The Upper Rhine Graben (URG), as a part of the wider European Cenozoic Rift System, is a tectonically active area that has been extensively investigated for its geothermal energy potential. In this study, we carry out a first investigation of the present-day thermo-mechanical stability of the area as based on a detailed 3D geological and thermal model. The overall goal is, therefore, to assess how the lithospheric strength varies within the URG in response to the natural tectonic setting as well as the internal thermal configuration, and how those variations can be related to the recorded seismicity. The results from the modeling indicate that there is a spatial correlation between the predictions for the graben-wide rheological configuration with both the deep thermal field and the configuration of the crystalline crust. We find that the regional characteristics of the long-term strength of the lithosphere match the spatial distribution of seismicity, indicating that the mechanical stability of the area is primarily controlled by resolved strength variations. By cross-plotting the modeled strength distribution with available seismicity catalogs, our results suggest that seismicity in the graben area is shallower and of lower intensity due to a hotter and weaker crust compared to its surrounding areas. In contrast, seismic energy release appears to occur at deeper levels and being of larger magnitudes east of the graben and in the adjacent Lower Rhine Graben to the north. These results demonstrate the relevance of a proper quantification of the lithospheric rheological configuration and its spatial variability in response to its tectonic inheritance as an asset to interpret the pattern and distribution of seismicity observed in the area.

上莱茵河格拉本河（URG）是更广泛的欧洲新生代裂谷系统的一部分，是一个构造活跃的地区，已经对其地热能潜力进行了广泛研究。在这项研究中，我们基于详细的3D地质和热力模型对该地区当今的热机械稳定性进行了首次调查。因此，总体目标是评估URG内岩石圈强度如何响应自然构造环境以及内部热构造，以及这些变化如何与记录的地震活动联系起来。建模的结果表明，在深热场和结晶壳的构型之间，在grab斗状流变构型的预测之间存在空间相关性。我们发现岩石圈的长期强度的区域特征与地震活动的空间分布相匹配，这表明该地区的机械稳定性主要受解析的强度变化控制。通过将模型化的强度分布与可用的地震活动目录进行交叉绘图，我们的结果表明，与周围地区相比，由于地壳较热和较弱，被抓区域的地震活动较浅，强度较低。相比之下，地震能量释放似乎发生在较深的水平，并且在被抓物以东以及在北部与之相邻的下莱茵格拉本（Lower Rhine Graben）以较大的幅度发生。