Crustal Structure in Alaska From Receiver Function Analysis
Crustal Structure in Alaska From Receiver Function Analysis
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DOI：
10.1029/2018gl081011
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发表时间：
2019-02
影响因子：
5.2
通讯作者：
Ying Zhang;Aibing Li;Hao Hu
中科院分区：
文献类型：
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作者：
Ying Zhang;Aibing Li;Hao Hu
新地图的地壳厚度和Vp/Vs在阿拉斯加和加拿大西部获得了使用P接收器功能记录在198个站从USAray便携式阵列和阿拉斯加区域网络。我们的研究结果表明，地形和莫霍面深度相关的地壳厚度变化从28到43公里，整个阿拉斯加。阿拉斯加南部和北部的山脉下有较厚的地壳，中部的地壳相对较薄。根据艾里等容线，布鲁克斯山脉下最深的地壳根可能已经失去了浮力。此外，阿拉斯加中东部的高地形需要有浮力的上地幔来支撑。阿拉斯加大部分地区的Vp/Vs在1.7到1.8之间，除了中南部地区的平均值为1.9。我们把这种高Vp/Vs归因于雅库特和太平洋洋壳的底侵作用。
New maps of crustal thickness and Vp/Vs in Alaska and western Canada were obtained using P receiver functions recorded at 198 stations from the USArray Transportable Array and the Alaska Regional Network. Our results indicate that topography and Moho depth are correlated as crustal thickness varies from 28 to 43 km across Alaska. A thick crust occurs under the mountains in the south and north with relatively thin crust in central Alaska. The deepest crustal root beneath the Brooks Range may have lost its buoyancy based on Airy isostasy. In addition, a buoyant upper mantle is required to support the high topography in east central Alaska. Vp/Vs is determined between 1.7 and 1.8 beneath most of Alaska except a high average of 1.9 in the south central region. We attribute this high Vp/Vs to the underplating of Yakutat and Pacific oceanic crust.