Details of the abstract

Title of paper 3D imaging of electrical conductivity structures in the Eastern Cheb Basin across the Hartoušov and Bublák mofettes
List of authors Aleid, B., Weckmann, U., Platz, A., Pek, J., Kováčiková, S., Klanica,R.
Affiliation(s) Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences, Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences, Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences, Institute of Geophysics of the Czech Academy of Sciences (Prague - Czech Republic), Institute of Geophysics of the Czech Academy of Sciences (Prague - Czech Republic), Institute of Geophysics of the Czech Academy of Sciences (Prague - Czech Republic),
Summary The mofette fields of Bublák and Hartoušov are among the most prominent CO2 degassing centers in Europe and located in cheb basin (Czech Republic). The massive degassing of CO2 in the mofette fields originates from great depths. With our research, we would like to contribute to a comprehensive and holistic interpretation of the tectonic regime and image of the conductive ascent paths of fluids. The magnetotelluric method was applied, which is sensitive to electrically conductive phases. A local dense grid of 97 MT stations was deployed close to mofette fields in the Cheb Basin. Unfortunately, there are many man-made electromagnetic noise sources. Their disturbances had to be removed from the recorded data during data processing before modelling and inversion. The presented high-resolution 3D image of the electrical conductivity of the area surrounding the mofettes matches the available drill logs from the Czech Geological Survey and the previous geophysical studies. Large-scale regional models hint at deep reaching pathways fostering the ascend of mantle derived fluids into the regions of mofettes and swarm earthquakes. However, the most prominent large-scale conductivity features of the other two regional models are several channels from the lower crust to the surface, possibly representing pathways for fluids into the earthquake swarm region, mofette fields, and known spas. However, such a conductive channel is absent in our local model beneath the surface expression of the mofettes. To assess whether the experimental layout, the reduced data quality, or inversion issues are responsible for the lack of such an ascending pathway, or if fluid migration in this area is rather horizontal than vertical, we applied a synthetic inversion test. Results from synthetic modelling studies and available geoscientific constraints hint that such a channel might exist directly beneath the mofette field. Still, it seems challenging to resolve due to the given data quality, station distribution, and the subsurface conductivity structure within a conductive sediment basin.
Session Keyword 2.0 Theory, Modelling and Inversion
File upload 2.0_3d_imaging_of_electrical_aleid.pdf
Back to list