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  • General

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  • 火山

    Olympus Mons, a massive shield volcano on Mars, showing its broad, gentle slopes.
     

    Is Earth the only planet to have volcanoes?
    ::地球是唯一有火山的星球吗?

    On Earth,  active volcanoes  are found on all continents except Australia. Volcanoes even erupt under the ice on Antarctica! Volcanoes are also common elsewhere in the  solar system . In  fact , the biggest volcano is on  . This image is of Olympus Mons, which is a  shield volcano . Olympus Mons is three times the height of Mt. Everest. But its slopes are very gentle.
    ::除了澳大利亚之外,所有大陆上都发现了活火山。火山甚至会在南极洲的冰下爆发。火山也是太阳系其他地方常见的。事实上,最大的火山在上。这个图像是奥林匹斯蒙斯(Olympus Mons),这是一个盾牌火山。奥林匹斯蒙斯是珠穆朗玛峰的三倍高。但是它的斜坡非常温和。

    Volcanoes
    ::火山体

    A volcano is a vent from which the material from a  magma chamber  escapes. This may include  lava ,   fragments, ash, and gases. Volcanic eruptions can come from many types of structures. Most people think of volcanoes as large, peaky cones. But volcanoes can be large and broad, or tiny little cones. Volcanic eruptions can come from fractured  domes , a vent in the ground, or from a giant hole in the ground.
    ::火山是一种火山喷口,岩浆室的物质从中逃出,其中可能包括熔岩、碎块、灰和气体。火山喷发可能来自多种结构。大多数人认为火山是巨大的、山峰锥。但火山可以是大而宽的,也可以是小锥。火山喷发可能来自断裂的穹顶、地面的喷口或地上的巨洞。

    Where They Are
    ::他们在哪里

    Volcanoes are a vibrant manifestation of  plate tectonics  processes. Volcanoes are common along convergent and divergent  plate boundaries . They are also found within lithospheric  plates  at  hotspots . Wherever mantle is able to melt, volcanoes are likely to be the result.
    ::火山是板块构造过程的生机勃勃的表现形式,火山在交汇和不同的板块边界上很常见,在热点的岩层板块中也发现了火山,在地壳能够熔化的地方,火山很可能是火山的结果。

    The Pacific  Ocean basin  is a good place to look for different  . The light blue wavy line that goes up the right-center of the diagram is the East Pacific Rise. The rise is made of volcanoes at a  divergent plate boundary .  Trenches  due to  subduction  are on the west and east sides of the  basin . Subduction creates island arcs that are seen in the Western Pacific. Subduction also creates continental arcs seen along Central and South America. Hawaii is the line of volcanoes trending southeast-northwest near the center-top of the image ( Figure   ). The Hawaiian volcanoes are due to a hotspot.
    ::太平洋海盆是寻找不同地点的好地方。图右中点上升的浅蓝色大浪线是东太平洋隆起。上升由不同板块边界的火山组成。由于潜入海盆的西面和东面,潜入海沟。潜入海盆会产生在西太平洋看到的岛弧。潜入海面还形成在中美洲和南美洲一带看到的大陆弧。夏威夷是靠近图像中端的东南-西北的火山线(菲古尔 ) 。夏威夷火山是由热点造成的。

    Map of the Pacific Ocean basin, highlighting volcanic activity along plate boundaries and hotspots.
     
    Volcanoes at divergent plate boundaries are in the East Pacific Rise. Convergent plate boundaries, where there are trenches, have volcanoes. Hotspot volcanoes are in chains in the middle of the ocean basin.

    Creating Magma
    ::正在创建 Magma

    Volcanoes erupt because mantle rock melts. This is the first stage in creating a volcano. How can rock melt? One way is if the   rises. Another way is if the pressure on the rock decreases; this will lower the rock's melting temperature. The melting temperature of a rock also goes down if  water  is added. Every time there is a volcanic  eruption , one or more of these things happens. For each type of volcano mentioned in these concepts, think about how and why melting occurs.
    ::火山之所以爆发,是因为地壳岩熔化。 这是创建火山的第一阶段。 岩浆如何熔化? 一种方法就是上升。 另一种方法是, 岩石的压力降低; 这将降低岩石的熔化温度。 如果增加水, 岩石的熔化温度也会下降。 每次火山爆发, 都会发生一种或多种此类事件。 对于这些概念中提到的每一种火山, 都要思考融化的方式和原因。

    Stages
    ::阶段

    Three volcanoes representing active, dormant, and extinct stages with varying visual features.
     
    Volcanoes can be active, dormant, or extinct.

    Of all the volcanoes in the world, very few are erupting at any given time. Scientists question whether a volcano that is not erupting will ever erupt again and then describe it as active,  dormant , or  extinct .
    ::在世界上所有火山中,很少有火山在任何特定时间喷发。 科学家们质疑没有喷发的火山是否会再次爆发,然后将它描述为活火山、休眠火山或灭绝火山。

    • Active : Currently erupting or showing signs of erupting soon.
      ::活性:目前爆发或出现爆发迹象。
    • Dormant : No current activity, but has erupted recently.
      ::Dormant:目前没有活动,但最近才爆发。
    • Extinct : No activity for some time; will probably not erupt again.
      ::灭绝:一段时间内没有活动;可能不会再爆发。

    Further Reading
    ::继续阅读

    Summary
    ::摘要

    • Volcanoes are located along convergent and divergent plate boundaries. They can be found in the middle of plates at hot spots.
      ::火山岩体位于交汇和不同的板块边界沿线,可在热点的板块中间找到。
    • Magma can be created when temperature rises, pressure lowers, or water is added.
      ::当温度上升、压力降低或水增加时,可以产生磁ma。
    • Volcanoes may be active, dormant, or extinct. This depends on whether there is the possibility of magma in their magma chambers.
      ::火山可能是活性、休眠或绝种的,这取决于岩浆室中是否存在岩浆的可能性。

     

    Review
    ::回顾

    1. Where do most volcanoes occur? Why?
      ::大多数火山在哪里发生?为什么?
    1. What is needed for magma to form?
      ::岩浆形成需要什么?
    1. If a volcano is dormant, can it become active? Can it become extinct?
      ::如果火山处于休眠状态,它会变得活跃吗?它会灭绝吗?