报告地点：教学行政楼 5101 教室
报告时间：2024-11-26 从 16:00 到 18:00
报告人：Jean-Paul Montagner（Université Paris Cité- IPG Paris, Institut Universitaire de France）
报告题目：1.Anisotropic Seismology - Applications to Geology and Geodynamics 2.Monitoring of seismogenic and volcanic zones from ambient noise anisotropy
报告人简介（续）：
and the Beno Gutenberg Medal (EGU. 2010). He has served as an invited professor at institutions such as MIT, Caltech and the University of Tokyo, contributing to seismic tomography, anisotropy, and planetary missions.
报告简介：
Seismic Anisotropy is present from microscopic scale up to macroscopic scale. lt is the rule not the exception. The goal of this talk is to introduce for students and advanced scientists the scientific potential of seismic anisotropy at different scales, for understanding all present and past processes from the microscopic scale (10-10m) up to the Earth scale (>1,000km). The investigation of seismic anisotropy was always considered as a difficult topic. The main goal of this talk is to make accessible the universe of anisotropy to a large community of geoscientists, and to convince the audience that the account of seismic anisotropy is absolutely inescapable for interpreting all seismic, geophysical, petrological and geological data.
When Earth minerals and rocks are deformed over geological timescales, mineral grains and aggregates tend to align by crystal preferred orientation (C.P.O.) which can lead to bulk anisotropy. Additional anisotropy can also come up when crack distribution (in the crust) or fluid inclusions (asthenosphere, inner core) are present within the material (shape preferred orientation, S.P.O.). Water and partial melt content may also play a key role in alignment mechanisms. In the upper mantle, the different minerals present are strongly anisotropic. lt is a bit more complicated in the lower mantle.
I will present some geological and geodynamical applications of seismic anisotropy. Whereas isotropic heterogeneities enable to map hot and cold regions within the Earth, seismic anisotropy gives access to the convective flow at the global scale and to deformation processes at smaller scales. l will focus on recent results, in order to show that seismic anisotropy provide new visions of the lithosphere-asthenosphere boundary, on the structure of continents, and the structure below Central Asia.