Core-Mantle Boundary Dynamic Topography: Influence of Postperovskite Viscosity
文献类型：期刊论文
| 作者 | Deschamps, Frederic2; Li, Yang1 |
| 刊名 | JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
 |
| 出版日期 | 2019-08-01 |
| 卷号 | 124期号:8页码:9247-9264 |
| 关键词 | convection mantle dynamics core-mantle boundary topography postperovskite |
| ISSN号 | 2169-9313 |
| DOI | 10.1029/2019JB017859 |
| 英文摘要 | Core-mantle boundary (CMB) topography may provide useful hints on the deep mantle thermochemical structure, as clusters of thermal plumes and piles of chemically differentiated material, which are usually proposed as end-member explanations for the large low shear-wave velocity regions observed in the deep mantle, have different actions on this topography. CMB topography is further sensitive to several parameters, including mantle viscosity and its variations with thermal and compositional changes. Here we assess the influence of the postperovskite (pPv) phase viscosity on deep mantle dynamics and on CMB topography. We perform numerical simulations of thermal and thermochemical convection in spherical geometry, varying the ratio between pPv and bridgmanite viscosities, Delta eta(pPv), between 1 (regular pPv) and 10(-3) (weak pPv). Thermochemical structures are dominated by smaller-scale wavelengths (spherical harmonic degrees 3 to 6) and are more stable in weak than in regular pPv models. The amplitude of CMB topography is reduced by about a factor of 2 as Delta eta(pPv) changes from 1 to 10(-3), mostly due to a sharp drop in the depressions induced by downwellings reaching the CMB. By contrast, the topographies induced by plumes clusters and thermochemical piles are mostly unaffected. For all the values of Delta eta(pPv) we tested, long-wavelength CMB topography and reconstructed shear-wave tomography are anticorrelated in purely thermal models, and correlated in thermochemical models with strong chemical density contrast (Delta rho(C) = 140 kg/m(3)). In models with smaller density contrast (Delta rho(C) = 90 kg/m(3)), topography and tomography are anticorrelated at Delta eta(pPv) = 1, but correlated at Delta eta(pPv) = 10(-3). |
| WOS关键词 | POST-PEROVSKITE PHASE ; FREE-OSCILLATION SPECTRA ; PRIMORDIAL RESERVOIRS ; NORMAL-MODE ; THERMOCHEMICAL CONVECTION ; TRAVEL-TIMES ; CONSTRAINTS ; DENSITY ; VELOCITY ; STABILITY |
| 资助项目 | Academia Sinica Investigator Award[AS-IA-108-M03] ; Ministry of Science and Technology (MoST) of Taiwan[107-2116-M-001-010] ; Chinese Academy of Sciences (CAS) Pioneer Hundred Talent Program |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:000491283500088 |
| 出版者 | AMER GEOPHYSICAL UNION |
| 资助机构 | Academia Sinica Investigator Award ; Academia Sinica Investigator Award ; Ministry of Science and Technology (MoST) of Taiwan ; Ministry of Science and Technology (MoST) of Taiwan ; Chinese Academy of Sciences (CAS) Pioneer Hundred Talent Program ; Chinese Academy of Sciences (CAS) Pioneer Hundred Talent Program ; Academia Sinica Investigator Award ; Academia Sinica Investigator Award ; Ministry of Science and Technology (MoST) of Taiwan ; Ministry of Science and Technology (MoST) of Taiwan ; Chinese Academy of Sciences (CAS) Pioneer Hundred Talent Program ; Chinese Academy of Sciences (CAS) Pioneer Hundred Talent Program ; Academia Sinica Investigator Award ; Academia Sinica Investigator Award ; Ministry of Science and Technology (MoST) of Taiwan ; Ministry of Science and Technology (MoST) of Taiwan ; Chinese Academy of Sciences (CAS) Pioneer Hundred Talent Program ; Chinese Academy of Sciences (CAS) Pioneer Hundred Talent Program ; Academia Sinica Investigator Award ; Academia Sinica Investigator Award ; Ministry of Science and Technology (MoST) of Taiwan ; Ministry of Science and Technology (MoST) of Taiwan ; Chinese Academy of Sciences (CAS) Pioneer Hundred Talent Program ; Chinese Academy of Sciences (CAS) Pioneer Hundred Talent Program |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/95758]  |
| 专题 | 地质与地球物理研究所_岩石圈演化国家重点实验室 |
| 通讯作者 | Deschamps, Frederic |
| 作者单位 | 1.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing, Peoples R China 2.Acad Sin, Inst Earth Sci, Taipei, Taiwan |
| 推荐引用方式 GB/T 7714 | Deschamps, Frederic,Li, Yang. Core-Mantle Boundary Dynamic Topography: Influence of Postperovskite Viscosity[J]. JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,2019,124(8):9247-9264. |
| APA | Deschamps, Frederic,&Li, Yang.(2019).Core-Mantle Boundary Dynamic Topography: Influence of Postperovskite Viscosity.JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,124(8),9247-9264. |
| MLA | Deschamps, Frederic,et al."Core-Mantle Boundary Dynamic Topography: Influence of Postperovskite Viscosity".JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH 124.8(2019):9247-9264. |
入库方式： OAI收割
来源：地质与地球物理研究所
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