3.17地核
Section outline
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Is this what the core looks like?
::核心是这个样子的吗?Yes! The outer core , anyway. The outer core is liquid metal, like in this photo. Of course, the metal is under an incredible amount of pressure.
::外核,外核是液态金属,像这张照片一样, 当然,金属承受着巨大的压力。Core
::核心核心核心核心核心The dense, iron core forms the center of the Earth. Scientists know that the core is metal. The inner core is solid, and the outer core is molten. Here are some of the reasons they know this:
::密密铁核心构成地球的中心。 科学家知道核心是金属。 内核是固态的, 外核是熔化的。 以下是他们知道的一些原因:- Metallic meteorites are thought to be from the same type of material that is found at the core ( Figure ).
::据认为,金属陨石来自核心发现的同类材料(图)。
An iron meteorite is the closest thing to the Earth’s core that we can hold in our hands.
::铁陨石是最接近地球核心的东西,我们可以握在手中。- Scientists calculate Earth's density from the planet's rotation . To match the total density, the inner layers must be denser than the outer layers. They must be as dense as metal.
::科学家根据地球的旋转量计算地球的密度。 为了与总密度相匹配, 内层必须比外层密度高。 它们必须像金属一样密度 。
- show that the outer core is liquid. The inner core is solid.
::显示外核为液体。内核为固体。
- For there to be a magnetic field , there must be liquid metal. The metal must be convecting. If the core did not have convecting metal, there would be no magnetic field.
::要有一个磁场,必须有液态金属。 金属必须是凝固的。 如果核心没有凝固的金属, 就不会有磁场 。
Summary
::摘要- Density calculations show that Earth's core is metal.
::密度计算表明 地球的核心是金属
- Seismic waves show that the inner core is solid and the outer core is liquid.
::地震波显示内核是固体的 外核是液态的
- Metallic meteorites and the magnetic field are also clues about the makeup of the core.
::金属陨石和磁场也是核心构成的线索。
Review
::回顾- What evidence is there that Earth's core is metal?
::有什么证据表明地球的核心是金属?
- What evidence is there that the outer core is molten?
::有什么证据表明外核熔化了?
- Why does Earth have a magnetic field?
::为什么地球有磁场?
Explore More
::探索更多Use this resource to answer the questions that follow.
::使用此资源回答下面的问题 。- What layers does the core have within it according to the study described in this video?
::根据影片描述的研究,核心内有多少层?
- How deep is the core? What is its temperature?
::核心有多深?
- What clues to researchers use to “see” what is in Earth’s interior?
::研究者用什么线索来“观察”地球内部是什么?
- What was the inner core thought to be previously?
::内核以前是怎么想的?
- What do scientists now think is inside the core? How big is it?
::科学家们现在认为核心里有什么?
- What is the interior made of? How do scientists know this is different from the material outside of it?
::内脏是由什么构成的?科学家怎么知道这与外壳不同?
- How are crystals aligned in the inner inner and outer inner cores?
::晶体如何在内心和外心核心中相互结合?
- Why is this information important?
::为什么这一信息很重要?
- Metallic meteorites are thought to be from the same type of material that is found at the core ( Figure ).
