3D crustal stress state of Germany according to a data-calibrated geomechanical model
oleh: S. Ahlers, A. Henk, T. Hergert, K. Reiter, B. Müller, L. Röckel, O. Heidbach, O. Heidbach, S. Morawietz, S. Morawietz, M. Scheck-Wenderoth, M. Scheck-Wenderoth, D. Anikiev
| Format: | Article |
|---|---|
| Diterbitkan: | Copernicus Publications 2021-08-01 |
Deskripsi
<p>The contemporary stress state in the upper crust is of great interest for geotechnical applications and basic research alike. However, our knowledge of the crustal stress field from the data perspective is limited. For Germany basically two datasets are available: orientations of the maximum horizontal stress (<span class="inline-formula"><i>S</i><sub>Hmax</sub></span>) and the stress regime as part of the World Stress Map (WSM) database as well as a complementary compilation of stress magnitude data of Germany and adjacent regions. However, these datasets only provide pointwise, incomplete and heterogeneous information of the 3D stress tensor. Here, we present a geomechanical–numerical model that provides a continuous description of the contemporary 3D crustal stress state on a regional scale for Germany. The model covers an area of about <span class="inline-formula">1000×1250</span> km<span class="inline-formula"><sup>2</sup></span> and extends to a depth of 100 km containing seven units, with specific material properties (density and elastic rock properties) and laterally varying thicknesses: a sedimentary unit, four different units of the upper crust, the lower crust and the lithospheric mantle. The model is calibrated by the two datasets to achieve a best-fit regarding the <span class="inline-formula"><i>S</i><sub>Hmax</sub></span> orientations and the minimum horizontal stress magnitudes (<span class="inline-formula"><i>S</i><sub>hmin</sub></span>). The modeled orientations of <span class="inline-formula"><i>S</i><sub>Hmax</sub></span> are almost entirely within the uncertainties of the WSM data used and the <span class="inline-formula"><i>S</i><sub>hmin</sub></span> magnitudes fit to various datasets well. Only the <span class="inline-formula"><i>S</i><sub>Hmax</sub></span> magnitudes show locally significant deviations, primarily indicating values that are too low in the lower part of the model. The model is open for further refinements regarding model geometry, e.g., additional layers with laterally varying material properties, and incorporation of future stress measurements. In addition, it can provide the initial stress state for local geomechanical models with a higher resolution.</p>