检索结果-南通市图书馆

中国科学院地质与地球物理研究所2012年度（第12届）...

作者： Lijuan He State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of Sciences

[1]Several factors influence the topography of the overriding plate in a subduction zone:mantle wedge flow caused by motion of the descending slab,hthosphere elasticity,and interaction between the solid Hthosphere and the viscous asthenosphere.This paper presents the results of new subduction modeling that incorporates both elastic/elastoplastic deformation in the overriding plate and viscous deformation in the asthenosphere.The effects of fluid-solid coupling and interaction were considered using an arbitrary Lagrangian-Eulerian technique that solves for the continuous deformation of fluid flow in contact with the rigid plate.Modeling results show that thicker lithosphere,which is harder to deform,contributes to the development of broadly shallower back-arc basins.As lithospheric strength decreases,its ability to withstand outside force(fluid load) resulting from flow in the mantle wedge also declines,leading to the development of deep and narrow basins.Large-scale deformation of the hthosphere modifies both the mantle wedge geometry and the wedge flow pattem,which in turn increases the fluid load and thereby enhances topographic variation.Generally,the effect of interaction is enhanced with lithospheric deformation.The elastoplastic model also leads to a weaker hthosphere and a correspondingly larger deflection in the lithosphere. Similarly to previous studies,back-arc basins are deeper when mantle viscosity is higher.For a 50 km thick elastic lithosphere,the lithosphere-asthenosphere interaction is negligible when the asfhenospheric viscosity is less than 4×10 Pa s.Increasing the rate of subduction or decreasing the dip angle will also lead to the development of deeper basins.

关键词： fluid-solid coupling lithosphere-asthenosphere interaction numerical modeling subduction zone topography

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Tidal drag and westward drift of the lithosphere

引用

Geoscience Frontiers 2023年第6期14卷 102-116页

作者： Vincenzo Nesi Oscar Bruno Davide Zaccagnino Corrado Mascia Carlo Doglioni Dipartimento di Matematica Guido Castelnuovo Piazzale Aldo Moro5Roma 00185Italy Istituto Nazionale di Geofisica e Vulcanologia Via di Vigna Murata605Roma 00143Italy Computing and Mathematical Sciences Department Caltech1200 E.California Blvd.MC 305-16Pasadena 91125CAUSA Dipartimento di Scienze della Terra Piazzale Aldo Moro5Roma 00185Italy

Tidal forces are generally neglected in the discussion about the mechanisms driving plate tectonics despite a worldwide geodynamic asymmetry also observed at subduction and rift zones.The tidal drag could theoretically explain the westerly shift of the lithosphere relative to the underlying mantle.Notwithstanding,viscosity in the asthenosphere is apparently too high to allow mechanical decoupling produced by tidal forces.Here,we propose a model for global scale geodynamics accompanied by numerical simulations of the tidal interaction of the Earth with the Moon and the Sun.We provide for the first time a theoretical proof that the tidal drag can produce a westerly motion of the lithosphere,also compatible with the slowing of the Earth’s rotational spin.Our results suggest a westerly rotation of the lithosphere with a lower bound ofω≈(0.1-0.2)°/Myr in the presence of a basal effective shear viscosityη≈10^(16)Pa-s,but it may rise toω>1°/Myr with a viscosity ofη≈≤3×10^(14)Pa-s within the Low-Velocity Zone(LVZ)atop the asthenosphere.This faster velocity would be more compatible with the mainstream of plate motion and the global asymmetry at plate boundaries.Based on these computations,we suggest that the super-adiabatic asthenosphere,being vigorously convecting,may further reduce the viscous coupling within the LVZ Therefore,the combination of solid Earth tides,ultra-low viscosity LVZ and asthenospheric polarized small-scale convection may mechanically satisfy the large-scale decoupling of the lithosphere relative to the underlying mantle.Relative plate motions are explained because of lateral viscosity heterogeneities at the base of the lithosphere,which determine variable lithosphere-asthenosphere decoupling and plate interactions,hence plate tectonics.

关键词： Tidal drag Plate motions Polarized plate tectonics lithosphere-asthenosphere interaction

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A three-dimensional Moho depth model beneath the Yemeni highlands and rifted volcanic margins of the Red Sea and Gulf of Aden, Southwest Arabia

引用

China Geology 2023年第4期6卷 611-622页

作者： Amin Noman Al Kadasi Department of Geology Faculty of Applied ScienceTaiz UniversityTaiz 04Yemen

Knowing Moho discontinuity undulation is fundamental to understanding mechanisms of lithosphereasthenosphere interaction, extensional tectonism and crustal deformation in volcanic passive margins such as the study area, which is located in the southwestern corner of the Arabian Peninsula bounded by the Red Sea and the Gulf of Aden. In this work, a 3D Moho depth model of the study area is constructed for the first time by inverting gravity data from the Earth Gravitational Model(EGM2008) using the ParkerOldenburg algorithm. This model indicates the shallow zone is situated at depths of 20 km to 24 km beneath coastal plains, whereas the deep zone is located below the plateau at depths of 30 km to 35 km and its deepest part coincides mainly with the Dhamar-Rada ’a Quaternary volcanic field. The results also indicate two channels of hot magmatic materials joining both the Sana’a-Amran Quaternary volcanic field and the Late Miocene Jabal An Nar volcanic area with the Dhamar-Rada’a volcanic field. This conclusion is supported by the widespread geothermal activity(of mantle origin) distributed along these channels,isotopic data, and the upper mantle low velocity zones indicated by earlier studies.

关键词： Bouguer gravity anomaly Earth gravitational model(EGM2008) Moho discontinuity Mantle upwelling lithosphere-asthenosphere interaction Volcanic passive margin Isostasy Gulf of Aden Red Sea Arabian Peninsula

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：