08 Mar 2022
08 Mar 2022
Status: this preprint is open for discussion.

The analysis of slip tendency of major tectonic faults in Germany

Luisa Röckel1, Steffen Ahlers2, Birgit Müller1, Karsten Reiter2, Oliver Heidbach3,4, Andreas Henk2, Tobias Hergert2, and Frank Schilling1 Luisa Röckel et al.
  • 1Institute of Applied Geosciences, TU Darmstadt, 64287 Darmstadt, Germany
  • 2Institute of Applied Geosciences, KIT, 76131 Karlsruhe, Germany
  • 3Helmholtz Zentrum Potsdam, Deutsches GeoForschungsZentrum GFZ, 14473 Potsdam, Germany
  • 4Institute of Applied Geosciences, TU Berlin, 10587 Berlin, Germany

Abstract. Seismic hazard during subsurface operations is often related to the reactivation of pre-existing tectonic faults. The analysis of the slip tendency, i.e. the ratio of shear to normal stress acting on the fault plane, allows an assessment of the reactivation potential of faults. We use the total stresses that result from a large-scale 3D geomechanical-numerical model of Germany and adjacent areas to calculate the slip tendency for three 3D fault geometry sets with increasing complexity. This allows to draw general conclusions about the influence of the fault geometry on the reactivation potential.

In general, the fault reactivation potential is higher in Germany for faults that strike NW-SE and NNE-SSW. Due to the prevailing normal stress regime in the geomechanical-numerical model results, faults dipping at an angle of about 60° generally show higher slip tendencies in comparison to steeper or shallower dipping faults. Faults implemented with a straight geometry show higher slip tendencies than those represented with a more complex, uneven geometry. Pore pressure has been assumed as hydrostatic and has shown to have a major influence on the calculated slip tendencies. Compared to slip tendency values calculated without pore pressure, the consideration of pore pressure leads to an increase of slip tendency of up to 50 %. The qualitative comparison of the slip tendency with the occurrence of seismic events with moment magnitudes Mw > 3.5 shows an overall good spatial correlation between areas of elevated slip tendencies and seismic activity for one of the investigated fault sets.

Luisa Röckel et al.

Status: open (until 19 Apr 2022)

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Luisa Röckel et al.

Data sets

3D fault sets of Germany and adjacent areas Röckel, Luisa; Müller, Birgit I. R.; Ahlers, Steffen; Reiter, Karsten; Hergert, Tobias; Henk, Andreas; Heidbach, Oliver; Schilling, Frank

Luisa Röckel et al.

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Latest update: 03 Apr 2022
Short summary
Reactivation of tectonic faults can lead to earthquakes and jeopardize underground operations. The reactivation potential is linked to fault properties and the tectonic stress field. We create 3D geometries for major faults in Germany and use stress data from a 3D geomechanical-numerical model to calculate their reactivation potential and compare it to seismic events. The reactivation potential in general is highest for NNE-SSW and NW-SE striking faults and strongly depends on the fault dip.