Resolving crustal thickness using SS waveform stacks
Resolving crustal thickness using SS waveform stacks
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DOI：
10.1111/j.1365-246x.2009.04497.x
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发表时间：
2010-03
影响因子：
2.8
通讯作者：
C. Rychert;P. Shearer
中科院分区：
文献类型：
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作者：
C. Rychert;P. Shearer
我们利用SS波形叠加特征的变化来成像岩石圈界面，这种方法我们称之为SS岩石圈界面剖面（SSLIP）。这些变化是由反射相位引起的，即在SS射线路径中点附近的速度不连续处产生的底面反射（SS前兆）和顶面多次波（SS混响），来自大陆与海洋反弹点区域的叠加产生明显不同的SS波形，这与大陆/海洋地壳厚度的巨大差异一致。为了研究SS波形叠加限制大陆下莫霍面深度的潜力，我们开发了一种方法来拟合大陆反弹点叠加与地壳算子卷积的参考SS波形。SSLIP推断的莫霍面深度与亚洲地壳2.0模型中SS反弹点密度最高的区域一致。SSLIP深度与在半径为10°的样本箱上平均的CRUST 2.0值相关（相关系数为0.82）。SSLIP方法与大多数其他方法相比具有广泛的横向分辨率，用于解决地壳厚度，但有可能采样区域的台站覆盖可能是稀疏的。
We image lithospheric interfaces using variations in the character of SS waveform stacks, a method we term SS Lithospheric Interface Profiling (SSLIP). The variations are caused by reflected phases, that is, underside reflections (SS precursors) and topside multiples (SS reverberations), created at velocity discontinuities near the midpoint of the SS ray path. Stacks from continental versus oceanic bounce point regions produce distinctly different SS waveforms, consistent with the large continent/ocean difference in crustal thickness. To investigate the potential of SS waveform stacks to constrain Moho depths under continents, we develop a method to fit continental bounce point stacks with a reference SS waveform convolved with a crustal operator. The SSLIP inferred Moho depths agree with the CRUST 2.0 model in Asia for those regions where the SS bounce point density is the highest. The SSLIP depths are correlated (correlation coefficient 0.82) with the CRUST 2.0 values averaged over sample bins of 10° radius. The SSLIP method has broad lateral resolution in comparison to most other methods for resolving crustal thickness, but has the potential to sample regions where station coverage may be sparse.