SKS splitting observed at Romanian broad-band seismic network

• Published in: Tectonophysics 2008-12, Vol.462 (1), p.89-98
• Main Authors: Ivan, Marian, Popa, Mihaela, Ghica, Daniela
• Format: Article
• Language: English
• Subjects: Anisotropy; Romanian upper mantle; SKS splitting; Vrancea area
• ISSN: 0040-1951; 1879-3266
• DOI: 10.1016/j.tecto.2007.12.015

Shear-wave splitting results are presented for the broad-band stations of the Romanian seismic network. For stations BUC1 and CRAR (located in Moesian Platform), IAS (in East-European Platform), TIRR and CVD (in Central Dobrudja–Black Sea microplate), TIM and DRGR (in Dacia-Tisza plate, including Apuseni Mts.), BURAR, BZS and GZR (in, or very close to the Carpathian Arc), the fast directions ( φ) are around 135°. The mean delay values ( δt) of the slow wave are slightly greater for the stations placed in platform areas ( δt ~ 1.5 s) than for the stations situated in the (proximity) of Carpathians ( δt ~ 1.2 s). For the MLR station located in the South-Western part of Vrancea area, at the Carpathian Bend, the fast direction is 48°, similar to VOIR station (located in Southern Carpathians, 70 km West of MLR). At VRI and PLOR, located in the North-Eastern part of Vrancea, the fast axis is oriented approximately on North–South direction, with a possible dependence of the splitting parameters with back azimuth. At least for some stations, the splitting results are not consistent with vertical coherent lithospheric anisotropy.