UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS

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2024-11-23 18:26
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Conference: Bucharest University Faculty of Physics 2009 Meeting


Section: Atmosphere and Earth Science; Environment Protection


Title:
Imaging the Romanian crust using Ps converted waves


Authors:
Tataru Dragos(1)


Affiliation:
(1)National Institute for Earth Physics, Magurele


E-mail
dragos@infp.ro


Keywords:
receiver function, crust, Moho


Abstract:
The receiver function method is a powerful tool employed in the investigation of the earth’s shear velocity structure. By inverting receiver functions, it is possible to constrain the Moho depth and the average shear wave velocity beneath a recording station (Owens et al., 1987; Langston, 1989; Ammon, 1991). The receiver function is a time series, sensitive to velocity changes in the crust beneath a seismic station. It is obtained through the deconvolution of the vertical component from the horizontal components. The resulting waveform comprises of P-to-S converted phases, whose amplitude and timing can be modeled to provide constraints on the Moho depth and underling shear velocity structure. The processing steps follow the algorithm implemented by Kind ( Kind et al., 1995) and modified by Yuan (Yuan et al., 1999). Due to the deployment of Romanian broadband station in the last 5 years valuable data for the use in crustal structure studies become available. We selected 250 teleseismic earthquake records from witch we obtained individual receiver functions. The selected teleseismic events have epicentral distances between 30°-95°, magnitudes larger than 6 and a clear P onset with a high signal-to-noise ratio. The aim of this study is to investigate the depths of the discontinuities and the shear wave velocity. The RF results at stations in the Apuseni Mountains a shallow Moho (28–30 km depth at DRGR station). On the East European platform we find a crustal thickness of 35–39 km (VRI, MLR stations). Further to the south-east, in the Dobrogea platform (TIRR station) the Moho descends to 40 km depth.