Transversely isotropic lower crust of Variscan central Europe imaged by ambient noise tomography of the Bohemian Massif

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985530%3A_____%2F21%3A00544673" target="_blank" >RIV/67985530:_____/21:00544673 - isvavai.cz</a>

Result on the web

<a href="https://se.copernicus.org/articles/12/1051/2021/" target="_blank" >https://se.copernicus.org/articles/12/1051/2021/</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.5194/se-12-1051-2021" target="_blank" >10.5194/se-12-1051-2021</a>

Result language

angličtina

Original language name

Transversely isotropic lower crust of Variscan central Europe imaged by ambient noise tomography of the Bohemian Massif

Original language description

The recent development of ambient noise tomog-raphy, in combination with the increasing number of permanent seismic stations and dense networks of temporary stations operated during passive seismic experiments, provides a unique opportunity to build the first high-resolution 3-D shear wave velocity (upsilon(S)) model of the entire crust of the Bohemian Massif (BM). This paper provides a regional-scale model of velocity distribution in the BM crust. The velocity model with a cell size of 22 km is built using a conventional two-step inversion approach from Rayleigh wave group velocity dispersion curves measured at more than 400 stations. The shear velocities within the upper crust of the BM are similar to 0.2 km s(-1) higher than those in its surroundings. The highest crustal velocities appear in its southern part, the Moldanubian unit. The Cadomian part of the region has a thinner crust, whereas the crust assembled, or tectonically transformed in the Variscan period, is thicker. The sharp Moho discontinuity preserves traces of its dynamic development expressed in remnants of Variscan subductions im- printed in bands of crustal thickening. A significant feature of the presented model is the velocity-drop interface (VDI) modelled in the lower part of the crust. We explain this feature by the anisotropic fabric of the lower crust, which is characterised as vertical transverse isotropy with the low velocity being the symmetry axis. The VDI is often interrupted around the boundaries of the crustal units, usually above locally increased velocities in the lowermost crust. Due to the north-west-south-east shortening of the crust and the late-Variscan strike-slip movements along the north-east-south-west oriented sutures preserved in the BM lithosphere, the anisotropic fabric of the lower crust was partly or fully erased along the boundaries of original microplates.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10507 - Volcanology

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2021

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Solid Earth

ISSN

1869-9510

e-ISSN

1869-9529

Volume of the periodical

12

Issue of the periodical within the volume

5

Country of publishing house

DE - GERMANY

Number of pages

24

Pages from-to

1051-1074

UT code for WoS article

000651081700001

EID of the result in the Scopus database

2-s2.0-85105773688