Upper Mantle Electrical Conductivity Variations Beneath North America and Adjacent Oceans

9714882 Mackie这是一项继续开展研究的建议，该研究是在一个为期一年的试点项目下开始的，该项目旨在利用甚长周期大地电磁数据调查北美大陆和周围海洋的上地幔电导率结构。对主要在海洋附近和岛屿上收集的现有长期数据集进行重新分析，将辅之以在大陆地区获取新的大地电磁测深数据集，目前大陆地区缺乏这方面的数据。PIS建议使用电话线连接到地磁观测站附近的埋地电极来记录电场数据，这些数据将与来自观测站的地磁数据相结合，以计算MT响应函数。在试点项目下，他们已经成功地为俄克拉荷马州塔尔萨的磁性天文台提供了仪器，并计划在1997年初为科罗拉多州的博尔德天文台提供仪器。这笔续期赠款将为另外两个观测站提供仪器，并在三年内继续记录，以获得长期大地电磁响应功能的稳定估计。***

9714882 Mackie This is a proposal to continue research begun under a one-year pilot project for investigating upper mantle electrical conductivity structure under the North American continent and urrounding oceans using very long period magnetotelluric (MT) data. A reanalysis of existing long period data sets collected primarily near oceans and on islands will be complemented with the acquisition of new MT data sets in continental areas, for which there is currently a paucity of data. The PIs propose to use telephone lines connected to buried electrodes near magnetic observatories for recording the electric field data, which will be combined with the magnetic data from the observatory to compute MT response functions. Under the pilot project, they have successfully instrumented the Tulsa, Oklahoma magnetic observatory, and they plan to instrument the Boulder, Colorado observatory in early 1997. This continuation grant will provide funding to instrument two additional observatories, and to continue the recording over a period of three years in order to obtain stable estimates of the long period MT response functions. ***