acoustic waves from atmospheric nuclear explosions ... · the acoustic wave records (figure 14b)...
TRANSCRIPT
ACOUSTIC WAVES FROM ATMOSPHERIC NUCLEAR EXPLOSIONS RECORDED BY INFRASOUND
AND SEISMIC STATIONS OF KAZAKHSTAN
(T2.3-P3)
Inna Sokolova
Institute of Geophysical Research AEC ME RK, Almaty, Kazakhstan
,
Availability of the acoustic wave on the record of microbarograph is one of discriminate signs of atmospheric nuclear explosions. Nowadays
there is large number of air wave records from chemical explosions recorded by the IMS infrasound stations installed during recent decade.
But there is small number of air wave records from nuclear explosions as air and contact nuclear explosions had been conducted since 1945
to 1962, before the Limited Test Ban Treaty was signed in 1963 (the treaty banning nuclear weapon tests in the atmosphere, in outer space
and under water) by the Great Britain, USSR and USA. First infrasound stations in the USSR appeared in 1954, and by the moment of the
USSR collapse the network consisted of 25 infrasound stations, 3 of which were located on Kazakhstan territory - in Kurchatov (East
Kazakhstan), in Borovoye Observatory (North Kazakhstan) [1] and Talgar Observatory (Northern Tien Shan).
Beginning from 2005 the IGR RK conducts work on scanning and digitizing of nuclear explosions seismograms, records of calibration
chemical explosions and earthquakes from Test Sites areas, and large Central Asia earthquakes (with M>5.5). Works on historical
seismograms digitization were conducted under methodical support of Lamont-Doherty Observatory (LDEO, USA), and under financial
support of Kazakhstan budget, LDEO, Norwegian Seismic Center NORSAR.
“NXSCAN” software which allows in semi-automated mode to digitize previously scanned seismograms was used. Fragments of
analogue seismograms digitized by NXSCAN [2] are saved in SAC format, and then converted into CSS 3.0 format. The testing results
showed that digitized seismograms have good concordance with original visually and by kinematic and dynamic parameters.
At the present time this database is used to solve different investigation tasks of seismology: precise parameters of historical large
earthquake and nuclear explosions; construction of regional travel-time curves of seismic waves; investigation of spatial-temporal variations
of attenuation field of shear waves; for tasks of seismic discrimination of nuclear explosions and earthquakes; for calibration of stations of
the International Monitoring System CTBTO; to study geodynamic processes and consequences of nuclear explosions influence on
environment.
Figure 1 shows an example of original and digitization results of atmospheric nuclear explosion seismogram 10/20/1962, t0=9:21:45.6,
=50.4227, =77.7231, mb=3.0. recorded by Mikhailovka station, epicentral distance was 333 km.
Figure 1.а) Analogue seismogram of air explosion recorded by
Mikhailovka station on October 20, 1962, epicentral distance is 333
km.
Figure 1.b) Digitization result of seismogram of air explosion
recorded by Mikhailovka station on October 20, 1962, epicentral
distance is 333 km.
The seismograms from the archives of SEME MES RK in Almaty (Seismological Experience-Methodical Expedition), CSE IPE RAS in
Talgar (Complex Seismological Expedition of the Institute of Physics of the Earth Russian Academy of Science), IGR RK at seismic stations
Kurchatov, Borovoye, Aktyubinsk, Makanchi and IS KR in Bishkek (Institute of Seismology in Kyrgyzstan) have been digitized. Total number
of the digitized seismograms is 6845 seismic records (Fig. 2, 3). The records of atmosphere nuclear explosions recorded by standard
seismometers contain acoustic signals. In addition to seismograms, the archive of Complex Seismological Expedition contains microbarograph
records installed on the territory of Talgar Observatory; these also were scanned and digitized.
Figure 2. The map of nuclear explosions epicenters (stars) on
the territory of Eurasia, seismic stations (triangles), which
seismograms were digitized by the RSE IGR.
3074
717
1074
381
392
79 54 537
32 260 21 224 STS
Novaya Zemlya
PNE
Chemic
Nevada
In-Ekker
Pokharan
LopNor
Chagay
Mururoa
Amchitka
Earthquakes
Figure 3. The diagram of the digitized seismograms
distribution by the Test Sites and source type.
In 1960-s, a standard microbarograph with recording on photopaper that recorded several atmosphere nuclear explosions conducted at
Novaya Zemlya and Semipalatinsk Test Site had been installed on the territory of Talgar seismic observatory (Fig. 4, 5, 6).
Figure 4. Location of TLG station
and Novaya Zemlya and STS Test Sites
Figure 5. Design of
microbarograph sensor
Figure 6. Dependence of microbarograph sensor sensitivity
on oscillation period
The Novaya Zemlya Test Site is located in the Russian Federation on the territory of Novaya Zemlya archipelago being a
part of Archangelsk region. The archipelago consists of two large islands – northern and southern separated by Matochkin
Shar Strait (Fig. 7). 130 nuclear tests were conducted at Novaya Zemlya Test Site in 1955-1990, among them were: 88 air
explosions, 3 underwater explosions and 39 underground nuclear explosions. At zone A (the region of Chernaya inlet) there
were kiloton air nuclear explosions, underground nuclear explosions in shafts, and a surface nuclear explosion, 3 underwater
and 2 above-water nuclear explosions. At zone B the underground nuclear explosions were conducted in tunnels (mountainous
regions of Moiseyev and Lazarev). At zone C there were tests of multi-megaton nuclear charges thrown off the airplanes [3-8].
Figure 7. Boundaries of the testing subareas of the Novaya
Zemlya Test Site (NZTS). A, B, and C denote three main areas (zones)
of military activity: A = Guba (Bay) Chernaya. B = Guba
Mityushikha, south Bank of Matochkin Shar. C = Sukhoy Nos Cape
and its vicinity [3].
We found 19 records of acoustic signals from Novaya Zemlya Test Site at epicentral distance ~3600 km; the signals were recorded
by Talgar station (Fig. 4, 8); in some cases seismic record of atmosphere nuclear explosion was absent, there was only a record of
acoustic wave by microbarograph. The microbarograph records were acquired and digitized.
For two explosions conducted on December 18 and December 20, 1962 the origin time absent in nuclear explosions catalogues was
calculated by infrasound signals. The range of explosions yield for which the acoustic signals were found was 8.3 kt – 25 Mt. The
signals are long-period, maximum period is 210 s, average propagation time to the station is ~3 h 11 min, the acoustic wave velocity is
vi= 313±4 m/s.
Figure 8. The microbarograph record of nuclear explosion of August 27, 1962, t0=09-00-50.9, =74.7, =50.3, height is 3000
m, yield Y=4200 kt, by TLG station, a) analog record, b) digitized record, c) spectrum.
Figures 9 a, b show dependences of maximum amplitudes on explosion yield and periods of acoustic signals of atmosphere nuclear
explosions by Talgar station; good correlation is observed. Thus, the investigation results of acoustic waves parameters from
atmosphere nuclear explosions can be used in current nuclear tests monitoring for different tasks such as detection, identification of a
source type and assessment of explosion yield.
Amax= -288,73+79,61*lg(Y), R=0.85
Tmax=-105.64+68.62(lg(Y), R=0.88
0 5000 10000 15000 20000 25000
0
50
100
150
200
250
Y, kt
A,mkbar
1000 10000
60
80
100
120
140
160
180
200
220
Y,kt
Tmax,s
Figure 9. Dependence of maximum amplitudes а) and periods b) acoustic signals of atmosphere nuclear explosions at the Novaya
Zemlya Test Site on explosion yield by Talgar station.
The works [9, 1] note that the peculiarity of seismic records of air and contact nuclear explosions recorded by standard long-period
seismometers (Ts≥20s) is availability of featured oscillations in seismograms which arrival time and form coincide with corresponding
records of microbarographs, especially at its initial part. The reason of nuclear explosions acoustic waves recording by a seismometer is
ground motion caused by change of ground surface load when air wave passes the seismometer installation place. 6 acoustic wave
records were found for air explosions in seismograms of Alma-Ata (AAA) and Talgar (TLG) stations (Fig.10).
Figure 10. Seismogram air nuclear explosion, of December, 24, 1962, t0=11:11:42.0, =76.600 N., =57.500 E,
Y=24 Mt by the station Talgar (TLG) at distance 3830 km.
Nuclear explosions had been conducted at the STS in 1949-1989, air explosions (86) and surface (30) were conducted at Opytnoye Polye site,
underground explosions (340) in boreholes at Balapan and Sary-Uzen sites, and in tunnels of Degelen site (Fig. 11) [4, 7, 10, 11].
Figure 11 a)
The map of the test
sites location at the
STS.
Figure 11 b) The
map of Opytnoye Polye
site.
We have processed 15 records of acoustic signals from Semipalatinsk Test Site at epicentral distance ~800 km; the signals were
recorded by Talgar station (Fig. 4). The microbarograph records were acquired and digitized (Fig. 12, 13).
Acoustic signals were found for the explosions yield 2.5-18 kt, HOB was 310-725 m [7]. The signals have maximum period 3-10 s,
average propagation time to the station is ~43 min 6 s, the acoustic wave velocity is vi= 311±3 m/s.
Figure 12. The microbarograph record of nuclear explosion of October
13, 1962, t0=09-00-17.5, =50.4227, =77.7231, height is 720 m, yield Y=4.9
kt, by TLG station, a) digitized record, b) spectrum.
10
0
20
40
60
80
100
120
140
Y,kt
A,mbar
10
2
3
4
5
6
7
8
Y,kt
T,s
Figure 13. Dependence of maximum amplitudes а) and
periods b) acoustic signals of atmosphere nuclear explosions
at the Semipalatinsk Test Site on explosion yield by Talgar
station.
The database of digitized seismograms of atmospheric nuclear explosions contains 309 records from 24 seismic stations at distances 175-1480 km
[10].
The records of atmospheric nuclear explosions at Opytnoye Polye site of the STS have all features of air explosions, high-amplitude surface waves,
weak P arrival, S/P ratio more than 1, many seismograms have a record of acoustic wave (Figure 14).
The acoustic wave was recorded along the profile by the following stations: Nikolayevka (NCE), Mikhaylovka (MIKH), Karakum (KKUM),
Chingyuzha (CHNG), Leninogorsk (LNGR) , Ust’-Kan (USTK), Kzyl-Agach (KAC) at epicentral distances 322-556 km (Figure 15).
50 records of acoustic wave were found and processed. The acoustic wave records (Figure 14b) are clearly seen on horizontal and vertical components
representing oscillations train with periods 1-3 s. Propagation velocity is V~(0.323 ± 0.013) km/s.
Researchers are very interested in dependence of acoustic waves on explosion yield, the amplitudes were measured for MIKH station as this station
has the largest number of records (Figure 16). During analysis, weather conditions and atmosphere model were not considered as it is impossible to restore
that data for years 1961-1962. The height of the explosions was not considered too, it was in the range of 310 – 695 m.
The equation of linear regression for this dependence is:
lg(A)=0.802+0.061*Y at R= 0.68,
where А – amplitude of air wave (nm), Y – air explosion yield (kt), R – correlation coefficient. Air wave amplitude increase depending on explosion yield is
observed.
Figure 14 а) Seismograms of air
explosion of October 20, 1962, t0=09-21-
45.6, =50.4227, =77.7231, by station
NCE (328 km).
Figure 14 b) A seismogram of air
wave from atmosphere explosion of
October 20, 1962, t0=09-21-45.6,
=50.4227, =77.7231, by station
NCE (328 km).
Figure 15 The map of
Opytnoye Polye site location (star)
and seismic stations which records
have an acoustic wave (triangles).
2 4 6 8 10 12 14 16 18 20
0,4
0,6
0,8
1,0
1,2
1,4
1,6
1,8
2,0
2,2
Y,kt
lg(A/T)
Figure 16. Dependence of
amplitudes of air wave
record on air explosions
yield, MIKH station.
CONCLUSION
The IGR has created a database of digitized historical seismic and infrasound records of nuclear explosions.
2. Unique records of a microbarograph installed in 1960-s at Talgar Observatory near Almaty (Kazakhstan) were found.
The historical analog records of the microbarograph were analyzed on the availability of the acoustic wave, selected records were
digitized, the database of acoustic signals from nuclear explosions was created.
3. The peculiarities of the wave pattern and spectral content of the acoustic wave records, and relation regularities of acoustic wave
amplitude and periods with explosion yield were investigated.
4. The created database can be applied in different monitoring tasks, such as infrasound stations calibration, discrimination of
nuclear explosions, precision of nuclear explosions parameters, determination of the explosion yield etc.
REFERENCE
Vasilyev A.P. To the history of infrasound detection method of nuclear explosions // Vestnik NNC RK. Issue 2. 2004.
NXSCAN. Manual. IRIS, 1992.
Khalturin V.I., Rautian T.G., Richards P.G., Leith W.S. A Review of Nuclear Testing by the Soviet Union at Novaya Zemlya, 1955-1990. // Science and
Global Security, 2005, V.13., p. 1-42.
Mikhailov V.N. ed. USSR Nuclear weapons tests and peaceful nuclear explosions, 1949 through 1990 // RFNC-VNIIEF. 1996. Sarov. 96
Dyubasov Yu.V., Matyushenko A.M., Mikhailov V.N. Nuclear explosions of the USSR. Northern Test Site. Reference publication. // St. Petersburg,
Published by V.G. Khlopin Radium Institute. 1999. 163 Pp.
Logachyov V.A. et al. The Test Site at Novaya Zemlya. General and radiological safety after nuclear tests. Facts, evidences, recollections. // M. Published
by AT. 2000. 485 Pp.
Internet resource: Nuclear Tests--Databases and Other Material http://www.johnstonsarchive.net/nuclear/tests/index.html.
Adushkin V.V., Khristophorov B.D. Nuclear explosions in Guba Chyornaya waters // Nuclear explosions in the Arctic region. Institute of Strategic
Stability. The Federal Atomic Energy Agency (Rosatom).
Pasechnik I.P. Characteristics of seismic waves at nuclear explosions and earthquakes // Moscow. Science. 1970. 194 Pp.
Sokolova I.N., Velikanov A.Ye. Precision of small nuclear explosions parameters from the Semipalatinsk Test Site basing on historical seismograms
investigation// Vestnik NNC RK. 2013. Issue 2. P. 49-56.
V.I. Khalturin, T.G. Rautian, P.G. Richards A study of small magnitude seismic events durig 1961-1989 on and near the Semipalatinsk Test Site,
Kazakhstan // Pure and Applied Geophysics. 2001. P. 143-171.
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