E. Qorbani1 , I. Bianchi2 , D. Zigone3 , P. Kolínský2 , G. Bokelmann2
1CTBTO Preparatory Commission
2University of Vienna
3University of Strasbourg
Abstract:
In this study, we show results from ambient noise tomography at the Continental Deep Drilling Project (KTB) drilling site, Germany. During the KTB project crustal rocks have been drilled down to 9 km depth and several active seismic studies have been performed in the surrounding. The aim of this study is to present a new shear-wave velocity model of the area while comparing the results to the previous velocity models and hints for anisotropy depicted by former passive and active seismological studies. We use a unique data-set composed of two years of continuous data recorded at nine 3-component temporary stations installed from July 2012 to July 2014 located on top and vicinity of the drilling site. Moreover, we included a number of permanent stations in the region in order to improve the path coverage and density. Cross correlations of ambient noise are computed between the station pairs. Dispersion curves of surface waves are extracted in the 0.07 to 3 Hz frequency band and are then inverted to obtain group velocity maps. We present here a new velocity model of the upper crust, which shows that velocity variations at short periods correlate well with geology of the region.