P′P′ Precursors Under Africa: Evidence for Mid-Mantle Reflectors
P′P′ Precursors Under Africa: Evidence for Mid-Mantle Reflectors
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DOI：
10.1126/science.270.5233.74
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发表时间：
1995-10
期刊：
影响因子：
56.9
通讯作者：
Yves LeStunff;C. Wicks;B. Romanowicz
中科院分区：
文献类型：
--
作者：
Yves LeStunff;C. Wicks;B. Romanowicz
在加州的一系列宽带台站上，对斐济群岛最近一次异常大的深震（矩震级= 7.6）的P′P′前兆进行了观测，发现在南部非洲裂谷下785公里和1200公里深处附近存在中地幔反射体。这种观察，以前报道的主要是在俯冲带，表明这些反射可能具有全球性的字符。我们的分析也表明了一个尖锐的，隆起的670公里的不连续性，证明了稀疏的区域宽带阵列的力量，在地球深部结构的弱，频率依赖的功能的研究。
Observations of precursors to P′P′ from a recent exceptionally large deep earthquake in the Fiji Islands (moment magnitude = 7.6) at an array of broadband stations in California revealed mid-mantle reflectors near depths of 785 kilometers and 1200 kilometers under the southern African rift. Such observations, previously reported primarily in subduction zones, suggest that these reflectors may have a global character. Our analysis, which also indicated a sharp, uplifted 670-kilometer discontinuity, demonstrates the power of sparse regional broadband arrays for the study of weak, frequency-dependent features in deep-Earth structure.