Seismic Network (data acquisition system, seismometers, accelerometers, DAS interrogator unit)

科隆是德国唯一一个有100多万居民面临重大地震危险的城市。周围的下莱茵河海湾也包括几个大型露天褐煤矿。该提案旨在翻新Bensberg地震观测站的强震台网，该台网由科隆60公里范围内的23个台站组成，并通过增加五个新的强震台站和五个新的微震台站以及一个创新的基于激光的DAS（分布式声学传感）询问单元来增强现有地震台网的性能，该单元可以利用光纤中的光散射以前所未有的空间分辨率测量地面运动。强震网络的数据采集在过去的15年里一直处于24/7连续运行状态，并且越来越容易出现故障。此外，它已经过时，不再与当前（64位）计算机兼容，因此需要完全更换。新的数据采集将提供连续的实时数据访问，并以标准格式生成数据，以便通过欧洲开放数据计划轻松交换和共享，并与邻近的地震调查进行更密切的合作。强震台网的主要目的，除了帮助定位每个台站附近的微震事件外，是在发生强震时对地面运动的无损记录。这些记录，也在震源附近的位置，对于导出与地震工程相关的参数，并相应地在开发该地区的地面运动预测方程和估计地震危险性方面具有重要作用。由于下莱茵河河口很少发生大地震（即5.0级地震的估计复发间隔为15至20年），因此必须进行连续的长期监测。额外的强震台站将有助于解决复垦区与自然沉积沉积物对地面运动振幅的影响问题，这对于估计受露天褐煤矿影响地区的地震地面运动具有高度相关性。增加微震台站将提高微震监测台网的检测效率和性能。DAS询问装置提供了新的观测资料，具有多种优势，如地震定位、断层制图、研究地下结构及其小尺度变化，对地震时地面运动的放大具有重要意义。我们的目标是在专门的测量活动中使用DAS询问器单元，例如在已知或可疑的断层上，在沉积覆盖的地区，更好地了解地下弹性参数将有利于危害评估和微地震事件定位，或者在余震监测中，充分利用这项创新技术。

Cologne is the only German city with more than one million inhabitants exposed to a significant seismic hazard. The surrounding Lower Rhine Embayment also includes several large-scale open-pit lignite mines. This proposal aims to refurbish the strong motion network ot the Bensberg seismic observatory, consisting of 23 stations within 60 km of Cologne, and enhance the performance of the existing seismic networks by adding five new strong motion and five new microseismic stations as well as an innovative laser-based DAS (Distributed Acoustic Sensing) interrogator unit that can measure ground motion with unprecedented spatial resolution by using light scattering in optical fibres. The data acquisition of the strong motion network has been in continuous 24/7 operations for the past 15 years and is increasingly prone to failures. Besides, it is outdated and no longer compatible with current (64-bit) computers, so it needs to be replaced completely. The new data acquisition will provide continuous real-time data access and produce data in a standard format, for easy exchange and sharing via European Open Data initiatives and closer collaboration with neighbouring seismological surveys. The main aim of the strong motion network, besides aiding in locating microseismic events in the vicinity of each individual station, is the unclipped recording of ground motion in case of strong earthquakes. These recordings, also at locations close to the source, are instrumental for deriving parameters of relevance to earthquake engineering, and accordingly in developing ground motion prediction equations for the region and estimating seismic hazard. Since large earthquakes are rare in the Lower Rhine Embayment (i.e. have an estimated recurrence interval of 15 to 20 years for magnitude 5.0), continuous long-term monitoring is mandatory. The additional strong motion stations will help to address the question of the influence of recultivated areas vs. naturally deposited sediments on the amplitudes of ground motion, which is of high relevance for estimates of seismic ground motion in the areas affected by open-pit lignite mines. Additional microseismic stations will increase the detection efficiency and performance of the network in microseismic monitoring. The DAS interrogator unit provides new observables with multiple benefits, e.g. to earthquake location, mapping of faults, studying the sub-surface structure and its small-scale variations, which have important implications for amplification of ground motion during earthquakes. We aim to use the DAS interrogator unit in dedicated measurement campaigns, e.g. across known or suspected faults, in areas with sedimentary cover where a better knowledge of the elastic parameters of the subsurface would be beneficial for both hazard assessment and microseismic event location, or in aftershock monitoring, to make the best use of this innovative technology.