Waveform inversion for S‐wave structure in the lowermost mantle beneath the Arctic: Implications for mineralogy and chemical composition
Waveform inversion for S‐wave structure in the lowermost mantle beneath the Arctic: Implications for mineralogy and chemical composition
复制标题
北极下地幔横波结构的波形反演：对矿物学和化学成分的影响
DOI：
10.1029/2010gl043654
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发表时间：
2010
影响因子：
5.2
通讯作者：
N. Fuji
中科院分区：
文献类型：
--
作者：
K. Kawai;R. Geller;N. Fuji
我们进行波形反演的径向剖面剪切波速度在最低的地幔在北极之下。我们使用的波形从CANOE（卡纳迪诺维实验）阵列，这大大提高了分辨率，在最低的地幔相比，早期的研究。我们发现，从2500到2700公里的深度速度增加，从2700公里到核幔边界（CMB）的深度速度降低。我们将速度增加解释为与从钙钛矿（pv）到后钙钛矿（ppv）的相变相关，并且速度降低是由于热边界层中的温度增加。核幔边界（CMB）上方的剪切波速度为7.11 km/s，而中美洲下方的剪切波速度为7.25 km/s。这表明，北极下方的Mg-pv或Mg-ppv中杂质的比例比中美洲下方的高6mol%。
We perform waveform inversion for the radial profile of shear wave velocity in the lowermost mantle beneath the Arctic. We use waveforms from the CANOE (CAnadian NOrthwest Experiment) array, which greatly enhances the resolution in the lowermost mantle as compared to earlier studies. We find a velocity increase at depths from 2500 to 2700 km and a velocity decrease at depths from 2700 km to the core‐mantle boundary (CMB). We interpret the velocity increase as associated with the phase transition from perovskite (pv) to post‐perovskite (ppv), and the velocity decrease as due to a temperature increase in the thermal boundary layer. The shear wave velocity immediately above the core‐mantle boundary (CMB) is 7.11 km/s, while that beneath Central America is 7.25 km/s. This suggests that the proportion of impurities in Mg‐pv or Mg‐ppv beneath the Arctic is 6 mol% larger than that beneath Central America.