Upper mantle seismic model of Central Europe (including the Alpine orogen) based on seismic events from the Lubin Copper Basin

• Autorzy: Nita B. , Thybo H.
• Języki publikacji: EN

Abstrakty

EN

The Lubin Copper Basin in Poland is situated in the vicinity of the Trans- -European Suture Zone, in the region of the Variscan orogen. It is characterized by high seismicity, mainly induced by mining. The epicentral location is particu-larly suitable for the determination of lithospheric velocity structure for the two tectonic units in Central Europe: Alpine orogen and Variscides. We analyze traveltime curves constructed on the basis of the P-wave arrival times reported by European stations and listed in the International Seismic Bulletins for the pe-riod 1985-2000. The dense azimuthal coverage of the stations situated around the Alps and in the Variscides enables the determination of 1-D velocity struc-ture down to 180 km depth. Corrections for origin times, focal depths and station elevation were applied. The main feature visible in the obtained traveltime and velocity-depth distributions is the considerable difference in the upper mantle seismic structure between the two tectonic regions. The delay of P-wave arrivals is by about 3 s larger at the Alpine stations than at the stations located in the Variscides. We at-tribute this delay to differences between "fast" and "slow" structures in the "cold" and "hot" upper mantle, respectively. The 8° discontinuity can be clearly distinguished in the proposed models by a distinct delay at the offsets around 800-900 km from the source.

Słowa kluczowe

EN

upper mantle; 8° seismic discontinuity; traveltime curve; P-wave velocity distribution

• Wydawca: Instytut Geofizyki PAN
• Czasopismo: Acta Geophysica Polonica
• Rocznik: 2005
• Tom: Vol. 53, nr 2
• Strony: 127--141
• Opis fizyczny: Bibliogr. 20 poz.

Twórcy

autor

Nita B.

• Institute of Geophysics, Polish Academy of Sciences, Księcia Janusza 64, 01-452 Warszawa, Poland

autor

Thybo H.

• Geological Institute, University of Copenhagen Øster Voldgade 10, DK-1350 Copenhagen, Denmark

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