特提斯造山带地壳-上地幔顶部地震波Q值模型及其地球动力学意义

土耳其-伊朗-青藏高原地区是特提斯造山带的核心区域。陆陆碰撞的动力学过程产生大规模的造山构造运动，同时也伴随着强烈的热运动。这些过程改变壳幔岩石材料的本构关系，影响地质块体的流变学特性，进而支配着地壳和上地幔中不同的物质运移模式。深入研究特提斯造山带的构造演化不仅对揭示自然发展的奥秘具有重要的科学意义，而且对区域内的地缘政治、经济、国防等具有巨大的现实意义。上述过程也同时影响到区域内地震波传播特征的变化，其中特别以地震波衰减对构造活动和热运动最为敏感。据此，提出利用穿过特提斯构造带之下地壳和上地幔的区域地震资料联合反演多种震相在该区域的Q值，建立对于Lg、Pn和Sn波等多波、宽频带、高分辨率的统一衰减模型。进而利用地质统计方法和区域地震波数值模拟方法建立壳幔Q值与具有不同特征的地质单元的相关关系，以期利用所获得的地震波衰减信息并结合其它地球物理数据来研究特提斯构造演化的地球动力学过程。

The central part of the Tethys orogenic belt is composed of the Turkish, Iranian and Tibetan plateaus, where the continental-to-continental collisions dominated the large-scale orogenesis. At the same time, these processes were also accompanied by numerals geothermal activities in the crust and upper mantle. Jointly, they changed the constitutive equations of materials forming the lithosphere, and affected the rheological properties of different geological blocks. These further controlled the movement of materials in the crust and upper mantle. Investigating the evolution history of the Tethys orogenesis is not only scientifically significant, but also benefits the regional geopolitics, economics, and national defense in this area. The orogenesis can affect the seismic wave propagations through different aspects, among them, the seismic wave attenuation is the most sensitive to areas with strong heterogeneities and geothermal related processes. Therefore, studying the attenuation information carried by the regional phases Lg, Pn and Sn waves can provide us with important constrains to the orogenesis. Based on these, we propose using seismic attenuation of regional phases passing through the crust and upper mantle to investigate the Tethys orogenic belt. First, the broadband, high-definition, multi-phase and unified regional attenuation models for Lg, Pn and Sn waves will be created. The geostatistical methods will be used to search for the correlations between the seismic attenuation and geological units at different evolution stages in the Tethys orogenic belt. In this way, the seismic attenuation information, together with other seismology and geophysics information, can be used to investigate the geodynamics in the Tethys orogenic belt.