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  • General

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  • 板块运动

    A conveyor belt system in an industrial setting, illustrating plate movement in tectonics.
     

    What is tectonics?
    ::什么是构造?

    Dividing the  lithosphere  into  plates  is one thing. Having the plates move around on the  planet  is another! A conveyor belt is a good analogy for how a plate moves. How the plates move and where they move is the "tectonics" part of  plate tectonics .
    ::将平地圈分解为板块是一回事。 让板块在行星上移动是另一回事。 传送带是板块移动的一个很好的比喻。 板块移动的方式和移动地点是板块构造的“ 构造” 部分 。

    Plate Motions
    ::计票动议

    Scientists have determined the direction that each plate is moving ( Figure  ). Plates move around the Earth’s surface at a rate of a few centimeters a  year . This is about the same rate that fingernails grow.
    ::科学家已经决定了每个板块移动的方向(图 ) 。 板块以每年几厘米的速度环绕地球表面移动。 这与指甲生长的速度差不多。

    Color-coded map showing Earth's tectonic plates and their movement directions with arrows.
     
    Earth's plates are shown in different colors. Arrows show the direction the plate is moving.

    How Plates Move
    ::如何移动平台

    Convection  within the Earth’s mantle causes the plates to move. Mantle material is heated above the  core . The hot mantle rises up toward the surface ( Figure  ). As the mantle rises, it cools. At the surface, the material moves horizontally away from a  mid-ocean ridge   crest . The material continues to cool. It sinks back down into the mantle at a deep sea  trench . The material sinks back down to the core. It moves horizontally again, completing a  convection cell .
    ::地壳内的对流使板块移动。 金属材料在核心上方加热。 热材料向地表上升( 图 ) 。 随着地壳的上升, 它会冷却 。 在表面, 材料水平从中海脊顶部移动。 材料继续冷却, 它会回落到深海海沟的地壳中。 材料会回落到核心上方。 它会再次水平移动, 完成对流细胞 。

    Convection cells in Earth’s mantle and tectonic plate movements.
     
    Plates move for two reasons. Upwelling mantle at the mid-ocean ridge pushes plates outward. Cold lithosphere sinking into the mantle at a subduction zone pulls the rest of the plate down with it.

    Seafloor spreading  takes place as plates move apart from each other at a mid-ocean ridge. Mantle convection drives seafloor spreading.
    ::海底扩张随着板块在洋中脊相互移动而发生,Mantle对流驱动海底扩张。

    Summary
    ::摘要

    • Plates move by seafloor spreading
      ::通过海底扩散移动的平板板块
    • Seafloor spreading is driven by mantle convection.
      ::海底扩散是由地壳对流驱动的。
    • Plates move as if on a conveyor belt.
      ::平板像在传送带上一样移动。

    Review
    ::回顾

    1. Describe how convection takes place in the mantle.
      ::描述对流在地皮中是如何发生的。
    1. How does mantle convection cause seafloor spreading?
      ::地壳对流如何导致海底扩散?
    1. How does seafloor spreading move plates?
      ::海底扩张板的移动方式如何?

    Explore More
    ::探索更多

    Use the resource below to answer the questions that follow.
    ::利用以下资源回答以下问题。

    1. What would the Earth look like without the biosphere and atmosphere?
      ::没有生物圈和大气层,地球会是什么样子?
    1. What are plates?
      ::什么是车牌?
    1. How fast are the plates moving?
      ::车牌移动多快?
    1. What happens at the ridges?
      ::山脊那边发生了什么?
    1. What are subduction zones?
      ::什么是潜入区?
    1. What heats Earth's interior?
      ::地球内部什么热度?