A Short-Period Surface-Wave Dispersion Dataset for Model Assessment of Africa’s Crust: ADAMA
A Short-Period Surface-Wave Dispersion Dataset for Model Assessment of Africa’s Crust: ADAMA
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DOI：
10.1785/0220210355
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发表时间：
2022-03
影响因子：
3.3
通讯作者：
T. Olugboji;Siyu Xue
中科院分区：
文献类型：
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作者：
T. Olugboji;Siyu Xue
我们提出了用于调查非洲岩石圈（ADAMA）的一系列数据集和模型评估产品中的第一个。这是一个短周期站间表面波色散测量和不确定度的综合目录。它是通过处理所有公开可用的三分量地震记录的连续记录得来的，这些记录跨越40年，来自部署在非洲大陆及其周围的62个地震网的~ 1372个站点。它包括由频域环境噪声互相关函数（nfc）导出的洛夫波和瑞利波色散。然后，使用路径平均先验地球模型的谱元表示，通过nfc的迭代非线性波形拟合获得相位和群色散及其不确定性。我们的目录代表了以下进展：(1)短周期频散测量的大分布：周期在5秒到40秒之间的约114,000个站间对，(2)包含了对整个大陆模型建立的正则化有用的不确定性，(3)对大陆不同构造域的初步模型评估，(4)通过贝叶斯反演获得的典型的Love-wave相速度图揭示了以前未发现的详细特征。ADAMA将用于准备短周期、高分辨率色散图，并用于评估和更新广泛使用的地壳地震速度模型，该模型横跨大陆上的多种地形。
We present the first in a series of dataset and model assessment products for investigating Africa’s lithosphere (ADAMA). This is a comprehensive catalog of short-period interstation surface-wave dispersion measurements and uncertainties. It is derived from processing continuous recordings of all publicly available three-component seismograms, spanning four decades, from ∼1372 stations, across 62 seismic networks deployed in and around the African continent. It includes Love- and Rayleigh-wave dispersion derived from frequency-domain ambient noise cross-correlation functions (NCFs). Phase and group dispersion, as well as their uncertainties, are then obtained with an iterative nonlinear waveform fitting of the NCFs, using a spectral element representation of a path-average a priori Earth model. Our catalog represents the following advances: (1) a large distribution of short period dispersion measurements: ∼114,000 interstation pairs at periods between 5 s and 40 s, (2) inclusion of uncertainties useful for regularization in continent-wide model building, (3) preliminary model assessments for different tectonic domains on the continent, and (4) an exemplary Love-wave phase velocity map obtained by Bayesian inversion revealing detailed features not previously detected. ADAMA will be used to prepare short-period, high-resolution dispersion maps, and for assessment and updates of widely used seismic velocity models of the crust across a diversity of terranes on the continent.