On the feasibility and use of teleseismic P wave coda autocorrelation for mapping shallow seismic discontinuities
On the feasibility and use of teleseismic P wave coda autocorrelation for mapping shallow seismic discontinuities
复制标题
DOI：
10.1002/2017jb013975
复制
发表时间：
2017-05
期刊：
影响因子：
--
通讯作者：
Thanh‐Son Phạm;H. Tkalčić
中科院分区：
文献类型：
--
作者：
Thanh‐Son Phạm;H. Tkalčić
来自遥远地震的地震体波在记录站下方垂直传播，为以高垂直分辨率对浅层地球结构进行成像提供了工具。最常用的技术（例如 P 波和 S 波接收器函数）利用从 P 波到 S 波的模式转换（反之亦然）来检索有关地壳和上地幔弹性属性梯度的信息。在这里，我们展示了通过改进的远震 P 波尾自相关方法利用反射信号的可行性和优势。我们独立地恢复垂直和径向分量的清晰反射，这为地下结构提供了补充约束。对来自不同地质环境的两个站的现场数据进行了分析，其中一个是南极洲的冰站，另一个是南非卡普瓦尔克拉通的基岩站。两项分析结果表明该方法揭示冰岩界面和莫霍面不连续面的纵波和横波反射信号的可行性。进行了大量的合成实验来证实我们的结果。
Seismic body waves from distant earthquakes, which propagate near vertically beneath recording stations, provide tools for imaging shallow Earth structures with high vertical resolution. The most commonly used techniques such as P and S wave receiver functions utilize mode conversions from P to S waves or vice versa to retrieve information on the gradients of elastic properties in the crust and upper mantle. Here we demonstrate the feasibility and advantage of utilizing reflection signals through an improved method of teleseismic P wave coda autocorrelation. We recover clear reflections independently on vertical and radial components, which provide complementary constraints on the subsurface structures. Field data from two stations from different geological settings are analyzed, one of which is an ice station in Antarctica and the other is a bedrock station on the Kaapvaal craton in South Africa. The results from both analyses show the feasibility of the method to unveil P and S wave reflection signals from the ice‐rock interface and the Moho discontinuity. Extensive synthetic experiments are set up to corroborate our results.