Recent developments in optical fiber cable technology allows the use of existing and future submarine telecommunication cables to provide seismic and sea level information. In this work we study the impact of three different technologies, i) SMART, Science Monitoring and Reliable Telecommunications; ii) DAS, Distributed Acoustic Sensing, and; iii) LI, Laser Interferometry, for effective earthquake and tsunami monitoring capabilities on the NE Atlantic. The SW Iberia is the source area of the largest destructive earthquake that struck Europe since the year 1000, the 1st November 1755 event. This earthquake generated also a destructive tsunami affecting the whole basin. This tectonically active area is crossed by the CAM (Continent-Azores-Madeira) submarine cable on a ring configuration. Due to the end of cable lifetime the current cables need to be replaced by 2024 and the technical requirements must be defined in mid-2021. The Azores archipelago is the focus of frequent seismic crises and occasionally destructive earthquakes. A common feature of these seismic events is that they take place offshore, an area that is difficult to monitor from land-based instruments. In this work we evaluate the contribution of SMART cables to the earthquake monitoring and tsunami early warning system in SW Iberia and show how DAS and LI can improve earthquake monitoring on two active domains of the Azores. For tsunami early warning we show how the offshore sea-level measurements provide clean offshore tsunami records when compared to coastal observations by tide gauges, which greatly improves the efficiency of the system. For earthquake monitoring, the data processing operational routine is examined using Monte-Carlo simulations. These take into consideration the errors in phase picking and the uncertainty on the 1D velocity model used for earthquake location. Quality of earthquake location is examined using the difference between true and the centroid of the computed epicenters and by the overall ellipse of uncertainty obtained from 100 runs. The added value provided by instrumented submarine telecommunication cables to mitigate earthquake and tsunami risk demonstrated in this work will help authorities and the society in general to take the political decisions required for its full implementation worldwide.

中文翻译：

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海底光缆对东北大西洋地震和海啸监测的贡献

光纤电缆技术的最新发展允许使用现有和未来的海底电信电缆来提供地震和海平面信息。在这项工作中，我们研究了三种不同技术的影响，i) 智能、科学监测和可靠的电信；ii) DAS、分布式声学传感，以及；iii) LI，激光干涉测量法，用于在东北大西洋进行有效的地震和海啸监测。西南伊比利亚是自 1000 年（1755 年 11 月 1 日事件）以来袭击欧洲的最大破坏性地震的震源区。这次地震还产生了影响整个盆地的破坏性海啸。CAM（大陆-亚速尔群岛-马德拉群岛）海底电缆以环形结构穿过该构造活动区。由于电缆寿命结束，目前的电缆需要在 2024 年更换，技术要求必须在 2021 年中期确定。亚速尔群岛是频繁发生地震危机和偶尔发生破坏性地震的中心。这些地震事件的一个共同特征是它们发生在海上，这是一个难以通过陆基仪器监测的区域。在这项工作中，我们评估了 SMART 电缆对伊比利亚西南地区地震监测和海啸预警系统的贡献，并展示了 DAS 和 LI 如何改善亚速尔群岛两个活跃区域的地震监测。对于海啸预警，我们展示了与潮汐计的沿海观测相比，近海海平面测量如何提供干净的近海海啸记录，这大大提高了系统的效率。对于地震监测，使用蒙特卡洛模拟检查数据处理操作程序。这些考虑了相位拾取的误差和用于地震定位的一维速度模型的不确定性。使用真实和计算震中质心之间的差异以及从 100 次运行中获得的整体不确定性椭圆来检查地震位置的质量。这项工作中展示的仪器化海底电信电缆为减轻地震和海啸风险提供的附加值将帮助当局和整个社会做出在全球全面实施所需的政治决策。这些考虑了相位拾取的误差和用于地震定位的一维速度模型的不确定性。使用真实和计算震中质心之间的差异以及从 100 次运行中获得的整体不确定性椭圆来检查地震位置的质量。这项工作中展示的仪器化海底电信电缆为减轻地震和海啸风险提供的附加值将帮助当局和整个社会做出在全球全面实施所需的政治决策。这些考虑了相位拾取的误差和用于地震定位的一维速度模型的不确定性。使用真实和计算震中质心之间的差异以及从 100 次运行中获得的整体不确定性椭圆来检查地震位置的质量。这项工作中展示的仪器化海底电信电缆为减轻地震和海啸风险提供的附加值将帮助当局和整个社会做出在全球全面实施所需的政治决策。