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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 1:42 |
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Conference: Bucharest University Faculty of Physics 2018 Meeting
Section: Atmosphere and Earth Science; Environment Protection
Title:
Variability of the fundamental frequency of resonance along Pannonian Basin
Authors:
A. COMAN(1,2), E. F. MANEA(2), A. PREDOIU(2), C.O. CIOFLAN(2), C. PANAIOTU(1)
Affiliation:
1) University of Bucharest, Faculty of Physic, 077125, Magurele, Bucharest, Romania
2) National Institute for Earth Physics, RO - 077825, Calugareni st, no 12, Magurele, Ilfov, Romania
E-mail
coman@infp.ro
Keywords:
fundamental frequency, H/V, Pannonian Basin, seismic noise
Abstract:
Pannonian Basin is located in the Eastern Central Europe and is one of the largest sedimentary basin in the Carpathian region. It is surrounded by the Alpine, Carpathian and Dinaric mountain belts and its topographic features developed as a consequence of the continental collision between the Adriatic microplate and the European continent. The entire area is subjected to a moderate degree of seismicity manifested in the Earth crust. The study of the seismic catalogues reveals important effects (VIII MSK) of rare crustal events in Banat, Hungary and more often in Serbia. In order to adequately assess the seismic amplification of the local geological structure under the Pannonian Basin we need to retrieve the essential soil properties like shear wave velocity and sediment thickness. In this aim, the non - invasive Horizontal - to - Vertical Spectral Ratios (HVSR) was applied. The data set consist in ambient noise records provided by more than 100 seismic stations with three velocity sensors of the Romanian Seismic Network or deployed during two temporary networks within the South Carpathian Project seismic projects (SCP, 2009-2011) and the Carpathian Basin Project (CBP, 2005-2007). The H/V results shows significant variability over the Pannonian Basin and suggest that the bedrock is outcropping in some areas as can be observed from its geological feature. These curves exhibit multiple peaks indicating the presence of multiple geological interfaces within the sub-soils of Pannonian Basin. The fundamental peak, between 0.1-10 Hz, is attributed to the geophysical bedrock, interpreted as the interface between Miocene and Pliocene (Balázs et al., 2016), which spatial distribution confirms that the bedrock is dipping towards the center of (the) Great Hungarian Plain and to the Vienna Basin (Little Hungarian Plain). A second resonance peak (0.45-3.8 Hz) of the H/V curves is interpreted as the interface between Quaternary and Pliocene (Tari and Horvath, 2006) deposits which is also deeping in the same directions as the geophysical bedrock. The next step of this study will be the application of the same method to the earthquake records available in this area in order to interpret the complex nature of the H/V resonance peaks and to add more constrains to the velocity model of this sedimentary basin.
References:
Balázs, Attila, et al. "The link between tectonics and sedimentation in back‐arc basins: New genetic constraints from the analysis of the Pannonian Basin." Tectonics 35.6 (2016): 1526-1559.
Tari, Gbor C., and Frank Horvath. "Alpine evolution and hydrocarbon geology of the Pannonian Basin: An overview." (2006): 605-618.
Acknowledgement:
This paper contains data sets deployed during two temporary networks South Carpathian Project seismic projects (SCP, 2009-2011) and the Carpathian Basin Project (CBP, 2005-2007).
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