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About the journal

NAUKA I TEKHNOLOGICHESKIE RAZRABOTKI (SCIENCE AND TECHNOLOGICAL

DEVELOPMENTS), ISSN: 2079-5165, eISSN: 2410-7948, DOI: 10.21455/std;

https://elibrary.ru/title_about.asp?id=32295; http://std.ifz.ru/. The journal was founded in 1992.

TEMPORAL VARIATIONS OF S-WAVE ATTENUATION FIELD
IN THE REGION OF LOP NOR NUCLEAR TEST SITE

Yu.F. Kopnichev1, I.N. Sokolova2

1 Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences, Moscow, Russia

2 Institute of Geophysical Research of the Ministry of Energy of the Republic of Kazakhstan, Almaty, Kazakhstan

Corresponding author: Yu.F. Kopnichev, e-mail: yufk777@mail.ru

Highlights

– Records of nuclear explosions and earthquakes by station BRVK were processed

– Methods of relative Sn level and P-coda slope analysis were used

– S wave attenuation in the lithosphere of the test site increased during 40 years

– Similar results were obtained for the regions of Semipalatinsk and Nevada test sites

– The effect is connected with fluid migration due to intense anthropogenic influence

Abstract. We studied characteristics of shear wave attenuation field in the region of Сhinese nuclear test site Lop Nor. We used methods, based on an analysis of relative level of Sn and Pn waves (parameter Sn/Pn), and also on a slope of P-coda envelopes. Sn wave is formed by shear waves reflected from multiple boundaries in the upper mantle, and P-coda is formed by conversion of S-P type in the lithosphere of the source region.
26 recordings of underground nuclear explosions (UNEs) and earthquakes, obtained by station BRVK at epicentral distances of ~1800–2000 km have been processed. It was established, that since the end of 1960s till the middle of 1990s at the recordings of the UNEs mean values Sn/Pn diminished essentially, and P-coda envelope slope increased in the area of test site. These effects testify to attenuation increasing in the lithosphere of the source region. Diminishing Sn/Pn parameter with time on the recordings of earthquakes in the region of test site was observed also after finishing the UNEs series. Similar results were obtained earlier for the regions of Semipalatinsk and Nevada nuclear test sites. We suppose that the effects revealed are caused by deep fluid migration as a result of long-term intense anthropogenic effect.

Keywords: Lop Nor test site, Sn wave, P-coda, S-wave attenuation, deep-seated fluids.

Cite this article as: Kopnichev Yu.F., Sokolova I.N. Temporal variations of S-wave attenuation field in the region of Lop Nor nuclear test site, Nauka i Tekhnologicheskie Razrabotki (Science and Technological Developments), 2018, vol. 97, no. 3, pp. 25–32. [in Russian]. DOI: 10.21455/std2018.3-3

References

Aki K., Richards P. Quantitative seismology – theory and methods. San Francisco, Freeman W.H. 1980, vol. 1, 557 p., vol. 2. 373 p.  (A Series of books in geology. Geology Series). ISBN 0 7167 1058 7 (vol. 1), 0 7167 1059 5 (vol. 2).

Barabanov V.L. 1rinevsky A.O., Kissin I.G., Nikolaev A.V. About some results of the vibrational seismic effect on the water-saturated medium. Comparison of them with the effects of remote strong earthquakes, Doklady Rossiiskoi Akademii Nauk (Reports of the Russian Academy of Sciences), 1987, vol. 297, no. 1, pp. 53–56. [in Russian].

Fisk M. Accurate locations of nuclear explosions at the Lop Nor test site using alignment of seismograms and ICONOS satellite imagery, Bull. Seismol. Soc. Amer., 2002, vol. 92, no. 8, pp. 2911–2525. DOI: 10.1785/0120010268

Koper K., Fatehi A. Array analysis of regional-distance P-coda in South Asia, Bull. Seismol. Soc. Amer., 2009, vol. 99, no. 4, pp. 2509–2522. DOI: 10.1785/0120080271

Kopnichev Yu.F., Arakelyan A.R. On the nature of short-period seismic fields at distances up to 3000 km, Vulkanologiya i seismologiya (Volcanoloty and Seismology), 1988, no. 4, pp. 77–92. [in Russian].

Kopnichev Yu.F., Sokolova I.N. Spatio-temporal variations in the structure of the shear wave absorption field in the Semipalatinsk polygon region, Fizika Zemli (Physics of the Earth), 2001, no. 11, pp. 73–86. [in Russian].

Kopnichev Yu.F., Sokolova I.N. Spatio-temporal variations of the S-wave absorption field in the focal zones of strong earthquakes in the Tien Shan, Fizika Zemli (Physics of the Earth), 2003, no. 7, pp. 25–34. [in Russian].

Kopnichev Yu.F., Sokolova I.N. Heterogeneity of the absorption field of short-period S-waves in the Earth's crust and mantle tops in the area of the Lobnor polygon, Doklady Rossiiskoi Akademii Nauk (Reports of the Russian Academy of Sciences), 2008, vol. 420, no. 2, pp. 239–242. [in Russian].

Kopnichev Yu.F., Sokolova I.N. On geodynamical processes within the areas of three large nuclear test sites (based on s-wave attenuation data), Vestnik Natsional'nogo yadernogo tsentra Respubliki Kazakhstan (Bulletin of the National Nuclear Center of the Republic of Kazakhstan), 2009, Issue 3, pp. 48–54. [in Russian].

Kopnichev Yu.F., Sokolova I.N. Heterogeneities of the shear wave attenuation field in the lithosphere of East Tien Shan and their relationship with seismicity, Doklady Earth Sciences, 2012, vol. 442, no. 2, pp. 292–295. DOI: 10.1134/S1028334X12020249

Kopnichev Yu.F., Gordienko D.D., Sokolova I.N. Space-time variations of the shear wave attenuation field in the upper mantle of seismic and low seismicity areas, Journal of Volcanology and Seismology, 2009, vol. 1, pp. 44–58. DOI: 10.1134/S0742046309010059

Kopnichev Yu.F., Shepelev O.M., Sokolova I.N. Investigations on seismic recognition of nuclear explosions at the Lobnor test site, Fizika Zemli (Physics of the Earth), 2001, no. 12, pp. 64–77. [in Russian].

Kopnichev Y.F., Sokolova I.N., Sokolov K.N. Spatio-temporal variations in the structure of the attenuation field of the S-wave in the region of Nevada nuclear test site, Izvestiya, Physics of the Solid Earth, 2013, vol. 49, no. 6, pp. 786–795. DOI: 10.1134/S1069351313060086

Miyazawa M., Mori J. Evidence suggesting fluid flow beneath Japan due to periodic seismic triggering from the 2004 Sumatra-Andaman earthquake, Geophys. Res. Lett., 2006, vol. 33, L05303. DOI: 10.1029/2005GL025087

Shchukin Yu.K., Ryaboy V.Z. (Ed.). Deep Structure of Weak Seismic Regions of the USSR. Moscow, Nauka, 1987, 238 p.

About the authors

KOPNICHEV Yuri Fedorovich – Doctor of Physical and Mathematical Sciences, major scientist, Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences. 123242, Moscow, ul. Bolshaya Gruzinskaya 10, stroenie 1. Tel.: +7(727) 295-63-50. E-mail: yufk777@mail.ru

SOKOLOVA Inna Nikolayevna – Doctor of Physical and Mathematical Sciences, senior scientist, Institute of Geophysical Research of the Ministry of Energy of the Republic of Kazakhstan, 050020, Republic of Kazakhstan, Almaty, Chaikinoy 4. Tel.: +7(727) 263-13-30. E-mail: sokolova@kndc.kz