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From Paleogeographic maps to Evolving Deep-time Digital Earth models 被引量:2
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作者 Sabin ZAHIROVIC Tristan SALLES +10 位作者 Dietmar MüLLER michael gurnis CAO Wenchao Carmen BRAZ Lauren HARRINGTON Youseph IBRAHIM Rhiannon GARRETT Simon WILLIAMS CHEN Anqing HOU Mingcai James G.OGG 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2019年第S01期73-75,共3页
Major advances in computational power,as well as community modelling workflows and an improvement in data availability,has revolutionized Earth sciences over the last decade.Geological data has been synthesized into f... Major advances in computational power,as well as community modelling workflows and an improvement in data availability,has revolutionized Earth sciences over the last decade.Geological data has been synthesized into flexible and open access plate tectonic and paleogeographic reconstructions using the open-source and cross-platform GPlates(www.gplates.org)software since 2008(Muller et al.,2018;Muller et al.,2008). 展开更多
关键词 PALEOGEOGRAPHY TECTONICS TETHYS GPlates Digital Earth
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East African topography and volcanism explained by a single,migrating plume 被引量:1
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作者 Rakib Hassan Simon E.Williams +1 位作者 michael gurnis Dietmar Muller 《Geoscience Frontiers》 SCIE CAS CSCD 2020年第5期1669-1680,共12页
Anomalous topographic swells and Cenozoic volcanism in east Africa have been associated with mantle plumes.Several models involving one or more fixed plumes beneath the northeastward migrating African plate have been ... Anomalous topographic swells and Cenozoic volcanism in east Africa have been associated with mantle plumes.Several models involving one or more fixed plumes beneath the northeastward migrating African plate have been suggested to explain the space-time distribution of magmatism in east Africa.We devise paleogeographically constrained global models of mantle convection and,based on the evolution of flow in the deepest lower mantle,show that the Afar plume migrated southward throughout its lifetime.The models suggest that the mobile Afar plume provides a dynamically consistent explanation for the spatial extent of the southward propagation of the east African rift system(EARS),which is difficult to explain by the northeastward migration of Africa over one or more fixed plumes alone,over the last≈45 Myr.We further show that the age-progression of volcanism associated with the southward propagation of EARS is consistent with the apparent surface hotspot motion that results from southward motion of the modelled Afar plume beneath the northeastward migrating African plate.The models suggest that the Afar plume became weaker as it migrated southwards,consistent with trends observed in the geochemical record. 展开更多
关键词 Numerical mantle flow models Deep mantle flow LLSVP morphology Plume dynamics Plume motion Dynamic topography
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伴随数据同化方法及其在地幔对流中的应用 被引量:1
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作者 刘丽军 michael gurnis 《地学前缘》 EI CAS CSCD 北大核心 2010年第3期139-148,共10页
伴随数据同化方法是一个基于梯度法的反演技巧,尤其适用于对非线性问题的反演。最近几年里,该方法在地球物理问题中的应用取得了长足发展。文中试图从理论推导到其在地幔对流中的应用对该方法进行系统阐述,并附例图加以说明。伴随数据... 伴随数据同化方法是一个基于梯度法的反演技巧,尤其适用于对非线性问题的反演。最近几年里,该方法在地球物理问题中的应用取得了长足发展。文中试图从理论推导到其在地幔对流中的应用对该方法进行系统阐述,并附例图加以说明。伴随数据同化方法的基础是扰动理论,将模型输出与观测值的差别归因于模型输入中存在的误差,而该输入误差可以通过输出误差的最小二乘对输入条件的一阶倒数(梯度)来表示,这个联系就称作伴随算子。非线性问题的反演需要用到多次迭代;对输入误差的预估程度会直接影响计算和结果收敛的速度。作为描述当前地幔结构最有力证据的地震层析成像技术的不断进步,不论是在区域还是全球尺度上,都为地幔对流的反演提供了一个出发点。通过进一步同化或者比较相关的地质学证据特别是地表动力沉降观测,地幔对流反演可以克服目前仍然存在的地幔动力学各参数的不确定性的影响,从而进一步揭示壳幔系统的动力学机制。讨论的一个实际的例子是如何使用该方法反推出Farallon板块于晚白垩世时期在北美板块下的平俯冲过程以及该研究所导致的地球物理学及地质学意义。 展开更多
关键词 伴随数据同化方法 时间反演 地幔对流 地震层析成像
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