Heterogeneity, Anisotropy, and Seismic Attenuation in Earth's Inner Core and Lower Mantle

地球内核和下地幔的非均质性、各向异性和地震衰减

• 批准号: 0229586
• 负责人: Vernon Cormier
• 金额: $ 36万
• 依托单位: University of Connecticut
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0229586&HistoricalAwards=false
• 关键词: Heterogeneity; Anisotropy; Seismic; Attenuation; Earth

The small-scale structural fabric of Earth's inner core and lower mantle is important to the understanding of mantle convection, slab cycling, plume formation, and solidification of the inner core, including the dynamic deformation of the inner core boundary and its relation to the differential rotation of the inner core and mantle and the earth's magnetic field. Seismic modeling will be performed to image the small-scale (1-1000 km) fabric of the inner core and lowermost mantle that are important to these processes. Waveforms of the PKIKP seismic phase will be modeled to determine the depth dependence, lateral variation, anisotropy, and frequency dependence of inner core visco-elasticity, and crystalline fabric to constrain models of inner core solidification. Seismic waveform modeling will also be performed to constrain the statistical and deterministic structure of the lowermost mantle, which can provide important signatures that can enable a discrimination among the proposed origins of the heterogeneous structure in this region: remnant slabs, solid-solid phase transitions, pools of primitive mantle, partial melt, and core-mantle chemical reactions.--

地核和下地幔的小尺度结构组构对于理解地幔对流、板片旋回、羽流的形成和内核的固化具有重要意义，包括内核边界的动态变形及其与内、地幔的差异旋转和地球磁场的关系。将进行地震模拟，以成像对这些过程很重要的内核和最低地幔的小尺度(1-1000公里)组构。将模拟PKIKP地震震相的波形，以确定内核粘弹性的深度相关性、横向变化、各向异性和频率相关性，以及晶体组构，以约束内核固化的模型。还将进行地震波形模拟，以限制最低地幔的统计和确定性结构，这可以提供重要的特征，使人们能够区分该地区非均质结构的拟议来源：残留板、固体-固体相变、原始地幔池、部分熔融和核-地幔化学反应。