南海西南次海盆反射莫霍面成像及其地质意义

发布时间：2018-06-04 09:41

  本文选题：反射莫霍面成像 + 层间多次波压制　； 参考：《海洋地质与第四纪地质》2017年02期

【摘要】：深部地质结构是研究海盆动力成因的重要基础。南海西南次海盆以往多道地震资料中莫霍面的成像普遍不清,选取NH973-1测线长排列多道地震数据对西南次海盆的莫霍面反射成像进行研究。该地震资料中层间多次波非常发育,严重掩盖或干扰了莫霍面有效反射信号。针对地震资料特征,首先采用抛物线型Radon变换滤波对部分层间多次波进行压制以拾取一个相对准确的初始速度,在此基础上进一步采用速度滤波和内切除组合方法对层间多次波进行压制。从资料处理效果看,层间多次波得到有效压制,莫霍面成像清晰,呈现出断断续续的特征。由此解释的海盆区地壳(除沉积层外)厚度整体较薄,约为2.3~3.9km,有别于正常洋壳结构,更接近于构造拉伸主导型的地壳。
[Abstract]:The deep geological structure is the important foundation of studying the dynamic origin of the basin. The imaging of Moho surface in the southwest subbasin of the South China Sea is generally unclear. The reflection imaging of the Moho surface of the southwest subbasin of the South China Sea is studied by selecting the NH973-1 line length and arranging the multi-channel seismic data. The multiples between the middle layers of the seismic data are very developed, which masked or interfered with the effective reflection signal of Moho surface seriously. According to the characteristics of seismic data, parabolic Radon transform filter is firstly used to suppress partial interlayer multiples to pick up a relatively accurate initial velocity. Furthermore, the interlaminar multiples are suppressed by the combination of velocity filtering and internal resection. From the effect of data processing, interlayer multiples are effectively suppressed, Moho imaging is clear, and it presents intermittent characteristics. The thickness of the crust (except sedimentary layer) in the basin is relatively thin, about 2.3 ~ 3.9km, which is different from the normal oceanic crust structure and is closer to the tectonic-extensional crust.
【作者单位】： 中国科学院边缘海与大洋地质重点实验室中国科学院南海海洋研究所;中国科学院大学;
【基金】：国家自然科学基金项目(91328205,41376062) 729工程项目(GZH20110205)
【分类号】：P631.4;P736
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本文编号：1976902