The Upper Rhine Graben (URG) undergoes continuous micro-seismicity recorded by seismic monitoring networks and moderate-magnitude earthquakes, such as in the zone north of the Alpine front, which includes the Jura thrust front, the Vosges, the Black Forest, the Swabian Jura and the Alsace plain. The surface velocity field is a good indication of the occurrence and location of strain gradients likely associated with seismogenic structures. To explore that possibility, we use long time series of displacements measured from 2002 to 2018 with the dense GURN network (GNSS Upper Rhine Graben Network). The processing based on double-differences of phase measurements offers an up-to-date surface velocity field of the Upper Rhine Graben and surrounding areas. The surface velocity field relative to the Eurasia reference frame (ITR2014) points out some areas where coherent movements are present for groups of stations. The heterogeneous velocity field across the Rhine Graben (Vosges, Upper Rhine Graben, Black Forest, and Swabian Jura) displays velocity values below 0.2 mm/yr. We compute a deformation field from the GNSS velocities to link the deformation to the spatial distribution of earthquakes in the Rhine Graben. The earthquakes are concentrated south of an east-west line passing through Strasbourg to the Alpine front. Instrumental and historical seismicity presents spatial similarities in the Vosges and Swabian Jura. Considering the consistent northward movement observed in the Alpine front, we suggest that the strong seismicity in the south of the Upper Rhine Graben is caused by the shortening of the Alps. North of the URG, the seismicity is more dispersed where the velocity field does not show coherent movements.

中文翻译：

---

根据GNSS数据，上莱茵河格拉本地区现今的变形

上莱茵河格拉本（URG）受到地震监测网络和中度地震记录的连续微震，例如在阿尔卑斯山锋以北的地区，其中包括侏罗冲刺锋，孚日山脉，黑森林，斯瓦比亚山脉朱拉和阿尔萨斯平原。地表速度场很好地表明了可能与成地震构造有关的应变梯度的出现和位置。为了探索这种可能性，我们使用2002年至2018年的长时间位移序列，使用密集的GURN网络（GNSS上莱茵格拉本网络）。基于相位测量的双差的处理提供了上莱茵河格拉本及其周围地区的最新表面速度场。相对于欧亚大陆参考系（ITR2014）的地表速度场指出了某些区域的站群存在连贯的运动。横跨莱茵河格拉本（Vosges，上莱茵河格拉本，黑森林和斯瓦比亚朱拉）的非均匀速度场显示的速度值低于0.2毫米/年。我们从GNSS速度计算变形场，以将变形与莱茵河格拉本地震的空间分布联系起来。地震集中在通过斯特拉斯堡到达阿尔卑斯山前线的东西线以南。仪器和历史地震活动性在孚日省和斯瓦比亚汝拉州表现出空间相似性。考虑到在阿尔卑斯山前沿观察到的一致的北移，我们认为，上莱茵河格拉本南部的强烈地震活动是由于阿尔卑斯山的缩短而引起的。在URG以北，地震活动更加分散，速度场没有显示出连贯的运动。