The 21 March 2022 Mw 5.1 Tampen Spur earthquake is the largest event in the North Sea over the last 33 yr. The earthquake was recorded by a 10,708 sensors permanent reservoir monitoring system (PRM) deployed at the Snorre field only a few kilometers away from the epicenter. The event was also recorded on regional networks, as well as at teleseismic distances. Here, we take advantage of this large number of observations to relocate this seismic event, estimate a moment tensor, and refine the depth of the earthquake. The different data sets and location methods yield similar locations, suggesting a well‐constrained earthquake location with a depth of 22 ± 5 km. Furthermore, a moment tensor is estimated, which indicates a thrust fault mechanism. Deep crustal earthquakes (>20 km) have been documented within several continental rifts, for example, in Basin and Range in the United States and in northern Germany. Studying deep intraplate earthquakes such as the event observed here can offer insights into the rheology and structures in the deeper portions of the crust. This thrust earthquake implies the reactivation of an older fault in the lower crust consistent with the ridge‐push forces from the mid‐Atlantic ridge. Such brittle failure at depth indicates a lower crust with little to no fluids present at this depth within the Tampen Spur region.

中文翻译：

---

2022 年 3 月 21 日北海 Mw 5.1 Tampen Spur 地震：位置、矩张量和背景

2022 年 3 月 21 日发生的 Mw 5.1 Tampen Spur 地震是过去 33 年来北海发生的最大地震。此次地震是由部署在距离震中仅几公里的 Snorre 油田的永久性水库监测系统 (PRM) 记录的，该系统包含 10,708 个传感器。该事件也被记录在区域网络和远震距离上。在这里，我们利用大量的观测来重新定位该地震事件，估计矩张量，并细化地震的深度。不同的数据集和定位方法产生相似的位置，表明地震位置受到良好约束，深度为 22 ± 5 km。此外，还估计了力矩张量，该力矩张量表明了逆冲故障机制。在几个大陆裂谷内，例如美国的盆地和山脉以及德国北部，已记录了深部地壳地震（> 20 公里）。研究深部板内地震（例如这里观察到的事件）可以深入了解地壳深层的流变和结构。这次逆冲地震意味着下地壳中较旧断层的重新激活，与来自大西洋中脊的山脊推力一致。这种深度的脆性破坏表明在 Tampen Spur 区域的这个深度存在下地壳，几乎没有流体。