Regional conductivity structure of Cascadia: Preliminary results from 3D inversion of USArray transportable array magnetotelluric data
Regional conductivity structure of Cascadia: Preliminary results from 3D inversion of USArray transportable array magnetotelluric data
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DOI：
10.1029/2008gl035326
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发表时间：
2008-10
影响因子：
5.2
通讯作者：
P. Patro;G. Egbert
中科院分区：
文献类型：
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作者：
P. Patro;G. Egbert
与EarthScope的USAray组件一起，在美国大陆的一系列阵列中获得了长周期大地电磁（MT）数据。2006年和2007年的初始部署在覆盖美国太平洋西北部的110个站点采集了数据（10- 10，000 s），这些站点以与USAray地震移动式阵列相同的标称间距（1075 km）分布。该数据集的初始三维反演揭示的最显著和最强大的特征是俄勒冈州东南部和喀斯喀特山脉下方下地壳中广泛的高电导率区域，与Siletzia和哥伦比亚湾的高电阻地壳形成对比。上地幔电导率的显着变化也揭示了反演，与华盛顿弧后的最导电的地幔，和最电阻对应的俯冲洋地幔。
In conjunction with the USArray component of EarthScope, long period magnetotelluric (MT) data are being acquired in a series of arrays across the continental US. Initial deployments in 2006 and 2007 acquired data (10–10,000 s) at 110 sites covering the US Pacific Northwest, distributed with the same nominal spacing as the USArray seismic transportable array (∼75 km). The most striking and robust features revealed by initial three‐dimensional inversion of this dataset are extensive areas of high conductivity in the lower crust beneath all of southeastern Oregon, and beneath the Cascade Mountains, contrasting with very resistive crust in Siletzia and the Columbia Embayment. Significant variations in upper mantle conductivity are also revealed by the inversions, with the most conductive mantle beneath the Washington backarc, and the most resistive corresponding to subducting oceanic mantle.