Effects of the Iceland plume on Greenland's lithosphere: New insights from ambient noise tomography
Effects of the Iceland plume on Greenland's lithosphere: New insights from ambient noise tomography
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DOI：
10.1016/j.polar.2018.06.004
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发表时间：
2018-09-01
期刊：
影响因子：
1.8
通讯作者：
Lees, Jonathan M.
中科院分区：
文献类型：
--
作者：
Antonijevic, Sanja Knezevic;Lees, Jonathan M.
环境噪声层析成像是用来成像格陵兰岛的岩石圈，通过冰岛羽之间类似于70和类似于40马。利用GLISN地震台网21个台站的互相关资料，反演了8 ~ 40 s共14个周期的二维瑞利波相速度图。我们发现，瑞利波相速度在格陵兰岛各地有很大的不同，与西北-东南走向冰岛羽轨迹相一致的速度慢。在格陵兰岛东部，在较长的时期（33- 40秒）检测到的速度降低反映了大量变薄的岩石圈，热烧蚀的羽。从东部来看，约化速度以较短的周期（12- 20秒）向西北方向移动，表明与地幔柱有关的缓慢异常变浅。在格陵兰岛中北部，降低的速度出现在羽流附近类似于60马，反映了岩石圈内仍然存在的余热的存在下，岩石圈弱化。我们的研究结果提供了重要的新的约束格陵兰岛的地壳和上地幔的地震速度结构的变化，揭示了长期的影响，地幔柱的跨越克拉通。
Ambient noise tomography is used to image Greenland's lithosphere, which passed over the Iceland plume between similar to 70 and similar to 40 Ma. Cross-correlations from 21 stations from GLISN seismic network were used to invert for 2-D Rayleigh wave phase velocity maps for 14 periods between 8 and 40 s. We find that Rayleigh wave phase velocities substantially vary across Greenland, with slow velocities coinciding with NW-SE trending Iceland plume track. In east Greenland the detected velocity reduction at longer periods (33-40s) reflects substantially thinned lithosphere, thermally ablated by the plume. From the east, the reduced velocities shift NW at shorter periods (12-20s), indicating shallowing of the plume-related slow anomaly. In north-central Greenland, the reduced velocities appear in the proximity of the plume similar to 60 Ma, reflecting lithospheric weakening in the presence of residual heat that still persists within the lithosphere. Our results provide important new constraints on variations in the seismic velocity structure of Greenland's crust and uppermost mantle, revealing prolonged effects of the mantle plume on the overpassing craton.