周尚哲. 冰期天文理论的演变[J]. 华南师范大学学报(自然科学版), 2014, 46(2).
引用本文: 周尚哲. 冰期天文理论的演变[J]. 华南师范大学学报(自然科学版), 2014, 46(2).
The Evolution of Astronomical Theory of Ice Age[J]. Journal of South China Normal University (Natural Science Edition), 2014, 46(2).
Citation: The Evolution of Astronomical Theory of Ice Age[J]. Journal of South China Normal University (Natural Science Edition), 2014, 46(2).

冰期天文理论的演变

The Evolution of Astronomical Theory of Ice Age

  • 摘要: 冰期天文理论是运用地球轨道偏心率、地轴倾角和地转轴进动的3种参数的变化幅度与周期来解释上新世——第四纪期间冰期——间冰期交替变化的一种理论.该理论1842年由Adhemar提出, 经过Croll发展到Milankovitch最终完成,经历了整100年的时间。上世纪60年代开始,深海、黄土、冰芯等大量的地质记录都揭示出3种周期变化,从而证实冰期天文理论的正确性,同时也对冰期天文理论带来了一些概念上的修正.但是,Berger计算的天文曲线至少从6 Ma以来展示同一规律的变化,然而地质记录却显示清晰的分段响应模式:41 kyr的地轴倾角周期在5.3~1.4 Ma期间一直是记录曲线的主要特征;北半球冰川作用只是在2.7 Ma BP才开始大规模出现;0.8 Ma开始100 Ka周期转变为主要周期,称之为中更新世转型(MPT).还有:11阶段和全新世是2个偏心率很低的时期,但记录中却是冰期——间冰期振幅最大的时期,即大的间冰期为何出现于低偏心时期;由间冰期进入冰期比由冰期进入间冰期时来的快,意味大冰盖建造需要很长的时间,而消融则比较迅速.这些都是冰期天文理论本身不能解释的问题,正在由地球响应系统的研究来探索答案.

     

    Abstract: The astronomical theory of ice age provide an update solution to Quaternary glacial- interglacial cycles based on the long-term variations of three earth’s orbital parameters, eccentricity, obliquity and precession. This theory had been under modification over one hundred years since it was suggested by Adlhemar in 1842, developed by Croll and finished by Milankovitch in 1941. Since 1960s, numerous geological records from sea, loess and ice core have been exhibiting the three different cycles of 100kyr, 41kyr and 21kyr, demonstrating the validity of the theory, and meanwhile, brought some revision to the theory. However, there are still a lot of brainteaser between the geological records and the theory that needs to resolve. The calculation by A. Berger indicates that the curve of insolation controlled by the three orbital parameters exhibits similar changes for at least past 6Ma, but the curves of geological records present piecewise response. For example, obliquity of 41kyr cycle was dominant between 5.3~1.4Ma; Onset of the major northern hemispheric glaciation started up at approximately 2.7 Ma; 100kyr periodicity of eccentricity substituted 41kyr periodicity of obliquity around 0.8 Ma, which is called the Event of Middle Pleistocene Transition. In addition, why the most prominent glacial–interglacial transition occurred at time of minimal eccentricity of Stage-11 and Holocene; How to explain the slow transitions from interglacial to glacial and the quick transition from glacial to interglacial in 100kyr cycles, and so on. Those questions associated with the response mechanism of the complex earth system to the orbital forcing, and were warmly discussed in the past decade.

     

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