SCALING OF TWO CORNER FREQUENCIES OF SOURCE SPECTRA FOR EARTHQUAKES OF THE BERING FAULT
Аннотация и ключевые слова
Аннотация (русский):
The Komandorsky Islands region, tectonically, is unique, being at the junction of the Pacific plate and Bering plate, surrounded by edges of two subduction zones. The tectonic deformation is distributed in the region between a few sub parallel shear faults, of which the Aleutian transform is the most evident. Another one, the Bering fault, was activated again in 2017, when on its section the Mw7.8" role="presentation" style="position: relative;">Mw7.8Mw7.8Mw 7.8 earthquake caused a tsunami of limited scale. In this paper for the first time for earthquakes of this region with ML" role="presentation" style="position: relative;">MLMLM_{L} of 3.0-7.0, using more than 500 records of 6 stations equipped by accelerometers, within 300 km from the epicenters, source spectra of S-waves were recovered. The seismic moment and two corner frequencies were determined. Also, the presence of two separate corner frequencies were checked with the spectral ratio method. The estimates of the first, fc1" role="presentation" style="position: relative;">fc1fc1f_{c1}, and second, fc2" role="presentation" style="position: relative;">fc2fc2f_{c2}, corner frequencies were used to study their scaling properties. We found that fc1" role="presentation" style="position: relative;">fc1fc1f_{c1} scales as M0−0.34±0.02" role="presentation" style="position: relative;">M-0.34±0.020M0-0.34±0.02M_{0}^{-0.34\\pm0.02} what agrees with assumption of source similarity, and fc2" role="presentation" style="position: relative;">fc2fc2f_{c2} scales as M0−0.18±0.01" role="presentation" style="position: relative;">M-0.18±0.010M0-0.18±0.01M_{0}^{-0.18\\pm0.01} what disagrees. In few cases, the third corner frequency of source acceleration spectra were observed.

Ключевые слова:
earthquake, Bering fault, source spectra, seismic moment, corner frequency
Список литературы

1. Abubakirov, I. R., A. A. Gusev, E. M. Guseva, et al. (2018) , Mass determination of moment magnitudes Mw and establishing the relationship between MwMw and MLML for moderate and small Kamchatka earthquakes, Izvestiya, Physics of the Solid Earth, 54, no. 1, p. 33-47, https://doi.org/10.1134/S1069351318010019

2. Boore, D. M., J. Boatwright (1984) , Average body-wave radiation coefficients, Bulletin of the Seismological Society of America, 74, no. 5, p. 1615-1621

3. Brune, J. N. (1970) , Tectonic stress and the spectra of seismic shear waves from earthquakes, Journal of geophysical research, 75, no. 26, p. 4997-5009, https://doi.org/10.1029/JB075i026p04997

4. Chebrov, V. N., D. V. Droznin, Yu. A. Kugaenko, et al. (2013) , The system of detailed seismological observations in Kamchatka in 2011, Journal of Volcanology and Seismology, 7, no. 1, p. 16-36, https://doi.org/10.1134/S0742046313010028

5. Chebrov, V. N., Yu. A. Kugaenko, I. R. Abubakirov, et al. (2017) , The July 17th, 2017 MwMw=7.8 earthquake on the border of the Komandor seismic gap (western part of the Aleutian Arc), Bulletin of Kamchatka Regional Association "Educational-Scientific Center". Earth Sciences, 35, no. 3, p. 22-25

6. Cross, R. S., J. T. Freymueller (2008) , Evidence for and implications of a Bering plate based on geodetic measurements from the Aleutians and western Alaska, Journal of Geophysical Research: Solid Earth, 113, p. B7, https://doi.org/10.1029/2007JB005136

7. Duda, S. J. (1978) , Physical significance of the earthquake magnitude: the present state of interpretation of the concept, Tectonophysics, 49, no. 3-4, p. 119-130, https://doi.org/10.1016/0040-1951(78)90161-0

8. Dziewonski, A. M., T. A. Chou, J. H. Woodhouse (1981) , Determination of earthquake source parameters from waveform data for studies of global and regional seismicity, Journal of Geophysical Research: Solid Earth, 86, no. B4, p. 2825-2852, https://doi.org/10.1029/JB086iB04p02825

9. Ekstr{ö}m, G., M. Nettles, A. M. Dziewo{}ski (2012) , The global CMT project 2004-2010: Centroid-moment tensors for 13,017 earthquakes, Physics of the Earth and Planetary Interiors, 200, p. 1-9, https://doi.org/10.1016/j.pepi.2012.04.002

10. Gusev, A. A., A. A. Skorkina (2020) , Empirical spectral characteristics of the media near the seismic strong ground motion stations in Kamchatka, Russian Geology and Geophysics, 61, no. 2, p. 224-233, https://doi.org/10.15372/RGG2019121

11. Gusev, A. A., A. A. Skorkina, D. V. Chebrov (2017) , Parameters of source spectra of Mw=3-6 Eastern Kamchatka earthquakes based on shear wave data, Bulletin of Kamchatka Regional Association "Educational-Scientific Center". Earth Sciences, 35, no. 3, p. 36-49

12. Hanks, T. C., M. Wyss (1972) , The use of body-wave spectra in the determination of seismic-source parameters, Bulletin of the Seismological Society of America, 62, no. 2, p. 561-589

13. Hanks, T. C., H. Kanamori (1979) , A moment magnitude scale, Journal of Geophysical Research: Solid Earth, 84, no. B5, p. 2348-2350, https://doi.org/10.1029/JB084iB05p02348

14. Imanishi, K., W. L. Ellsworth (2006) , Source scaling relationships of microearthquakes at Parkfield, CA, determined using the SAFOD pilot hole seismic array, Earthquakes: Radiated Energy and the Physics of Faulting, 170, p. 81-90, https://doi.org/10.1029/170GM10

15. Kanamori, H. (1977) , The energy release in great earthquakes, Journal of Geophysical Research, 82, no. 20, p. 2981-2987, https://doi.org/10.1029/JB082i020p02981

16. Kuzin, I. P. (1974) , Focal zone and the upper mantle structure in the region of eastern Kamchatka, 131 pp., Nauka, Moscow

17. Lay, T., L. Ye, Y. Bai, et al. (2017) , Rupture along 400 km of the Bering fracture zone in the Komandorsky Islands earthquake (MW 7.8) of 17 July 2017, Geophysical Research Letters, 44, no. 24, p. 12,161-12,169, https://doi.org/10.1002/2017GL076148

18. Lemzikov, V. K., A. A. Gusev (1991) , Coda-based energy classification of near Kamchatka earthquakes, Journal of Volcanology and Seismology, 11, p. 558-578

19. Mackey, K. G., K. Fujita, L. V Gunbina, et al. (1997) , Seismicity of the Bering strait region: evidence for a Bering block, Geology, 25, no. 11, p. 979-982, https://doi.org/10.1130/0091-7613(1997)025%3C0979:SOTBSR%3E2.3.CO;2

20. Skorkina, A. A., A. A. Gusev (2017) , Determination of corner frequencies of source spectra for subduction earthquakes in Avacha Gulf (Kamchatka), Russian Geology and Geophysics, 58, no. 7, p. 844-854, https://doi.org/10.1016/j.rgg.2017.06.007

21. Yokoi, T., K. Irikura (1991) , Meaning of source controlled fmax in empirical Green function technique based on a T2-scaling law, Annuals of Disaster Prevention Research Institute, Kyoto University, 34, p. 177-189

Войти или Создать
* Забыли пароль?