Hovsgol earthquake 5 December 2014, M W = 4.9: seismic and acoustic effects
- 54 Downloads
A moderate shallow earthquake occurred on 5 December 2014 (M W = 4.9) in the north of Lake Hovsgol (northern Mongolia). The infrasonic signal with duration 140 s was recorded for this earthquake by the “Tory” infrasound array (Institute of Solar-Terrestrial Physics of the Siberian Branch of the Russian Academy of Science, Russia). Source parameters of the earthquake (seismic moment, geometrical sizes, displacement amplitudes in the focus) were determined using spectral analysis of direct body P and S waves. The spectral analysis of seismograms and amplitude variations of the surface waves allows to determine the effect of the propagation of the rupture in the earthquake focus, the azimuth of the rupture propagation direction and the velocity of displacement in the earthquake focus. The results of modelling of the surface displacements caused by the Hovsgol earthquake and high effective velocity of propagation of infrasound signal (~ 625 m/s) indicate that its occurrence is not caused by the downward movement of the Earth’s surface in the epicentral region but by the effect of the secondary source. The position of the secondary source of infrasound signal is defined on the northern slopes of the Khamar-Daban ridge according to the data on the azimuth and time of arrival of acoustic wave at the Tory station. The interaction of surface waves with the regional topography is proposed as the most probable mechanism of formation of the infrasound signal.
KeywordsInfrasound signal Earthquake Surface waves Source parameters Focal mechanism Hovsgol
We thank Dr. A. Sorokin for providing access to infrasound data and for a discussion of the work and also Dr. N. Perevalova for valuable constructive comments that helped to improve our paper. We are very grateful to our reviewer Dr. David N. Green for the valuable comments and suggestions that helped to improve our paper.
- Arrowsmith S, Hale J, Burlacu R, Pankow K, Stump B, Hayward C, Randall G, Taylor S (2011) Infrasound signal characteristics from small earthquakes. Proceedings of 2010 Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies. ADA569478 (2):743–754Google Scholar
- Atlas of Lake Hovsgol: Mongolian People's Republic M (1989) Ch. Ed. B. A. Bogoyavlensky. M.: Main Directorate of Geodesy and Cartography under the Council of Ministers of the USSR 120 (in Russian)Google Scholar
- Haskell NA (1964) Total energy spectral density of elastic wave radiation from propagating faults. Bull Seismol Soc Am 54:1811–1841Google Scholar
- Masalsky OK, Gileva NA, Khaidurova EV, Tubanov TSA (2016). Lake Baykal and Transbaykal regions. The earthquakes of Russia in 2014./ Ch. Ed. A.A. Malovichko Obninsk. 37–42. In RussianGoogle Scholar
- Ponomarev EA, Rudenko GV, Sorokin AG, Dmitrienko IS, Lobycheva IY, Baryshnikov AK (2006) The normal-mode method for probing the infrasonic propagation for purposes of CTBT. J Atm and Solar-Terr Phys 68:559–614Google Scholar
- Ryan, W.B.F., S.M. Carbotte, J.O. Coplan, S. O’Hara, A. Melkonian, R. Arko, R.A. Weissel, Ferrini, A. Goodwillie, F. Nitsche, J. Bonczkowski and R.Zemsky, 2009. Global multi-resolution topography synthesis. Geochem Geophys Geosyst 10(3):Q03014. https://doi.org/10.1029/2008GC002332
- Sorokin AG (2013) Infrasonic radiation of Chelyabinsk meteoroid. J Sol-Terr Phys 24:58–63 In Russian with English abstractGoogle Scholar
- Sorokin АG, Dobrynina АА (2017) Comparative analysis of seismic and infrasonic signals during pulsed events and earthquakes. Bull Irkutsk State University Series «Earth Sciences» 20:106–116 In Russian with English abstractGoogle Scholar
- Trifunac MD (1972) Tectonic stress and the source mechanics of the Imperial Valley, California, Earthquake of 1940. Bull Seism Soc Am 62:1283–1302Google Scholar