Source characteristics of the seismic sequences in the Eastern Carpathians foredeep region (Romania)

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• 作者：Popescu ; Emilia ; Radulian ; Mircea
• 关键词：Carpathians Mountains foredeep ; earthquake sequence ; empirical Green's function deconvolution ; source scaling relations
• 刊名：Tectonophysics
• 出版年：2001
• 出版时间：August 30, 2001
• 年：2001
• 卷：338
• 期：3-4
• 页码：325-337
• 全文大小：422 K

文摘

The source parameters and scaling properties for two seismic areas (Vrâncioaia and Râmnicu Sarat) of the Carpathians Mountains foredeep, adjacent to the Vrancea seismic region, are analyzed by standard time and frequency domain methods and empirical Green's function deconvolution. The study area is characterized by distinct shallow seismicity clusters with small and moderate-size earthquakes (M<5). The digital short-period and broad-band waveforms recorded by the Romanian seismic network are considered. The analysis of the retrieved source parameters possibly outlines a heterogeneous faulting process. A significant difference in the stress drop value is emphasized between Vrâncioaia and Râmnicu Sarat earthquakes, which is assumed to be ascribed to differences in the local seismotectonics and reology. Our paper shows the efficiency of the empirical Green's function deconvolution in eliminating the instrument, path and site effects for the earthquake sequences in the Râmnicu Sarat region. The apparent source time function is generally well constrained, as demonstrated by our tests using in parallel both, appropriate Green's functions of different sizes, and instruments with different frequency bandwidth.