华南师范大学学报(自然科学版)
華南師範大學學報(自然科學版)
화남사범대학학보(자연과학판)
JOURNAL OF SOUTH CHINA NORMAL UNIVERSITY (NATURAL SCIENCE EDITION)
2014年
2期
1-9
,共9页
轨道参数变化发现%深海氧同位素记录%冰期理论修正
軌道參數變化髮現%深海氧同位素記錄%冰期理論脩正
궤도삼수변화발현%심해양동위소기록%빙기이론수정
discovery of orbital variations%benthic δ18 O records%evolution of Astronomical theory of ice ages
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,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得迅速,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.
冰期天文理論是運用地毬軌道偏心率、地軸傾角和地轉軸進動的3種參數的變化幅度與週期來解釋上新世-第四紀期間冰期-間冰期交替變化的一種理論.該理論1842年由Adhemar提齣,經過Croll髮展到Milankovitch最終完成,經歷瞭整100年的時間.上世紀60年代開始,深海、黃土、冰芯等大量的地質記錄都揭示齣3種週期變化,證實冰期天文理論的正確性,同時也對冰期天文理論帶來瞭一些概唸上的脩正.但是, Berger 計算的天文麯線至少從6 Ma以來展示同一規律的變化,然而地質記錄卻顯示清晰的分段響應模式:41 kyr的地軸傾角週期在5.3~1.4 Ma期間一直是記錄麯線的主要特徵;北半毬冰川作用隻是在2.7 Ma BP纔開始大規模齣現;0.8 Ma開始100 ka週期轉變為主要週期,稱之為中更新世轉型( MPT).還有:11階段和全新世是2箇偏心率很低的時期,但記錄中卻是冰期-間冰期振幅最大的時期,即大的間冰期為何齣現于低偏心時期;由間冰期進入冰期比由冰期進入間冰期時來得迅速,意味大冰蓋建造需要很長的時間,而消融則比較迅速.這些都是冰期天文理論本身不能解釋的問題,正在由地毬響應繫統的研究來探索答案.
빙기천문이론시운용지구궤도편심솔、지축경각화지전축진동적3충삼수적변화폭도여주기래해석상신세-제사기기간빙기-간빙기교체변화적일충이론.해이론1842년유Adhemar제출,경과Croll발전도Milankovitch최종완성,경력료정100년적시간.상세기60년대개시,심해、황토、빙심등대량적지질기록도게시출3충주기변화,증실빙기천문이론적정학성,동시야대빙기천문이론대래료일사개념상적수정.단시, Berger 계산적천문곡선지소종6 Ma이래전시동일규률적변화,연이지질기록각현시청석적분단향응모식:41 kyr적지축경각주기재5.3~1.4 Ma기간일직시기록곡선적주요특정;북반구빙천작용지시재2.7 Ma BP재개시대규모출현;0.8 Ma개시100 ka주기전변위주요주기,칭지위중경신세전형( MPT).환유:11계단화전신세시2개편심솔흔저적시기,단기록중각시빙기-간빙기진폭최대적시기,즉대적간빙기위하출현우저편심시기;유간빙기진입빙기비유빙기진입간빙기시래득신속,의미대빙개건조수요흔장적시간,이소융칙비교신속.저사도시빙기천문이론본신불능해석적문제,정재유지구향응계통적연구래탐색답안.
The astronomical theory of ice age provides 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 revisions to the theory .However , there are still a lot of brainteasers 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 6 Ma, but the curves of geological records present piecewise response .For example , obliquity of 41 kyr cycle was dominant between 5.3~1.4 Ma;Onset of the major northern hemispheric glaciation started up at approximately 2.7 Ma;100 kyr periodicity of eccentricity substituted 41kyr periodicity of obliquity around 0.8 Ma, which is called the Event of Middle Pleisto-cene Transition.In addition, why the most prominent glacial-interglacial transition occurred at time of minimal ec-centricity of Stage-11 and Holocene;How to explain the slow transitions from interglacial to glacial and the quick transition from glacial to interglacial in 100 kyr 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 .