Fig. 11
modified from Nussbaum et al. (2017)
Forward modelled NNW-SSE cross section along the Mont Terri tunnel from Nussbaum et al. (2017). Absolute locations obtained in this study (see Fig. 4 for details) for shallow earthquakes are overlaid. Vertical bars indicate absolute errors of focal depths. The thick error bar indicates the combined depth uncertainties obtained from both absolute and relative relocations. Colors indicate origin time. Size of symbols is proportional to magnitude. The focal mechanism of the strongest event based on first-motion polarities suggests a north-dipping low-angle thrust mechanism. As the sense of motion disagrees with the basal decollement, a backthrust rooting in the top of the Lias Group (Staffelegg Formation in the Lithostratigraphic Lexicon of Switzerland) in the footwall of the Mont Russelin ramps is more likely to be the active plane of the 2000 seismic sequence. Note that the lexicon of the lithostratigraphic column follows the lexicon of Switzerland. The corresponding European lexicon of the lithostratigraphic groups for the Triassic and Jurassic epochs is also indicated. For more information about the definition of the units in the Lithostratigraphic Lexicon of Switzerland, as well as further cross-links to other units, please visit www.strati.ch. Figure