地震波三重震相在地幔转换区结构研究中的应用  

Application of seismic triplications to image the structures of the mantle transition zone

作　　者：崔冉 周元泽 CUI Ran;ZHOU Yuanze(College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;Key Laboratory of Computational Geodynamics,Chinese Academy of Sciences,Beijing 100049,China;China Earthquake Networks Center,Beijing 100045,China)

机构地区：[1]中国科学院大学地球与行星科学学院,北京100049 [2]中国科学院计算地球动力学重点实验室,北京100049 [3]中国地震台网中心,北京100045

出　　处：《地震地磁观测与研究》2024年第5期11-19,共9页Seismological and Geomagnetic Observation and Research

摘　　要：地幔转换区位于上、下地幔之间,作为地球内部物质循环的关键场所而被地学界长期关注。410 km和660 km间断面是地幔转换区的上下边界,对这2个间断面附近的速度结构及间断面起伏形态进行成像,有助于了解地球内部物质和能量循环。地震波三重震相对速度缓变的结构较为敏感,因而可用于直接约束间断面附近的速度结构及间断面起伏形态。本文概要介绍三重震相对地幔转换区结构的响应特征,并对三重震相波形拟合方法获得的全球多个地幔转换区的速度结构及间断面起伏特征等方面的成果进行综合分析,并据此探讨地幔转换区间断面起伏形态和俯冲滞留物质等对地幔物质组分、温度变化、地幔矿物含水量、地幔动力学过程和地球内部物质循环过程的约束能力。The mantle transition zone is between the upper and lower mantle.As a key region for the material cycling in Earth,the mantle transition zone has long been a concern of the geoscience community.The 410 and 660 discontinuities are the upper and lower boundaries of the mantle transition zone.Imaging the velocity structure near the 410 and 660 discontinuities and the undulation pattern of the discontinuities can help to understand the cycling of materials and energy between the upper and lower mantle.Seismic triplications are sensitive to the velocity structure with slow changes.So,it can be used to directly constrain the velocity structure near the discontinuity and the undulation pattern of the discontinuity.In this paper,we briefly introduce the response characteristics of the triplications to the structure of the mantle transition zone and the research results of several mantle transition zones around the world using the triplications waveform fitting method.We discuss the ability of the mantle transition section undulations and subduction-retained materials to constrain the mantle material composition,temperature changes,mantle mineral water content,mantle dynamic processes,and the earth's internal material circulation process.

关 键 词：地震波 三重震相 地幔转换区 速度结构 

分 类 号：P315.31[天文地球—地震学]