Receiver functions in northeast China – implications for slab penetration into the lower mantle in northwest Pacific subduction zone
Receiver functions in northeast China – implications for slab penetration into the lower mantle in northwest Pacific subduction zone
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DOI：
10.1016/s0012-821x(03)00555-7
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发表时间：
2003-12
影响因子：
5.3
通讯作者：
Xueqing Li;X. Yuan
中科院分区：
文献类型：
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作者：
Xueqing Li;X. Yuan
对日本和中国东北地区西北太平洋俯冲带俯冲岩石圈和上地幔不连续面的地震研究表明，俯冲作用是相反的。对于俯冲板片是穿透上地幔不连续面进入下地幔，还是在660公里不连续面顶部偏转数百公里的问题，人们几乎没有达成共识。本文计算了中国东北地区一个宽带地震台网的接收函数，发现了上地幔不连续面的地形变化。在400公里的区域内观察到一个比正常深660公里的不连续性，它与地震层析成像的停滞板相吻合。660公里长的不连续面局部凹陷超过35公里，过渡区在与板片相遇的区域东部加厚超过20公里。这些观测结果提供了板片在地幔过渡带聚集并局部穿透下地幔的证据。
Seismic studies of the subducting lithosphere and the upper mantle discontinuities in the northwest Pacific subduction zone beneath Japan and northeast China have suggested contrary subduction scenarios. There was little consensus on the issue whether the subducting slab penetrates the upper mantle discontinuities into the lower mantle or it is deflected atop of the 660-km discontinuity over several hundred kilometers. We calculate receiver functions from a recent seismic broadband station network located in northeast China and find topographic variations of the upper mantle discontinuities. A deeper-than-normal 660-km discontinuity is observed over an area of 400 km and it coincides with the stagnant slab imaged by seismic tomography. The 660-km discontinuity is locally depressed by more than 35 km and the transition zone is thickened by more than 20 km in the east of the region where it encounters the slab. These observations provide evidence of the slab accumulating in the mantle transition zone and locally penetrating into the lower mantle.