ANELASTICITY OF INNER CORE
ANELASTICITY OF INNER CORE
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DOI：
10.1111/j.1365-246x.1974.tb04131.x
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发表时间：
1974-01-01
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影响因子：
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通讯作者：
DOORNBOS, DJ
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作者：
DOORNBOS, DJ
形成了源、接收器相同、地幔射线路径基本相同的短周期岩心相的频谱比，从而推导出1 Hz纵波在核内的AQ结构。来自一个大型阵列(Norsar)的数据已用于提取相关相，包括对(PKIKP，PKiKP)、(PKIKP，PKP(BC))、(PKIIKP，PKiKP)、(PKIIKP，PKKP(BC))。尤其需要一个阵列来分离PKIKP和PKKP，以识别PKIIK。在形成光谱比率时，使用了光谱形成和瞬时光谱分析等技术。这些数据已经使用了许多不同的速度模型进行了反演。所得Q模型的基本特征是相同的：Q值从接近内核边界的约200上升到400公里深度时的约600。在450公里深度以下，Q结构没有受到很好的约束，但可能低于2000的值。结果表明，核内界的温度接近铁的熔点，部分熔化至少发生在核的一部分。低Q结构对PKIIKPK和PKJKP等位相的振幅有很大影响。证明了PKIIKP只有在例外情况下才能观察到，并提出了PKJKP太小而不能观察的论点。
Spectral ratios of short-period core phases with common source and receiver and with nearly the same ray paths in the mantle have been formed to derive aQ-structure for 1 Hz compressional waves in the inner core. Data from one large array (NORSAR) have been used to extract the relevant phases, including the pairs (PKIKP, PKiKP), (PKIKP, PKP(BC)), (PKIIKP, PKiKP), (PKIIKP, PKKP(BC)). An array is needed in particular to separatePKIKPandPKiKPand to identifyPKIIKP.In forming the spectral ratios, techniques like spectraforming and instantaneous spectral analysis have been employed. The data have been inverted using a number of different velocity models. The essential features of the resultingQ-models are the same:Qrises from a value of about 200 near the inner core boundary to about 600 at 400 km depth penetration. Below 450 km depth theQ-structure is not well constrained, but probably is below a value of 2000. It is suggested that the temperature at the inner core boundary is close to the melting point of iron and that partial melting occurs in at least part of the inner core. The lowQ-structure greatly affects the amplitudes of phases likePKIIKPandPKJKP. It is verified thatPKIIKPis observable only in exceptional cases and arguments are presented thatPKJKPis too small to be observed.