Mantle Transition Zone Receiver Functions for Bermuda: Automation, Quality Control, and Interpretation
Mantle Transition Zone Receiver Functions for Bermuda: Automation, Quality Control, and Interpretation
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DOI：
10.1029/2020jb020177
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发表时间：
2021-03-01
影响因子：
3.9
通讯作者：
Simons, Frederik J.
中科院分区：
文献类型：
--
作者：
Burky, Alexander L.;Irving, Jessica C. E.;Simons, Frederik J.
百慕大隆起的起源仍然模糊不清，尽管，或者可能是因为，有时不协调的地震波速度和不连续模型的存在，在亚东印度洋地幔。因此，百慕大是否是地幔柱的表面表现仍然存在疑问。使用最大的数据集的地震记录从百慕大到目前为止，我们估计径向接收器功能在全球地震台网站BBSR在多个频带，使用迭代时域反褶积。出于使用轴对称谱元素正演波形建模的合成实验，我们设计了一个质量度量我们的接收器功能，以帮助自动化和复制地幔过渡带不连续性研究。我们解释了复杂的信号，我们观察到的地幔过渡带不连续结构的矿物学控制，并得出结论，我们的结果可能是一个比平均厚的地幔过渡带的指示。我们的结果与橄榄石主导的地幔中整个地幔柱的典型模型不相容;然而，对石榴子石系统中相变的考虑将使我们能够将我们的观察结果与百慕大下方可能存在的持续高温异常相一致。
The origin of the Bermuda rise remains ambiguous, despite, or perhaps because of, the existence of sometimes incongruous seismic wave-speed and discontinuity models in the sub-Bermudian mantle. Hence, whether Bermuda is the surface manifestation of a mantle plume remains in question. Using the largest data set of seismic records from Bermuda to date, we estimate radial receiver functions at the Global Seismographic Network station BBSR in multiple frequency bands, using iterative time-domain deconvolution. Motivated by synthetic experiments using axisymmetric spectral-element forward waveform modeling, we devise a quality metric for our receiver functions to aid in the automation and reproduction of mantle transition zone discontinuity studies. We interpret the complex signals we observe by considering the mineralogical controls on mantle transition zone discontinuity structure, and conclude that our results are likely to be indicative of a thicker than average mantle transition zone. Our result is incompatible with the canonical model of a whole mantle plume in an olivine dominated mantle; however, considerations of phase transitions in the garnet system would allow us to reconcile our observations with the possible presence of a through-going hot thermal anomaly beneath Bermuda.