Comparison of near-surface layers spectral characteristics under the seismic stations «Trosnyk», «Uzhgorod», «Mezhgirya» calculated using finite element method and obtained experimentally
Journal Title: Геофизический журнал - Year 2018, Vol 40, Issue 6
Abstract
The purpose of this work was to calculate the theoretical transfer characteristics of the sedimentary layers under the seismic stations «Trosnyk», «Uzhgorod», «Mizhgirya» of the Carpathian seismic network using the Finite element method (FEM). These results are used for comparison with the dynamic parameters of near-surface layers received experimentally; for checking the conformity of investigated environment resonance properties obtained by these methods for the possibility of their application in regional seismological studies. The research was carried out by solving the direct dynamic seismic problem using the finite element method. This method of mathematical modeling allows making calculations for models that are complex in their structure. When solving the direct dynamic seismic problem using FEM, the opportunity to take into account various exchange effects inside the model does not forfeit. Also, we can calculate models with the complex geometric environment structure and various inclusions. Using the developed technique of wave field simulation by finite element method, oscillations for models of the seismic section under the «Trosnyk», «Uzhgorod» and «Mizhgirya» stations were investigated. According to the simulation results, theoretical spectral ratios for these stations were calculated. For the Seismic Station «Mizhgirya», we observe the coincidence of two interference maxima at a frequency of 4 and 10 Hz for both charts: experimental and theoretical. For the Seismic Station «Uzhgorod», the graphs obtained by the experimental and modeling method showed identical behavior throughout the frequency range. These charts provide a stable source of noise within the city. For the Seismic Station «Trosnyk» there is a discrepancy in the behavior of experimental and model charts above 6 Hz. Such results are due to the high level of groundwater under the seismic station, which was not taken into account in the creation of the model for calculating using the finite element method. The spectral characteristics of near-surface layers under the «Trosnyk», «Uzhgorod» and «Mizhgіrya» seismic stations were calculated by the finite element method for the first time. The results of mathematical modeling were compared with experimental measurements. The knowledge about the dynamic parameters of the upper sediment layers under seismic stations, which are the largest filter of oscillation frequencies in the spectral range, will allow more accurate interpretation of registered by these stations occurrences. The calculated spectral ratios give a possibility to estimate the degree of environmental influence on stations’ seismic signals recording, which will be the largest at frequencies corresponding to the received resonance maxima and minima. These results should be taken into account when evaluating the parameters of possible seismic effects in the territory.
Authors and Affiliations
B. Ye. Kuplevskyi, T. Brych
Keywords
Related Articles
- EP ID EP477858
- DOI 10.24028/gzh.0203-3100.v40i6.2018.151023
- Views 89
- Downloads 0
Basement oil of sedimentary basins is an alternative of “shale” scenario of global FEC development (West Siberia as an example)
Concepts on structure, composition and oil presence of the West Siberia basement are considered in the paper. Information on oil and gas presence in the basement of the world is presented, its inexhaustible potential is...
Studies of the Poltava seismic-tidal records during the period of explosions events in Balakliya and Kalynivka
The seismic-tidal records obtained at the Poltava gravimetric observatory of the IGF NAS of Ukraine (PGO) studied before, during and after events in Balaklija (March 22—23) and in Kalinovka (September 26—27) 2017 (explos...
The nature and origin of magnetic anomalies over the Gölcük caldera; Isparta; South-Western Turkey
For the first time; ground magnetic survey was performed which data were inverted by means of total horizontal derivative; horizontal gradient analytic signal; and hyperbolic tilt angle techniques to identify subsurface...
Secular variations of the geomagnetic field on litosphere plates of the Earth
The dependence of the value and sign of the geomagnetic secular variations (SV) refined of 3- and 11-year components on the position of observatories at different tectonic plates is investigated. The observatories of the...
Problems of geodynamics of the Ukrainian shield in Precambrian
The main achievements of Ukrainian geologists and geophysicists in the studies of processes of geodynamic development of the Ukrainian Shield in the Archean—Early Proterozoic are considered as well as the main problems a...