Institute of Geophysics, ETH Zürich, Sonneggstrasse 5, Zürich, Switzerland.
Department of Geological Sciences/Cooperative Institute for Research In Environmental Sciences (CIRES), University of Colorado, Boulder, CO 80305-3337, USA.
Sci Adv. 2016 Sep 30;2(9):e1600798. doi: 10.1126/sciadv.1600798. eCollection 2016 Sep.
The tidal flow of electrically conductive oceans through the geomagnetic field results in the generation of secondary magnetic signals, which provide information on the subsurface structure. Data from the new generation of satellites were shown to contain magnetic signals due to tidal flow; however, there are no reports that these signals have been used to infer subsurface structure. We use satellite-detected tidal magnetic fields to image the global electrical structure of the oceanic lithosphere and upper mantle down to a depth of about 250 km. The model derived from more than 12 years of satellite data reveals a ≈72-km-thick upper resistive layer followed by a sharp increase in electrical conductivity likely associated with the lithosphere-asthenosphere boundary, which separates colder rigid oceanic plates from the ductile and hotter asthenosphere.
导电海洋的潮汐流动穿过地磁场会产生次生磁场信号，这些信号提供了有关地下结构的信息。新一代卫星的数据显示存在因潮汐流动而产生的磁场信号，但目前尚无报告表明这些信号已被用于推断地下结构。我们利用卫星探测到的潮汐磁场来绘制海洋岩石圈和上地幔的全球电结构图像，深度可达约 250 公里。该模型源自 12 年以上的卫星数据，揭示了一个约 72 公里厚的上阻性层，其后导电性急剧增加，可能与分隔较冷刚性海洋板块与较软和较热地幔的岩石圈-软流圈边界有关。
