Analysis of Antarctic Broad Band PASSCAL Data for Surface Wave Dispersion

南极宽带PASSCAL面波色散数据分析

• 批准号: 9418114
• 负责人: Arthur Lerner-Lam
• 金额: $ 2.7万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-07-15 至 1997-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9418114&HistoricalAwards=false
• 关键词: Analysis; Antarctic; Broad; Band; PASSCAL

Abstract This award supports a study of the technical feasibility of collecting and analyzing broad-band teleseismic data from the Antarctic continental interior using portable seismometers. The West Antarctic Ice Sheet overlies a region of the Antarctic continent which may be in extension. However, very little is actually known about the seismic structure of the crust and upper mantle. The deployment of portable broad-band seismometers for passive teleseismic studies may offer the most effective means of acquiring data on the deep structure of this continent. Data collected with broad-band PASSCAL seismometers deployed as an augmentation to the ICEQUAKE network in central West Antarctica represents useful records with several well defined teleseismic events (about 10-20 events) that were recorded over a period of five weeks. The data are of sufficient quality to allow the estimation of fundamental mode dispersion curves down to periods as low as 50 seconds, and the analysis of body phases for boundary interactions and travel time anomalies. This should provide first-order constraints on the shear velocity structure of the crust and upper mantle down to a depth of approximately 200 km. Additionally, the data contain sufficient information to develop ambient noise models for ice sheets. Consequently, if successful, this work will lead to important guidance for the technical design elements necessary for developing an important experimental resource for seismic studies that may lead to significant advances in understanding the Antarctic continent.

该奖项支持一项使用便携式地震仪从南极大陆内陆收集和分析宽带远程地震数据的技术可行性研究。西南极冰盖覆盖在南极大陆的一个区域上，该区域可能正在延伸。然而，对地壳和上地幔的地震结构实际上知之甚少。部署用于被动远震研究的便携式宽带地震仪可能是获取该大陆深部结构数据的最有效手段。用PASSCAL宽频带地震仪收集的数据是对西南极洲中部的冰震网络的补充，其中包括在五周内记录的几次清晰的远震事件(约10-20次)。这些数据具有足够的质量，可以估计低至50秒的周期的基模色散曲线，并分析边界相互作用和旅行时间异常的物体相位。这将对地壳和上地幔向下至约200公里深度的剪切速度结构提供一级约束。此外，这些数据包含了足够的信息来开发冰盖的环境噪声模型。因此，如果这项工作取得成功，将为开发地震研究的重要实验资源所需的技术设计要素提供重要指导，这可能导致在了解南极大陆方面取得重大进展。