Alternative Mechanisms of the Microseisms Excitation

0435072 - ÚGN 2015 RIV TR eng O - Others
Kalenda, Pavel - Wandrol, I. - Holub, Karel - Rušajová, Jana
Alternative Mechanisms of the Microseisms Excitation.
European Conference on Earthquake Engineering and Seismology (2ECEES) /2./. Istanbul: Turkish Earthquake Foundation Earthquake Engineering Committee, 2014
R&D Projects: GA MŠMT LM2010008
Institutional support: RVO:68145535 ; RVO:67985891
Keywords : microseisms * thermoelastic waves * annual drift
Subject RIV: DC - Siesmology, Volcanology, Earth Structure

The annual drift is typical for microseisms. We propose a model based on the generation of thermoelastic waves, which explains the highest microseisms during winter by the higher stress level. If we remove the average influence of the stress background from the microseisms, we obtain the residua of microseisms, which show the semiannual periods with the maxima in March and October. The histogram of occurrence of anomalous microseisms has the same form as the variations of Length Of the Day (LOD). This mechanism was recognized as a secondary order mechanism after the annual drift. The synoptic situations and earthquakes were recognized as imminent triggers of anomalous microseisms. This synoptic situation is consistent with the uplift of the northern part of Europe after the ice cup melting.
Permanent Link: http://hdl.handle.net/11104/0239007