Evidence for an Independent 26-s Microseismic Source near the Vanuatu Islands
Evidence for an Independent 26-s Microseismic Source near the Vanuatu Islands
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瓦努阿图群岛附近存在独立 26 秒微震源的证据
DOI：
10.1007/s00024-014-0811-1
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发表时间：
2014-04
影响因子：
2
通讯作者：
Ni, Sidao
中科院分区：
文献类型：
--
作者：
Zeng, Xiangfang;Ni, Sidao
环境地震噪声频谱中的26 s峰值在全球台站持续激发和观测。使用噪声互相关函数（NCF），位置表明，源可能位于几内亚湾和斐济盆地。然而，斐济海盆被认为是几内亚湾源的镜像站点（近对极），而不是独立的源，假设表面波更有效地传播沿着海洋运动的主要弧路径。为了研究瑞利波沿着大陆和海洋路径的传播，我们分析了几内亚湾附近地震记录的面波数据，发现瑞利波沿沿着大陆小弧路径传播比沿沿着海洋大弧路径传播更有效。然后，我们找到了源在西太平洋的群速度测量地震数据通过使用旅行时间失配NCF校准后，得出的结论是，源是在瓦努阿图群岛。而且，西太平洋地震台站观测到的26 s微震峰值的时间变化与几内亚湾附近台站有很大不同，这表明它们是由独立的震源激发的。因此，瓦努阿图震源应是一个独立的微震震源。由于太平洋26 s微地震源靠近瓦努阿图群岛的火山，因此可能受到岩浆过程的激发，这也是长周期火山震颤的原因。
The 26 s peak in the ambient seismic noise spectrum is persistently excited and observed at stations globally. Using noise cross-correlation functions (NCFs), the location suggests that the source could be situated in the Gulf of Guinea and Fiji Basin. However, the Fiji Basin was proposed to be the mirror site (near antipode) of the Gulf of Guinea source instead of an independent source, assuming that the surface waves more efficiently propagate along the major-arc paths of oceanic movements. To investigate the propagation of the Rayleigh waves along continental and oceanic paths, we analyzed the surface wave data recorded from an earthquake near the Gulf of Guinea and found that Rayleigh waves travel along continental minor-arc paths more efficiently than along oceanic major-arc paths. We then located the source in the western Pacific Ocean from group velocities measured with earthquake data by using the travel time misfit in NCFs after calibration and concluded that the source is in the Vanuatu Islands. Moreover, the temporal variation of the 26 s microseismic peak observed in the western Pacific seismic stations is very different from that in stations near the Gulf of Guinea, which suggests that they are excited by independent sources. Therefore, the Vanuatu source should be an independent microseismic source. As it is close to volcanoes in the Vanuatu islands, the Pacific 26 s microseismic source might be excited by magmatic processes, which are also responsible for very-long-period volcanic tremors.
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影响因子：
5.2
作者：
Xiangfang Zeng;S. Ni
通讯作者：
Xiangfang Zeng;S. Ni
影响因子：
3
作者：
L. Holcomb
通讯作者：
L. Holcomb
影响因子：
5.2
作者：
D. Legrand;D. Rouland;M. Frogneux;R. Carniel;D. Charley;G. Roult;C. Robin
通讯作者：
D. Legrand;D. Rouland;M. Frogneux;R. Carniel;D. Charley;G. Roult;C. Robin
影响因子：
2.8
作者：
Bensen, G. D.;Ritzwoller, M. H.;Yang, Y.
通讯作者：
Yang, Y.
影响因子：
5.2
作者：
Y. Gu;C. Dublanko;A. Lerner-Lam;Keith Brzak;M. Steckler
通讯作者：
Y. Gu;C. Dublanko;A. Lerner-Lam;Keith Brzak;M. Steckler