The Journal of the Petrological Society of Korea (암석학회지)

The Petrological Society of Korea (한국암석학회)
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On an Apparatus of Visualization for Magnetic Reversal and Magnetic Stripes

자기역전 시각화 장치와 지자기띠에 대하여

  • Ryoo, Chung-Ryul (Mineral Resources Research Division, Korea Institute of Geoscience and Mineral Resources)
  • 류충렬 (한국지질자원연구원 광물자원연구본부)
  • Received : 2016.03.10
  • Accepted : 2016.03.23
  • Published : 2016.03.31
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Abstract

The new rocks of the oceanic crust, like basalt, are created in the mid-oceanic ridge, and the magnetic polarities of the rocks are supposed to be oriented as following the Earth's magnetic field. An extensive magnetic survey of total field at sea level reveals mainly unusual north-south magnetic stripes parallel to the axis of the mid-oceanic ridge, especially in the Atlantic Ocean. From this stripes the Earth's magnetic field is considered as repeatedly 'flipped'(the N pole becoming the S pole, and vice versa) and many times over geological time. The discovery of stripes of alternately normal and reversed-magnetized rocks forming the ocean floor has been a key evidence for the sea-floor spreading, continental drift, and plate tectonics. This study introduces a simple apparatus to explain a possible mechanism of the magnetic reversal in the new oceanic crust, which makes a magnetic stripe adjacent to the mid-oceanic ridge. The apparatus shows a bar magnet effect of adjoined stripes to have a special magnetic polarity on the rocks in the center of the mid-oceanic ridge. The new magnetic stripe seems to be generated not only by Earth's magnetic field, but also by neighbored stripes in the mid-oceanic ridge, acting as a bar magnet.

중앙해령에서는 해양지각으로 현무암과 같은 암석이 새로이 생겨나며, 암석에는 자기방향이 당시의 지구자기장에 따라 배열된다. 해수면상에서의 광범위한 자력탐사에 의해 대부분의 중앙해령-특히 대서양 중앙해령-의 중심축과 평행한 남-북 방향의 자기띠(또는 자기 줄무늬)가 알려져 있다. 이러한 지자기띠에 기초하여, 지구의 자기장은 지질시대 동안 여러 번에 걸쳐 반복하여 역전된 것으로 고려되어 왔다. 해양지각에서의 지자기 역전의 발견은 해양저확장과 대륙이동설 그리고 판구조론을 설명하는 중요한 증거가 되었다. 이 논문에서는 중앙해령 근처에서 지자기띠를 이루며 새로이 생겨나는 해양지각 자기역전의 가능한 메커니즘을 설명하는 간단한 장치를 소개하고자 한다. 이 장치는 중앙해령의 중심에서 암석이 가지는 특정한 자기극성을 가지도록 근처에 인접하는 자기띠가 막대자석의 역할을 함을 보인다. 따라서 새로이 생겨나는 지자기띠는 일반적인 지구자기장 뿐 만 아니라 국지적으로 마치 막대자석처럼 작용하는 중앙해령 근처에 이웃하는 기존의 지자기띠에 의해 영향을 받았을 가능성이 있는 것으로 사료된다.

Keywords

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