论文部分内容阅读
利用距离为118°-140°的PKIKP和PKiKP波形检验了地球内核最上部 100 km的结构。在赤道地带发现的内核最上部低速层的证据主要位于西经20°至东经 140°。在纬度方向,从南纬35°印度洋下面至北纬60°亚洲的下面可以监测到这一异常。用波形模拟方法可以推断该低速层的最大厚度为40 km,此时波速突变约3％。我们认为,该层可能为新近固结的地核区域,在该区域同时存在活跃的外核成分对流和内核新晶体增长。
The structure of the uppermost 100 km of the Earth’s core was examined using the PKIKP and PKiKP waveforms at a distance of 118 ° -140 °. Evidence of the uppermost low-speed core found in the equatorial zone lies mainly between 20 ° W and 140 ° E. In the latitudinal direction, this anomaly can be monitored from below the Indian Ocean at latitude 35 ° to below 60 ° North Latitude. Using the waveform simulation method, it can be inferred that the maximum thickness of the low-velocity layer is 40 km, at which time the wave velocity changes by about 3%. In our opinion, this layer may be a newly consolidated core area where both active core component convection and new core crystal growth are simultaneously present.