Investigators have mathematically projected these satellite measurements down to the top of the core using the assumption that the electric currents of the earth ' s mantle are negligible 假设地函的电流可以忽略，研究者可以利用卫星观测到的这些结果，以数学方法推算出磁场在地核顶部的分布。
According to most theories , the prevailing forces in the sicilian crust are similar to those in rift zones ? extensional stresses that cause thinning of the crust and upwelling of the underlying mantle 根据大多数的理论，西西里岛所在的地壳，主要遭受到的应力与张裂带类似：张力使地壳变薄、下方地函上涌。
Target drilling sites include areas where the mantle has been brought closest to the surface by tectonic action or where the crust is relatively thin , such as the nankai trough off japan ' s pacific coast 钻探的目标包括了某些因板块运动而使地函接近地表的区域，或是地壳相对较薄的地方，例如日本太平洋海岸外的南海海槽。
This critical layer surrounds a solid inner core of nearly pure iron that underlies 2 , 900 kilometers of solid rock that form the massive mantle and the ultrathin crust of continents and ocean floors 这关键性的外核包覆著几乎是由纯铁所组成的固态内核，深埋在厚重的地函与极薄的大陆、海洋地壳之下，距离地表的深度约2900公里。
Patches of intense magnetic flux , both normal and reversed , form on the core - mantle boundary when eddies and vortices interact with east - west - directed magnetic fields , described as toroidal , that are submerged within the core 具有强大磁通量的斑块，不论方向是正是反，都是涡旋与地核内部的东?西向环状磁场交互作用时，在地核?地函交界面上所形成。
On the other hand , if the new lava carries the fingerprint of fresh magma from the mantle and does not contain old zircons , then it very likely came from a large volume of new magma that has filled the chamber from below 不过，如果新熔岩显示的特徵，是来自地函的新鲜岩浆，而且不含古老的锆石，那麽它的来源很有可能是：从岩浆库下方填充上来的大量新岩浆。
Hakodate , which has the port that arose as japan s first international one , with historical remains and aspects of overseas cultures , is the central city in southern hokkaido and provides many places of interest , including a famous night - view spot and a foreign cemetery 日本初国际贸易港?展、 ?史异国文化今残道南中心地函馆、夜景始外人墓地见所、宿泊地渔火望汤川温泉。
The core - mantle boundary is the closest researchers can get to the much more intense and complicated magnetic field that exists within the core , where magnetic fluctuations actually originate ; strong electric currents in the core prevent direct measurements of the magnetic field there 地核内具有更为剧烈、复杂的磁场，而且也是磁场变动的真正发源处，但是研究人员可推算的极限是在地核?地函交界处；因为地核内的电流极强，因此无法直接测量内部的磁场。
