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基于湖北神农架青天洞1支长179mm石笋的8个~(230)Th年龄、890条纹层和445个氧同位素数据,建立了早全新世8.8~7.9kaB.P.时段平均分辨率为2a的亚洲季风气候记录。结果显示,8.34~8.10kaB.P.期间石笋δ~(18)O明显正偏,指示了一次持续约240a的弱夏季风事件。该弱夏季风事件与同期格陵兰冰芯记录的中心事件(在8.21kaB.P.,持续70a)及淡水注入模拟结果基本一致,表明“8.2ka”事件与淡水注入导致的大西洋经向翻转流减弱或关闭有关。然而,“8.2ka”事件发生前约120a,亚洲季风已开始逐渐减弱,与太阳活动明显减弱时间相对应,据此推测太阳活动可能对“8.2ka”事件具有一定的触发作用。
Based on 8 ~ (230) Th ages, 890 striped layers and 445 oxygen isotope data of 179 mm stalagmite of Qingtian Cave in Shennongjia, Hubei Province, Asia with an average resolution of 2a in 8.8 ~ 7.9kaB.P. Monsoon climate record. The results show that δ 18 O from the stalagmite is obviously positive during 8.34 ~ 8.10kaB.P., indicating a weak summer monsoon event lasting about 240 years. The weak summer monsoon event coincides with the central event recorded in the same period of Greenland ice core (at 8.21kaB.P., lasting for 70 years) and the simulation results of freshwater injection, indicating that the events of “8.2ka” and the transversal of Atlantic ocean caused by freshwater injection Flow weakened or shut down. However, about 120 years before the occurrence of the “8.2 ka” event, the Asian monsoon started to gradually decrease, corresponding to the time when the solar activity obviously decreased. Therefore, it is speculated that the solar activity may have a certain trigger on the “8.2 ka” event.