海底地形校正在正确拾取OBS震相中的重要作用
发布时间：2018-12-11 16:23
【摘要】：海底地震仪(ocean bottom seismometer,OBS)探测是获得海底深部地壳结构的首选方法。正确拾取OBS记录中折射/反射震相,对获得准确的深部速度结构非常重要。当OBS布设在崎岖海底时,起伏的海底地形会影响OBS地震记录剖面中Pg、Pm P、Pn等岩石圈内部震相的展布特征,如南海东部次海盆中横穿珍贝-黄岩海山链的A4M4地震测线和西南印度洋中脊横穿扩张脊的Y3Y4测线,强烈的地形高差变化增加了这些测线上OBS台站地震剖面的震相识别难度。在震相拾取之前,通过地形校正方法消除海底地形对震相的影响;地形校正后,根据震相视速度及其展布趋势可以准确地识别震相,有效地提高了震相识别的可靠性。地形校正方法在上述地区的震相识别与速度结构研究方面发挥了重要作用,同时为今后在其他地形变化复杂地区的OBS震相识别提供了经验与借鉴。
[Abstract]:Submarine seismograph (ocean bottom seismometer,OBS) is the preferred method to obtain deep crustal structure. It is very important to correctly pick up the refraction / reflection phase in the OBS records to obtain the accurate deep velocity structure. When the OBS is laid on the rugged seabed, the undulating submarine topography will affect the distribution characteristics of the internal facies of the Pg,Pm Pu PN lithosphere in the OBS seismic record section. For example, the A4M4 seismic line across the Jebel Huang Yan seamounts chain in the subbasin of the eastern South China Sea and the Y3Y4 line across the spreading ridge of the middle ridge of the southwest Indian Ocean, the strong variation of topographic height increases the difficulty of seismic phase identification of the seismic profile of the OBS station on these lines. Before phase pickup, the influence of submarine topography on seismic phase is eliminated by topographic correction, and the phase can be accurately identified according to the apparent velocity of seismic phase and its distribution trend after terrain correction, which effectively improves the reliability of seismic phase identification. The method of terrain correction plays an important role in the study of seismic phase identification and velocity structure in the above-mentioned areas, and provides experience and reference for the identification of OBS seismic phases in other areas with complex terrain changes in the future.
【作者单位】： 中国科学院边缘海与大洋地质重点实验室(南海海洋研究所);中国科学院大学;
【基金】：国家自然科学基金重大研究计划(91428204,91028002) 国家自然科学基金项目(41404050,41176053,41606064)~~
【分类号】：P736.1
本文编号：2372857
[Abstract]:Submarine seismograph (ocean bottom seismometer,OBS) is the preferred method to obtain deep crustal structure. It is very important to correctly pick up the refraction / reflection phase in the OBS records to obtain the accurate deep velocity structure. When the OBS is laid on the rugged seabed, the undulating submarine topography will affect the distribution characteristics of the internal facies of the Pg,Pm Pu PN lithosphere in the OBS seismic record section. For example, the A4M4 seismic line across the Jebel Huang Yan seamounts chain in the subbasin of the eastern South China Sea and the Y3Y4 line across the spreading ridge of the middle ridge of the southwest Indian Ocean, the strong variation of topographic height increases the difficulty of seismic phase identification of the seismic profile of the OBS station on these lines. Before phase pickup, the influence of submarine topography on seismic phase is eliminated by topographic correction, and the phase can be accurately identified according to the apparent velocity of seismic phase and its distribution trend after terrain correction, which effectively improves the reliability of seismic phase identification. The method of terrain correction plays an important role in the study of seismic phase identification and velocity structure in the above-mentioned areas, and provides experience and reference for the identification of OBS seismic phases in other areas with complex terrain changes in the future.
【作者单位】： 中国科学院边缘海与大洋地质重点实验室(南海海洋研究所);中国科学院大学;
【基金】：国家自然科学基金重大研究计划(91428204,91028002) 国家自然科学基金项目(41404050,41176053,41606064)~~
【分类号】：P736.1
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