江苏海洋地震台站建设与效能分析

Construction and Efficiency Analysis of Jiangsu Marine Seismic Stations

利用GL-PS2一体化短周期地震计分别在江苏海上风电平台升压站及高抗站建成两个海洋地震观测台站,并在升压站同址相临架设GL-PCS60一体化宽频带地震计对比观测。结果表明:基于海上风电平台开展海洋地震观测系统设计简单,成本较低,运行稳定可靠。相比于陆地台站,海上风电平台白天与夜晚噪声水平差异较小,但受风力天气影响显著。以升压站为例,海浪干扰集中在0.15~0.3 Hz频段附近,固有频率为1.4 Hz。地震过程频谱分析获得的地震集中频段作为地震波形滤波处理依据可以提高信噪比,获得清晰震相。基于海上风电平台开展海洋地震观测在提高海洋地震监测预警能力的同时,地震过程频谱分析固有频率稳定性以及地震集中频段可为海上风电平台结构在发震过程中的影响情况做出安全评估。

Two marine seismic observation stations have been built at the booster and high resistance stations of an offshore wind power platform using the GL-PS2 integrated short-period seismometer.The GL-PCS60 integrated broadband seismometer has also been deployed at the same site as the booster station to enable comparative observations.The results show that the offshore marine observation system,based on the offshore wind power platform,is simple,cost-effective,stable and reliable.When compared with the terrestrial stations,the noise level differences of the offshore wind power platform are smaller in the daytime and at night,but they are significantly affected by wind weather conditions.Taking the booster station as an example,the wave interference is concentrated in the 0.15-0.3 Hz band and the natural frequency is 1.4 Hz.The signal-to-noise ratio can be enhanced and a clear phase can be obtained by using earthquake concentration frequency derived from the spectrum analysis of the seismic process as the basis of seismic waveform filtering.The evolution of marine seismic observation,based on offshore wind power platforms,can improve the monitoring and early warning capability for marine earthquakes.The natural frequency stability and earthquake concentration frequency derived from the spectrum analysis of the seismic process can also provide a safe assessment of the influence of offshore wind power platform structures during the earthquake generation process.