Very Deep Electrical Soundings Beneath Oceans and Cratons

9706681 Care由于其商业运营商最近拒绝了模拟海底电话电缆，因此出现了在全球范围内在无动力电缆上进行全球范围的地电场测量的机会。目前，美国和日本的调查人员正在两条大西洋和九条太平洋电缆上收集此类数据；记录长度目前为两到七年。拟议的工作是利用这些数据，加上标准观测站和专用磁力计的地磁变化测量，以与地震正常模式相当的分辨率研究大西洋和太平洋海底地幔深部(100-600公里)电性结构的垂直和横向变化。海洋结构将与加拿大中部太古代克拉通下的结构进行比较，并将设计出对差异的岩石物理解释。***

9706681 Chave Due to the recent turndown of analog submarine telephone cables by their commercial operators, an opportunity has arisen to make planetary scale measurements of the geoelectric field on unpowered cables around the globe. At present, such data are being collected on two Atlantic and nine Pacific cables by US and Japanese investigators; the record length is currently two to seven years. The proposed work is to use these data, together with geomagnetic variations measurements from standard observatories and dedicated magnetometers, to study the vertical and lateral variability of the deep (100-600 km) electrical structure of the sub-oceanic mantle beneath the Atlantic and Pacific with a resolution comparable to that from seismic normal modes. The oceanic structure will be compared to that beneath an Archaean craton in central Canada, and a petrophysical interpretation for the differences will be devised. ***