Seismic Tomography: The Three-Dimensional Structure of the East Pacific Rise

地震层析成像：东太平洋海隆的三维结构

• 批准号: 9000177
• 负责人: Sean Solomon
• 金额: --
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-03-15 至 1993-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9000177&HistoricalAwards=false
• 关键词: Seismic; Tomography; Three; Dimensional; Structure

In January 1988 a seismic tomography experiment was carried out on the East Pacific Rise at 9 degrees 30'N to image in three- dimensions the seismic velocity structure of the rise axis. This experiment yielded a seismic data set consisting of more that 8000 records from approximately 500 shots and 15 ocean bottom seismometers. Initial results from the tomographic inversion of P wave delay times indicate substantial heterogeneity in structure both across and along the rise axis; for instance, the axial low velocity anomaly at 2 km depth is 1.5km/s slower than off axis; the along-axis variations in this velocity anomaly exceed 20%. This renewal will continue the investigation of seismic velocity models using improved inversion techniques, will explore methods of utilizing waveform amplitude information to constrain further the 3-D seismic structure, and will analyze and interpret the gravity, magnetic, and microearthquake data obtained during the course of the tomography experiment.

1988年1月，在北纬9度30'的东太平洋海隆上进行了地震层析成像实验，以三维方式对海隆轴的地震速度结构进行成像。 该实验产生了一个地震数据集，其中包含来自大约 500 次发射和 15 个海底地震仪的 8000 多个记录。 P 波延迟时间层析反演的初步结果表明，沿上升轴和横轴结构均存在显着的异质性； 例如，2公里深度的轴向低速异常比离轴慢1.5公里/秒；该速度异常的沿轴变化超过 20%。 本次更新将继续使用改进的反演技术研究地震速度模型，探索利用波形振幅信息进一步约束 3-D 地震结构的方法，并将分析和解释课程期间获得的重力、磁力和微地震数据断层扫描实验。