Seismic anisotropy indicates organized melt beneath the Mid-Atlantic Ridge aids seafloor spreading
Seismic anisotropy indicates organized melt beneath the Mid-Atlantic Ridge aids seafloor spreading
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DOI：
10.1130/g51550.1
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发表时间：
2023-08-04
期刊：
影响因子：
5.8
通讯作者：
Tharimena, S.
中科院分区：
文献类型：
--
作者：
Kendall, J. M.;Schlaphorst, D.;Tharimena, S.
岩石圈板块在洋中脊处分裂，软流圈地幔物质随之上升。上升的材料减压，这可能导致部分熔化，潜在地影响系统的驱动力。然而，熔体向脊轴迁移时的几何形状和空间分布仍有争议。有组织的熔体结构可以引起强烈的地震各向异性，这可以诊断熔体，尽管这通常在脊上没有发现。本文研究了2016年3月至2017年3月在赤道大西洋中脊（MAR）附近0-80 Ma岩石圈部署的39台海底地震仪阵列的各向异性约束。局部和SKS测量显示远离脊轴的各向异性快速方向，这与短延迟时间的板块运动引起的应变和相关结构一致，& delta；t (
Lithospheric plates diverge at mid-ocean ridges and asthenospheric mantle material rises in response. The rising material decompresses, which can result in partial melting, potentially impacting the driving forces of the system. Yet the geometry and spatial distribution of the melt as it migrates to the ridge axis are debated. Organized melt fabrics can cause strong seismic anisotropy, which can be diagnostic of melt, although this is typically not found at ridges. We present anisotropic constraints from an array of 39 ocean-bottom seismometers deployed on 0-80 Ma lithosphere from March 2016 to March 2017 near the equatorial Mid-Atlantic Ridge (MAR). Local and SKS measurements show anisotropic fast directions away from the ridge axis, which are consistent with strain and associated fabric caused by plate motions with short delay times, & delta;t (