1975 Soviet nuclear tests

1975
Information
Country	Soviet Union
Test site	Atyrau, Kazakhstan; Balapan, Semipalatinsk, Kazakhstan; Degelen, Semipalatinsk, Kazakhstan; Krasnoyarsk, Russia; NZ Area A, Chyornaya Guba, Novaya Zemlya, Russia; NZ Area B, Matochkin Shar, Novaya Zemlya, Russia; Sakha, Russia
Period	1975
Number of tests	19
Test type	underground shaft, underground tunnel
Max. yield	1.3 megatonnes of TNT (5.4 PJ)
Navigation
Previous test series	1974 Soviet nuclear tests
Next test series	1976 Soviet nuclear tests

The Soviet Union's 1975 nuclear test series^[1] was a group of 19 nuclear tests conducted in 1975. These tests ^{[note 1]} followed the 1974 Soviet nuclear tests series and preceded the 1976 Soviet nuclear tests series.

Soviet Union's 1975 series tests and detonations

Name [note 2]	Date time (UT)	Local time zone [note 3][2]	Location [note 4]	Elevation + height [note 5]	Delivery, [note 6] Purpose [note 7]	Device [note 8]	Yield [note 9]	Fallout [note 10]	References	Notes
417 - 1	20 February 1975 05:33:00.0	ALMT (6 hrs)	Degelen, Semipalatinsk, Kazakhstan: 163 49°46′42″N 78°00′11″E / 49.77837°N 78.00296°E	749 m (2,457 ft) +	underground tunnel, weapon effect		unknown yield		[1][3][4][5][6]
417 - 2	20 February 1975 05:33:00.0	ALMT (6 hrs)	Degelen, Semipalatinsk, Kazakhstan: 163 49°46′42″N 78°00′11″E / 49.77837°N 78.00296°E	749 m (2,457 ft) +	underground tunnel, weapon effect		unknown yield		[1][3][4][5][6]
417 - 3	20 February 1975 05:33:00.0	ALMT (6 hrs)	Degelen, Semipalatinsk, Kazakhstan: 163 49°46′42″N 78°00′11″E / 49.77837°N 78.00296°E	749 m (2,457 ft) +	underground tunnel, weapon effect		unknown yield		[1][3][4][5][6]
418	20 February 1975 05:33:??	ALMT (6 hrs)	Degelen, Semipalatinsk, Kazakhstan: 156 49°47′43″N 78°00′30″E / 49.79516°N 78.0084°E	665 m (2,182 ft) +	underground tunnel, weapon effect		55 kt		[1][4][5][6][7]
419	11 March 1975 05:43:00.1	ALMT (6 hrs)	Degelen, Semipalatinsk, Kazakhstan: 101 49°44′46″N 78°06′22″E / 49.7462°N 78.106°E	650 m (2,130 ft) +	underground tunnel, weapons development		24 kt		[1][4][5][6][7]
420 Galit A2.1 (Halite)	25 April 1975 05:00:00.0	SHET (5 hrs)	Atyrau, Kazakhstan: A-II-2 47°54′32″N 47°54′43″E / 47.909°N 47.912°E	- 600 m (2,000 ft)	underground shaft, industrial		350 t		[1][3][5][6][7]	A-II, in cavity produced by #280.
421	27 April 1975 05:36:59.78	ALMT (6 hrs)	Balapan, Semipalatinsk, Kazakhstan: 1205 49°56′24″N 78°54′22″E / 49.94006°N 78.90611°E	330 m (1,080 ft) +	underground shaft, weapons development		29 kt		[1][4][5][6][7]
422	8 June 1975 03:27:00.0	ALMT (6 hrs)	Degelen, Semipalatinsk, Kazakhstan: 165 49°45′38″N 78°00′45″E / 49.7606°N 78.0125°E	722 m (2,369 ft) +	underground tunnel, peaceful research		32 kt		[1][4][5][6][7]
423	30 June 1975 03:27:00.25	ALMT (6 hrs)	Balapan, Semipalatinsk, Kazakhstan: A 49°59′10″N 78°53′45″E / 49.9862°N 78.89576°E	330 m (1,080 ft) +	underground shaft, weapons development		8 kt		[1][4][5][6][7]
424 - 1	15 July 1975 02:57:00.0	ALMT (6 hrs)	Degelen, Semipalatinsk, Kazakhstan: 133 49°47′44″N 78°05′44″E / 49.79556°N 78.09568°E	686 m (2,251 ft) +	underground tunnel, weapons development		unknown yield		[1][3][4][5][6]
424 - 2	15 July 1975 02:57:00.0	ALMT (6 hrs)	Degelen, Semipalatinsk, Kazakhstan: 133 49°47′44″N 78°05′44″E / 49.79556°N 78.09568°E	686 m (2,251 ft) +	underground tunnel, weapons development		unknown yield		[1][3][4][5][6]
425 - 1	7 August 1975 03:57:00.1	ALMT (6 hrs)	Degelen, Semipalatinsk, Kazakhstan: 122 49°48′14″N 78°07′24″E / 49.8038°N 78.1234°E	711 m (2,333 ft) +	underground tunnel, weapons development		14 kt		[1][4][5][6][7]
425 - 2	7 August 1975 03:57:00	ALMT (6 hrs)	Degelen, Semipalatinsk, Kazakhstan: 123 49°48′11″N 78°07′21″E / 49.80319°N 78.12254°E	752 m (2,467 ft) +	underground tunnel, weapons development		unknown yield		[1][3][4][5][6]
426 Gorizont 4 (Horizon)	12 August 1975 15:00:00.6	YAKT (9 hrs)	Sakha, Russia: G-4 70°45′49″N 126°57′08″E / 70.76367°N 126.95232°E	- 500 m (1,600 ft)	underground shaft, seismic sounding		7.6 kt		[1][3][5][6][8]	Seismic probing program. 120 km SW Tiksi.
427 - 1	23 August 1975 08:59:58.25	MSK (3 hrs)	NZ Area B, Matochkin Shar, Novaya Zemlya, Russia: A-10 73°20′02″N 54°40′55″E / 73.334°N 54.682°E	100 m (330 ft) - 700 m (2,300 ft)	underground tunnel, weapon effect		1.1 Mt	Venting detected on site	[1][3][5][6][7]
427 - 2	23 August 1975 08:59:58.3	MSK (3 hrs)	NZ Area B, Matochkin Shar, Novaya Zemlya, Russia: A-10 73°20′02″N 54°40′55″E / 73.334°N 54.682°E	100 m (330 ft) +	underground tunnel, weapon effect		unknown yield		[1][3][5][6][8]
427 - 3	23 August 1975 08:59:58.3	MSK (3 hrs)	NZ Area B, Matochkin Shar, Novaya Zemlya, Russia: A-10 73°20′02″N 54°40′55″E / 73.334°N 54.682°E	100 m (330 ft) +	underground tunnel, weapon effect		unknown yield		[1][3][5][6][8]
427 - 4	23 August 1975 08:59:58.3	MSK (3 hrs)	NZ Area B, Matochkin Shar, Novaya Zemlya, Russia: A-10 73°20′02″N 54°40′55″E / 73.334°N 54.682°E	100 m (330 ft) +	underground tunnel, weapon effect		unknown yield		[1][3][5][6][8]
427 - 5	23 August 1975 08:59:58.3	MSK (3 hrs)	NZ Area B, Matochkin Shar, Novaya Zemlya, Russia: A-10 73°20′02″N 54°40′55″E / 73.334°N 54.682°E	100 m (330 ft) +	underground tunnel, weapons development		unknown yield		[1][3][5][6][8]
427 - 6	23 August 1975 08:59:58.3	MSK (3 hrs)	NZ Area B, Matochkin Shar, Novaya Zemlya, Russia: A-10 73°20′02″N 54°40′55″E / 73.334°N 54.682°E	100 m (330 ft) +	underground tunnel, weapons development		unknown yield		[1][3][5][6][8]
427 - 7	23 August 1975 08:59:58.3	MSK (3 hrs)	NZ Area B, Matochkin Shar, Novaya Zemlya, Russia: A-10 73°20′02″N 54°40′55″E / 73.334°N 54.682°E	100 m (330 ft) +	underground tunnel, weapons development		unknown yield		[1][3][5][6][8]
427 - 8	23 August 1975 08:59:58.3	MSK (3 hrs)	NZ Area B, Matochkin Shar, Novaya Zemlya, Russia: A-10 73°20′02″N 54°40′55″E / 73.334°N 54.682°E	100 m (330 ft) +	underground tunnel, weapons development		unknown yield		[1][3][5][6][8]
428 Gorizont 3 (Horizon)	29 September 1975 11:00:00.4	KRAT (7 hrs)	Krasnoyarsk, Russia: G-3 69°34′41″N 90°20′13″E / 69.578°N 90.337°E	- 830 m (2,720 ft)	underground shaft, seismic sounding		7.6 kt		[1][3][5][6][7]	Seismic probing program. 80 km E Norilsk.
429	5 October 1975 04:27:00.0	ALMT (6 hrs)	Degelen, Semipalatinsk, Kazakhstan: 192 49°46′53″N 78°05′26″E / 49.78143°N 78.09052°E	635 m (2,083 ft) +	underground tunnel, weapons development		200 t		[1][4][5][6][7]
431	18 October 1975 08:59:59.4	MSK (3 hrs)	NZ Area A, Chyornaya Guba, Novaya Zemlya, Russia: Yu-7 70°47′42″N 53°42′43″E / 70.795°N 53.712°E	30 m (98 ft) +	underground shaft, weapons development		600 kt		[1][5][6][7][9]
430 - 1	18 October 1975 09:00:??	MSK (3 hrs)	NZ Area A, Chyornaya Guba, Novaya Zemlya, Russia: Yu-6N 70°59′N 53°42′E / 70.99°N 53.7°E	30 m (98 ft) - 1,100 m (3,600 ft)	underground shaft, weapons development		600 kt	Venting detected	[1][3][5][6][7]
430 - 2	18 October 1975 09:00:??	MSK (3 hrs)	NZ Area A, Chyornaya Guba, Novaya Zemlya, Russia: Yu-6N 70°59′N 53°42′E / 70.99°N 53.7°E	30 m (98 ft) +	underground shaft, weapons development		600 kt		[1][3][5][6][7]
432 - 1	21 October 1975 11:59:58.03	MSK (3 hrs)	NZ Area B, Matochkin Shar, Novaya Zemlya, Russia: A-12 73°19′09″N 54°55′37″E / 73.31907°N 54.9269°E	100 m (330 ft) - 700 m (2,300 ft)	underground tunnel, weapons development		1.3 Mt	Venting detected off site, 300 kCi (11,000 TBq)	[1][5][6][7][9]
432 - 2	21 October 1975 11:59:58.0	MSK (3 hrs)	NZ Area B, Matochkin Shar, Novaya Zemlya, Russia: A-12 73°18′57″N 54°55′51″E / 73.3158°N 54.93087°E	100 m (330 ft) +	underground tunnel, weapons development		unknown yield		[1][3][5][6][8]
432 - 3	21 October 1975 11:59:58.0	MSK (3 hrs)	NZ Area B, Matochkin Shar, Novaya Zemlya, Russia: A-12 73°18′52″N 54°56′12″E / 73.31435°N 54.93673°E	100 m (330 ft) +	underground tunnel, weapons development		unknown yield		[1][3][5][6][8]
432 - 4	21 October 1975 11:59:58.0	MSK (3 hrs)	NZ Area B, Matochkin Shar, Novaya Zemlya, Russia: A-12 73°18′52″N 54°56′12″E / 73.31435°N 54.93673°E	100 m (330 ft) +	underground tunnel, weapons development		unknown yield		[1][3][5][6][8]
432 - 5	21 October 1975 11:59:58.0	MSK (3 hrs)	NZ Area B, Matochkin Shar, Novaya Zemlya, Russia: A-12 73°18′52″N 54°56′12″E / 73.31435°N 54.93673°E	100 m (330 ft) +	underground tunnel, weapons development		unknown yield		[1][3][5][6][8]
433	29 October 1975 04:46:59.89	ALMT (6 hrs)	Balapan, Semipalatinsk, Kazakhstan: 1206 49°57′14″N 78°52′26″E / 49.95389°N 78.87389°E	330 m (1,080 ft) +	underground shaft, weapons development		36 kt		[1][4][5][6][7]
434	13 December 1975 04:56:59.99	ALMT (6 hrs)	Degelen, Semipalatinsk, Kazakhstan: 604 49°48′27″N 78°06′52″E / 49.8076°N 78.1144°E	770 m (2,530 ft) +	underground tunnel, weapons development		8 kt		[1][4][5][6][7]
435	25 December 1975 05:16:59.67	ALMT (6 hrs)	Balapan, Semipalatinsk, Kazakhstan: 1067 50°02′56″N 78°49′08″E / 50.04884°N 78.81882°E	330 m (1,080 ft) +	underground shaft, weapons development		59 kt		[1][4][5][6][7]

1. 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". Mikhailov, V. N., Editor in Chief. "Catalog of World Wide Nuclear Testing". Begell-Atom, LLC.
2. 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.
3. 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. All historical timezone data are derived from here:
4. 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.
5. 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.
6. 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.
7. Include weapons development, weapon effects, safety test, transport safety test, war, science, joint verification and industrial/peaceful, which may be further broken down.
8. 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.
9. Estimated energy yield in tons, kilotons, and megatons. A ton of TNT equivalent is defined as 4.184 gigajoules (1 gigacalorie).
10. 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.

References

1. Yang, Xiaoping; North, Robert; Romney, Carl (August 2000). CMR Nuclear Explosion Database (Revision 3) (Technical report). SMDC Monitoring Research.
2. "Timezone Historical Database". iana.com. Retrieved March 8, 2014.
3. Nuclear explosions in the USSR: The North Test Site reference material, version 4 (PDF) (Technical report). IAEA Dept. of Nuclear Safety and Security. December 1, 2004. Retrieved December 13, 2013.
4. Khalturin, Vitaly I.; Rautian, Tatyana G.; Richards, Paul G. (2000). "Chemical explosions during 1961-1989 on the Semipalatinsk Test Site, Kazakhstan" (PDF). Pure and Applied Geophysics 158: 143–171. doi:10.1007/pl00001153. Retrieved December 13, 2013.
5. Podvig, Pavel, ed. (2001). Russian Strategic Nuclear Forces. Cambridge, MA: MIT Press. Retrieved January 9, 2014.
6. USSR Nuclear Weapons Tests and Peaceful Nuclear Explosions 1949 through 1990. Sarov, Russia: RFNC-VNIIEF. 1996. The official Russian list of Soviet tests.
7. Cochran, Thomas B.; Arkin, William M.; Norris, Robert S.; Sands, Jeffrey I. Nuclear Weapons Databook Vol. IV: Soviet Nuclear Weapons. New York, NY: Harper and Row.
8. Andrushkin, Vitaly V.; Leith, William (September 1, 2001). The containment of Soviet underground nuclear explosions (PDF) (Open File Report 01-312). USGS. Retrieved December 13, 2013.
9. Kim, Won-Young; Richards, Paul G.; Andrushkin, Vitaly; Ovtchinnikov, Vladimir (April 1, 2001). Borovoye digital seismogram archive for underground nuclear tests during 1966-1996 (PDF) (Technical report). LDEO. Retrieved December 13, 2013.