Two Searches for Observational Evidence of Inner Core Rotation

对内核旋转观测证据的两次搜索

• 批准号: 0125691
• 负责人: Paul Richards
• 金额: $ 12万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-01-01 至 2003-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0125691&HistoricalAwards=false
• 关键词: Two; Searches; Observational; Evidence; Inner

RichardsEAR-0125691This project will develop and apply two seismological methods for improving estimates of the inner core's rate of rotation with respect to the rest of the solid Earth. First, the investigators shall search for doublets in pertinent source regions, to enable very precise measurement of differential travel times that are indicative of inner core rotation. (A doublet, is a pair of earthquakes occurring at different times but in almost exactly the same location. A differential travel time is the time between two signals on the same seismogram.) Second, they shall search for indications of travel time change in seismic waves that have traveled almost vertically in the Earth, from a seismic source (an earthquake, or a nuclear explosion) to its antipode. By working with examples of seismic waves that have passed very deeply into the inner core, and are thus more sensitive to effects of anisotropy and inhomogeneity in the inner core, the investigators will be better able to understand the basic mechanism causing travel time changes.

该项目将开发和应用两种地震学方法，以改进对内核相对于固体地球其他部分的旋转速率的估计。 首先，研究人员应在相关的震源区寻找双峰，以便能够非常精确地测量指示内核旋转的差分旅行时间。（双重地震，是一对发生在不同时间但几乎完全相同位置的地震。 差走时是同一地震图上两个信号之间的时间。）第二，他们将寻找在地球上几乎垂直传播的地震波的传播时间变化的迹象，从震源（地震或核爆炸）到其对极。 通过研究已经非常深入地进入内核的地震波的例子，从而对内核中的各向异性和不均匀性的影响更加敏感，研究人员将能够更好地理解引起旅行时间变化的基本机制。