Upper crustal structure at the KTB drilling site from ambient noise tomography

Autor(en)

Ehsan Qorbani, Petr Kolinsky, Irene Bianchi, Dimitri Zigone, Götz Bokelmann

Abstrakt

In this study, we show results from ambient noise tomography around the KTB (Kontinentales Tiefbohrprogramm der Bundesrepublik Deutschland), a continental deep drilling site located at the western edge of the Bohemian Massif, within the Variscan belt of Europe. At the KTB site, crustal rocks have been drilled down to 9 km depth. Before the drilling activity started, several active seismic surveys had been performed to explore its surroundings during the 1980s and early 1990s, in the frame of an extensive exploration of the area aimed at unravelling the characteristics of the continental lower crust that is exposed at surface in this location. Despite the exploration campaigns held at and around the KTB drilling site, there are important targets that are worth further investigation; these are related in particular to the obduction of lower crustal units to the surface, and to the mechanism of orogenic processes in general. Here we present a new 3-D shear wave velocity model of the area from cross-correlations of ambient seismic noise. The model is obtained by a unique data set composed of 2 yr of continuous data recorded at nine 3-component temporary stations (installed from July 2012 to July 2014) located on top and around the drilling site, and together with the data from 19 permanent stations throughout the region. This paper is focusing on the upper crustal layers, and we show velocity variations at short scales that correlate well with known geological structures in the region of the KTB site, at the surface and at depth. These are used to discuss features that are less well-resolved at present.

Organisation(en)

Institut für Meteorologie und Geophysik

Externe Organisation(en)

Czech Academy of Sciences, Istituto Nazionale di Fisica Nucleare (INFN), Roma, CTBTO Preparatory Comission, Université de Strasbourg

Journal

Geophysical Journal International

Band

231

Seiten

982-995

Anzahl der Seiten

14

ISSN

0956-540X

DOI

https://doi.org/10.1093/gji/ggac233

Publikationsdatum

07-2022

Peer-reviewed

Ja

ÖFOS 2012

105122 Seismik

Schlagwörter

ASJC Scopus Sachgebiete

Geochemistry and Petrology, Geophysics

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/087a5665-31e0-457f-bb21-55721226fbf0