欧洲南部410km间断面的波速结构
|
摘要
地球内部结构的研究显示,上地幔中400km深度附近存在一个波速和密度的间断面,通常称为410km间断面.普遍认为,橄榄岩α态与β态之间的转换导致了这个间断面的形成,而且在PREM等被广泛采用的地球模型中,这一间断面通常被处理为一个尖锐的跳变.然而,近年来的一些研究提出该间断面在某些地区存在着更复杂的结构.利用欧洲台网所观测到的宽频带数据,对发生在意大利中部的1998-05-18地震事件进行了分析研究,在PREM模型的基础上,通过对不同的410km间断面结构模型的波形模拟,得到了更适用于这一区域的半跳变半渐变模型.
引文
1Benz H M,Vidale J E.The sharpness of upper mantle discontinuities determined from high-frequency P'P'precursors.Nature,1993,365:147—150
2Ni S D,Ding X,Helmberger D V.Constructing synthetics from deep earth tomographic models.Geophys J Int,2000,140:71—82
3Dziewnski A M,Anderson D L.Preliminary reference earth model.Phys Earth Planet Int,1981,25:297—356
4Helffrich G,Wood B.410km discontinuity sharpness and the form of the olivine alpha beta phase diagram-resolution of the apparent seismic contradictions.Geophys J Int,1996,126:F7—F12
5Gaherty J B,Wang Y B,Jordan T H,et al.Testing plausible upper-mantle compositions using fine-scale models of the410-km dis-continuity.Geophys Res Lett,1999,26(11):1641—1644
6Melbourne T,Helmberger D.Fine Structure of the410-km discontinuity.J Geophys Res,1998,103(B5):10091—10102
7Nakanishi I.Reflections of P′P′from upper mantle discontinuities beneath the mid-Atlantic ridge.Geophys J Int,1998,93:335—346
8Zhu L,Rivera L A.A note on the dynamic and static displacements from a point source in multilayered media.Geophys J Int,2002,148:619—627
9Spakman W,Van der Lee S,Van der Hilst R D.Travel-time tomography of the European-Mediterranean mantle down to1400km.Phys Earth Planet Int,1993,79:73—74
10Chambers K.Topography of the410-km discontinuity from PP and SS precursors.Earth Planet Sci Lett,2005,235:610—622
11Grunewald S.The upper mantle under Central Europe:indications for the Eifel plume.Geophys J Int,2001,147:590—601
2Ni S D,Ding X,Helmberger D V.Constructing synthetics from deep earth tomographic models.Geophys J Int,2000,140:71—82
3Dziewnski A M,Anderson D L.Preliminary reference earth model.Phys Earth Planet Int,1981,25:297—356
4Helffrich G,Wood B.410km discontinuity sharpness and the form of the olivine alpha beta phase diagram-resolution of the apparent seismic contradictions.Geophys J Int,1996,126:F7—F12
5Gaherty J B,Wang Y B,Jordan T H,et al.Testing plausible upper-mantle compositions using fine-scale models of the410-km dis-continuity.Geophys Res Lett,1999,26(11):1641—1644
6Melbourne T,Helmberger D.Fine Structure of the410-km discontinuity.J Geophys Res,1998,103(B5):10091—10102
7Nakanishi I.Reflections of P′P′from upper mantle discontinuities beneath the mid-Atlantic ridge.Geophys J Int,1998,93:335—346
8Zhu L,Rivera L A.A note on the dynamic and static displacements from a point source in multilayered media.Geophys J Int,2002,148:619—627
9Spakman W,Van der Lee S,Van der Hilst R D.Travel-time tomography of the European-Mediterranean mantle down to1400km.Phys Earth Planet Int,1993,79:73—74
10Chambers K.Topography of the410-km discontinuity from PP and SS precursors.Earth Planet Sci Lett,2005,235:610—622
11Grunewald S.The upper mantle under Central Europe:indications for the Eifel plume.Geophys J Int,2001,147:590—601
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心