章节大纲

  • 常规

    全部折叠 展开全部

  • 地球的内层

    Earth's inner layers: inner core, outer core, mantle, and crust.
     

    What's below our feet? What's way below?
    ::我们脚下是什么?

    If we could cut Earth open, we'd see the following layers from inside to outside: inner  core , outer core, mantle, and  crust . Alternatively, you can think of the brittle  lithosphere  riding on the plastic  asthenosphere . Whew!
    ::如果我们能将地球开阔开阔, 我们就能从内到外看到以下层: 内核、外核、地壳和地壳。 或者, 你可以想到塑料的极地圈在塑料的地表上。 Whew!

    Layers by Composition
    ::按组成排列的图层

    The layers scientists recognize are pictured below ( Figure  ).
    ::科学家们所认识的层层图示如下(图)。

    Cross-section of Earth showing crust, mantle, outer core, and inner core with labels.
     
    A cross-section of Earth showing the crust, mantle, outer core, and inner core. The lithosphere includes the crust and uppermost mantle, and the asthenosphere sits just below the lithosphere.

    Core, mantle, and crust are divisions based on composition:
    ::核心、地壳和地壳是根据组成划分的:

    1. The  crust  is less than 1% of Earth by mass. The two types are  oceanic crust  and  continental crust .
      ::地壳质量不到地球的1%,这两类是海洋地壳和大陆地壳。
    1. The  mantle  is hot, dense, dark (ultramafic)  . It represents about 68% of Earth's mass.
      ::地壳是热、稠密、黑暗的(幅画),约占地球质量的68%。
    1. The  core  is mostly iron metal. The core makes up about 31% of the Earth. Earth's metallic core has two layers: a solid inner layer and a liquid outer layer.
      ::核心大部分是铁金属,核心约占地球的31%。地球的金属核心有两层:坚固的内层和液态外层。

    The terms core, mantle, and crust will be described in more detail in the next three concepts.
    ::今后三个概念将更详细地说明核心、地壳和地壳等术语。

    Layers by Mechanical Properties
    ::机械属性图层

     are divisions based on mechanical properties:
    ::系基于机械特性的分区:

    1. The  lithosphere  is composed of both the crust and the uppermost mantle. The lithosphere is a brittle, rigid solid. It is easily cracked or broken.
      ::岩层由地壳和最上层的地壳组成。岩层是坚固的,坚固的,很容易碎裂或碎裂。
    1. The  asthenosphere  is below the lithosphere. The asthenosphere is also in the upper mantle. This layer is solid, but it can flow and bend. A solid that can flow is like silly putty.
      ::等离子层在平流层下。 等离子层也在上层层层。 这个层是固体的, 但是它可以流动和弯曲。 一个能流动的固体就像愚蠢的泥土。

    Summary
    ::摘要

    • By composition, Earth is divided into core, mantle, and crust.
      ::根据构成,地球分为核心、地壳和地壳。
    • By mechanical properties, the crust and upper mantle are divided into lithosphere and asthenosphere.
      ::根据机械特性,地壳和上层地壳分为地圈和地圈。
    • The core-mantle-crust divisions are based on composition.
      ::信条核心分界线以组成为基础。
    • The lithosphere-asthenosphere divisions are based on mechanical properties.
      ::地圈-测代层的分界线以机械特性为基础。

    Review
    ::回顾

    1. What are the the layers of Earth, based on composition? Where are they located?
      ::根据组成情况,地球的层次是什么?它们在哪里?
    1. What is the composition of the different layers?
      ::不同层次的组成是什么?
    1. How do the lithosphere and asthenosphere differ from each other?
      ::地圈和地圈之间有何不同?

    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 is the core?
      ::核心是什么?
    1. Explain the core's structure.
      ::解释一下核心的结构
    1. What is the mantle?
      ::地壳是什么?
    1. What is the crust?
      ::地壳是什么?
    1. Why does the Earth have layers?
      ::为什么地球有层?