The United States began using the Marshall Islands as a nuclear testing site beginning in 1946.

The location of the Marshall Islands, where the Pacific Proving Grounds were located.

The Pacific Proving Grounds was the name used to describe a number of sites in the Marshall Islands, in the Pacific Ocean, used by the United States to conduct nuclear testing at various times between 1946 and 1962. 67 atmospheric (i.e., not underground) nuclear tests were conducted there, many of which were of extremely high yield. While the Marshall Islands testing comprised on 14% of all U.S. tests, it comprised nearly 80% of the total yields of those detonated by the U.S., with an estimated total yield of 174 megatons, with the largest being the 15 Mt Castle Bravo shot of 1954 which spread considerable nuclear fallout on many of the islands. Image File history File links The Baker shot of Operation Crossroads, at the Bikini Atoll, 1946. ... Image File history File links The Baker shot of Operation Crossroads, at the Bikini Atoll, 1946. ... A nuclear test explosion is an experiment involving the detonation of a nuclear weapon. ... 1946 was a common year starting on Tuesday. ... Wikipedia does not have an article with this exact name. ... A nuclear test explosion is an experiment involving the detonation of a nuclear weapon. ... 1946 was a common year starting on Tuesday. ... 1962 was a common year starting on Monday (link will take you to calendar). ... A megaton or megatonne is a unit of mass equal to 1,000,000 metric tons, i. ... Castle Bravo was the code name given to the first U.S. test of a so-called dry fuel thermonuclear device, detonated on March 1, 1954 by the United States, as the first test of Operation Castle (a longer series of tests of various devices). ... 1954 was a common year starting on Friday of the Gregorian calendar. ... Fallout is the residual radiation hazard from a nuclear explosion and is named from the fact that it falls out of the atmosphere in to which it is spread during the explosion. ...

Testing chronology

Operation Crossroads (1946)

The "Baker" shot of Operation Crossroads in 1946 was an underwater shot.

Main article: Operation Crossroads

The first use of the Pacific Proving Grounds was during Operation Crossroads, the first nuclear testing done after the atomic bombing of Hiroshima and Nagasaki. Two fission bombs were detonated at the Bikini Atoll, one ("Able") from an altitude of 520 ft (158 m) on July 1, 1946, and another ("Baker") was detonated a depth of 90 ft (27 m) underwater on July 25. Download high resolution version (800x629, 70 KB)A 21 kiloton underwater nuclear weapons effects test, known as Operation CROSSROADS (Event Baker), conducted at Bikini Atoll (1946). ... Download high resolution version (800x629, 70 KB)A 21 kiloton underwater nuclear weapons effects test, known as Operation CROSSROADS (Event Baker), conducted at Bikini Atoll (1946). ... A 21 kiloton underwater nuclear weapons effects test, known as Operation Crossroads (Event Baker), conducted at Bikini Atoll (1946). ... 1946 was a common year starting on Tuesday. ... A 21 kiloton underwater nuclear weapons effects test, known as Operation Crossroads (Event Baker), conducted at Bikini Atoll (1946). ... A 21 kiloton underwater nuclear weapons effects test, known as Operation Crossroads (Event Baker), conducted at Bikini Atoll (1946). ... Citizens of Hiroshima walk by the A-Bomb Dome, the closest building to have survived the citys atomic bombing. ... Bikini Atoll - NASA NLT Landsat 7 (Visible Color) Satellite Image Bikini Atoll (also known as Pikinni Atoll) is an uninhabited 6. ... July 1 is the 182nd day of the year (183rd in leap years) in the Gregorian Calendar, with 183 days remaining. ... 1946 was a common year starting on Tuesday. ... July 25 is the 206th day (207th in leap years) of the year in the Gregorian calendar, with 159 days remaining. ...

Operation Sandstone (1948)

Main article: Operation Sandstone

Three weapons were detonated on the Enewetak Atoll as part of Operation Sandstone in 1948. Operation Sandstone was the third American series of nuclear weapon tests conducted in 1948 at Eniwetok Atoll. ... Enewetak (or Eniwetok) is an atoll in the Marshall Islands of the central Pacific Ocean. ... Operation Sandstone was the third American series of nuclear weapon tests conducted in 1948 at Eniwetok Atoll. ... 1948 is a leap year starting on Thursday (link will take you to calendar). ...

Operation Greenhouse (1951)

Main article: Operation Greenhouse

Four weapons were detonated on the Enewetak Atoll as part of Operation Greenhouse in 1951. Two are of particular note: Greenhouse "Item" was the first use of a boosted fission weapon, and "George" was a thermonuclear experiment designed to prove the feasibility of the Teller-Ulam design for the possibility of developing hydrogen bombs. Operation Greenhouse was the fifth American nuclear test series, the second conducted in 1951 and the first to test thermonuclear weapons (hydrogen bombs). ... Operation Greenhouse was the fifth American nuclear test series, the second conducted in 1951 and the first to test thermonuclear weapons (hydrogen bombs). ... 1951 was a common year starting on Monday; see its calendar. ... Boosted fission weapons are 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 basics of the Teller-Ulam configuration: a fission bomb uses radiation to compress and heats a separate section of fusion fuel. ...

Operation Ivy (1952)

Main article: Operation Ivy

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 kilotons, and the other, Ivy Mike, was the first hydrogen bomb device (it was too large to be an actual weapon), with a yield of 10.6 Mt. This page is about Operation Ivy, the nuclear test. ... This page is about Operation Ivy, the nuclear test. ... 1952 - Wikipedia, the free encyclopedia /**/ @import /skins-1. ... Ivy Kings mushroom cloud. ... A megaton or megatonne is a unit of mass equal to 1,000,000 metric tons, i. ... The mushroom cloud from the Mike shot. ... A megaton or megatonne is a unit of mass equal to 1,000,000 metric tons, i. ...

Operation Castle (1954)

The Castle Bravo test of 1954 spread nuclear fallout across the Marshall Islands.

Main article: Operation Castle

Six very large nuclear tests were conducted at the Bikini Atoll and the Enewetak Atoll as part of Operation Castle in 1954. The most notable was Castle Bravo, 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 was the largest weapon ever detonated by the United States. It spread nuclear fallout over a wide area, including the Enewetak Atoll, Rongerik Atoll, Aninginae Atoll, and Rongelap Atoll. An evacuation ensued, but many of the natives exposed suffered from cancers and a high incident of birth defects. A Japanese fishing boat was additionally exposed and resulted in one death from radiation sickness, which gained considerable international attention. Castle Bravos Mushroom Cloud. ... Castle Bravos Mushroom Cloud. ... Castle Bravo was the code name given to the first U.S. test of a so-called dry fuel thermonuclear device, detonated on March 1, 1954 by the United States, as the first test of Operation Castle (a longer series of tests of various devices). ... 1954 was a common year starting on Friday of the Gregorian calendar. ... Fallout is the residual radiation hazard from a nuclear explosion and is named from the fact that it falls out of the atmosphere in to which it is spread during the explosion. ... Operation Castle was a series of nuclear weapon tests that the USA conducted in 1954. ... Bikini Atoll - NASA NLT Landsat 7 (Visible Color) Satellite Image Bikini Atoll (also known as Pikinni Atoll) is an uninhabited 6. ... Operation Castle was a series of nuclear weapon tests that the USA conducted in 1954. ... 1954 was a common year starting on Friday of the Gregorian calendar. ... Castle Bravo was the code name given to the first U.S. test of a so-called dry fuel thermonuclear device, detonated on March 1, 1954 by the United States, as the first test of Operation Castle (a longer series of tests of various devices). ... Fallout is the residual radiation hazard from a nuclear explosion and is named from the fact that it falls out of the atmosphere in to which it is spread during the explosion. ... Rongerik Atoll - NASA NLT Landsat 7 (Visible Color) Satellite Image Map of Rongerik Atoll, taken from the 1893 map Schutzgebiet der Marshall Inseln, published in 1897. ... Rongelap Atoll is an island-atoll located in Micronesia. ... A congenital disorder is a medical condition or defect that is present at or before birth (for example, congenital heart disease). ... Radiation poisoning, also called radiation sickness, is a form of damage to organic tissue due to excessive exposure to ionizing radiation. ...

Operation Redwing (1956)

Main article: Operation Redwing

Seventeen nuclear weapons were detonated on the Bikini and Enewetak Atolls as part of Operation Redwing in 1956. Many of them were designed to prove the feasibility of numerous thermonuclear weapon designs, with yields ranging from around 2 to 5 Mt. 1956 was a leap year starting on Sunday of the Gregorian calendar. ...

Operation Hardtack I (1958)

Main article: Operation Hardtack I

35 weapons were detonated at the Bikini Atoll, Enewetak Atoll, and Johnston Island as part of Operation Hardtack I in 1958. Hardtack Oak mushroom cloud Hardtack Sorocco mushroom cloud An RB-57 Canberra observes Juniper. ... Johnston Atoll is a 2. ... Hardtack Oak mushroom cloud Hardtack Sorocco mushroom cloud An RB-57 Canberra observes Juniper. ... 1958 was a common year starting on Wednesday of the Gregorian calendar. ...

Partial Test Ban Treaty (1963)

The signing of the Partial Test Ban Treaty in 1963 forbade atmospheric and underwater nuclear weapons, and so all further U.S. tests were conducted at the Nevada Test Site until the end of testing in 1992. The Treaty Banning Nuclear Weapon Tests in the Atmosphere, in Outer Space, and Under Water, often abbreviated as the Partial Test Ban Treaty (PTBT), Limited Test Ban Treaty (LTBT), or Nuclear Test Ban Treaty (NTBT), although the former also refers to the Comprehensive Test Ban Treaty (CTBT), is a treaty... 1963 was a common year starting on Tuesday (link will take you to calendar). ... The Nevada Test Site is a United States Department of Energy reservation located in Nye County, Nevada, about 65 miles (105 km) northwest of the City of Las Vegas, near 37°07′ N 116°03′ W. Formerly known as the Nevada Proving Ground the site, established on January 11, 1951... 1992 is a leap year starting on Wednesday of the Gregorian calendar. ...

Remediation and compensation

Because of the large amount of atmospheric testing, and especially the Castle Bravo accident of 1954, many of the islands which were part of the Pacific Proving Grounds continue to be contiminated by nuclear fallout, and many of those who were living on the islands at the time of testing have suffered from increased incidence of various types of cancers and birth defects. The passing of the Radiation Exposure Compensation Act of 1990 allowed for a systematic filing of compensation claims in relation to testing as well as those employed at nuclear weapons facilities. Since 1956, at least $759 million USD has been paid to Marshall Islanders as compensation for their exposure to U.S. nuclear testing. $15.3 million was paid to Japan following the Castle Bravo accident.[1] Castle Bravo was the code name given to the first U.S. test of a so-called dry fuel thermonuclear device, detonated on March 1, 1954 by the United States, as the first test of Operation Castle (a longer series of tests of various devices). ... 1954 was a common year starting on Friday of the Gregorian calendar. ... Fallout is the residual radiation hazard from a nuclear explosion and is named from the fact that it falls out of the atmosphere in to which it is spread during the explosion. ... When normal cells are damaged or old they undergo apoptosis; cancer cells, however, avoid apoptosis. ... A congenital disorder is a medical condition or defect that is present at or before birth (for example, congenital heart disease). ... 1990 is a common year starting on Monday of the Gregorian calendar. ... 1956 was a leap year starting on Sunday of the Gregorian calendar. ... The United States dollar is the official currency of the United States. ...

See also

• Nuclear weapons and the United States

Nuclear program start date: October 21, 1939 First nuclear weapon test: July 16, 1945 First fusion weapon test: November 1, 1952 Last nuclear test: September 23, 1992 Largest yield test: 15 Mt (October 31, 1954) Total tests: 1,054 detonations Peak stockpile: 32,193 warheads (1966) Current stockpile: 10,450...

External links

• "Gallery of U.S. Nuclear Tests" at Carey Sublette's NuclearWeaponArchive.org
• Bikini Atoll official website
• Republic of the Marshall Islands Nuclear Claims Tribunal