科學家認識地球內部的方法

Mostly by any seismic activities such as earthquakes and atomic bomb blasts. Any of these events will generate a lot of mechanical waves. By detecting how these waves travel, scientists can tell what state the materials are inside the earth (solid or fluid). In conjunction with magnetic activities and detection, scientists can guess what materials form the inner core of the earth.

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2009-03-09 08:07:36 補充：
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2009-03-09 08:07:53 補充：
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