WORLDWIDE TESTING IN MAY
MAY 1ST
U.S. tests: 5 (6 devices)
French tests: 1
British tests: 1
Total Yield: ≈150 kilotons.
The Details:
1952 - ‘Dog’ detonated 1,050 feet (320m) above Yucca Flat at 16:29 GMT with a yield of 19 kilotons from the LANL weapons development device, a TX-7 warhead, after being air-dropped during Operation Tumbler-Snapper, releasing 2.9 million curies of Iodine-131 into the atmosphere. 26th U.S. test. Coordinates: 37.0841, -116.0211.
Side Note: Marines participated in ‘Dog’ by setting up military equipment near ground zero which they then visited after the detonation. As they approached the display area, radiation readings exceeding 10 roentgens per hour were detected 900 yards from ground zero and the trip was cancelled until radiation levels fell.
1962 - ‘Béryl’ detonated in a tunnel within Taourirt Tan Afella mountain near In Ekker, French Algeria at 10:00 GMT with a yield of 40 kilotons, venting massive amounts of raw fission products and radioactive lava in what became known as the Béryl incident. 6th French test. Coordinates: 24.06319, 5.04171.
Side Note: The detonation of ‘Béryl’ was attended by many VIPs, including French Defense Minister Pierre Messmer and Minister of Scientific Research Gaston Palewski. Due to improper engineering of the spiral tunnel and inadequate stemming, when ‘Béryl’ detonated, the containment cavity did not form as hoped and the massive concrete tunnel plug was pulverized, allowing blast forces to vent directly out the tunnel after blasting through four steel doors and the polyurethane foam contained between them. According to Messmer, a few seconds after the ground trembling caused by the explosion, the spectators saw “a kind of gigantic blowtorch flame that started exactly horizontal in our direction… This gigantic flame was extinguished rather quickly and was followed by the release of a cloud which was ochre-colored at first, but then quickly turned black.” Seven military personnel received high doses of radiation and over 100 spectators received significant amounts. Gaston Palewski died 22 years later of leukemia linked back to the 'Béryl’ Incident.
1970 - ‘Beebalm’ detonated in a vertical shaft 1,280 feet (390m) beneath Yucca Flat area U3 at 14:13 GMT with a yield of 1 kiloton from the LANL weapons development device during Operation Mandrel, causing a 4.2 magnitude ground shock. 643rd U.S. test. Coordinates: 37.0592, -116.02892.
-- Twelve minutes later at 14:25 GMT, ‘Hod-C (Blue)’ detonated in a vertical shaft beneath Yucca Flat area U9 with a yield of <20 kilotons as part of a safety test of the LLNL device. 644th U.S. test. Coordinates: 37.13843, -116.03216.
-- Fifteen minutes later at 14:40 GMT, ‘Hod- A (Green)’ and ‘Hod-B (Red)’ detonated simultaneously in adjacent vertical shafts beneath Yucca Flat area U9 with yields of 9 and 4 kilotons respectively from the two LLNL weapons development devices causing a 4.5 magnitude ground shock and leaving subsidence craters 515 feet (157m) and 360 feet (110m) in diameter respectively. 645th U.S. test.
‘Hod-A (Green)’ coordinates: 37.11236, -116.08281. Depth of burial: 870 feet (265m)
‘Hod-B (Red)’ coordinates: 37.13295, -116.03495. Depth of burial: 791 feet (241m)
1974 - ‘Plomo’ detonated in a vertical shaft 490 feet (149m) beneath Yucca Flat area U3 with a yield of <20 kilotons from the LANL weapons development device during Operation Arbor. 747th U.S. test. Coordinates: 37.03109, -115.98633.
1984 - ‘Mundo’ detonated in a vertical shaft 1,856 feet (566m) beneath Yucca Flat area U7 at 19:05 GMT with a yield of 77 kilotons from the British device, a Trident missile warhead, causing a 5.4 magnitude ground shock. 38th British test. Coordinates: 37.10622, -116.02238
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MAY 2ND
U.S. tests: 5
Total Yield: 1,265.25 kilotons.
The Details:
1962 - ‘Arkansas’ detonated 5,030 feet (1,533m) above the Christmas Island (Kiritimati) area in the Pacific Ocean at 18:02 GMT with a yield of 1,090 kilotons from the LANL weapons development device, a XW-56 warhead, after being dropped from a B-52 bomber and parachute retarded during Operation Dominic. 230th U.S. test. Coordinates: 1.58, -157.26.
Side Note: This test was the third device to be dropped at Christmas Island during Operation Dominic and the first parachute-retarded device dropped in that series. It missed its intended air zero point by 600 feet but at 1.1 megatons it really did not matter. The aim point was a raft moored off the southern end of Christmas Island.
The W56 was a thermonuclear warhead with 1,000 produced starting in 1963 which saw service on the Minuteman I and II ICBMs until retired in 1993. It had a rated yield of 1.2 megatons.
1972 - ‘Misty North’ detonated in a tunnel 1,233 feet (376m) beneath Rainier Mesa area U12 at 19:15 GMT with a yield of 19 kilotons from the LANL device as part of a DOD weapons effects test during Operation Grommet, causing a 5.0 magnitude ground shock. 698th U.S. test. Coordinates: 37.20762, -116.20963.
1980 - ‘Canfield’ detonated in a vertical shaft 1,150 feet (350m) beneath Yucca Flat area U3 at 18:46 GMT with a yield of 6 kilotons from the LANL weapons development device during Operation Tinderbox, causing a 4.5 magnitude ground shock and creating a 656 foot (200m) diameter subsidence crater. 870th U.S. test. Coordinates: 37.05598, -116.0197.
1984 - ‘Orkney’ detonated in a vertical shaft 690 feet (210m) beneath Yucca Flat area U10 at 13:50 GMT a yield of 0.25 kilotons (250 tons) from the LLNL weapons development device during Operation Fusileer, causing a 3.4 magnitude ground shock and venting Xenon-133 during drill-back operations. 942nd U.S. test. Coordinates: 37.19843, -116.05484.
1985 - ‘Towanda’ detonated in a vertical shaft 2,166 feet (660m) beneath Pahute Mesa area U19 at 20:00 GMT with a yield of 150 kilotons from the LANL weapons development device during Operation Grenadier, causing a 5.8 magnitude ground shock and creating a 1,279 foot (390m) diameter subsidence crater. 961st U.S. test. Coordinates: 37.25335, -116.32609.
MAY 3RD
U.S. tests: 1
Total Yield: 2 kilotons.
The Details:
1968 - ‘Hatchet’ detonated in a vertical shaft 789 feet (240m) beneath Yucca Flat at 16:00 GMT with a yield of 2 kilotons from the LANL weapons development device during Operation Crosstie, causing a 4.1 magnitude ground shock and creating a 393 foot (120m) diameter subsidence crater. 545th U.S. test. Coordinates: 37.02853, -116.0206.
MAY 4TH
U.S. tests: 4
Russian tests: 1
Chinese tests: 1
Total Yield: 14,363 kilotons.
The Details:
1954 - ‘Yankee’ detonated 14 feet (4.3m) above the surface of Bikini Atoll Lagoon on a barge off Yurochi (Dog) Island at 18:10 GMT with a yield of 13,500 kilotons (13.5 megatons) from the LANL weapons development device prototype, the Emergency Capabilities EC-24, during Operation Castle. 48th U.S. test. Coordinates: 11.6656, 165.3869.
1956 – ‘Lacrosse’ detonated atop a 16 foot (5m) platform on the reef of Runit (Yvonne) Island, Eniwetok Atoll at 18:25 GMT with a yield of 40 kilotons from the LANL weapons development mock-up of the TX-39 during the first test of Operation Redwing, blasting a 600 foot (122m) diameter crater. 69th U.S. test. Coordinates: 11.55392, 162.34808.
Side Note: The ‘Lacrosse’ crater remains today next to the concrete dome covering the crater created by ‘Cactus’ during Operation Hardtack I two years later on May 5th 1958 that was used to dump 111,000 cubic yards (85,000 m3) of radioactive contaminated soil and debris into and covered with concrete during clean-up of the atoll between 1977 and 1980. Even with that effort and subsequent remediation work which included a potassium decontamination project, Eniwetok remains uninhabitable.
1962 - ‘Questa’ detonated 5,230 feet (1,594m) above the Christmas Island (Kiritimati ) area at 19:05 GMT with a yield of 670 kilotons (lower than expected) from the LANL weapons development device, a XW-59, after being dropped by a B-52 during Operation Dominic I. 231st U.S. test. Coordinates: 1.63, -157.32.
1966 - ‘Traveler’ detonated in a vertical shaft 645 feet (196m) beneath Yucca Flat area U2 at 13:32 GMT with a yield of 20 kilotons from the LLNL weapons development device during Operation Flintlock, causing a 5.5 magnitude ground shock, creating a 190 foot (58m) diameter subsidence crater, and venting 170 curies of Xenon-133 during drill-back operations. 455th U.S. test. Coordinates: 37.13705, -116.13807.
1983 - China detonated a device in a tunnel at Lop Nor at 04:59 GMT with a yield of 1 kiloton, causing a 4.5 magnitude ground shock. This was a second attempt at a neutron bomb, but was a failure. 30th Chinese test. Coordinates: 41.7227, 88.3653.
1988 - ‘942’ detonated in a vertical shaft beneath Balapan, Semipalatinsk at 00:57 GMT with a yield of 132 kilotons as part of a fundamental science test, causing a 6.09 magnitude ground shock. 696th Russian test. Coordinates: 49.94944, 78.75028.
MAY 5TH
U.S. tests: 5
French tests: 1
Total Yield: 90 kilotons
The Details:
1955 - ‘Apple-2’ detonated atop a 500 foot (152m) tower on Yucca Flat area 1 at 12:10 GMT with a yield of 29 kilotons from the LANL weapons development device during Operation Teapot, releasing 4.1 million curies of Iodine-131 into the atmosphere as well as many other radionuclides. 62nd U.S. test. Coordinates: 37.053, -116.1034.
Side Notes:
‘Apple-2’ was a retry of the ‘Apple-1’ test on March 29 in which the fission primary failed, creating less than intended yield.
Desert Rock VI, a military operation, took place during the ‘Apple-2’ shot with 11,000 military personnel involved and 8,000 participating in tactical maneuvers using tanks and other armored vehicles to attack and take objectives after the detonation. Tanks participating were directed to seal all apertures with duct tape and to verify the integrity of hatch seals. The tanks were to be absolutely light-tight. New York Times reporter Anthony Leviero was inside of a tank at the moment of detonation, reporting, “Erie light flooded into the tank. It poured through the two slits and seemed to come through other apertures, even though all the other openings were baffled in one way or another. The unearthly light seemed to last a long time, but it was about twenty seconds. Before anyone could figure out just what was going on, the earth shook. The tank, with its front of four-inch armor facing the atomic blast, rocked upward slightly, then settled. Dust billowed and darkened the inside of the turret.” After the blast, the tanks and personnel in helicopters then attacked their objectives, but one group became lost and approaching within 400 yards of ground zero found radiation readings exceeding 500 roentgen/hour and broke off their engagement.
Operation Cue, a civil defense exercise, was also conducted as part of the ‘Apple-2’ shot. Various buildings were constructed, including one and two-story residential houses, electrical substations, gas storage facilities, and radio stations and towers. It was nicknamed "Doom Town.” The buildings were populated with mannequins donated by J.C. Penny and stocked with different types of canned and packaged foods. Cameras were placed inside and out to capture the action. Civil Defense volunteers were placed in trenches two miles from ground zero and most observers watched from News Nob eight miles from the shot tower. A short film about the exercise was distributed by the Federal Civil Defense Administration. https://www.youtube.com/watch?v=zU9lCKDzKSY
1958 - ‘Cactus’ detonated 3 feet (1m) above the surface of Runit (Yvonne) Island, Eniwetok Atoll, at 18:15 GMT with a yield of 18 kilotons from the LANL device, a MK-43 thermonuclear primary, during Operation Hardtack I, creating a crater 596 feet (182m) in diameter and 37 feet deep. 121st U.S test. Coordinates: 11.55255, 162.34727.
Side Note: The crater left from ‘Cactus’ was used during Eniwetok clean-up operations between 1977 and 1980 to dump radioactive contaminated soil and material into the 'Cactus' crater, then covered with a concrete dome. Military personnel of the Army, Navy, and Air Force served six-month tours at Eniwetok working mostly in shorts and chukka boots since tropical conditions made wearing protective suits and masks impossible. Many Eniwetok veterans have developed cancers and other radiation induced illnesses but are yet denied medical benefits by the U.S. government. Most of Eniwetok remains uninhabitable, particularly Runit Island.
1966 - ‘Cyclamen’ detonated in a vertical shaft 1000 feet (304m) beneath Yucca Flat area U3 at 14:00 GMT with a yield of 12 kilotons from the LANL weapons development device during Operation Flintlock, causing a 4.4 magnitude ground shock, and creating a 547 foot (167m) diameter subsidence crater. 456th U.S. test. Coordinates: 37.05056, -116.03873.
Side Note: ‘Cyclamen’ was a test involving the generation of heavier isotopes of Einsteinium and Fermium through bombardment of a target of U-238 with the neutron flux of a detonation.
1970 - ‘Mint Leaf’ detonated in a tunnel 1,300 feet (396m) beneath Rainier Mesa at 15:30 GMT with a yield of 20 kilotons from the LLNL device as part of a weapons effects test during Operation Mandrel, causing a 5.2 magnitude ground shock and venting 960,000 curies of Iodine-131, Xenon-133 and other fission products during venting of the tunnel. 646th U.S test. Coordinates: 37.21649, -116.18441.
1983 - ‘Crowdie’ detonated in a vertical shaft 1,280 feet (390m) beneath Yucca Flat area U2 at 15:20 GMT with a yield of 6 kilotons from the LLNL weapons development device during Operation Phalanx, causing a 4.5 magnitude ground shock, creating a 262 foot (80m) diameter subsidence crater, and venting 7 curies of Xenon-133 during drill-back and gas sampling operations. 923rd U.S. test. Coordinates: 37.14567, -116.09021.
1987 - ‘Jocaste’ detonated in a shaft beneath Mururoa Atoll lagoon at 16:58 GMT with a yield of 5 kilotons, causing a 4.77 magnitude ground shock. 168th French test. Coordinates: -21.84369, -138.846.
MAY 6TH
U.S. tests: 3
Russian tests: 2 (3 devices)
French tests: 1
Total Yield: 736.5 kilotons.
The Details:
1962 - ‘Frigate Bird’ detonated 8,350 feet (2,530m) above the Pacific Ocean at 23:30 GMT with a yield of 600 kilotons from the LLNL device, a W-47 warhead carried inside a Polaris Mk-1 reentry vehicle, during Operation Dominic I. 232nd U.S. test. Coordinates: 4.833, -149.417.
Side Note: ‘Frigate Bird’ was the only U.S. test of an operational ballistic missile with a live warhead. This test involved firing a Polaris A1 missile from a submerged ballistic missile submarine. The missile was launched by the USS Ethan Allen (SSBN-608) at 23:18 GMT from a position 1,500 nm northeast of Christmas Island. (12.448, -134.854) The MK-1 re-entry vehicle and W-47 warhead flew 1,020 nm downrange toward Johnston Island before re-entering the atmosphere 12.5 minutes later, and detonating in an airburst at 8,350 feet. However, the launch was not without problems as shown in historical naval records.
“Adverse weather in the impact area delayed the start of the initial countdown for approximately two hours – unfortunately after the missile safety systems had been switched to internal battery power. Finally, the countdown was started and had reached within 30 seconds of launching the primary missile, when the fire control system bypassed the first weapon because of a “muzzle hatch” limit-switch failure and cued up a second Polaris. The backup missile was also bypassed – because of a false “safe/ready” indication – and although both problems were easily correctable, Rear Admiral Mustin declared a range-safety hold to be sure that observation aircraft in the impact area were still correctly positioned. Then, just before the new launch time, the weather deteriorated in the firing area, and a further hold was imposed. By this time, the batteries in the onboard tracking-beacon and destruct systems of the first two missiles were running down, which necessitated replacing them before countdown could be resumed. But just as that procedure was getting underway, favorable cloud conditions materialized overhead, and the decision was quickly taken to fire the third of the four test missiles on hand. Following only a short delay caused by a minor hydraulic problem, Ethan Allen successfully launched this third weapon.”
1966 - ‘Chartreuse’ detonated in a vertical shaft 2,187 feet (666m) beneath Pahute Mesa area U19 at 15:00 GMT with a yield of 73 kilotons from the LANL weapons development device during Operation Flintlock, causing 5.5 magnitude ground shock. 457th U.S. test. Coordinates: 37.34795, -116.32283.
1979 - ‘633’ and ‘634’ detonated simultaneously in a tunnel within Degelen Mountain, Semipalatinsk at 03:17 GMT with a combined yield of 15 kilotons from the two weapons development devices, causing a 5.22 magnitude ground shock. 518th Russian test. Coordinates: 49.7643, 77.9993.
1982 - ‘Kryddost’’ detonated in a vertical shaft 1,099 feet (563m) beneath Yucca Flat area U2 at 20:00 GMT with a yield of 3.5 kilotons from the LLNL weapons development device during Operation Praetorian, causing a 4.3 magnitude ground shock. 904th U.S. test. Coordinates: 37.11662, -116.12821
1986 - ‘Ceto’ detonated beneath the rim of Mururoa Atoll at 16:58 GMT with a yield of 5 kilotons from the weapons development device, causing a 4.75 magnitude ground shock. 161st French test. Coordinates: -21.872185, -138.9293.
1987 - ‘908’ detonated in a tunnel within Degelen Mountain, Semipalatinsk at 04:02 GMT with a yield of 40 kilotons from the fundamental science device, causing a 5.6 magnitude ground shock. 676th Russian test. Coordinates: 49.7742, 77.9986.
MAY 7TH
U.S. tests: 6
Russian tests: 2 (4 devices)
French tests: 1
Total Yield: ≈301 kilotons.
The Details:
1952 - ‘Easy’ detonated atop a 300 foot (90m) tower on Yucca Flat area 1 at 12:14 GMT with a yield of 12 kilotons from the LANL weapons development device, a Mk-12 warhead using a light-weight beryllium tamper, during Operation Tumbler-Snapper, releasing 1.8 million curies of Iodine-131 into the atmosphere along with mixed fission products. 27th U.S. test. Coordinates: 37.053, -116.1064.
1962 - ‘Paca’ detonated in a vertical shaft 847 feet (258m) beneath Yucca Flat area U3 at 19:33 GMT with a yield of 8 kilotons from the LANL weapons development device during Operation Nougat, creating a 485 foot (148m) diameters subsidence crater and venting fission byproducts from surface ground zero fissures for over two hours after detonation. 233rd U.S. test. Coordinates: 37.04654, -116.02567.
1964 - ‘Driver’ detonated in a vertical shaft 486 feet (148m) beneath Yucca Flat area U9 at 13:00 GMT with a yield of <20 kilotons from the LLNL weapons development device during Operation Niblick, venting raw fission byproducts from surface ground zero shaft casing for over 3 hours after detonation. 365th U.S. test. Coordinates: 37.12021, -116.04116
1965 - ‘Tee’ detonated in a vertical shaft 624 feet (190m) beneath Yucca Flat area U2 at 15:47 GMT with a yield of 7 kilotons from the LLNL device as part of a weapons effects test during Operation Whetstone, creating a 383 foot (117m) subsidence crater and venting 1,600 curies of gross fission products from the surface ground zero line of sight (LOS) pipe and surface fissures for over 107 hours after detonation. 412th U.S. test. Coordinates: 37.14042, -116.06745.
1966 - ‘257’ detonated in a tunnel within Degelen Mountain, Semipalatinsk at 03:58 GMT with a yield of 4 kilotons as part of a peaceful research test, causing a 4.8 magnitude ground shock. 249th Russian test. Coordinates: 49.7429, 78.105.
1969 - ‘Purse’ detonated in a vertical shaft 1,964 feet (598m) beneath Pahute Mesa area U20 at 13:45 GMT with a yield of 90 kilotons from the LLNL weapons development device during Operation Bowline, causing a 5.8 magnitude ground shock and creating a 449 foot (137m) diameter subsidence crater. 597th U.S. test. Coordinates: 37.28283, -116.50153.
1982 - ‘Bouschet’ detonated in a vertical shaft 1,850 feet (563m) beneath Yucca Flat area U3 at 18:17 GMT with a yield of 99 kilotons from the LANL weapons development device during Operation Praetorian, causing a 5.7 magnitude ground shock, creating a 623 foot (190m) diameter subsidence crater and venting Xenon and Iodine during cement-back operations. 905th U.S. test. Coordinates: 37.069, -116.04666.
1988 - ‘943’, ‘944’ and ‘945’ detonated simultaneously in a tunnel 984 feet (300m) beneath Area B, Matochkin Shar, Novaya Zemlya, Russia at 22:49 GMT with a combined yield of 80 kilotons as part of a weapons effects test, causing a 5.58 magnitude ground shock and venting 1,100 curies of radiation. 697th Russian test. Coordinates: 73.314, 54.553.
1991 - ‘Mélanippe’ detonated in a shaft beneath Moruroa Atoll lagoon at 17:00 GMT with a yield of 1 kiloton from the weapons development device, causing a 4.25 magnitude ground shock. 199th French test. Coordinates: -21.8314, -138.846.
MAY 8TH
U.S. tests: 5
French tests: 2
Total Yield: ≈438 kilotons.
The Details:
1951 - ‘George’ detonated atop a 203 foot (60m) tower on the island of Eberiru ("Ruby") at Eniwetok Atoll at 20:30 GMT with a yield of 225 kilotons from the LANL weapons development device, the largest detonation to-date, during Operation Greenhouse. 14th U.S. test. Coordinates: 11.62703, 162.29626.
Side Note: ‘George’ was the first test of the thermonuclear concept. The thermonuclear portion of the experiment was developed by Edward Teller, but based on a device patented by Johann Von Neumann and Klaus Fuchs in 1946. A small amount of liquid tritium and deuterium was placed at the center of the core. An over-sized plutonium pit was used to ensure ignition of the heavy hydrogen. Analysis of weapons residue and streak photography confirmed ignition of the hydrogen fuel although it contributed little to the yield, acting more like a boosted fission device, but it proved the concept of fast neutrons increasing the fission rate of uranium by causing the U-238 tamper to fission, increasing the yield.
1953 - ‘Encore’ detonated 2,430 feet (740m) above Frenchman Flat at 15:29 GMT with a yield of 27 kilotons from the LANL device (Mk-6D) after being dropped by a B-50 bomber as part of a weapons effects test during Operation Upshot-Knothole, releasing 3.9 million curies of Iodine-131 into the atmosphere. 40th U.S. test. Coordinates: 36.8, -115.929.
Side Notes: During ‘Encore ‘ soldiers were brought in to view the blast as part of the Desert Rock exercises. 3,500 soldiers from all over the country participated in the exercises, and were formed into Combat Battalion teams. In addition to this, six hundred high-ranking personnel and congressmen were on hand to view the exercises, which were aimed to "indoctrinate troops in atomic weapons in order that they will know how to protect themselves and their equipment in event of an enemy atomic attack in combat situations."
The 412th Engineer Construction Battalion dug trenches, bunkers and foxholes near ground zero and the 3623rd Ordnance Company placed various equipment in the area including jeeps, machine guns and light artillery. Medical teams brought live sheep into the area, unwilling participants in this weapons effects test.
Immediately after the detonation at 08:30 local time, troops assaulted their objectives three miles and one mile from ground zero and entered the equipment area to walk through the rubble of damaged and destroyed equipment. F-80 drone aircraft with monkeys and mice on-board flew through the mushroom cloud at 25,000 feet about seven minutes after detonation. By 10:45 the objectives had been taken with no casualties, except for the monkeys and mice who were found to be dying from severe radiation poisoning (duh) and were put to death.
As 'Encore' was an effects test, multiple objects were subjected to the blast, including trees. Since the Nevada Test Site sits in a desert and does not contain trees, the United States Forest Service transported 145 Ponderosa pines from a nearby Mt. Charleston canyon to Area 5. The trees were then placed in holes and cemented into the ground 6,500 feet from ground zero. The initial release of thermal radiation ignited many of the trees, and the subsequent blast wave blew 20 percent of them down. You can see the tree test at: https://www.youtube.com/watch?v=Q0kxCjiIyBA
'The House in the Middle' was filmed during 'Encore' and depicted what could happen to residential properties during a nuclear detonation that were not kept neat, tidy and well-maintained.
https://www.youtube.com/watch?v=7axLlxDBt9M
1962 - ‘Yukon’ detonated 2,881 feet (878m) above the Christmas Island (Kiritimati) area at 18:01 GMT with a yield of 100 kilotons from the LLNL weapons development device (Calliope II) after being dropped by a B-52 in a parachute-retarded casing during Operation Dominic I. 234th U.S. test. Coordinates: 1.62, -157.32.
1968 - ‘Crock’ detonated in a vertical shaft 596 feet (181m) beneath Yucca Flat at 14:10 GMT with a yield of 1 kiloton from the LLNL weapons development device during Operation Crosstie, causing a 3.9 magnitude ground shock and venting 140 curies of Xenon during drill-back operations. 546th U.S. test. Coordinates: 37.15731, -116.03582.
1974 - ‘Jib’ detonated in a vertical shaft 592 feet (180m) beneath Yucca Flat at 16:55 GMT with a yield of <20 kilotons from the LLNL weapons development device during Operation Arbor. 748th U.S. test. Coordinates: 37.00095, -116.00234.
1984 - ‘Démophon’ detonated in a shaft beneath the rim of Moruroa Atoll at 17:26 GMT with a yield of 5 kilotons, causing a 5.32 magnitude ground shock. 144th French test. Coordinates: -21.88318, -138.95231.
1985 - ‘Nisos’ detonated in a shaft beneath Moruroa Atoll lagoon at 20:28 GMT with a yield of 80 kilotons, causing a 5.82 magnitude ground shock. 153rd French test. Coordinates: -21.86923, -138.97854.
MAY 9TH
U.S. tests: 3
Chinese tests: 1
Total Yield: ≈358 kilotons.
The Details:
1962 - ‘Mesilla’ detonated 2,451 feet (747m) above the Christmas Island area at 17:01 GMT with a yield of 100 kilotons from the LANL weapons development device after being dropped from a B-52 during Operation Dominic I. 235th U.S. test. Coordinates: 1.58, -157.3
Side Note: ‘Mesilla’ was a free-fall airdrop of the LANL “Zippo-I” device in a Mk-15 drop case. The aim-point was a target raft which it missed by 700 feet. This was an advanced concepts test for both primary and secondary weapon designs. The yield was considerably lower than expected.
1963 - ‘Gundi Prime’ detonated in a vertical shaft 891 feet (271m) beneath Yucca Flat area U3 at 18:19 GMT with a yield of 8 kilotons from the LANL weapons development device during Operation Storax, creating a 492 foot (150m) diameter subsidence crater. 318th U.S. test. Coordinates: 37.04933, -116.01631.
1966 – An air-dropped device detonated over Lop Nor at 08:00 GMT with a yield of 250 kilotons. 3rd Chinese test. Coordinates: 41.50000, 88.50000.
1973 - ‘Mesita’ detonated 489 feet (149m) beneath Yucca Flat in a vertical shaft at 13:30 GMT with a yield of <20 kilotons from the LANL weapons development device during Operation Toggle, venting Xenon-133 during cement-back operations. 725th U.S. test. Coordinates: 37.00626, -116.01681.
MAY 10TH
U.S. tests: 3
Total Yield: ≈22 kilotons.
The Details:
1962 - ‘Arikaree’ detonated 547 feet (166m) beneath Yucca Flat in a vertical shaft at 15:00 GMT with a yield of <20 kilotons from the LLNL device, a W45 warhead, during Operation Nougat, venting 2,000 curies of Xenon-133 for a period of five hours during drill-back operations. 236th U.S. test. Coordinates: 37.12754, -116.04917.
1967 - ‘Mickey’ detonated 1,639 feet (499m) beneath Yucca Flat in a vertical shaft at 13:40 GMT with a yield of 22 kilotons from the LANL weapons development device during Operation Latchkey, causing a 5.0 magnitude ground shock and creating a 183 foot (56m) diameter subsidence crater. 499th U.S. test. Coordinates: 37.07781, -115.99617.
1978 – Firing signals were sent to ‘Transom’ 2,100 feet (640m) beneath Yucca Flat in a vertical shaft at 15:00 GMT resulting in ZERO yield from the LANL weapons development device during Operation Cresset when the device failed to detonate. 836th U.S. test. Coordinates: 37.08773, -116.0535.
Side Note: The ‘Transom’ device could not be retrieved and was destroyed during the ‘Hearts’ detonation on September 6, 1979 during Operation Quicksilver. Can’t leave defective nuclear devices laying around, even buried 2,100 feet underground.
MAY 11TH
U.S. tests: 6
Indian tests: 3
Russian tests: 1
French tests: 2
Total Yield: ≈1,572.5 kilotons.
The Details:
1958 - ‘Fir’ detonated 9.8 feet (3m) above Bikini Atoll lagoon on a barge anchored off Namu (Charlie) island at 17:50 GMT with a yield of 1,360 kilotons (1.36 megatons) from the LLNL weapons development device during Operation Hardtack I. 122nd U.S. test. Coordinates: 11.6908, 165.2733.
Side Note: ‘Fir’ was a clean 2-stage thermonuclear device, only 90 kilotons of yield came from fission (6.6%), the rest from the fusion reaction.
1958 - On the same day of the ‘Fir’ detonation, ‘Butternut’ detonated 9.8 feet (3m) above Eniwetok Atoll Lagoon on a barge anchored off Runit (Yvonne) island at 18:15:00 GMT with a yield of 81 kilotons from the LANL weapons development device, a TX-46 primary, during Operation Hardtack I. 123rd U.S. test. Coordinates: 11.53859, 162.34367.
1962 - ‘Muskegon’ detonated 2,995 feet (913m) above the Christmas (Kiritimati) Island area at 15:37:00 GMT with a yield of 50 kilotons from the LLNL device (Calliope IV ) after being parachuted by a B-52 during Operation Dominic I. 237th U.S. test. Coordinates: 1.59, -157.32.
1962 - On the same day of the ‘Muskegon’ test, ‘Swordfish’ detonated 650 feet (198m) beneath the Pacific 400 nautical miles SW of San Diego at 20:02 GMT with a yield of <10 kilotons from the LANL device, a W-44 warhead, as part of a weapons effects test during Operation Dominic I. 238th U.S. test. Coordinates: 31.245, -124.212.
Side Note: ‘Swordfish’ was the fifth US underwater nuclear detonation. It was a DOD sponsored full scale test of the ASROC anti-submarine rocket system. The ASROC used the LANL developed W-44 warhead which had a nominal yield of 10 kilotons. This shot had a number of objectives:
1. A weapons effects test to evaluate how it would affect U.S. ships, submarines, and sonar systems in the area (a target array of four destroyers and a surfaced submarine were positioned at distances between 2200 and 4600 yards from surface zero);
2. A safety test to evaluate the radiation hazard to the launching vessel;
3. A proof firing of the ASROC by a regular Navy crew under simulated wartime conditions.
The ASROC was fired from the destroyer USS Agerholm (DD-826) at a target raft 4,348 yards away. The rocket missed its sub-surface zero point by 20 yards and exploded 40 seconds later at a depth of 650 feet in water that was 17,140 feet deep.
The spray dome from the detonation was 3,000 feet across, and rose to 2,100 feet in 16 seconds. The detonation left a huge circle of foam-covered radioactive water. Within two days it had broken up into small patches and spread out for 5 to 8 miles.
1965 - ‘244’ detonated in a tunnel within Degelen Mountain, Semipalatinsk at 06:40 GMT with a yield of 14 kilotons, causing a 5.20 magnitude ground shock. 236th Russian test. Coordinates: 49.77306, 77.99139.
1972 - ‘Kara’ detonated in a vertical shaft 850 feet (259m) beneath Yucca Flat at 14:00 GMT with a yield of 500 tons from the LLNL weapons development device during Operation Grommet, causing a 3.6 magnitude ground shock and venting 7 curies of Xenon-133 during drill-back operations. 699th U.S. test. Coordinates: 37.11247, -116.08525.
1979 - ‘Freezeout’ detonated in a vertical shaft 1,100 feet (335m) beneath Yucca Flat at 16:00 GMT with a yield of 5 kilotons from the LANL weapons development device during Operation Quicksilver, causing a 4.4 magnitude ground shock and creating a 492 foor (150m) diameter subsidence crater. 853rd U.S. test. Coordinates: 36.99818, -116.01844.
1988 – ‘Nelee’ detonated beneath Mururoa Atoll lagoon at 17:00 GMT with a yield of 20 kilotons, causing a 5.28 magnitude ground shock. 176th French test. Coordinates: -21.83300, -138.94500.
1989 - ‘Epelos’ detonated beneath Mururoa Atoll lagoon at 16:45 GMT with a yield of 16 kilotons, causing a 5.21 magnitude ground shock. 184th French test. Coordinates: -21.81200, -138.88400.
1998 - ‘Shakti I’, ‘Shakti II’, and ‘Shakti III’ detonated simultaneously in three separate vertical shafts (‘White Ho’, ‘Taj Maha’, and ‘Kumhbaran’) beneath Pokoran, India at 10:13 GMT with reported yields of 45, 15, and .02 kilotons respectively, a total of 60 kilotons, causing a 5.2 magnitude ground shock. In reality, seismic signals and other data show that yields were actually 4, 12, and .02 kilotons for a total of 16 kilotons. The ‘Shatki I’ test was reported to be a thermonuclear device which failed when the primary did not achieve sufficient yield to compress and ignite the thermonuclear secondary. ‘Shakti III’ was either a safety test or device that fizzled. 2nd, 3rd, and 4th Indian tests. Coordinates: Shakti I: 27.07160, 71.76120, Shakti II: 27.07200, 71,76100, Shakti III: 27.07300, 71.76100.
MAY 12TH
U.S. tests: 7
French tests: 1
Total Yield: ≈2,016 kilotons.
The Details:
1958 - ‘Koa’ detonated 6-1/2 feet (3m) above the dry surface of Teiter (Gene) island at Eniwetok Atoll at 18:30 GMT with a yield of 1,370 kilotons (1.37 megatons) from the LANL XW-35 weapons development device during Operation Hardtack I, essentially blowing the island away, leaving a 4,229 foot wide crater. 124th U.S test. Coordinates: 11.66997, 162.19847.
Side Note: The XW-35 was intended for the Atlas ICBM, but when the accuracy of the Atlas was shown to be inferior to predictions, the XW-35 design had to be altered to give a higher yield. The ‘Koa’ device produced 380 kilotons less than expected (1.75 megatons) with a fission yield of 750 kilotons of the 1,000 kilotons predicted.
1962 - ‘Encino’ detonated 5,509 feet (1,675m) above the Christmas (Kiritimati) Island area at 17:03 GMT with a yield of 500 kilotons from the LANL weapons development device, a XW-43 warhead, after being free-fall air-dropped by a B-52 during Operation Dominic I. The mushroom cloud rose to 62,500 feet. 239th U.S. test. Coordinates: 1.58, -157.31.
- One hour and fifty-seven minutes later at 19:00 GMT, ‘Aardvark’ detonated in a vertical shaft 1,424 feet (434m) beneath Yucca Flat area U3 with a yield of 40 kilotons from the LANL weapons development device, a TX-33 artillery shell code-named ‘Fleegle,’ during Operation Nougat, causing a 4.6 magnitude ground shock, creating a 925 foot (282m) diameter subsidence crater and venting fission products from surface ground zero cables for a period of 45 minutes after detonation. 240th U.S. test. Coordinates: 37.06512, -116.03092.
Side Note: The TX-33 was a uranium-fueled gun-type device rather than an plutonium-fueled implosion device. It was an advanced prototype of the W-33 nuclear artillery shell, fired from an 8 inch (203 mm) M110 howitzer and M115 howitzer. It was a multiple-yield device: 5, 10 and 40 kilotons.
1965 - ‘Buteo’ detonated in a vertical shaft 2,282 feet (695m) beneath Pahute Mesa area U20 at 18:15 GMT with a yield of <20 kilotons from the LANL weapons development device during Operation Whetstone. 413th U.S. test. Coordinates: 37.24261, -116.43175.
1966 - ‘Tapestry’ detonated in a vertical shaft 810 feet (247m) beneath Yucca Flat area U2 at 19:37 GMT with a yield of 10 kilotons from the LLNL weapons development device during Operation Flintlock, causing a 4.3 magnitude ground shock, creating a 295 foot (90m) diameter subsidence crater, and venting 8,600 curies of Xenon-133 from surface ground zero fissures for a period of 57 hours after detonation and then again for 49 days during drill-back operations. 458th U.S. test. Coordinates: 37.13423, -116.07198.
1970 - ‘Diamond Dust’ detonated in a tunnel 728 feet (221m) beneath NTS Area 16 at 14:00 GMT with a yield of <20 kilotons from the LANL device during Operation Mandrel as part of a joint verification Vela Uniform seismic test. 647th U.S. test. Coordinates: 37.0104, -116.20277.
1976 - ‘Mighty Epic’ detonated in a tunnel 1,300 feet (396m) beneath Rainier Mesa area U12 at 19:50 GMT with a yield of 20 kilotons from the LLNL device as part of a weapons effects test during Operation Anvil, causing a 4.9 magnitude ground shock. 797th U.S. test. Coordinates: 37.20901, -116.21333.
1984 - ‘Midas’ detonated in a shaft beneath Moruroa Atoll lagoon at 17:31 GMT with a yield of 56 kilotons, causing a 5.65 magnitude ground shock. 145th French test. Coordinates: -21.85965, -138.93121.
MAY 13TH
U.S. tests: 3
Indian tests: 2
Total Yield: 1,826.8 kilotons.
The Details:
1954 - ‘Nectar’ detonated 14 feet (4m) above Eniwetok Atoll lagoon on a barge where Elugelab (Flora) island used to exist - before it was blown away two years earlier when Operation Ivy ‘Mike’ detonated - at 18:20 GMT with a yield of 1,690 kilotons from the LANL weapons development device, a TX-15 warhead code-name ‘Zombie’, during Operation Castle, the last test of the series. 49th U.S. test. Coordinates: 11.6705, 162.1964.
Side Note: The 'Zombie' device was a 3-stage fission-fusion-fission weapon that used fast neutrons from the fusion reaction to fission the U-238 tamper which normally will not sustain a chain reaction but under the intense fast neutron flux from the fusion secondary will add to the bomb's yield although the yield will be quite "dirty" in the amount of fallout produced.
1966 - ‘Piranha’ detonated in a vertical shaft 1,800 feet (548m) beneath Yucca Flat area U7 at 13:30 GMT with a yield of 120 kilotons from the LANL weapons development device during Operation Flintlock, causing a 5.6 magnitude ground shock and creating a 1,197 foot (365m) diameter subsidence crater. 459th U.S. test. Coordinates: 37.08681, -116.03431.
1988 - ‘Schellbourne’ detonated in a vertical shaft 1,519 feet (463m) beneath Yucca Flat area U2 at 15:35 GMT with a yield of 16 kilotons from the LLNL weapons development device during Operation Touchstone, causing a 4.8 magnitude ground shock, creating a 623 foot (190m) diameter subsidence crater and venting Hydrogen-3 and Cesium-137 during gas sampling activities, and Xenon-133 and Iodine-131 during drill-back operations. 1,007th U.S. test. Coordinates: 37.12439, -116.073.
1998 - ‘Shakti IV’ and ‘Shakti V’ detonated simultaneously in separate vertical shafts (NT1 and NT2) beneath Pokhran, India at 06:51 GMT with yields of 0.5 and 0.3 kilotons respectively. These tests were either to validate new ideas or were safety tests. 5th and 6th Indian tests. Coordinates: 27.07347, 71.71353.
MAY 14TH
U.S. tests: 7
Chinese tests: 1
Total Yield: 580.75 kilotons.
The Details:
1948 - ‘Zebra’ detonated atop a 200 foot (90m) tower on Runit (Yvonne) Island at Eniwetok Atoll at 18:04 GMT with a yield of 18 kilotons from the LANL weapons development device during the final test of Operation Sandstone. ’Zebra’ used highly enriched U-235 in a levitated pit instead of plutonium 239. It had superior efficiency, at least for its size. 6th U.S. test. Coordinates: 11.5352, 162.36063.
1955 - ‘Wigwam’ detonated 2,000 feet (610m) beneath the Pacific Ocean about 500 miles southwest of San Diego at 20:00 GMT with a yield of 30 kilotons from the LANL device, a Mk-90 depth charge, as a weapons effects test, the only test during Operation Wigwam. 64th U.S. test. Coordinates: 28.7333, -126.2667.
Side Notes: ‘Wigwam’ was a deep water effects test to investigate the vulnerability of submarines to nuclear weapons and the feasibility of using depth bombs in combat as there was considerable concern about problems with surface contamination. The test device was a B-7 (Mk-90) Betty depth bomb in a sealed caisson suspended by a 2000 foot cable from a shot barge. The dry weight of the bomb was 8,250 lb, 5,700 lb when submerged.
- 6,800 personnel on 30 ships participated in ‘Wigwam’. A six mile tow-line connected the fleet tug, Tawasa and the shot barge. Suspended from this line at varying distances from the barge were three "Squaws" - sub-scale submarine-like pressure hulls equipped with instruments and cameras. All were destroyed when ‘Wigwam’ detonated.
- The ships conducting the test were placed five miles upwind from the shot barge with the exception of the USS George Eastman (YAG-39) and USS Granville S. Hall (YAG-40). These two ships were equipped with heavy shielding and were stationed five miles downwind. Both ships were contaminated by the radioactive base surge, but the heavy shielding kept exposures within the Operation Wigwam dose limit of 3.9 RADS, still way too high.
1962 - ‘Swanee’ detonated 2,940 feet (896m) above the Pacific Ocean 10 miles south of Christmas (Kiritimati) Island area at 15:22 GMT with a yield of 97 kilotons from the LLNL XW-56 device after being dropped from a B-52 in a parachute-retarded Mk-36 drop case during Operation Dominic I. The XW-56 was an experimental "clean" prototype intended to be used as a Sprint anti-ballistic missile warhead to produce a large flux of neutrons that would theoretically destroy incoming warheads. 241st U.S. test. Coordinates: 1.57, -157.32.
1964 - ‘Backswing’ detonated in a vertical shaft 536 feet (163m) beneath Yucca Flat area U9 at 14:40 GMT with a yield of 8 kilotons from the LLNL weapons development device during Operation Niblick, creating a 478 foot (146m) diameter subsidence crater and venting 37 curies of Xenon-133, Cesium-138, and other radionuclides from the surface ground zero casing and LOS pipe for 16 minutes following detonation, and for 48 hours from cable cuttings during drill-back operations. 366th U.S. test. Coordinates: 37.11729, -116.03981.
1965 - China detonated an air-dropped device 1,640 feet (500m) above Lop Nor AT 02:00 GMT with a yield of 35 kilotons. 2nd Chinese test. Coordinates: 41.5, 88.5.
1965 - ‘Cambric’ detonated in a vertical shaft 965 feet (294m) beneath Frenchman Flat area at 14:57 GMT with a yield of 0.75 kilotons from the LLNL weapons development device during Operation Whetstone. ‘Cambric’ was intended to study radioactivity movement in ground water beneath the Nevada Test Site. 414th U.S. test. Coordinates: 36.82334, -115.9677.
– Two hours and thirty-five minutes later at 17:32 GMT, ‘Scaup’ detonated in a vertical shaft 1,401 feet (427m) beneath Yucca Flat area U3 with a yield of 12 kilotons from the LANL weapons development device during Operation Whetstone, creating a 570 foot (174m) subsidence crater. 415th U.S. test. Coordinates: 37.05875, -116.0125.
1975 - ‘Tybo’ detonated in a vertical shaft 2,510 feet (765m) beneath Pahute Mesa at 14:00 GMT with a yield of 380 kilotons from the LLNL weapons development device during Operation Bedrock, causing a 6.0 magnitude ground shock. 773rd U.S. test. Coordinates: 37.22071, -116.47527.
MAY 15TH
U.S. tests: 6 (9 devices)
Chinese tests: 1
British tests: 1
French tests: 1
Total Yield: ≈532 kilotons.
The Details:
1955 - ‘Zucchini’ detonated atop a 490 foot (150m) tower on Yucca Flat area 7 at 11:59 GMT with a yield of 28 kilotons from the LANL weapons development device during Operation Teapot, venting 4 million curies of Iodine-131 and other radionuclides. This was the last test of the 14 shot operation. 63rd U.S. test. Coordinates: 37.0947, -116.0248.
1957 – ‘Grapple 1/Short Granite’ detonated 7,874 feet (2,400m) above the Malden Line Island area at 19:37 GMT with a yield of 300 kilotons from the ‘Green Granite Small’ device after being dropped from a British Valiant B1 bomber during Operation Grapple. The yield was far short of the expected 1,000 kilotons. 10th British test. Coordinates: -4.05, -154.9.
1963 - ‘Double Tracks’ detonated on the surface of the Nellis Air Force Tonopah Range at 09:55 GMT with no yield from the joint U.S./U.K. device during Operation Roller Coaster. It was a storage-transportation safety experiment. The device was fired 'one point safe' so there would be no yield, but would pulverize the plutonium pit and depleted uranium tamper. The purpose was to disperse plutonium to see what it would do. It contaminated a large section of desert This was the first of four tests in that operation, all similar in nature. 319th U.S. test. Coordinates: 37.70527, -116.98715.
Side Note: ‘Double Tracks’ was not intended to produce a nuclear yield. The intent was to see how the plutonium would disperse in the case of an accident where the device detonated one-point safe. The area remained contaminated until it was cleaned up in 1995-1996. 53,500 cubic feet of contaminated soil was scraped from the surface of a 2-1/2 acre area and buried at Nevada Test Site Area 3 Radioactive Waste Management Site.
1964 - ‘Minnow’ detonated in a vertical shaft 791 feet (241m) beneath Yucca Flat area U3 at 16:15 GMT with a yield of 6 kilotons from the LANL weapons development device during Operation Niblick, creating a 416 foot (127m) diameter subsidence crater. 367th U.S. test. Coordinates: 37.04167, -116.01297.
1969 - ‘Aliment’ detonated in a vertical shaft 789 feet (240m) beneath Yucca Flat area U2 at 18:00 GMT with a yield of 2 kilotons from the LANL weapons development device during Operation Bowline, causing a 4.1 magnitude ground shock. 598th U.S. test. Coordinates: 37.01185, -115.98583.
1970 - ‘Cornice-Yellow-1’ and ‘Cornice-Green-2’ detonated simultaneously in separate but adjacent vertical shafts 1,280 feet (390m) beneath Yucca Flat area U10 with yields of 45 and 40 kilotons respectively from the two LLNL weapons development devices during Operation Mandrel, causing a 5.3 magnitude ground shock and creating two subsidence craters. 648th U.S. test.
‘Cornice-Yellow-1’ coordinates: 37.16588, -116.03636, 790 foot (241m) diameter crater.
‘Cornice-Green-2’ coordinates: 37.16186, -116.03981, 820 foot (250m) diameter crater.
1970 - ‘Andromeda’ detonated beneath a balloon 720 feet (220m) above the Denise area of Moruroa Atoll at 18:00 GMT with a yield of 13 kilotons. 32nd French test. Coordinates: -21.83, -138.88.
1989 - ‘Palisade-1’, ‘Palisade-2’, and ‘Palisade-3’ detonated simultaneously beneath Yucca Flat area U4 in the same vertical shaft at depths of 1,132 feet (345m), 1,286 feet (392m) and 1,325 feet (404m) respectively at 13:10 GMT with yields of 5 kilotons, <20 kilotons (safety test), and 8 kilotons respectively from the three LLNL weapons development devices during Operation Cornerstone, causing a 4.4 magnitude ground shock. 1,023rd U.S. test. Coordinates: 37.10756, -116.12176.
1995 - China detonated a device in a vertical shaft beneath Lop Nor at 04:05 GMT with a yield of 95 kilotons, causing a 6.1 magnitude ground shock. It was a one-point safety test of the DF-31 Mobile ICBM warhead that obviously failed. 44th Chinese test. Coordinates: 41.5524, 88.7524.
MAY 16TH
U.S. tests: 2
Russian tests: 3
British tests: 1
Total Yield: 89.5 kilotons.
The Details:
1956 - ‘Mosaic G1’ detonated atop a 100 foot (31m) tower on Trimouille Island, Montebello Islands, West Australia at 03:50 GMT with a yield of 15 kilotons from the weapons development device which included the use of deuterium intended to boost the yield but which failed to do so. 4th British test. Coordinates: -20.38207, 115.54796.
1958 - ‘Wahoo’ detonated 490 feet (150m) beneath the Pacific Ocean off Pokon (Irvin) island, Eniwetok Atoll in water 3,200 feet (980m) deep at 01:30 GMT with a yield of 9 kilotons from the LANL device, a Mk-90 “Betty” depth charge, as part of a weapons effects tests during Operation Hardtack I. 125th U.S. test. Coordinates: 11.32646, 162.16309.
1964 - ‘230’ detonated in a tunnel 850 feet (260m) beneath Degelen Mountain, Semipalatinsk at 06:00 GMT with a yield of 23.7 kilotons from the weapons development device, causing a 5.55 magnitude ground shock. 223rd Russian test. Coordinates: 49.8077, 78.102.
1969 - ‘321’ detonated in a tunnel 2,064 feet (629m) beneath Degelen Mountain, Semipalatinsk at 04:02 GMT with a yield of 16 kilotons from the weapons development device, causing a 5.26 magnitude ground shock. 300th Russian test. Coordinates: 49.7594, 78.0758.
1974 - ‘450’ detonated in a tunnel 2,139 feet (652m) beneath Degelen Mountain, Semipalatinsk at 03:03 GMT with a yield of 18 kilotons from the weapons development device, causing a 5.3 magnitude ground shock.. 399th Russian test. Coordinates: 49.7459, 78.0374.
1984 - ‘Bellow’ detonated in a vertical shaft 680 feet (207m) beneath Yucca Flat area U4 at 16:00 GMT with a yield of 0.8 kilotons from the LLNL device as part of Operation Fusileer, causing a 3.8 magnitude ground shock. 943rd U.S. test. Coordinates: 37.09244, -116.09412.
MAY 17TH
U.S. tests: 5 (7 devices)
Total Yield: ≈127 kilotons.
The Details:
1963 - ‘Harkee’ detonated in a vertical shaft 792 feet (241m) beneath Yucca Flat area U3 at 14:55 GMT with a yield of <20 kilotons from the LANL weapons development device during Operation Storax. 320th U.S. test. Coordinates: 37.04388, -116.01637.
-- At the same instant, ‘Tejon’ detonated in an adjacent shaft 242 feet (74m) deep with a yield of <20 kilotons from the LANL device as part of a safety test during Operation Storax. 321st U.S. test. Coordinates: 37.04831, -116.0331.
1968 - ‘Clarksmobile’ detonated in a vertical shaft 1,550 feet (472m) beneath Yucca Flat area U2 at 13:00 GMT with a yield of 20 kilotons from the LLNL weapons development device during Operation Crosstie, causing a 4.7 magnitude ground shock and creating a 770 foot (235m) diameter subsidence crater. 547th U.S. test. Coordinates: 37.12001, -116.0597.
1972 - ‘Zinnia’ detonated in a vertical shaft 1,059 feet (322m) beneath Yucca Flat area U2 at 14:10 GMT with a yield of 8 kilotons from the LLNL weapons development device during Operation Grommet, causing a 4.4 magnitude ground shock, creating a334 foot (102m) diameter subsidence crater and venting 7 curies of Xenon-133 during drill-back operations. 700th U.S. test. Coordinates: 37.12056, -116.08883.
1973 - ‘Rio Blanco-1’, ‘Rio Blanco-2’, and ‘Rio Blanco-3’ detonated simultaneously in the same vertical shaft beneath Western Colorado at 16:00 GMT at depths of 5,768 feet (1,758 m), 6,152 feet (1,875m), and 6,611 feet (2,015m) respectively about 36 miles (57km) NW of Rifle, Colorado with yields of 33 kilotons from each of the three LLNL peaceful research devices as part of a Project Plowshares gas stimulation experiment during Operation Toggle, causing a 5.4 magnitude ground shock. 726th U.S. test. Coordinates: 39.79322, -108.3672.
Side Note: ‘Rio Blanco’ was the third Project Plowshares experiment to determine the feasibility of using nuclear explosives to stimulate natural gas production. It was a joint U.S. government/oil industry experiment. Detonation of a nuclear device at great depth would fracture rock and shale which would theoretically release more natural gas from the rock formation. Old-timer oil-drillers often used dynamite exploded in oil wells that were running dry to further squeeze oil from rock formations so it was not a stretch to think a nuclear device would do the same, just on a larger scale. If successful, plans called for hundreds of underground gas stimulation nuclear detonations annually to produce upwards of 20 years worth of natural gas. ‘Rio Blanco’ did in fact stimulate gas production, but as in the two previous gas stimulation nuclear detonations in New Mexico and Colorado, ‘Gasbuggy’ and ‘Rulison’, the gas produced was radioactive and could not be used commercially. As a result, ‘Rio Blanco’ was the last gas stimulation nuclear detonation conducted and the next scheduled test, ‘Wagon Wheel’, in Wyoming which was planned to use five 100 kiloton devices was cancelled. Reality had set in. But at least Edward Teller got to detonate more weapons.
MAY 18TH
French tests: 1
Total Yield: 20 kilotons.
The Details:
1991 - ‘Alcinos’ detonated in a vertical shaft beneath Moruroa Atoll lagoon at 17:14 GMT with a yield of 20 kilotons, causing a 5.21 magnitude ground shock. 199th French test. Coordinates: -21.83200, -139.01400.
MAY 19TH
U.S. tests: 5
Russian tests: 1
Total Yield: 325.2 kilotons.
The Details:
1953 - ‘Harry’ detonated atop a 300 foot (90m) steel tower on Yucca Flat area 3 at 12:04 GMT with a yield of 32 kilotons from the LANL weapons development device during Operation Upshot-Knothole, releasing 4.6 million curies of Iodine-131 into the atmosphere. 41st U.S. atmospheric test detonation. Coordinates: 37.0402, -116.0261.
Side Notes:
- ‘Harry’ was designed by Ted Taylor of LANL who became known for his miniaturization of nuclear warheads, including ‘Scorpion’, ‘Bee’ and ‘Viper.’ The ‘Harry’ device, known as ‘Hamlet’, was the most efficient pure fission design ever exploded. ‘Hamlet’ was the first use of a hollow core plutonium pit rather than a solid pit. The fireball lasted an unusually long time - 17 seconds - indicating a long burn consuming more fissile material and producing a greater yield with less plutonium. More efficient. Ted’s design was not adopted as at this point in time there was a large amount of plutonium being churned out by Hanford and Savannah for an ever-increasing number of warheads.
- ‘Harry’ was also known as ‘Dirty Harry’ as it resulted in the heaviest contamination of towns in the path of fallout from any previous U.S. continental test. The "downwinders" paid dearly. St. George, Utah was heavily dusted by fallout with people reporting a strange metallic taste in their mouths, probably microscopic iron parts from the vaporized detonation tower. People who remained outdoors suffered radiation burns to exposed skin, in some cases their hair began to fall out. 18,000 – 20,000 sheep being herded towards Cedar City and under the plume of radioactive fallout sickened as they grazed the radioactive grasses. Then ewes began miscarrying in large numbers and at the lambing yards wool sloughed off in clumps revealing blisters on adult sheep. New lambs were stillborn with grotesque deformities or born so weak they were unable to nurse. Over a third of the sheep died. AEC scientists told residents the sheep were suffering from "malnutrition" in spite of overwhelming evidence that it was radiation. “Everything is OK.” The AEC did not want the American public to know the danger from fallout. Iodine-131 in the milk reached such levels that a child who drank a liter of milk a day for three weeks after ‘Harry’ would receive a dose of radiation to their thyroid between 125 and 440 roentgens. Leukemia rates among children increased.
- The ‘Harry’ shot is notable for another reason. A Hollywood film crew including John Wayne, Susan Hayward and Thomas Gomez were in Snow Canyon in the Escalante Desert near St. George that summer filming ‘The Conqueror’. This area had been heavily coated by the fallout from 'Harry.' During filming, large wind machines were used to stir up the dust and tons of soil scraped from the surface were trucked back to a sound stage in Hollywood. More than 90 people on the film crew developed cancers years later, many dying including the three stars.
1962 – ‘Eel’ detonated in a vertical shaft 714 feet (217m) beneath Yucca Flat area U9 at 15:00 GMT with a yield of 4.5 kilotons from the LLNL weapons development device during Operation Nougat, creating 232 foot (71m) diameter subsidence crater and venting 1.9 million curies of raw radioactive effluents from a nearby shaft in the form of a geyser for more than 40 minutes. Coordinates: 37.12256, -116.04809.
-- 37 minutes later at 15:37 GMT, ‘Chetko’ detonated 6,906 feet (2,105m) above the Christmas (Kiritimati) Island area with a yield of 73 kilotons from the LLNL weapons development device (‘Calliope I ‘) after being parachuted from a B-52 during Operation Dominic I. 244rd U.S. test. Coordinates: 1.6, -157.33.
1966 - ‘Dumont’ detonated in a vertical shaft 2,200 feet (670m) beneath Yucca Flat area U2 at 13:56 GMT with a yield of 200 kilotons from the LLNL weapons development device during Operation Flintlock, causing a 5.9 magnitude ground shock, creating a 1,213 foot (370m) diameter subsidence crater, and venting Xenon-133 during drill-back operations. 460th U.S. test. Coordinates: 37.11109, -116.05879.
1972 - ‘Monero’ detonated in a vertical shaft 1,763 feet (537m) beneath Yucca Flat area U3 at 17:00 GMT with a yield of 12 kilotons from the LANL weapons development device during Operation Grommet, causing 4.9 magnitude ground shock. 701st U.S test. Coordinates: 37.06469, -116.0025.
1976 - ‘513’ detonated in a tunnel 2,457 feet (749m) beneath Degelen Mountain, Semipalatinsk at 02:57 GMT with a yield of 3.7 kilotons, causing 4.72 magnitude ground shock. 442nd Russian test. Coordinates: 49.777, 78.0009
MAY 20TH
U.S. tests: 4
French tests: 2
Total Yield: 4,038.5 kilotons.
The Details:
1956 – ‘Cherokee’ detonated 4.330 feet (1320m) above Namu (Charlie) Island, Bikini Atoll at 17:50 GMT with a yield of 3,800 kilotons (3.8 megatons) from the LANL device, a TX-15, after being free-fall air-dropped from a B-52 during Operation Redwing. 70th U.S. test. Coordinates: 11.73973, 165.33985.
Side Note: ‘Cherokee’ was the first air-deliverable thermonuclear warhead. A navigation error put the bomb 4 mi (6.4 km) off the aim point (Namu Island) which negated efforts to gather weapons effects data.
1958 - ‘Holly’ detonated 13 feet (4m) above Eniwetok lagoon atop a barge anchored off Runit (Yvonne) island at 18:30 GMT with a yield of 5.9 kilotons from the LANL weapons development device during Operation Hardtack I. 126th U.S. test. Coordinates: 11.54029, 162.35039.
1967 - ‘Commodore’ detonated in a vertical shaft 2,449 feet (746m) beneath Yucca Flat area U2 at 15:00 GMT with a yield of 200 kilotons from the LLNL weapons development device during Operation Latchkey, causing a 5.9 magnitude ground shock and creating a 1,118 foot (341m) diameter subsidence crater. 500th U.S. test. Coordinates: 37.13011, -116.0652.
1976 - ‘Rivoli’ detonated in a vertical shaft 655 feet (199m) beneath Yucca Flat area U2 at 17:30 GMT with a yield of 0.6 kilotons (600 tons) from the LLNL weapons development device during Operation Anvil. 798th U.S. test. Coordinates: 37.13715, -116.06745.
1987 - ‘Lycomede’ detonated in a shaft beneath Mururoa Atoll lagoon at 17:05 GMT with a yield of 30 kilotons, causing a 5.42 magnitude ground shock. 169th French test. Coordinates: -21.86193, -138.94008.
1989 - ‘Tecmessa’ detonated beneath Mururoa Atoll lagoon at 17:59 GMT with a yield of 2 kilotons, causing a 4.47 magnitude ground shock. 185th French test. Coordinates: -21.83047, -138.87541.
MAY 21ST
U.S. tests: 6
Russian tests: 1
Chinese tests: 1
Total Yield: 721.6 kilotons.
The Details:
1958 - ‘Nutmeg’ detonated 9.8 feet (3m) above Bikini Atoll lagoon on a barge anchored off Eninmen (Tare) island at 21:20 GMT with a yield of 25.1 kilotons from the LLNL weapons development device, W-47 2-stage thermonuclear weapon, during Operation Hardtack I. 127th U.S. test. Coordinates: 11.50355, 165.3722.
Video: https://www.youtube.com/watch?v=Dokm_KU3Xlo...
https://www.youtube.com/watch?v=HB2rd92XmIo
1965 – ‘Tweed’ detonated in a vertical shaft 922 feet (281m) beneath Yucca Flat area U9 at 13:08 GMT with a yield of 15 kilotons from the LLNL weapons development device during Operation Whetstone, creating a 629 foot (192m) subsidence crater and releasing 600 curies of Iodine-131 and Xenon-133 over a period of four days during drill-back operations. 416th U.S. test. Coordinates: 37.11848, -116.02843.
1968 -‘Pamuk’ detonated in a vertical shaft 8, 010 feet (2,440m) beneath Kashkadarya, Uzbekistan at 03:59 GMT with a yield of 47 kilotons as part of an industrial experiment to extinguish an underground fire, causing a 5.4 magnitude ground shock. 282nd Russian test. Coordinates: 38.916, 65.159
1970 - ‘Manzanas’ detonated in a vertical shaft 797 feet (240m) beneath Yucca Flat area U3 at 14:00 GMT with a yield of 1 kiloton from the LANL weapons development device during Operation Mandrel, causing a 3.5 magnitude ground shock. 649th U.S. test. Coordinates: 37.01214, -115.99265.
-- 15 minutes later at 14:15 GMT, ‘Morrones’ detonated in a vertical shaft 1,583 feet (482m) beneath Yucca Flat area U3 with a yield of 29 kilotons from the LANL weapons development device during Operation Mandrel, causing a 5.1 magnitude ground shock. 650th U.S. test. Coordinates: 37.07076, -116.01387
1986 - ‘Panamint’ detonated in a vertical shaft 1,570 feet (480m) beneath Yucca Flat area U2 at 13:59 GMT with a yield of 1 kiloton from the LLNL weapons development device during Operation Charioteer, venting 3 curies of Iodine-131 and Xenon-133 during post-shot drilling operations. 979th U.S. test. Coordinates: 37.12499, -116.06126.
1988 - ‘Laredo’ detonated in a vertical shaft 1,153 feet (351m) beneath Yucca Flat area U3 at 22:30 GMT with a yield of 3.5 kilotons from the LANL weapons development device during Operation Touchstone, causing a 4.3 magnitude ground shock and creating a 164 foot (50m) diameter subsidence crater. 1,008th U.S. test. Coordinates: 37.03245, -115.98814.
1992 - China detonated a nuclear device 5,541 feet (1,689m) beneath Lop Nur, China at 04:59 GMT with a yield of 600 kilotons, causing a 6.5 magnitude ground shock. 38th Chinese test, the largest test conducted by China. Coordinates: 41.5437, 88.7641.
MAY 22ND
U.S. tests: 3
Russian tests: 1 (3 devices)
French tests: 1
Total Yield: ≈281.5 kilotons.
The Details:
1963 - ‘Stones’ detonated in a vertical shaft 1,295 feet (394m) beneath Yucca Flat area U9 at 15:40 GMT with a yield of 20 kilotons from the LANL weapons development device during Operation Storax, causing a 4.84 magnitude ground shock, creating a 853 foot (260m) diameter subsidence crater and venting over 5,800 curies of mixed fission products over a 10 hour period during drill-back operations. 322nd U.S. test. Coordinates: 37.11101, -116.03993.
1970 - ‘Cassiopee’ detonated beneath a tethered balloon 1,600 feet (500m) above the Dindon zone of Moruroa Atoll’s lagoon at 18:30 GMT with a yield of 224 kilotons from the thermonuclear device, a TN-60 warhead for a submarine-launched ballistic missile. 33rd French test. Coordinates: -21.83, -138.88.
1974 - ‘Grove’ detonated in a vertical shaft 1,030 feet (314m) beneath Yucca Flat area U2 at 14:15 GMT with a yield of 2.5 kilotons from the LLNL weapons development device during Operation Arbor, causing a 4.2 magnitude ground shock, creating a 164 foot (50m) diameter subsidence crater and venting 26 curies of Xenon-133 during drill-back operations. 749th U.S. test. Coordinates: 37.11486, -116.07544.
1980 - ‘Flora’ detonated in a vertical shaft 1,101 feet (341m) beneath Yucca Flat area U3 at 13:00 GMT with a yield of <20 kilotons from the LANL weapons development device during Operation Tinderbox, venting 1,000 curies of Iodine-131 and Xenon-133 during the dismantling of post-shot drilling equipment . 871st U.S. test. Coordinates: 37.00304, -116.03214
1980 - ‘683’, ‘684’ and ‘685’ detonated simultaneously in the same tunnel 2,267 feet (691m) beneath Degelen Mountain, Semipalatinsk at 03:57 GMT with a combined yield of 35 kilotons from the three weapons development devices, causing a 5.53 magnitude ground shock. 547th Russian test. Coordinates: 49.7739, 78.0287.
MAY 23RD
U.S. tests: 1
Russian tests: 1
British tests: 1
Total Yield: 175.001 kilotons.
The Details:
1967 - ‘Scotch’ detonated in a vertical shaft 3,206 feet (977m) beneath Pahute Mesa at 14:00 GMT with a yield of 155 kilotons from the LANL weapons development device during Operation Latchkey, causing a 5.7 magnitude ground shock. 501st U.S. detonation. Coordinates: 37.27503, -116.37086.
1968 - ‘298’ detonated in a tunnel 2,024 feet (617m) beneath Degelen Mountain, Semipalatinsk at an unspecified time with a yield of 0.001 kilotons. A probable safety test. 283rd Russian test. Coordinates: 49.83067, 78.0881.
1974 - ‘Fallon’ detonated in a vertical shaft 1,529 feet (466m) beneath Yucca Flat at 13:38 GMT with a yield of 20 kilotons from the British device during Operation Arbor, causing a 4.8 magnitude ground shock, creating a 623 foot (190m) diameter subsidence crater and venting 72 curies of Xenon-133 during drill-back operations. 27th British test. Coordinates: 37.12455, -116.07975.
MAY 24TH
U.S. tests: 3
Russian tests: 1
Total Yield: 62.501 kilotons.
The Details:
1951 - ‘Item’ detonated atop a 203 foot (62m) tower on Enjebi Island ("Janet") at Eniwetok Atoll at 17:16 GMT with a yield of 45.5 kilotons from the LANL weapons development device during Operation Greenhouse. 15th U.S. test. Coordinates: 11.66604, 162.24254.
Side Note: ‘Item‘ was a test of "boosting" fission using a thermonuclear fusion reaction to generate neutrons and increase the rate of fissioning in a nuclear core to boost its yield and ensure more efficient burning of fissile material. ‘Item’ used a deuterium-tritium gas inside an enriched uranium core which doubled the yield over its expected unboosted value.
1973 - ‘Cabresto’ detonated in a vertical shaft 649 feet (197m) beneath Yucca Flat area 7 at 13:30 GMT with a yield of 15 kilotons from the LANL weapons development device as part of Operation Toggle, causing a 4.8 magnitude ground shock. 727th U.S. test. Coordinates: 37.078, -116.03164.
-- One hour later at 14:30 GMT, ‘Kashan’ detonated in a vertical shaft 870 feet (260m) beneath Yucca Flat area 10 with a yield of 2 kilotons from the LLNL weapons development device during Operation Toggle, causing a 4.1 magnitude ground shock, creating a 360 foot (110m) subsidence crater and venting 270 curies of Xenon-133 over 6 hours during drill-back operations. 728th U.S. test. Coordinates: 37.16222, -116.05689.
1978 - ‘576’ detonated in a tunnel 1,293 feet (394m) beneath Degelen Mountain, Semipalatinsk at 03:07 GMT with a yield of 0.001 kilotons as part of a safety test. 484th Russian test. Coordinates: 49.74721, 78.05809.
MAY 25TH
U.S. tests: 6
Russian tests: 2
French tests: 1
North Korean tests: 1
Total Yield: 180.2 kilotons.
The Details:
1952 - ‘Fox’ detonated atop a 300 foot (90m) tower on Yucca Flat area 4 at 11:59 GMT with a yield of 11 kilotons from the LANL device, a Mk-5, during Operation Tumbler-Snapper, releasing 1.6 million curies of Iodine-131 into the atmosphere. 28th U.S. test. Coordinates: 37.0955, -116.1064.
Side Notes: Army troops from the First Armored Division participated, mostly as observers in trenches about four miles from ground zero and as radiation monitors. They had placed various items of military equipment near ground zero such as jeeps, tanks, rifles and machine guns. This had been done during previous detonations with the result only being scorched paint and minor damage. However, when the troops returned to the area after the ‘Fox’ detonation, they found demolished equipment: jeeps smashed flat and a tank picked up and thrown by the blast and melted by the fireball. Radiation levels 400 yards from ground zero exceeded 2,000 roentgens per hour.
'Fox' was initially set to detonate on May 13 but misfired, meaning that it did not function. Postmortem investigation turned up the cause of the misfire — not in the bomb’s circuitry but in an instrumentation system. One device failed to switch on and overrode the automatic firing sequence without warning. 'Fox' was rescheduled to May 25.
1953 - ‘Grable’ detonated 524 feet (160m) above Frenchman Flat area 5 at 15:30 GMT with a yield of 15 kilotons from the LANL device, a Mk-9 cannon shell, after being fired from a 280MM cannon during Operation Upshot-Knothole as part of a weapons effects test, releasing 2.1 million curies of Iodine-131 into the atmosphere. 42nd U.S. test. Coordinates: 36.793, -115.9156.
Side Note: ‘Grable’ was fired by a M65 Atomic Cannon. The 805 pound (365kg) 280mm shell traveled 6.8 miles (11km) downrange before detonating via radio control at a third of the intended altitude of 1,500 feet (457m) and 2 kilotons less than predicted yield, but it decimated the equipment placed in the target area as part of the weapons effects test.
An excellent video of the 'Grable' detonation sequence and blast wave can be seen here: https://www.youtube.com/watch?time_continue=46&v=dflLFFZcZ0w
1962 - ‘White’ detonated in a vertical shaft 632 feet (192m) beneath Yucca Flat at 15:00 GMT with a yield of 8 kilotons from the LLNL weapons development device, possibly a W-58 primary, during Operation Nougat, creating a 488 foot (149m) diameter subsidence crater and venting 1,600 curies of Xenon-133 over a period of 8 hours during drill-back operations. 244th U.S. test. Coordinates: 37.12479, -116.05287.
-- One hour and nine minutes later at 16:09 GMT, ‘Tanana’ detonated 9,029 feet (2,752m) above the Christmas Island area with a yield of 2.6 kilotons (far less than expected) from the LLNL weapons development device after being parachuted from a B-52 during Operation Dominic. 245th U.S. test. Coordinates: 1.6, -157.3.
Side Note: ‘Tanana’ was an advanced design Calliope III device in a Mk 36 drop case. The thermonuclear secondary failed to burn resulting in essentially a fizzle although the primary functioned, resulting in a lower than planned yield. .
1963 - ‘Clean Slate I’ detonated on the surface of the Tonopah Test Range at 11:17 GMT with no yield from the British provided device as the second safety/transportation plutonium dispersal test during Operation Roller Coaster. Radioactive plutonium scattered over the test area and was detected off-site. 323rd U.S. test, joint with Britain. Coordinates: 37.70853, -116.65786.
Side Note: It was not until 2018 that the 'Clean Slate 1' test area was cleaned up by excavating, packaging, and disposing of contaminated soil and debris which included plutonium and americium.
1971 - ‘371’ detonated in a tunnel 2,497 feet (761m) beneath Degelen Mountain, Semipalatinsk at 05:00 GMT with a yield of 9 kilotons from the weapons development device, causing a 5.05 magnitude ground shock. 338th Russian test. Coordinates: 49.8016, 78.1388.
1977 - ‘Crewline’ detonated in a vertical shaft 1,851 feet (564m) beneath Yucca Flat at 17:00 GMT with a yield of 51 kilotons from the LANL weapons development device during Operation Fulcrum, causing a 5.3 magnitude ground shock. 812th U.S. test. Coordinates: 37.0943, -116.04574.
1981 - ‘Pirit’ detonated 4,957 feet (1,511m) beneath Nenetsky, Russia at 05:00 GMT with a yield of 37.6 kilotons as part of an underground oil/gas fire-extinguishing experiment, causing a 5.5 magnitude ground shock. 570th Russian test. Coordinates: 68.2, 53.5.
1983 - ‘Cinyras’ detonated beneath Mururoa Atoll lagoon at 17:31 with a yield of 42 kilotons, causing a 5.55 magnitude ground shock. 137th French test. Coordinates: -21.86737, -138.94077.
2009 - North Korea detonated a nuclear device in a tunnel complex at 00:54 GMT with a yield of 4 kilotons, causing a 4.7 magnitude ground shock. 2nd North Korean test. Coordinates: 41.306, 129.029.
MAY 26TH
U.S. tests: 9 (11 devices)
Russian tests: 1 (2 devices)
Chinese tests: 1
Total Yield: ≈737.175 kilotons.
The Details:
1958 - ‘Yellowwood’ detonated 9.8 feet (3m) above Eniwetok Atoll lagoon on a barge anchored off Enjebi (Janet) Island at 02:00 GMT with a yield of 330 kilotons from the LANL weapons development device, a TX-46/W-53, during Operation Hardtack I. 128th U.S. test. Coordinates: 11.65751, 162.22168.
-- Sixteen hours later at 18:00 GMT, ‘Magnolia’ detonated 13 feet (4m) above Eniwetok Atoll lagoon on a barge anchored off Runit (Yvonne) island with a yield of 57 kilotons from the LANL weapons development device, a proof test of the Cougar device, during Operation Hardtack I. 129th U.S. test. Coordinates: 11.53932, 162.34841.
Side Note: ‘Yellowwood’ was a fizzle due to a poor burn of the thermonuclear secondary. “The shot barge for Yellowwood was ballasted with 225 tons of silica sand in an attempt to reduce strontium-90. It was hoped that chemically inert strontium silicate would be formed.” No data is available to show whether it did or not.
1967 - ‘Absinthe’ detonated in a vertical shaft 389 feet (118m) beneath Yucca Flat area U3 at 12:30 GMT with a yield of <20 kilotons from the LANL device as part of a safety test during Operation Latchkey. 502nd U.S. test. Coordinates: 37.045, -116.01979.
-- Two hours and thirty minutes later at 15:00 GMT, ‘Knickerbocker’ detonated in a vertical shaft 2,069 feet (630m) beneath Pahute Mesa area U20 with a yield of 76 kilotons from the LLNL weapons development device during Operation Latchkey, causing a 5.54 magnitude ground shock and venting 110 curies of Xenon-133 over a period of 5.6 days during drill-back operations. 503rd U.S. test. Coordinates: 37.24789, -116.48106.
1970 - ‘Hudson Moon’ detonated in a tunnel 1,386 feet (422m) beneath Rainier Mesa area U12 at 14:16 GMT with a yield of 9 kilotons from the LLNL device as part of a weapons effects test during Operation Mandrel, causing a 5.9 magnitude ground shock and venting 3 curies of Xenon-135 in an uncontrolled release lasting 20 hours. 651st U.S. test. Coordinates: 37.18256, -116.21427.
-- Forty-four minutes later at 15:00 GMT, ‘Flask-Green-1’, ‘Flask-Yellow-2’, and ‘Flask-Red-3’ detonated simultaneously in separate but adjacent vertical shafts beneath Yucca Flat area U2 with varying yields from the three LLNL devices as part of a Project Plowshares fundamental research test on development of clean devices for hard rock excavation during Operation Mandrel, causing a 5.6 magnitude ground shock, creating a 974 foot (297m) diameter subsidence crater and venting 25,000 curies of Xenon-133 from surface ground zero pipes and cables. 652nd U.S. test.
‘Flask-Green-1’ coordinates: 37.11336, -116.06354 Depth: 1,735 feet (529m) Yield: 105 kilotons
‘Flask-Yellow-2’ coordinates: 37.11799, -116.06364 Depth: 500 feet (152.4m) Yield: 0.09 kilotons
‘Flask-Red-3’ coordinates: 37.11615, -116.06757 Depth: 1,099 feet (335m) Yield: 0.035 kilotons
1983 - ‘Mini Jade’ detonated in a cavity within a tunnel 1,244 feet (379m) beneath Rainier Mesa area U12 at 14:30 GMT with a yield of 4 kilotons from the LANL device as part of a weapons effects test during Operation Phalanx. 924th U.S. test. Coordinates: 37.20821, -116.20599.
-- Thirty minutes later at 15:00 GMT, ‘Fahada’ detonated in a vertical shaft 1,261 feet (384m) beneath Yucca Flat area U7 with a yield of 6 kilotons from the LANL weapons development device during Operation Phalanx, causing a 4.5 magnitude ground shock. 925th U.S. test. Coordinates: 37.10286, -116.00657.
1984 - 838’ and ‘839’ detonated simultaneously in the same vertical shaft 1,080 feet (330m) beneath Balapan, Semipalatinsk at 01:09 GMT with a combined yield of 150 kilotons, causing a 6.01 magnitude ground shock. 637th Russian test. Coordinates: 49.98011, 79.00611.
1989 - ‘Tulia’ detonated in a vertical shaft 1,305 feet (397m) beneath Yucca Flat area U4 at 18:07 GMT with a yield of 0.5 kilotons from the LANL weapons development device as part of Operation Cornerstone. 1,024th U.S. test. Coordinates: 37.08587, -116.05665.
1990 – China detonated a device beneath Lop Nor at 07:59 GMT with an unknown yield, causing a 5.5 magnitude ground shock. This was possibly a test of a Pakistani copy of the Chinese CHIC-4 device. 36th Chinese test. Coordinates: 41.56476, 88.71912.
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MAY 27TH
U.S. tests: 6 (7 devices)
Russian tests: 2
French tests: 1
Total Yield: ≈3,613.09 kilotons.
The Details:
1956 – ‘Zuni’ detonated 9.8 feet (3m) above the dry surface of Eninmen (Tare) island at Bikini Atoll at 17:56 GMT with a yield of 3.5 megatons from the LLNL Bassoon weapons development device during Operation Redwing, essentially blowing the island of Eninmem away. 73rd U.S. test. Coordinates: 11.50325, 165.37049.
-- Two hours later at 19:56 GMT, ‘Yuma’ detonated atop a 200 foot (60m) steel tower on Aomon (Sally) island at Eniwetok Atoll with a yield of 0.19 kilotons (a fizzle) from the LLNL ”Swift” weapons development device during Operation Redwing. 74th U.S. test. Coordinates: 11.61569, 162.31935.
Side Notes:
- ‘Zuni’ was the first test of 3- stage fission-fusion-fusion device. Eighty-five percent of its yield was from fusion as it was a clean version using a lead tamper instead of uranium. The dirty version using uranium had a yield of 25 megatons. The Bassoon design evolved into the MK-41, the largest deployed U.S. bomb.
- ‘Yuma’ was the smallest; 5 inches (130 mm) in diameter, and lightest; 96 pounds (44 kg) air defense warhead designed at this point in time. It was a boosted asymmetrical linear implosion device, but it fizzled when the tritium-deuterium boost didn't work.
1962 - ‘Nambe’ detonated 7,139 feet (2,176m) above the Christmas (Kiritimati) Island area at 17:03 GMT with a yield of 43 kilotons (lower than expected) from the LANL “Zippo-II” weapon development device after being free-fall air-dropped from a B-52 device during Operation Dominic I. 246th U.S. test. Coordinates: 1.59, -157.32.
1966 - ‘Discus Thrower’ detonated in a vertical shaft 1,105 feet (337m) beneath Yucca Flat area U8 at 20:00 GMT with a yield of 22 kilotons as part of a weapons effects test during Operation Flintlock, causing a 5.1 magnitude ground shock, and creating a 950 foot (291m) diameter subsidence crater. 461st U.S. test. Coordinates: 37.17834, -116.09862.
1969 - ‘Ipecac-A’ and ‘Ipecac-B’ detonated simultaneously in separate but adjacent vertical shafts 407 feet (124m) beneath Yucca Flat area U3 at 14:00 GMT with yields of <20 kilotons from the two LANL devices as part of a safety experiment during Operation Bowline, releasing Xenon gases from surface ground zero for a period of 2.8 hours after detonation. 599th U.S. test. Coordinates: 37.01498, -116.00292.
-- Fifteen minutes later at 14:15 GMT , ‘Torrido’ detonated in a vertical shaft 1,688 feet (514m) beneath Yucca Flat area U7 with a yield of 22 kilotons from the LANL weapons development device, causing a 5.0 magnitude ground shock and creating a 1,003 foot (306m) diameter subsidence crater during Operation Bowline. 600th U.S. test. Coordinates: 37.07506, -115.99617.
1970 - ‘347’ detonated in a tunnel 1,900 feet (580m) beneath Degelen Mountain, Semipalatinsk at 04:03 GMT with a yield of 0.9 kilotons, causing a 4.2 magnitude ground shock. 319th Russian test. Coordinates: 49.73183, 78.0975.
1981 - ‘728’ detonated in a vertical shaft 1,080 feet (330m) beneath Balapan, Semipalatinsk at 03:58 GMT with a yield of 20 kilotons, causing a 5.3 magnitude ground shock. 571st Russian test. Coordinates: 49.9887, 78.96913.
1986 - ‘Sthénélos’ detonated in a shaft beneath the rim of Mururoa Atoll at 17:15 GMT with a yield of 5 kilotons, causing a 4.67 magnitude ground shock. 162nd French test. Coordinates: -21.87027, -138.88091.
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MAY 28TH
U.S. tests: 4 (6 devices)
Russian tests: 1 (2 devices)
Pakistan tests: 1 (5 devices?)
Total Yield: ≈60 kilotons.
The Details:
1957 - ‘Boltzman’ detonated atop a 490 foot (150m) tower on Yucca Flat area 7 at 11:55 GMT with a yield of 12 kilotons from the LANL weapons development device - an XW-40 lightweight boosted fission warhead – during the first test of Operation Plumbbob, releasing 1.9 million curies of Iodine-131 and Strontium-90 into the atmosphere. 87th U.S. test. Coordinates: 37.0947, -116.0245.
1967 - ‘278’ and ‘279’ detonated simultaneously in a tunnel 2,510 feet (765m) beneath Degelen Mountain, Semipalatinsk at 04:07 GMT with a yield of 28 kilotons from ‘278’ and unknown yield from ‘279’ during a peaceful research experiment, causing a 5.46 magnitude ground shock. 267th Russian test. Coordinates: 49.7564, 78.0169.
1968 – ‘Adze’ detonated in a vertical shaft 787 feet (240m) beneath Yucca Flat area U3 at 14:45 GMT with a yield of <20 kilotons from the LANL weapons development device during Operation Crosstie, venting Iodine and Xenon at surface ground zero from cable pulls. 548th U.S. test. Coordinates: 37.00861, -115.99614.
1970 - ‘Piton-C’ detonated in a vertical shaft 330 feet (100m) beneath Yucca Flat area U9 at 11:45 GMT with a yield of 2.5 kilotons from the LLNL weapons development device during Operation Mandrel, causing a 4.2 magnitude ground shock and releasing 25,000 curies of effluents over a period of 2.4 hours from surface ground zero. 653rd U.S. test. Coordinates: 37.13842, -116.03079.
-- Fifteen minutes later at 12:00 GMT, ‘Piton-1’ and ‘Piton-2’ detonated simultaneously in separate 775 foot (236m) deep shafts beneath Yucca Flat area U9 with yields of 0.8 kilotons and <20 kilotons respectively from the two LLNL weapons development devices during Operation Mandrel, causing a 3.8 magnitude ground shock and venting >10 curies of Xenon from surface ground zero. 654th U.S. test.
‘Piton-1’ coordinates: 37.14393, -116.03349.
‘Piton-2’ coordinates: 37.14056, -116.03497.
1998 – ‘ Chagai-I’ - Pakistan simultaneously detonated five nuclear devices in a tunnel beneath Chagai Mountain in Pakistan with a reported combined yield of 40 kilotons, causing a 4.8 magnitude ground shock. Pakistan announced that five devices had been detonated, each a boosted fission device using uranium cores. 1st Pakistan nuclear test. Coordinates: 28.79273, 64.94565.
Side Note: The assertion of five devices detonated was probably intended to match the five India had detonated two weeks prior on May 11th and 13th. Dr. Abdul Qadeer Khan said the first device yielded 30 to 35 kilotons with the rest giving yields of 1 kiloton each, yet studies of seismic data indicates that in all probability only one device was really tested with a yield of 9 kilotons and that the other reported devices may have been safety or engineering tests that produced no yield.
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MAY 29TH
U.S. tests: 2
Russian tests: 2
French tests: 1
Total Yield: 157.5 kilotons.
The Details:
1963 - ‘Pleasant’ detonated in a vertical shaft 690 feet (210m) beneath Yucca Flat area U9 with a yield of 2 kilotons from the LANL weapons development device during Operation Storax, creating a 164 foot (50m) diameter subsidence crater and venting 760 curies of radioactive Iodine, Cesium, and Xenon from surface ground zero cables for 2.5 hours after detonation and during a 24 hour period during drill-back operations. 324th U.S test. Coordinates: 37.12805, -116.04429.
1977 - ‘539’ detonated in a vertical shaft beneath Balapan, Semipalatinsk at 02:57 GMT with a yield of 44 kilotons from the weapons development device, causing a 5.75 magnitude ground shock. 460th Russian test. Coordinates: 49.94639, 78.77167.
1978 - ‘677’ detonated in a tunnel 2,251 feet (686m) beneath Degelen Mountain, Semipalatinsk at 04:56 GMT with a yield of 3 kilotons as part of a weapons effects test. 485th Russian test. Coordinates: 49.7986, 78.1022.
1981 - ‘Aligote’ detonated in a vertical shaft 1,050 feet (320m) beneath Yucca Flat area U7 at 16:00 GMT with a yield of 2.5 kilotons from the LANL weapons development device during Operation Guardian, causing a 4.2 magnitude ground shock. 886th U.S. test. Coordinates: 37.1018, -116.00493.
1991 - ‘Périclyménos’ detonated in a shaft beneath Fangataufa Atoll lagoon at 18:50 GMT with a yield of 106 kilotons, causing a 5.88 magnitude ground shock. 201st French test. Coordinates: -22.24307, -138.72516.
MAY 30TH
U.S. tests: 1
Russian tests: 1 (2 devices)
French tests: 3
Pakistani tests: 1
Total Yield: ≈1,014.1 kilotons.
The Details:
1958 - ‘Tobacco’ detonated 9 feet (3m) above Eniwetok Atoll lagoon on a barge anchored off Enjebi (Janet) island at 02:15 GMT with a yield of 11.6 kilotons from the LANL weapons development device during Operation Hardtack I. 130th U.S. detonation. Coordinates: 11.66056, 162.22663.
Side Note: ‘Tobacco’ was an exploratory test of the Nike-Zeus XW-50 prototype. It fizzled when the thermonuclear secondary stage failed to ignite.
1965 - ‘Jade’ detonated in a tunnel beneath Ekker, French Algeria at 11:00 GMT with a yield of 2.5 kilotons, venting an unknown amount of radio nuclides. 14th French test. Coordinates: 24.055, 5.0508.
1970 - ‘Dragon’ detonated beneath a balloon 1,600 feet (500m) above Fangataufa Atoll at 17:59 GMT with a yield of 945 kilotons from the weapons development device. 34th French test. Coordinates: -22.309, -138.606
1983 -‘796’ and ‘797’ detonated simultaneously in a tunnel at depths of 804 feet (245m) and 590 feet (180m) respectfully beneath Degelen Mountain, Semipalatinsk at 03:33 GMT with a combined yield of 20 kilotons, causing a 5.43 magnitude ground shock. ‘796’ was a fundamental science experiment and ‘797’ a weapons development device. 610th Russian test. Coordinates: 49.7439, 78.1127.
1986 - ‘Galatée’ detonated in a shaft beneath Mururoa Atoll lagoon at with a yield of 30 kilotons from the weapons development device, causing a 5.43 magnitude ground shock. 163rd French test. Coordinates: -21.86742, -138.95046.
1998 - ‘Chagai –II’ detonated in shaft beneath the Kharan Desert, Pakistan with a claimed yield of 15 kilotons from the boosted fission device, but based upon seismic and other data,
independent sources say it was only 5 kilotons. Plutonium in vented air samples confirmed it as Pakistan’s first plutonium-fueled implosion bomb. It caused a 4.8 magnitude ground shock. 2nd Pakistan test. Coordinates: 28.35828, 63.85882.
MAY 31ST
U.S. tests: 3
Russian tests: 3 (6 devices)
British tests: 1
Total Yield: 1,038 kilotons.
The Details:
1957 - ‘Grapple 2/Orange Herald’ detonated 7, 900 feet (2,400m) above Malden Island at 19:41 GMT with a yield of 720 kilotons from the boosted fission device after being air-dropped. 11th British test. Coordinates: -4.05, -154.9.
1958 - ‘Sycamore’ detonated 10 feet (3m) above Bikini Atoll lagoon atop a barge anchored in the Castle Bravo crater off Namu (Charlie) island at 03:00 GMT with a yield of 92 kilotons from the LLNL weapons development device during Operation Hardtack I. 131st U.S. test. Coordinates: 11.69722, 165.27486.
Side Note: ‘Sycamore’ was a fizzle. The TX-41 device had a predicted yield of 5,000 kilotons but the thermonuclear secondary failed to burn properly.
1963 - ‘Clean Slate II’ was destroyed by conventional explosives on the surface of Cactus Flats within the Tonopah Test Area at 10:47 GMT with no yield from the British device as part of a safety/transportation plutonium dispersal test during Operation Roller Coaster. The area was contaminated with plutonium as a result. 325th U.S. test. (Joint with UK) Coordinates: 37.7614, -116.61378.
Side Note: The 'Clean Slate II' site was not cleaned up until late 2018. Over 7,500 cubic yards of surface dirt and debris was removed, packaged, transported and buried at the Nevada Test Site disposal area.
1969 - ‘301’ detonated in a vertical shaft beneath Sary-Uzen/Murzhik, Semipalatinsk, Kazakhstan at 05:01 GMT with a yield of 18 kilotons from the weapons development device, causing a 5.29 magnitude ground shock. 301st Russian test. Coordinates: 49.95107, 77.6865.
1974 - ‘451’ detonated in a vertical shaft 1,037 feet (316m) beneath Balapan, Semipalatinsk at 03:27 GMT with a yield of 71 kilotons from the peaceful research device, causing a 5.9 magnitude ground shock, creating a 656 foot (200m) diameter subsidence crater and venting radioactive effluents from surface ground zero which drifted over 127 observers with readings as high as 100-200 REM. 400th Russian test. Coordinates: 49.96148, 78.84253.
1979 - ‘635’, ‘636’, ‘637’, and ‘638’ detonated simultaneously in the same tunnel 2,444 feet (745m) beneath Degelen Mountain, Semipalatinsk at 5:55 GMT with a combined yield of 17 kilotons from the four weapons development devices, causing a 5.27 magnitude ground shock. 519th Russian test. Coordinates: 49.81765, 78.06755.
1984 - ‘Caprock’ detonated in a vertical shaft 1,968 feet (599m) beneath Yucca Flat area U4 at 13:04 GMT with a yield of 120 kilotons from the LANL weapons development device during Operation Fusileer, causing a 5.8 magnitude ground shock, creating a 787 foot (240m) diameter subsidence crater, and venting Tritium, Argon-37, Krypton-85 and Xenons during gas sampling operations. 944th U.S. test. Coordinates: 37.10333, -116.04967.
