Crustal Structure of the Greenland‐Iceland Ridge from Joint Refraction and Reflection Seismic Tomography
Crustal Structure of the Greenland‐Iceland Ridge from Joint Refraction and Reflection Seismic Tomography
复制标题
联合折射和反射地震层析成像显示格陵兰-冰岛海岭的地壳结构
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
Peter B. Kelemen
中科院分区：
文献类型：
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作者：
Xiaoyu Yuan;J. Korenaga;W. Steven Holbrook;Peter B. Kelemen
我们报告了对1996年格陵兰边缘地震调查（SIGMA）实验期间沿沿着格陵兰-冰岛海脊收集的活动源广角地震数据的再分析。解释火山裂陷边缘的地壳结构具有非唯一性，因为大陆-海洋过渡区的厚地壳可能不完全是火成岩成因的。在这方面，格陵兰-冰岛海脊提供了一个独特的机会，因为它与法罗-冰岛海脊一起，通常被认为构成了冰岛热点轨道，因此，其地壳的大部分可能被认为是火成的。从沿着290 km长的折射断面部署的15个海底仪器中，我们收集了5，383 Pg和1，118 PmP旅行时间，我们使用联合折射和反射地震层析成像与自适应重要性采样来反演它们，以构建格陵兰岛-冰岛海岭的二维压缩波速（Vp）模型。基于地壳厚度和Vp的协变，样带的西部可能几乎完全是大陆。即使是东部也可能包括相当大一部分先前存在的大陆地壳。当考虑到冰岛地壳的地震结构和地球化学特征，我们的研究结果表明，推定的冰岛地幔柱可能比通常假设的要弱得多。
We report a reanalysis of active‐source wide‐angle seismic data collected along the Greenland‐Iceland Ridge during the 1996 Seismic Investigation of the Greenland Margin (SIGMA) experiment. Interpreting the crustal structure of volcanic rifted margins has suffered from nonuniqueness because thick crust at the continent‐ocean transition may not be totally of igneous origin. In this regard, the Greenland‐Iceland Ridge presents a unique opportunity because, together with the Faroe‐Iceland Ridge, it is generally considered to constitute the Iceland hotspot track, and as such, the bulk of its crust may be considered to be of igneous origin. From 15 ocean‐bottom instruments deployed along a 290‐km‐long refraction transect, we collect 5,383 Pg and 1,118 PmP travel times, and we use joint refraction and reflection seismic tomography with adaptive importance sampling to invert them to construct a two‐dimensional compressional wave speed (Vp) model across the Greenland‐Iceland Ridge. Based on the covariation of crustal thickness and Vp, the western part of the transect may be almost entirely continental. Even the eastern part could include a significant fraction of preexisting continental crust. When considered together with the seismic structure of the Icelandic crust and its geochemical characteristics, our results suggest that the putative Iceland mantle plume could be considerably weaker than commonly assumed.
影响因子：
3.7
作者：
M. Richards;E. Contreras‐Reyes;C. Lithgow‐Bertelloni;M. Ghiorso;L. Stixrude
通讯作者：
M. Richards;E. Contreras‐Reyes;C. Lithgow‐Bertelloni;M. Ghiorso;L. Stixrude
影响因子：
3.5
作者：
Straume, E. O.;Gaina, C.;Hopper, J. R.
通讯作者：
Hopper, J. R.
影响因子：
2.9
作者：
Mihalffy, Peter;Steinberger, Bemhard;Schmeling, Harro
通讯作者：
Schmeling, Harro