Collaborative Research: Bridging the gap between long- and short- wavelength structure in the mantle

合作研究：弥合地幔长波长和短波长结构之间的差距

• 批准号: 1015172
• 负责人: Jeroen Ritsema
• 金额: $ 20.92万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-01 至 2013-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1015172&HistoricalAwards=false
• 关键词: Collaborative; Research; Bridging; gap; between

Images of the Earth?s interior are primarily produced by two types of techniques providing snapshots of the Earth at two end-members of resolution. (1) Tomographic imaging provides a whole-mantle view of Earth?s large-scale ( 2000-5000 km) seismic velocity anomalies; (2) Waveform modeling provides a small-scale (~100-500 km) view for specific geographic locations. Because the scale length of features resolved in these imaging techniques varies by an order of magnitude it remains challenging to reconcile these different pictures into one single model of the Earth?s interior. This project aims to reconcile the disparities observed in these images by: (1) Analyzing new seismic data recorded in North America from Earthscope?s Transportable Array (TA) and FlexArray deployments, ANSS Backbone stations, Canadian National Seismic Network Stations, and recent PASSCAL deployments; (2) Analyzing global- and regional-scale models previously introduced to the community by full waveform modeling techniques using the PSVaxi software. The primary goals are to assess the accuracy of the global and regional scale seismic models, and to decipher how complex structures in the deep mantle at all spatial scales affect broadband seismic waveforms.Seismological modeling of deep mantle structure is crucial in understanding the dynamic processes taking place within the Earth. This project will further develop software that is capable of simulating earthquake motions on the global scale. Ultimately this will aid in elucidating the Earth?s interior structure by comparing the simulated waveforms with the newly recorded data. They will test the validity of previously derived Earth models, assessing how structural features in the deep mantle affect the seismic waveforms. Ultimately, this will provide valuable waveform propagation tools and a rigorous assessment of the accuracy of seismic models and images to the community.

地球内部的图像主要通过两种类型的技术生成，以两种分辨率提供地球的快照。 （1）层析成像提供了地球大尺度（2000-5000公里）地震速度异常的全地幔视图； (2) 波形建模提供特定地理位置的小比例（~100-500 公里）视图。 由于这些成像技术所解析的特征的尺度长度存在一个数量级的变化，因此将这些不同的图像协调成一个地球内部的单一模型仍然具有挑战性。 该项目旨在通过以下方式协调这些图像中观察到的差异：(1) 分析在北美记录的新地震数据，这些数据来自 Earthscope 的可移动阵列 (TA) 和 FlexArray 部署、ANSS 骨干站、加拿大国家地震台网以及最近的 PASSCAL部署； (2) 使用 PSVaxi 软件通过完整波形建模技术分析先前向社区引入的全球和区域规模模型。 主要目标是评估全球和区域尺度地震模型的准确性，并破译所有空间尺度的深部地幔复杂结构如何影响宽带地震波形。深部地幔结构的地震建模对于理解深部地幔结构的动态过程至关重要。位于地球内。 该项目将进一步开发能够模拟全球范围地震运动的软件。 最终，通过将模拟波形与新记录的数据进行比较，这将有助于阐明地球的内部结构。 他们将测试先前推导的地球模型的有效性，评估深部地幔的结构特征如何影响地震波形。 最终，这将为社区提供有价值的波形传播工具以及对地震模型和图像准确性的严格评估。