West Africa could teach us much about the early tectonic history of Earth, but current seismic models of the regional crustal and lithospheric structure lack the resolution required to answer all but the most basic research questions. We have improved the resolution of group velocity maps of the West African Craton by complementing the uneven path distribution of earthquake-generated surface waves with surface waves reconstructed from ambient noise cross-correlations. Our joint dataset provides good spatial coverage of group velocity measurements from 20- to 100-s period, enabling us to reduce artifacts in our group velocity maps and improve their resolution. Our maps correlate well with regional geological features. At short periods, they highlight differences in crustal thickness, recent tectonic activity, and thick sediments. At long periods, we found lower velocities due to hot, thin lithosphere under the Pan-African mobile belt and faster velocities due to cold, thick lithosphere under the Man-Leo and Reguibat shields. Our higher resolution maps advance us a step towards revealing the detailed lithospheric structure and tectonic processes of West Africa.

中文翻译：

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利用区域地震和环境地震噪声的西非瑞利波群速度色散层析成像

西非可以为我们提供有关地球早期构造史的很多知识，但是当前地区地壳和岩石圈结构的地震模型缺乏回答所有最基本的研究问题所需的分辨率。通过用由环境噪声互相关重构的面波补充地震产生的面波的不均匀路径分布，我们提高了西非克拉通群速度地图的分辨率。我们的联合数据集提供了从20到100 s周期的团体速度测量的良好空间覆盖，从而使我们能够减少团体速度图中的伪影并提高其分辨率。我们的地图与区域地质特征密切相关。在短期内，它们突出显示了地壳厚度，近期构造活动和厚沉积物的差异。长期来看 我们发现，由于泛非移动带下方炎热的岩石圈较慢，速度较低；而由于曼利奥和雷吉巴特盾构较冷的岩石圈较厚，速度较快。我们的高分辨率地图使我们朝着揭示西非详细的岩石圈结构和构造过程迈出了一步。