Simultaneous infrasonic, seismic, magnetic and ionospheric observations in an earthquake epicentre

• Published in: Journal of atmospheric and solar-terrestrial physics Vol. 72; no. 16; pp. 1231 - 1240
• Main Authors: Laštovička, J., Baše, J., Hruška, F., Chum, J., Šindelářová, T., Horálek, J., Zedník, J., Krasnov, V.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-10-2010; Elsevier
• Subjects: Earth, ocean, space; Earthquake; Exact sciences and technology; External geophysics; Infrasonic effects; Ionospheric effects; Magnetic effects; Physics of the ionosphere; Physics of the magnetosphere; Central Europe; Czech Republic; Europe; Czech Rep; Infrasonic effects; Magnetic effects; Earthquake; Ionospheric effects; electrical field; Earth atmosphere; magnetic field
• ISSN: 1364-6826; 1879-1824
• DOI: 10.1016/j.jastp.2010.08.005

Various pre-seismic and co-seismic effects have been reported in the literature in the solid Earth, hydrosphere, atmosphere, electric/magnetic field and in the ionosphere. Some of the effects observed above the surface, particularly some of the pre-seismic effects, are still a matter of debate. Here we analyze the co-seismic effects of a relatively weak earthquake of 28 October 2008, which was a part of an earthquake swarm in the westernmost region of the Czech Republic. Special attention is paid to unique measurements of infrasonic phenomena. As far as we know, these have been the first infrasonic measurements during earthquake in the epicentre zone. Infrasonic oscillations (∼1–12
Hz) in the epicentre region appear to be excited essentially by the vertical seismic oscillations. The observed oscillations are real epicentral infrasound not caused by seismic shaking of the instruments or by meteorological phenomena. Seismo-infrasonic oscillations observed 155
km apart from the epicentre were excited in situ by seismic waves. No earthquake-related infrasonic effects have been observed in the ionosphere. Necessity to make vibration tests of instruments is pointed out in order to be sure that observed effects are not effects of mechanical shaking of the instrument.