New Candidate Ultralow-Velocity Zone Locations from Highly Anomalous SPdKS Waveforms
New Candidate Ultralow-Velocity Zone Locations from Highly Anomalous SPdKS Waveforms
复制标题
从高度异常的SPdKS波形中寻找新的候选超低速带位置
DOI：
10.3390/min10030211
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发表时间：
2020-02
期刊：
影响因子：
2.5
通讯作者：
M. Thorne;S. Pachhai;K. Leng;J. Wicks;T. Nissen‐Meyer
中科院分区：
文献类型：
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作者：
M. Thorne;S. Pachhai;K. Leng;J. Wicks;T. Nissen‐Meyer
核幔边界的超低速带（ULVZ）代表了地球地幔中一些最奇异的特征。这些区域很可能含有部分熔融物、铁含量极高的铁方镁石或两者的组合。我们分析了58，155个经过仔细处理和质量控制的地震相位SPdKS宽带记录的新集合，震中距离范围为106°至115°。这些数据按表面积对CMB的56.9%进行了采样。从这些记录中，我们寻找了最异常的地震波形，这表明ULVZ的存在。我们使用贝叶斯方法来识别具有最高概率包含ULVZ的CMB区域，从而识别16个感兴趣的区域。在这些区域中，我们证实了众所周知的ULVZ存在于南中国海，西南太平洋，萨摩亚热点，美国西南部/北方墨西哥和冰岛。我们在北非、东亚和巴布亚新几内亚北部的地下发现了新的超低硫区的有力证据。我们提供了进一步的证据，ULVZ在菲律宾海，太平洋西北部和亚马逊盆地的一些证据已经暗示过的地区。更多的证据表明，在卡罗琳，圣费利克斯和加拉帕戈斯热点的基础上潜在的ULVZ。
Ultralow-velocity zones (ULVZs) at the core–mantle boundary (CMB) represent some of the most preternatural features in Earth’s mantle. These zones most likely contain partial melt, extremely high iron content ferropericlase, or combinations of both. We analyzed a new collection of 58,155 carefully processed and quality-controlled broadband recordings of the seismic phase SPdKS in the epicentral distance range from 106° to 115°. These data sample 56.9% of the CMB by surface area. From these recordings we searched for the most anomalous seismic waveforms that are indicative of ULVZ presence. We used a Bayesian approach to identify the regions of the CMB that have the highest probability of containing ULVZs, thereby identifying sixteen regions of interest. Of these regions, we corroborate well-known ULVZ existence beneath the South China Sea, southwest Pacific, the Samoa hotspot, the southwestern US/northern Mexico, and Iceland. We find good evidence for new ULVZs beneath North Africa, East Asia, and north of Papua New Guinea. We provide further evidence for ULVZs in regions where some evidence has been hinted at before beneath the Philippine Sea, the Pacific Northwest, and the Amazon Basin. Additional evidence is shown for potential ULVZs at the base of the Caroline, San Felix and Galapagos hotspots.