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: 9000458
• 负责人: G. Michael Purdy
• 金额: $ 7.5万
• 依托单位: Woods Hole Oceanographic Institution
• 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: 1990-04-01 至 1992-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9000458&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月进行了地震层析成像实验 在北纬9度30分的东太平洋海隆上， 确定上升轴地震速度结构的尺寸。 这个实验产生了一个地震数据集， 这8000个记录来自大约500个镜头和15个海洋 海底地震仪 断层扫描的初步结果 P波延迟时间反演表明 上升轴两侧和沿着的结构不均匀性; 例如，2km深度处的轴向低速异常， 1.5km/s比离轴慢;沿轴的变化在这个 速度异常超过20%。 这次更新将继续 改进的地震速度模型研究 反演技术，将探索利用 波形幅度信息，以进一步约束三维 地震结构，并将分析和解释重力， 在课程中获得的地磁和微地震数据 断层扫描实验的结果