Analysis of Steep Angle Seismic Reflections from Earth's Inner and Outer Core

地球内核和外核的陡角地震反射分析

• 批准号: 0087330
• 负责人: Keith Koper
• 金额: $ 8.02万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-02-15 至 2001-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0087330&HistoricalAwards=false
• 关键词: Analysis; Steep; Angle; Seismic; Reflections

Abstract for proposal EAR0087330 (PH # 17x)Title: Analysis of Steep Angle Seismic Reflections from Earth's Inner and Outer CorePI: Keith D. Koper, University of ArizonaThe proposed research focuses on seismic constraints of global variations in topography on the inner core-outer core boundary (ICB) and the core-mantle boundary (CMB). Variations in steep angle (S,P)KiKP-(S,P)cP differential travel times will be used to estimate the ellipticity of the inner and outer core, to search for short-wavelength topography on these boundaries, to provide observational bounds on the homogeneity of the liquid outer core, and to search for evidence of differential rotation of Earth's inner core. Variations in steep angle outer core differential travel times, primarily ScP-PcP, will also be used to quantify global variations in vertical mantle profiles of bulk sound velocity. An unprecedented number of steep angle differential core reflection data are available from the seismicity catalog produced by the prototype International Data Center (pIDC). Approximately 20 of the globally distributed stations that report data to the pIDC consist of arrays of short period vertical component seismometers. Array stations are markedly more sensitive to steep angle core reflections than traditional three component stations, and the azimuth and slowness observations made by array stations greatly reduce phase misidentification. By considering the differential travel times of pairs of such reflections the effects of earthquake mislocation and upper mantle heterogeneity are substantially reduced and seismic structure at the CMB and ICB is revealed.

题目：地球内外核陡角地震反射分析（ei: Keith D. Koper, University of arizona）。拟研究的重点是内核-外核边界（ICB）和核-幔边界（CMB）全球地形变化的地震约束。KiKP-(S，P)cP差行程时间的变化将用于估计内外核的椭圆度，在这些边界上寻找短波长地形，提供液体外核均匀性的观测边界，并寻找地球内核微分旋转的证据。陡角外核差分传播时间的变化，主要是ScP-PcP，也将用于量化整体声速垂直地幔剖面的全球变化。由国际数据中心（pIDC）制作的地震活动目录提供了数量空前的陡角度差分岩心反射数据。向太平洋太平洋数据中心报告数据的全球分布的台站中，大约有20个是由短周期垂直分量地震仪阵列组成的。相对于传统的三分量台站，阵列台站对大倾角地心反射的敏感性明显提高，并且阵列台站的方位角和慢度观测大大减少了相位误认。通过考虑这些反射对的差分传播时间，大大减少了地震错位和上地幔非均质性的影响，揭示了CMB和ICB的地震结构。