Operation Grommet Explained

Operation Grommet
Picture Description:	Grommet Cannikin, 4.8Mt. Largest U.S. Underground nuclear test.
Country:	United States
Test Site:	Amchitka Island, Alaska NTS Area 12, Rainier Mesa NTS Area 16, Shoshone Mountain NTS Areas 5, 11, Frenchman Flat NTS Areas 1–4, 6–10, Yucca Flat
Period:	1971–1972
Number Of Tests:	34
Test Type:	underground shaft, tunnel
Max Yield:	4.8MtTNT
Next Series:	Operation Toggle

The United States's Grommet nuclear test series was a group of 34 nuclear tests conducted in 1971–1972. These tests^[1] followed the Operation Emery series and preceded the Operation Toggle series.

List of the nuclear tests

United States' Grommet series tests and detonations
- !style="background:#ffdead;"	Name^[2] !style="background:#efefef;"	Date time (UT) !style="background:#ffdead;"	Local time zone^[3] ^[4] !style="background:#efefef;"	Location^[5] !style="background:#ffdead;"	Elevation + height^[6] !style="background:#efefef;"	Delivery^[7] Purpose^[8] !style="background:#efefef;"	Device^[9] !style="background:#ffdead;"	Yield^[10] !style="background:#efefef;" class="unsortable"	Fallout^[11] !style="background:#ffdead;" class="unsortable"	References !style="background:#efefef;" class="unsortable"	Notes	- ! Diamond Mine	14:00:00.04	PST (–8 hrs)	NTS Area U16a.06 37.0115°N -116.2043°W	1896m (6,220feet) 266.15m (873.2feet)	tunnel, joint verification					Designed to test detection of underground nuclear tests; see Vela Uniform.	- ! Miniata	14:00:00.082	PST (–8 hrs)	NTS Area U2bu 37.1102°N -116.0527°W	1247m (4,091feet) 528.83m (1,735.01feet)	underground shaft, peaceful research			Venting detected, 180abbr=onNaNabbr=on		Project Plowshare device development.	- ! Bracken	14:00:00.16	PST (–8 hrs)	NTS Area U10aq 37.1644°N -116.0336°W	1297m (4,255feet) 304.8m (1,000feet)	underground shaft, weapons development			Venting detected, 1Ci			- ! Apodaca	13:33:00.05	PST (–8 hrs)	NTS Area U3gs 37.0144°N -115.9927°W	1195m (3,921feet) 241.4m (792feet)	underground shaft, weapons development						- ! Barranca	13:30:00.042	PST (–8 hrs)	NTS Area U3he 37.0261°N -116.0203°W	1187m (3,894feet) 270.74m (888.25feet)	underground shaft, weapons development						- ! Nama-Amarylis 1	18:07:45.2	PST (–8 hrs)	NTS Area U9itsxy3 37.145°N -116.0342°W	1273m (4,177feet) 272.8m (895feet)	underground shaft, weapons development					Simultaneous, separate holes.	- ! Nama-Mephisto 2	18:07:45.2	PST (–8 hrs)	NTS Area U9itsz27 37.1406°N -116.0321°W	1276m (4,186feet) +	underground shaft, weapons development					Simultaneous, separate holes.	- ! Baltic	14:31:00.16	PST (–8 hrs)	NTS Area U9itss25 37.1384°N -116.0418°W	1260m (4,130feet) 411.48m (1,350feet)	underground shaft, weapons development						- ! Algodones	14:00:00.03	PST (–8 hrs)	NTS Area U3jn 37.0572°N -116.0372°W	1206m (3,957feet) 527.61m (1,731feet)	underground shaft, weapons development						- ! Frijoles-Deming 1	14:00:00.037	PST (–8 hrs)	NTS Area U3jw 37.0216°N -116.0169°W	1186m (3,891feet) 149.86m (491.67feet)	underground shaft, safety experiment					Simultaneous, separate holes.	- ! Frijoles-Espuela 2	14:00:00.04	PST (–8 hrs)	NTS Area U3ju 37.0227°N -116.0171°W	1186m (3,891feet) +	underground shaft, safety experiment					Simultaneous, separate holes.	- ! Frijoles-Guaje 3	14:00:00.04	PST (–8 hrs)	NTS Area U3hf 37.0244°N -116.016°W	1186m (3,891feet) +	underground shaft, weapons development					Simultaneous, separate holes.	- ! Frijoles-Petaca 4	14:00:00.04	PST (–8 hrs)	NTS Area U3hz 37.0219°N -116.0196°W	1185m (3,888feet) +	underground shaft, weapons development					Simultaneous, separate holes.	- ! Pedernal	14:00:00.04	PST (–8 hrs)	NTS Area U3hg 37.011°N -116.0081°W	1180m (3,870feet) 378.68m (1,242.39feet)	underground shaft, weapons development						- ! Chantilly	14:30:00.14	PST (–8 hrs)	NTS Area U2di 37.1245°N -116.088°W	1280m (4,200feet) 330.71m (1,085.01feet)	underground shaft, weapons development						- ! Cathay	14:30:00.15	PST (–8 hrs)	NTS Area U9ch 37.1137°N -116.0382°W	1261m (4,137feet) 377.95m (1,239.99feet)	underground shaft, weapons development						- ! Lagoon	14:30:00.16	PST (–8 hrs)	NTS Area U10ar 37.1799°N -116.054°W	1286m (4,219feet) 304.8m (1,000feet)	underground shaft, weapons development						- ! Cannikin	22:00:00.06	BST (–11 hrs)	Amchitka Island, Alaska 51.4699°N 179.1067°W	63m (207feet) 1790m (5,870feet)	underground shaft, weapons development					A test of the Spartan ABM warhead. The largest underground nuclear test ever.	- ! Diagonal Line	20:15:00.17	PST (–8 hrs)	NTS Area U11g 36.8793°N -115.9359°W	1010m (3,310feet) 264.26m (866.99feet)	underground shaft, weapon effect			Venting detected off site, 6.8kCi		Picture of the "Ship of the Desert", a structure for capturing neutrons for experiments with this test: .	- ! Parnassia	15:45:00.15	PST (–8 hrs)	NTS Area U2bc 37.1605°N -116.0711°W	1302m (4,272feet) 330.71m (1,085.01feet)	underground shaft, weapons development						- ! Chaenactis	21:09:59.16	PST (–8 hrs)	NTS Area U2dl 37.1239°N -116.0905°W	1281m (4,203feet) 331.01m (1,085.99feet)	underground shaft, weapons development						- ! Hospah	21:10:01.04	PST (–8 hrs)	NTS Area U3je 37.0258°N -116.0299°W	1188m (3,898feet) 302.03m (990.91feet)	underground shaft, weapons development						- ! Yerba	21:10:01.04	PST (–8 hrs)	NTS Area U1c 37.0232°N -116.0596°W	1202m (3,944feet) 331.99m (1,089.21feet)	underground shaft, weapons development						- ! Mescalero	15:10:00.04	PST (–8 hrs)	NTS Area U3gu 37.0457°N -116.0303°W	1198m (3,930feet) 120.24m (394.49feet)	underground shaft, weapons development						- ! Cowles	21:45:00.04	PST (–8 hrs)	NTS Area U3hx 37.0011°N -116.0202°W	1178m (3,865feet) 301.78m (990.09feet)	underground shaft, weapons development						- ! Dianthus	19:02:00.16	PST (–8 hrs)	NTS Area U10at 37.1657°N -116.0571°W	1279m (4,196feet) 304.8m (1,000feet)	underground shaft, weapons development			Venting detected, 18Ci			- ! Sappho	18:50:00.16	PST (–8 hrs)	NTS Area U2dh2 37.113°N -116.0817°W	1266m (4,154feet) 197.82m (649.02feet)	underground shaft, weapons development			Venting detected, 9Ci			- ! Ocate 2 (with Onaja)	21:00:00.08	PST (–8 hrs)	NTS Area U3jp 37.0045°N -116.0157°W	1179m (3,868feet) +	underground shaft, weapons development						- ! Onaja 1 (with Ocate)	21:00:00.04	PST (–8 hrs)	NTS Area U3js 37.0055°N -116.0208°W	1180m (3,870feet) 279.04m (915.49feet)	underground shaft, weapons development						- ! Longchamps	16:32:00.16	PST (–8 hrs)	NTS Area U2dm 37.122°N -116.0849°W	1276m (4,186feet) 326.44m (1,071feet)	underground shaft, weapons development						- ! Jicarilla	16:42:00.05	PST (–8 hrs)	NTS Area U3jm 37.0066°N -116.0173°W	1180m (3,870feet) 148.11m (485.93feet)	underground shaft, weapons development						- ! Misty North	19:15:00.04	PST (–8 hrs)	NTS Area U12n.05 37.2076°N -116.2096°W	2199m (7,215feet) 376.08m (1,233.86feet)	tunnel, weapon effect						- ! Kara	14:00:00.16	PST (–8 hrs)	NTS Area U2dh3 37.1125°N -116.0853°W	1267m (4,157feet) 259.08m (850feet)	underground shaft, weapons development			Venting detected, 7Ci			- ! Zinnia	14:10:00.16	PST (–8 hrs)	NTS Area U2dk 37.1206°N -116.0888°W	1277m (4,190feet) 322.78m (1,058.99feet)	underground shaft, weapons development			Venting detected, 7Ci			- ! Monero	17:00:00.05	PST (–8 hrs)	NTS Area U3jg 37.0647°N -116.0025°W	1245m (4,085feet) 537.35m (1,762.96feet)	underground shaft, weapons development						- ! Merida	15:20:00.16	PST (–8 hrs)	NTS Area U2dn 37.1158°N -116.0862°W	1271m (4,170feet) 204.22m (670.01feet)	underground shaft, weapons development			Venting detected, 10Ci			- ! Capitan	14:41:00.19	PST (–8 hrs)	NTS Area U3jj 36.9926°N -116.023°W	1175m (3,855feet) 134.48m (441.21feet)	underground shaft, weapons development						- ! Tajique	16:30:00.07	PST (–8 hrs)	NTS Area U7aa 37.0696°N -115.9929°W	1274m (4,180feet) 332.31m (1,090.26feet)	underground shaft, weapons development						- ! Haplopappus	16:30:03.16	PST (–8 hrs)	NTS Area U9itsw22 37.1352°N -116.0361°W	1264m (4,147feet) 184.4m (605feet)	underground shaft, weapons development

Notes and References

A bomb test may be a salvo test, defined as two or more explosions "where a period of time between successive individual explosions does not exceed 5 seconds and where the burial points of all explosive devices can be connected by segments of straight lines, each of them connecting two burial points and does not exceed 40 kilometers in length". Web site: V. N.. Mikhailov. Catalog of World Wide Nuclear Testing. Begell-Atom. dead. https://web.archive.org/web/20140426102201/http://www.iss-atom.ru/ksenia/catal_nt/1.htm. April 26, 2014.
The US, France and Great Britain have code-named their test events, while the USSR and China did not, and therefore have only test numbers (with some exceptions Soviet peaceful explosions were named). Word translations into English in parentheses unless the name is a proper noun. A dash followed by a number indicates a member of a salvo event. The US also sometimes named the individual explosions in such a salvo test, which results in "name1 1 (with name2)". If test is canceled or aborted, then the row data like date and location discloses the intended plans, where known.
To convert the UT time into standard local, add the number of hours in parentheses to the UT time; for local daylight saving time, add one additional hour. If the result is earlier than 00:00, add 24 hours and subtract 1 from the day; if it is 24:00 or later, subtract 24 hours and add 1 to the day. Historical time zone data obtained from the IANA time zone database.
Web site: Time Zone Historical Database. iana.com. March 8, 2014. March 11, 2014. https://web.archive.org/web/20140311224729/http://www.ietf.org/timezones/. live.
Rough place name and a latitude/longitude reference; for rocket-carried tests, the launch location is specified before the detonation location, if known. Some locations are extremely accurate; others (like airdrops and space blasts) may be quite inaccurate. "~" indicates a likely pro-forma rough location, shared with other tests in that same area.
Elevation is the ground level at the point directly below the explosion relative to sea level; height is the additional distance added or subtracted by tower, balloon, shaft, tunnel, air drop or other contrivance. For rocket bursts the ground level is "N/A". In some cases it is not clear if the height is absolute or relative to ground, for example, Plumbbob/John. No number or units indicates the value is unknown, while "0" means zero. Sorting on this column is by elevation and height added together.
Atmospheric, airdrop, balloon, gun, cruise missile, rocket, surface, tower, and barge are all disallowed by the Partial Nuclear Test Ban Treaty. Sealed shaft and tunnel are underground, and remained useful under the PTBT. Intentional cratering tests are borderline; they occurred under the treaty, were sometimes protested, and generally overlooked if the test was declared to be a peaceful use.
Include weapons development, weapon effects, safety test, transport safety test, war, science, joint verification and industrial/peaceful, which may be further broken down.
Designations for test items where known, "?" indicates some uncertainty about the preceding value, nicknames for particular devices in quotes. This category of information is often not officially disclosed.
Estimated energy yield in tons, kilotons, and megatons. A ton of TNT equivalent is defined as 4.184 gigajoules (1 gigacalorie).
Radioactive emission to the atmosphere aside from prompt neutrons, where known. The measured species is only iodine-131 if mentioned, otherwise it is all species. No entry means unknown, probably none if underground and "all" if not; otherwise notation for whether measured on the site only or off the site, where known, and the measured amount of radioactivity released.