% to 1.8%), respectively, for the much larger populations exposed in mid-latitude locations including

Kwajalein Kwajalein Atoll (; Marshallese: ) is part of the Republic of the Marshall Islands (RMI). The southernmost and largest island in the atoll is named Kwajalein Island, which its majority English-speaking residents (about 1,000 mostly U.S. civil ...

and in southern locations including

Majuro Majuro (; Marshallese: ' ) is the capital and largest city of the Marshall Islands. It is also a large coral atoll of 64 islands in the Pacific Ocean. It forms a legislative district of the Ratak (Sunrise) Chain of the Marshall Islands. The ato ...

Compensation

Since 1956, the U.S. has paid at least $759 million to Marshall Islanders as compensation for their exposure to U.S. nuclear testing. Following the Castle Bravo accident on March 1, 1954, the U.S. paid $15.3 million to Japan. In June 1983, the U.S. and the Marshall islanders signed the

Compact of Free Association The Compact of Free Association (COFA) is an international agreement establishing and governing the relationships of free association between the United States and the three Pacific Island sovereign states of the Federated States of Micronesia (F ...

, which gave the Marshall Islands independence. The Compact became effective in 1986 and was subsequently modified by the Amended Compact that became effective in 2004. It also established the

Nuclear Claims Tribunal Marshall Islands Nuclear Claims Tribunal is an international arbitral tribunal established pursuant to the Agreement Between the Government of the United States and the Government of the Marshall Islands for the Implementation of Section 177 of the ...

, which was given the task of adjudicating compensation for victims and families affected by the nuclear testing program. Section 177 of the compact provided for reparations to the Bikini islanders and other northern atolls for damages. It included $150 million to be paid over a 15-year period ending in 2001. During that time, payments averaging about $18 million per year were made to the peoples of Bikini, Enewetak, Rongelap, and Utrik for medical and radiological monitoring, and in response to claims. The payments began in 1987 with $2.4 million paid annually to the entire Bikini population, while the remaining $2.6 million is paid into ''The Bikini Claims Trust Fund''. This trust is intended to exist in perpetuity and to provide the islanders a 5% payment from the trust annually. The United States also passed the

in 1990 to allow individuals to file claims for compensation in relation to testing as well as those employed at nuclear weapons facilities. On March 5, 2001, the Nuclear Claims Tribunal ruled against the United States for damages done to the islands and its people. The Nuclear Claims Tribunal awarded the islanders a total of $563,315,500 after deducting past awards. However, the U.S. Congress has failed to fund the settlement. The only recourse is for the Bikini people to petition the U.S. Congress to fund the payment and fulfill this award. The United States Supreme Court turned down the islanders' appeal of the

United States courts of appeals The United States courts of appeals are the intermediate appellate courts of the United States federal judiciary. The courts of appeals are divided into 11 numbered circuits that cover geographic areas of the United States and hear appeals f ...

decision that refused to compel the government to fund their claim. , trusts remaining from the settlement produced about USD$6 to $8 million annually in investment income, and the trusts paid out about USD$15,000 per family each year in benefits.

Testing chronology

Operation Crossroads (1946)

The first use of the Pacific Proving Grounds was during

Operation Crossroads Operation Crossroads was a pair of nuclear weapon tests conducted by the United States at Bikini Atoll in mid-1946. They were the first nuclear weapon tests since Trinity in July 1945, and the first detonations of nuclear devices since the ...

, the first nuclear testing done after the

atomic bombing of Hiroshima and Nagasaki The United States detonated two atomic bombs over the Japanese cities of Hiroshima and Nagasaki on 6 and 9 August 1945, respectively. The two bombings killed between 129,000 and 226,000 people, most of whom were civilians, and remain the on ...

. Two fission bombs, both with a yield of 21 kilotons, were

. "Able" was detonated at an altitude of 520 ft (158 m) on July 1, 1946, and "Baker" was detonated at a depth of 90 ft (27 m) underwater on July 25. Both tests used a flotilla of obsolete vessels from

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...

with the intent of learning the effects of nuclear weapons on naval fleets. The "Baker" shot created a large condensation cloud and spread much more

radioactive Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is consi ...

water onto the ships than was expected; many of the surviving ships became too "hot" to be used or decontaminated and eventually had to be sunk.

Operation Sandstone (1948)

Three weapons were detonated on the Enewetak Atoll as part of

Operation Sandstone Operation Sandstone was a series of nuclear weapon tests in 1948. It was the third series of American tests, following Trinity in 1945 and Crossroads in 1946, and preceding Ranger. Like the Crossroads tests, the Sandstone tests were carried ou ...

in 1948.

Operation Greenhouse (1951)

Four weapons were detonated on the Enewetak Atoll as part of

Operation Greenhouse Operation Greenhouse was the fifth American nuclear test series, the second conducted in 1951 and the first to test principles that would lead to developing thermonuclear weapons (''hydrogen bombs''). Conducted at the new Pacific Proving Gro ...

in 1951. Two are of particular note: Greenhouse "Item" was the first use of a

boosted fission weapon A boosted fission weapon usually refers to a type of nuclear bomb that uses a small amount of fusion fuel to increase the rate, and thus yield, of a fission reaction. The neutrons released by the fusion reactions add to the neutrons released ...

, and "George" was a

thermonuclear Thermonuclear fusion is the process of atomic nuclei combining or “fusing” using high temperatures to drive them close enough together for this to become possible. There are two forms of thermonuclear fusion: ''uncontrolled'', in which the re ...

experiment designed to prove the feasibility of the

Teller-Ulam design A thermonuclear weapon, fusion weapon or hydrogen bomb (H bomb) is a second-generation nuclear weapon design. Its greater sophistication affords it vastly greater destructive power than first-generation nuclear bombs, a more compact size, a lowe ...

for the possibility of developing hydrogen bombs.

Operation Ivy (1952)

Two weapons were detonated at the Enewetak Atoll as part of Operation Ivy in 1952. One of them, Ivy King, was the largest pure-fission bomb ever detonated, with a yield of 500

kiloton TNT equivalent is a convention for expressing energy, typically used to describe the energy released in an explosion. The is a unit of energy defined by that convention to be , which is the approximate energy released in the detonation of a ...

s, and the other,

Ivy Mike 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 ...

, was the first hydrogen bomb device (it was too large to be an actual weapon), with a yield of 10.4 Mt.

Operation Castle (1954)

Six very large nuclear tests were conducted at the

and the Enewetak Atoll as part of

Operation Castle Operation Castle was a United States series of high-yield (high-energy) nuclear tests by Joint Task Force 7 (JTF-7) at Bikini Atoll beginning in March 1954. It followed ''Operation Upshot–Knothole'' and preceded ''Operation Teapot''. Condu ...

in 1954. The most notable was

, which was the first deployable (dry fuel) hydrogen bomb developed by the United States. Its yield, at 15 Mt, was over twice as powerful as was predicted, and remains the largest weapon ever detonated by the United States. It spread

over a wide area, including the Enewetak Atoll,

Rongerik Atoll Rongerik Atoll or Rongdrik Atoll ( Marshallese: , ) is a coral atoll of 17 islands in the Pacific Ocean, and is located in the Ralik Chain of the Marshall Islands, approximately east of Bikini Atoll. Its total land area is only , but it enclose ...

, and

. The U.S. Navy evacuated the islanders within the next few days, but many of the natives were exposed to radiation prior to evacuation. The fishermen aboard the Japanese fishing vessel, the '' Daigo Fukuryu Maru'', were additionally exposed and one man died soon after from complications of radiation sickness, resulting in considerable international controversy.

Operation Redwing (1956)

Seventeen nuclear weapons were detonated on the Bikini and Enewetak Atolls as part of

Operation Redwing 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).Blumenson, Martin and Hugh D. Hexamer (1956). ''A History of ...

in 1956. Many of them were designed to prove the feasibility of numerous

thermonuclear weapon A thermonuclear weapon, fusion weapon or hydrogen bomb (H bomb) is a second-generation nuclear weapon design. Its greater sophistication affords it vastly greater destructive power than first-generation nuclear bombs, a more compact size, a low ...

designs, with yields ranging from around 2 to 5 Mt.

Operation Hardtack I (1958)

Thirty-five weapons were detonated at the Bikini Atoll, Enewetak Atoll, and

Johnston Island Johnston Atoll is an unincorporated territory of the United States, currently administered by the United States Fish and Wildlife Service (USFWS). Johnston Atoll is a National Wildlife Refuge and part of the Pacific Remote Islands Marine Natio ...

as part of

Operation Hardtack I 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 detonation ...

in 1958.

Operation Dominic (1962)

Thirty-six weapons were detonated at sites in the Pacific Ocean in the vicinity of

Christmas Island Christmas Island, officially the Territory of Christmas Island, is an Australian external territory comprising the island of the same name. It is located in the Indian Ocean, around south of Java and Sumatra and around north-west of the ...

and Johnston Atoll as part of Operation Dominic I. Though these tests were not conducted in the Marshall Islands, they are officially considered part of the Pacific Proving Grounds. The portion of the Dominic series of tests that were

high altitude nuclear explosion High-altitude nuclear explosions are the result of nuclear weapons testing within the upper layers of the Earth's atmosphere and in outer space. Several such tests were performed at high altitudes by the United States and the Soviet Union betwe ...

s were known as

Operation Fishbowl 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. Flight-test vehicles were designed and manufactured by Avco ...

, though not all were successful (one detonated on launchpad and resulted in a substantial

plutonium Plutonium is a radioactive chemical element with the symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, and forms a dull coating when oxidized. The element normally exhibi ...

contamination). Two of the tests were of operational weapons systems—the

ASROC The RUR-5 ASROC (for "Anti-Submarine Rocket") is an all-weather, all sea-conditions anti-submarine missile system. Developed by the United States Navy in the 1950s, it was deployed in the 1960s, updated in the 1990s, and eventually installed ...

anti-submarine rocket and the Polaris

SLBM A submarine-launched ballistic missile (SLBM) is a ballistic missile capable of being launched from submarines. Modern variants usually deliver multiple independently targetable reentry vehicles (MIRVs), each of which carries a nuclear warhe ...

(the latter test, Frigate Bird, was the only operational submarine-launched ballistic missile test with a live warhead ever undertaken by the USA).

Partial Test Ban Treaty

The signing of the

Partial Test Ban Treaty The Partial Test Ban Treaty (PTBT) is the abbreviated name of the 1963 Treaty Banning Nuclear Weapon Tests in the Atmosphere, in Outer Space and Under Water, which prohibited all test detonations of nuclear weapons except for those conducted ...

in 1963 forbade atmospheric and underwater nuclear weapons, and so no further U.S. tests were conducted at the Pacific Proving Grounds, with all but ten occurring at the

Nevada Test Site The Nevada National Security Site (N2S2 or NNSS), known as the Nevada Test Site (NTS) until 2010, is a United States Department of Energy (DOE) reservation located in southeastern Nye County, Nevada, about 65 miles (105 km) northwest of the ...

until the end of testing in 1992.

Geographical names

The Bikini and Enewetak Atolls are each a collection of islands. Various names have been assigned to the islands over time, and the confusion over the names (and their alternate transliterations) have been the source of much confusion, and in addition, over time islands appear, disappear, separate and join, and are excavated by bombs. Here are the islands listed in clockwise fashion starting with left side of the major inlet into the lagoon in each atoll. The names include the official Marshall Island names, the American military names used after occupation through the atomic testing period, and the Japanese names used while they occupied the islands during World War II, plus names gleaned from other sources.

Explanatory notes

References

External links

"Gallery of U.S. Nuclear Tests"
at Carey Sublette's NuclearWeaponArchive.org

* ttp://www.bikiniatoll.com/ Bikini Atoll official websitebr>Republic of the Marshall Islands Nuclear Claims Tribunal
{{US Nuclear Tests American nuclear test sites Nuclear weapons infrastructure of the United States Proving grounds Bikini Atoll Enewetak Atoll Nuclear test sites Trust Territory of the Pacific Islands 1947 establishments in the United States 1947 establishments in Oceania