3D shear velocity structure beneath the Gulf of California from Rayleigh wave dispersion
3D shear velocity structure beneath the Gulf of California from Rayleigh wave dispersion
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来自瑞利波色散的加利福尼亚湾下方 3D 剪切速度结构
DOI：
10.1016/j.epsl.2009.01.003
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发表时间：
2009
影响因子：
5.3
通讯作者：
T. Meier
中科院分区：
文献类型：
--
作者：
X. Zhang;H. Paulssen;S. Lebedev;T. Meier
加州湾的主动伸展以大陆裂谷向海底扩张的转变为特征。沿着沿着墨西哥湾的长度，构造和岩浆活动的模式都有令人困惑的变化，很可能与地幔的不均匀性有关。然而，由于该地区缺乏宽带地震台站，区域尺度的地幔结构一直难以约束。在这项研究中，我们利用了新的数据从部署的NARS-Baja阵列和其他网络，并计算了三维剪切速度模型的上地幔下的区域。应用互相关分析和多模式波形反演相结合，我们测量了450对站在一个广泛的周期范围为9-250秒的站间瑞利波频散。我们计算了相速度图，然后反演了剪切速度结构的相速度数据。我们的研究结果表明，从海底扩张（南）到大陆裂谷（北）在加州湾的过渡位置，以及在整个下加利福尼亚和海湾的火山活动的差异，可以解释为上地幔的异质性，特别是由板状遗迹的存在下中南部的一部分，并没有这样的板状遗迹下的北方部分的海湾。
Active extension in the Gulf of California is characterized by the transition from continental rifting to seafloor spreading. Puzzling variations in the patterns of both tectonics and magmatism are observed along the length of the gulf and are likely to be related to mantle heterogeneity. Regional-scale mantle structure, however, has been difficult to constrain due to the lack of broadband seismic stations in the region. In this study we utilized new data from the deployment of the NARS-Baja array and other networks, and computed a three-dimensional shear-speed model of the upper mantle beneath the region. Applying a combination of cross-correlation analysis and multimode waveform inversion, we measured interstation Rayleigh wave dispersion for 450 pairs of stations in a broad period range of 9–250 s. We computed phase velocity maps and then inverted the phase-velocity data for shear-speed structure. Our results suggest that the location of the transition from seafloor spreading (South) to continental rifting (North) in the Gulf of California, as well as differences in volcanism across Baja California and the gulf, can be explained by heterogeneity in the upper mantle, in particular by the presence of a slab remnant beneath the south-central part and an absence of such a slab remnant beneath the northern part of the gulf.
影响因子：
2.8
作者：
C. Plattner;R. Malservisi;T. Dixon;P. LaFemina;G. Sella;J. Fletcher;F. Suárez‐Vidal
通讯作者：
C. Plattner;R. Malservisi;T. Dixon;P. LaFemina;G. Sella;J. Fletcher;F. Suárez‐Vidal