Tomography study of the upper mantle around the TESZ based on PASSEQ experiment data

0475111 - GFÚ 2018 RIV NL eng J - Journal Article
Chyba, Jan - Plomerová, Jaroslava - Vecsey, Luděk - Munzarová, Helena
Tomography study of the upper mantle around the TESZ based on PASSEQ experiment data.
Physics of the Earth and Planetary Interiors. Roč. 266, May (2017), s. 29-38. ISSN 0031-9201. E-ISSN 1872-7395
R&D Projects: GA AV ČR IAA300120709; GA ČR GAP210/12/2381; GA MŠMT LM2010008; GA MŠMT(CZ) LM2015079
Institutional support: RVO:67985530
Keywords : European suture zone * resolution teleseismic tomography * Bohemian Massif
OECD category: Volcanology
Impact factor: 2.156, year: 2017

We present a detailed velocity-perturbation model of the Earth's upper mantle in the area around the Trans-European Suture Zone (TESZ) imaged by the teleseismic tomography. The model is based on 12473 P-wave arrival times measured on recordings of 273 stations of the PASsive Seismic Experiment (PASSEQ), which was active during 2006 and 2008. Station and teleseismic event distribution is sufficient to resolve the structure below the PASSEQ array down to a depth of similar to 350 km. The velocity-perturbation model clearly shows a similar to 250-km-thick uniform layer of positive velocity perturbations north-east of the Teisseyre-Tornquist Zone (TTZ) and similar to 150-km-thick layer south-west of the TTZ characterized by relatively lower velocity perturbations. The former we associate with the Precambrian mantle lithosphere of the European plate, while the latter represents the much younger Phanerozoic lithosphere. In the uppermost layer of the model (similar to 40 km), the boundary between the two regions closely follows the crustal trace of the TTZ. In deeper layers, the boundary shifts south-westward. At a depth of approximately 120 km the region with positive perturbations reaches the northern part of the Bohemian Massif (BM). The shift suggests that the Phanerozoic part of the European plate thrusts over the Precambrian lithosphere. The upper mantle below a depth of similar to 250 km lacks the pronounced division between the two regions around the TESZ, which allows us to associate these depths with asthenospheric part of the upper mantle.
Permanent Link: http://hdl.handle.net/11104/0271977