{"id":2470,"date":"2016-06-22T19:59:44","date_gmt":"2016-06-22T19:59:44","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/geologyxwaymakerxmaster\/?post_type=chapter&p=2470"},"modified":"2025-10-13T16:51:29","modified_gmt":"2025-10-13T16:51:29","slug":"reading-characteristics-of-the-inner-and-outer-core","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/geo\/chapter\/reading-characteristics-of-the-inner-and-outer-core\/","title":{"raw":"Reading: Characteristics of the Inner and Outer Core","rendered":"Reading: Characteristics of the Inner and Outer Core"},"content":{"raw":"
\r\n\r\nDo you want to take a journey to the center of the earth?<\/strong>\r\n\r\n\"Molten\r\n\r\nJules Verne's imagined core was fiery. But we know that the outer core is molten metal, as seen above. As hot as a journey to Verne's center of the earth might have been, a visit to the real location would be worse.\r\n\r\n<\/div>\r\n\r\n[caption id=\"attachment_2505\" align=\"alignright\" width=\"350\"]\"iron Figure 1. An iron meteorite is the closest thing to the Earth\u2019s core that we can hold in our hands.[\/caption]\r\n\r\nAt the planet\u2019s center lies a dense metallic core. Scientists know that the core is metal because:\r\n
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  1. The density of Earth's surface layers is much less than the overall density of the planet, as calculated from the planet\u2019s rotation. If the surface layers are less dense than average, then the interior must be denser than average. Calculations indicate that the core is about 85% iron metal with nickel metal making up much of the remaining 15%.<\/li>\r\n \t
  2. Metallic meteorites are thought to be representative of the core. The 85% iron\/15% nickel calculation above is also seen in metallic meteorites (Figure 1).<\/li>\r\n<\/ol>\r\nIf Earth's core were not metal, the planet would not have a magnetic field. Metals such as iron are magnetic, but rock, which makes up the mantle and crust, is not.\r\n\r\nScientists know that the outer core is liquid and the inner core is solid because:\r\n
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    1. S-waves do not go through the outer core.<\/li>\r\n \t
    2. The strong magnetic field is caused by convection in the liquid outer core. Convection currents in the outer core are due to heat from the even hotter inner core.<\/li>\r\n<\/ol>\r\nThe heat that keeps the outer core from solidifying is produced by the breakdown of radioactive elements in the inner core.\r\n

      Explore More<\/h2>\r\n

      Use this resource to answer the questions that follow.<\/p>\r\n\r\n