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，在东太平洋上升的9度上，进行了一次地震层析成像实验，以在三个维度上图像上升轴的地震速度结构。 该实验产生了一个地震数据集，其中包括大约500张照片和15个海洋底部地震米的8000个记录。 p波延迟时间层合截面的初始结果表明，跨轴和沿着轴的结构上存在很大的异质性。 例如，在2 km深度的轴向低速异常比轴慢1.5公里/s。该速度异常的及轴变化超过20％。 这种更新将使用改进的反转技术继续研究地震速度模型，将探索利用波形振幅信息进一步限制3-D地震结构的方法，并将分析和解释引力，磁性和微鞭打数据在persogrications实验过程中获得。