Sensitivity of seismic velocity towards tidal induced stress changes

地震速度对潮汐引起的应力变化的敏感性

• 批准号: 451271527
• 负责人: Dr. Tom Eulenfeld
• 金额: --
• 依托单位: Institut für Geowissenschaften
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/451271527?language=en
• 关键词: Sensitivity; seismic; velocity; towards; tidal

Rocks are not linear-elastic materials, because the seismic velocity also depends on the applied stress. By measuring the changes in the seismic velocity, it is therefore possible to draw conclusions about the applied stress, which is of fundamental importance for the understanding of earthquakes.Observing tidal-induced stresses and velocity changes is a good way to calibrate these measurements.The velocity changes are determined by measuring small changes in the phase of regularly calculated cross- and autocorrelation functions of the seismic ambient noise. The project aims at investigating the change of seismic velocity with Earth tides. Previous infrequent observations are to be complemented with more data points of the stress sensitivity of seismic velocity.Additionally, in the first part of the project, the expected depth dependence of the sensitivity due to the loading of overlying rocks will be investigated with the help of seismic arrays. In the second part of the project, it will be investigated whether the measured sensitivities allow to detect static stress changes caused by earthquakes by means of observations of the change of the seismic velocity.One possible future application that could contribute to the general understanding of earthquakes is the monitoring of the stress state of the Earth's crust.

岩石不是线弹性材料，因为地震速度也取决于施加的应力。因此，通过测量地震速度的变化，可以得出关于外加应力的结论，这对于理解地震是至关重要的。观测潮汐引起的应力和速度变化是校准这些测量的好方法。速度变化是通过测量地震环境噪声的定期计算的互相关函数和自相关函数的相位的微小变化来确定的。该项目旨在研究地震速度随固体潮的变化。此外，在项目的第一部分，将借助地震台阵研究由于上覆岩石加载而引起的敏感性的预期深度依赖关系。在该项目的第二部分，将调查测量的灵敏度是否允许通过观察地震速度的变化来检测地震引起的静态应力变化。未来可能有助于对地震的总体理解的一个应用是监测地壳的应力状态。