Shear-wave velocity structure beneath Alaska from a Bayesian joint inversion of Sp receiver functions and Rayleigh wave phase velocities
Shear-wave velocity structure beneath Alaska from a Bayesian joint inversion of Sp receiver functions and Rayleigh wave phase velocities
复制标题
来自 Sp 接收函数和瑞利波相速度的贝叶斯联合反演的阿拉斯加下方的剪切波速度结构
DOI：
10.1016/j.epsl.2021.116785
复制
发表时间：
2021
影响因子：
5.3
通讯作者：
Flesch, Lucy M.
中科院分区：
文献类型：
--
作者：
Gama, Isabella;Fischer, Karen M.;Eilon, Zachary;Krueger, Hannah E.;Dalton, Colleen A.;Flesch, Lucy M.
阿拉斯加现今的岩石圈结构是一个独特的构造历史的结果，俯冲和挤压增生，控制上板块的厚度和流变。为了提供新的约束阿拉斯加的地壳和上地幔的结构，我们联合反演Sp接收器功能和瑞利波相速度计算剪切波速度剖面。使用宽范围的频率（2-100秒），时域反卷积和K-均值聚类分析获得了强大的Sp接收器功能。贝叶斯联合反演与合成数据的测试表明，Sp接收函数提高了莫霍面和岩石圈-软流圈边界的速度梯度的分辨率，而瑞利面波提供有关绝对速度的信息。我们的结果表明，在阿拉斯加中部，在浅板之上，大陆岩石圈是最薄的（约60公里），软流圈有其最低的速度。该区域与德纳里火山口重合。大陆岩石圈在布鲁克斯山脉和北方北极阿拉斯加山脉之下向北增厚，达到110至130 km的值，岩石圈速度与太古代岩石圈相当。这种模式是一致的向北减少上板修改来自板的熔体和挥发分，除了固有的地幔速度和粘度之间的差异继承岩石圈地幔。岩石圈和软流圈的速度没有显着不同的内部和外部的德纳里火山间隙，但在该地区的边界岩石圈厚度迅速增加的北部和南部逐渐。在南部，俯冲的雅库特板块比俯冲的太平洋板块厚（100-120公里），可能是因为它的地壳更厚。
The present-day lithospheric structure of Alaska is the result of a unique tectonic history of subduction and terrane accretion that controls upper plate thickness and rheology. To provide new constraints on the structure of the crust and upper mantle beneath Alaska, we jointly inverted Sp receiver functions and Rayleigh wave phase velocities to calculate shear-wave velocity profiles. Robust Sp receiver functions were obtained using a broad range of frequencies (2–100 s), time-domain deconvolution, and K-means cluster analysis. Tests of the Bayesian joint inversion with synthetic data illustrate that Sp receiver functions enhance the resolution of the velocity gradients at the Moho and the lithosphere-asthenosphere boundary, while Rayleigh surface waves provide information about absolute velocities. Our results show that in central Alaska, above the shallow slab, the continental lithosphere is thinnest (∼60 km) and the asthenosphere has its lowest velocities. This zone coincides with the Denali Volcanic Gap. The continental lithosphere thickens to the north beneath the Brooks Range and the northern Arctic Alaska terrane, reaching values of 110 to 130 km, with high lithospheric velocities that are comparable to Archean cratons. This pattern is consistent with a northward decrease in upper plate modification by melt and volatiles derived from the slab, in addition to intrinsic mantle velocity and viscosity differences between inherited lithospheric terranes. Lithospheric and asthenospheric velocities are not significantly different inside and outside of the Denali Volcanic Gap, but at the boundaries of this region lithospheric thickness increases rapidly to the north and gradually to the south. In the south, the subducting Yakutat plate is thicker (∼100–120 km) than the subducting Pacific plate (∼80–90 km), likely due to its thicker crust.
登录
查看更多内容
阿拉斯加南部雅库塔特地体下方的莫霍面界面
DOI：
--
发表时间：
2013
期刊：
影响因子：
--
作者：
G. Christeson;H. Avendonk;S. Gulick;R. Reece;G. Pavlis;T. Pavlis
通讯作者：
T. Pavlis
影响因子：
5.2
作者：
Ying Zhang;Aibing Li;Hao Hu
通讯作者：
Ying Zhang;Aibing Li;Hao Hu
DOI：
10.1029/2018jb015967
发表时间：
2018-10
期刊：
Journal of Geophysical Research: Solid Earth
影响因子：
--
作者：
K. Ward;F. Lin
通讯作者：
K. Ward;F. Lin
影响因子：
5.3
作者：
Hasterok, D.
通讯作者：
Hasterok, D.
阿拉斯加下方的剪切波分裂和地幔流
DOI：
10.1029/2019jb018329
发表时间：
2020
期刊：
Journal of Geophysical Research: Solid Earth
影响因子：
--
作者：
McPherson, A. M.;Christensen, D. H.;Abers, G. A.;Tape, C.
通讯作者：
Tape, C.