Finite‐frequency Rayleigh wave tomography of the western Mediterranean: Mapping its lithospheric structure
Finite‐frequency Rayleigh wave tomography of the western Mediterranean: Mapping its lithospheric structure
复制标题
地中海西部的有限频率瑞利波层析成像：绘制其岩石圈结构
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
M. Harnafi
中科院分区：
文献类型：
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作者：
I. Palomeras;S. Thurner;A. Levander;Kaijian Liu;A. Villaseñor;R. Carbonell;M. Harnafi
利用瑞利波层析成像技术建立了地中海西部地壳和上地幔的三维剪切波速模型。我们分析了一批临时和永久性地震台阵记录的地震在20-167MHZ S周期段(6.0MHZ-50.MHZ)的基模。利用双平面波法，我们得到了一个各向同性的VS模型的相速度频散曲线，该模型从伊比利亚地块南部延伸到直布罗陀弧形山脉和阿特拉斯山脉，一直延伸到撒哈拉克拉通。我们研究的地中海西部地区自渐新世以来一直是非洲-欧洲汇聚过程中复杂的俯冲、板块回滚和同时挤压和伸展的地点。剪切速度模型显示，在65公里深度的RIF之下和从70公里深度的格拉纳达盆地之下，延伸到阿尔博兰域下方超过250公里处的高速速度，我们将其解释为悬挂在阿尔博兰海西部之下的一个近垂直的板块。该板块似乎附着在RIF之下的地壳上，也可能在格拉纳达盆地和内华达山脉之下，那里的低剪切速度(3.8公里/S)被映射到>；55公里深。附着的板块正在拉低直布罗陀弧形地壳，使其增厚，并在伊比利亚和摩洛哥下方的大陆边缘岩石圈地幔下降到更深的地幔时将其移开。阿尔博兰海下方、悬垂板块上方和东部以及新生代火山岩下方的上地幔速度非常低，表明岩石圈很薄。
We present a 3‐D shear wave velocity model for the crust and upper mantle of the western Mediterranean from Rayleigh wave tomography. We analyzed the fundamental mode in the 20–167 s period band (6.0–50.0 mHz) from earthquakes recorded by a number of temporary and permanent seismograph arrays. Using the two‐plane wave method, we obtained phase velocity dispersion curves that were inverted for an isotropic Vs model that extends from the southern Iberian Massif, across the Gibraltar Arc and the Atlas mountains to the Saharan Craton. The area of the western Mediterranean that we have studied has been the site of complex subduction, slab rollback, and simultaneous compression and extension during African‐European convergence since the Oligocene. The shear velocity model shows high velocities beneath the Rif from 65 km depth and beneath the Granada Basin from ∼70 km depth that extend beneath the Alboran Domain to more than 250 km depth, which we interpret as a near‐vertical slab dangling from beneath the western Alboran Sea. The slab appears to be attached to the crust beneath the Rif and possibly beneath the Granada Basin and Sierra Nevada where low shear velocities (3.8 km/s) are mapped to >55 km depth. The attached slab is pulling down the Gibraltar Arc crust, thickening it, and removing the continental margin lithospheric mantle beneath both Iberia and Morocco as it descends into the deeper mantle. Thin lithosphere is indicated by very low upper mantle velocities beneath the Alboran Sea, above and east of the dangling slab and beneath the Cenozoic volcanics.
影响因子：
2.8
作者：
C. Legendre;T. Meier;S. Lebedev;W. Friederich;L. Viereck-Götte
通讯作者：
C. Legendre;T. Meier;S. Lebedev;W. Friederich;L. Viereck-Götte