Clearly, geophysicists who seek to explain and forecast changes in the field must understand what happens in the outer core.
显然，试图解释和预测磁场变化的地球物理学家必须了解外核发生了什么。
2
The Earth's magnetic field is generated as the molten iron of the Earth's outer core revolves around its solid inner core; when surges in the molten iron occur, magnetic tempests are created.
地球磁场是由地球外核的熔铁围绕固体内核旋转而产生的；当铁水激增，就会发生磁暴。
3
This metallic core gives Earth its characteristic magnetic field, which has played an extremely important role in the history of our planet.