Global Surface Wave Tomography Using Seismic Hum
Global Surface Wave Tomography Using Seismic Hum
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DOI：
10.1126/science.1176389
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发表时间：
2008-12
期刊：
影响因子：
56.9
通讯作者：
Kiwamu Nishida;J. Montagner;H. Kawakatsu
中科院分区：
文献类型：
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作者：
Kiwamu Nishida;J. Montagner;H. Kawakatsu
来自海洋或大气扰动的长周期面波可用于上地幔的地震制图。地震面波层析成像技术的发展对研究地球深部动力学状态具有重要意义。人们自然认为，只有大地震才能产生长周期的地震波，这些地震波能穿透地球足够深，以便进行这种勘探。地震嗡嗡声的发现，地球的背景自由振荡，这是随机产生的海洋和/或大气扰动，现在提供了一种替代方法。我们目前的全球上地幔地震层析成像的结果，使用地震嗡嗡声，没有提到地震。在100至400秒的周期，瑞利波的相速度异常的测量通过模拟观测到的互相关函数之间的每对站从全球分布的54个地震台站。反演得到上地幔三维S波速度结构。我们的技术为探索具有大气层和/或海洋的类地行星，特别是火星内部的三维结构提供了新的手段。
Long-period surface waves from oceanic or atmospheric disturbances can be used for seismic mapping of the upper mantle. The development of global surface wave tomography using earthquakes has been crucial to exploration of the dynamic status of Earth’s deep. It is naturally believed that only large earthquakes can generate long-period seismic waves that penetrate deep enough into Earth for such exploration. The discovery of seismic hum, Earth’s background free oscillations, which are randomly generated by oceanic and/or atmospheric disturbances, now provides an alternative approach. We present results of global upper-mantle seismic tomography using seismic hum and without referring to earthquakes. At periods of 100 to 400 seconds, the phase-velocity anomalies of Rayleigh waves are measured by modeling the observed cross-correlation functions between every pair of stations from among 54 globally distributed seismic stations. The anomalies are then inverted to obtain the three-dimensional S-wave velocity structure in the upper mantle. Our technique provides a new means for exploring the three-dimensional structure of the interior of terrestrial planets with an atmosphere and/or oceans, particularly Mars.