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  • 海洋中发散的板块边界

    Sign for Midlina Bridge near rocky landscape, showcasing connection between North American and Eurasian plates.

     

    Why a photo of a bridge with some bleak looking rock?
    ::为什么要拍一张桥上满是阴暗的石头的照片?

    In Iceland, the Mid-Atlantic Ridge is above  sea level . It's the only place we can see a  mid-ocean ridge  out of the  water . The Midlina Bridge connects two  plates . On the west side is the North American plate. On the east side is the Eurasian plate. A mid-ocean ridge is where new  crust  is created. Eventually this spot will be beneath the Atlantic Ocean.
    ::在冰岛,中大西洋海脊位于海平面之上。 这是我们唯一能看到海平面外洋中脊的地方。 米德利纳大桥连接了两个板块。 在西面是北美板块。 在东面是欧亚板块。 在东面是欧亚板块。 在洋中海脊是新地壳的形成地。 最终, 这个点将位于大西洋下方。

    Divergent Plate Boundaries
    ::差异表边框

    Plates move apart at a  divergent plate boundary . This happens in the oceans at mid-ocean ridges. It happens on land in  continental rift  zones.
    ::在大洋中脊的海洋中发生这种情况,在大陆裂缝带的陆地发生这种情况。

    Mid-ocean Ridges
    ::中洋海脊

    In the oceans, plates move apart at mid-ocean ridges.  Lava  rises upward, erupts, and cools. Later, more lava erupts and pushes the original   outward. This is  seafloor spreading . Seafloor spreading forms new  oceanic crust . The rising  magma  causes the ridge to be buoyant. This is why there is a  mountain  range running through the oceans. The plates pulling apart cause  .
    ::在海洋中,板块在洋中脊处分开。岩浆向上上升,喷发,冷却。后来,更多的熔岩喷发,将原始岩浆推向外部。这就是海底的扩张。海底扩张形成了新的海洋地壳。上升的岩浆使海脊浮起来。这就是为什么有山脉横穿海洋。板块裂开的原因。

    Most mid-ocean ridges are located deep below the sea. The island of Iceland sits right on the Mid-Atlantic ridge ( Figure   ).
    ::大多数洋中脊位于海底深处,冰岛岛位于大西洋中脊(图)。

    Rift valley in Iceland, part of the Mid-Atlantic Ridge, showing snow and rocky terrain.

     

    The rift valley in Iceland that is part of the Mid-Atlantic Ridge.
    ::冰岛的裂谷是中大西洋海脊的一部分。

    Continental Rifting
    ::大陆裂动

    A divergent plate boundary can also occur within a  continent . This is called  continental rifting . Magma rises beneath the continent. The crust thins, breaks, and then splits apart. This first produces a rift  valley . The East African Rift is a rift valley. Eastern Africa is splitting away from the African continent. Eventually, as the  continental crust  breaks apart, oceanic crust will form. This is how the Atlantic Ocean formed when Pangaea broke up.
    ::大陆内部也会出现不同的板块边界。 这被称为大陆裂痕。 玛格玛在大陆下出现。 地壳薄, 断裂, 然后分裂。 这首先产生了裂谷。 东非裂谷是一个裂谷。 东非裂谷正在脱离非洲大陆。 最终, 随着大陆地壳破裂, 海洋地壳将形成。 这就是潘加亚解体时大西洋是如何形成的。

    Summary
    ::摘要

    • Divergent plate boundaries in the ocean create mid-ocean ridges. This is where new seafloor is created by upwelling magma.
      ::海洋的板块边界差异很大,形成了洋中脊。这里就是由不断上升的岩浆创造出新海底的地方。
    • Divergent plate boundaries rift a continent apart. Eventually a new ocean will form between the two continents.
      ::不同的板块边界将一个大陆分裂。 最终,两个大陆之间将形成新的海洋。
    • Iceland is a location where we can see a mid-ocean ridge above sea level.
      ::冰岛是一个我们可以看到海平面上洋中脊的地方。

    Review
    ::回顾

    1. In what direction are the plates moving at a divergent plate boundary?
      ::车牌在不同的车牌边界上朝什么方向移动?
    1. How does a convection cell in the mantle lead to volcanism at the mid-ocean ridge?
      ::地壳的对流细胞如何导致洋中脊的火山活动?
    1. How does a continent break apart to form an ocean basin?
      ::一个大陆如何分崩离析形成一个海洋盆地?

    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 causes divergence?
      ::造成差异的原因是什么?
    1. How is new crust created?
      ::新的地壳是如何创造的?
    1. What erupts on the ocean floor?
      ::海底喷发什么?
    1. How fast does divergence occur?
      ::差异产生的速度有多快?
    1. What is formed at a divergent boundary?
      ::什么是在不同的边界上形成的?