【摘要】 与地震初动震相相比,后续震相包含有更为丰富的地球内部信息,因此逐渐地在地震层析成像研究中得到重视。文中以赵大鹏等最近的层析成像研究为例,介绍了通过增加后续震相到时信息得到的新的层析成像研究成果,包括通过使用反射波,仅用两个地震台站就可以进行地壳成像研究;深度震相到时的增加,拓宽了区域成像范围,成功实现了台网外部层析成像;随着国际地震中心(ISC)提供的更丰富的各种后续震相到时,对后续震相的认识和使用促进了全球体波走时成像的发展和对地球深部结构及动力学过程的认识。另一方面,地震学相关领域的进步,使得更多的后续震相能够被拾取并被应用到成像研究中,这将大大提高对地震波形信息的挖掘,提高对研究地区下三维结构的认识,极大地促进地震层析成像学的发展。更多还原

【Abstract】 Seismic later-phase(reflected and converted wave)data contain abundant information of the Earth’s interior structure,hence recent seismic tomographic studies have started to use the later-phase data and have achieved unexpected new advances.In this work,we introduce and discuss these recent advances in seismic tomography,including(1)crustal tomography using only two seismic stations with multiple reflected waves in the crust,(2)tomographic imaging outside a seismic network through locating off-network earthquakes with sP depth-phase data,and(3)global tomography using various mantle and core phases leading to the imaging of mantle plumes and deep subducting slabs.The later phases are usually difficult to be detected in high-frequency waveforms from local and regional earthquakes,but such a problem can be solved by using the recent advances in waveform modeling.With increasing later-phase data becoming available,seismic tomography will make greater advances and will be able to reveal more details of the Earth’s interior structure.This will greatly improve our understanding of the seismic and volcanic activity and geodynamic processes of our planet.更多还原