Heinrich 1事件(H1事件)是末次冰期一系列冰漂碎屑事件中最为突出的寒冷事件.本文基于闽西连城县仙云洞石笋(编号:XYⅣ-3)8个^(230)Th年龄和256个氧同位素结果,获得了16.8~15.2 ka BP期间平均分辨率达7 a的东亚夏季风演变序列.该石笋氧...Heinrich 1事件(H1事件)是末次冰期一系列冰漂碎屑事件中最为突出的寒冷事件.本文基于闽西连城县仙云洞石笋(编号:XYⅣ-3)8个^(230)Th年龄和256个氧同位素结果,获得了16.8~15.2 ka BP期间平均分辨率达7 a的东亚夏季风演变序列.该石笋氧同位素记录最为显著的特征是在16.3~16.1 ka BP时段出现两个阶段的偏正过程,振幅达1.8‰,指示了一次显著的弱季风事件突变过程,对应于北大西洋显著的H1事件.与具有年层时标的南京葫芦洞和神农架青天洞石笋记录对比发现,尽管在定年误差范围内3个洞穴的石笋记录都捕捉到了H1事件的这次突变过程,但我国东南仙云洞记录的H1突变过程的时间(~260 a)明显比长江中下游的青天洞(18 a)和葫芦洞(19 a)长得多,表现出显著的差异响应.分析表明,在北半球突变事件诱发后,热带西太平洋的海气过程有可能是造成这种差异响应的原因.展开更多
基于湖北省神农架龙腑宫洞一支石笋(LFG21)7个U/Th年龄和461组氧、碳同位素数据,建立了末次冰消期12.42~10.53 ka B.P.平均分辨率达3 a的亚洲夏季风强度演化序列.LFG21石笋δ^(18)O详细记录了新仙女木事件(YD)期间的季风突变细节,揭示...基于湖北省神农架龙腑宫洞一支石笋(LFG21)7个U/Th年龄和461组氧、碳同位素数据,建立了末次冰消期12.42~10.53 ka B.P.平均分辨率达3 a的亚洲夏季风强度演化序列.LFG21石笋δ^(18)O详细记录了新仙女木事件(YD)期间的季风突变细节,揭示了YD事件内部的不稳定性.在YD事件结构特征和转型模式上,石笋记录与格陵兰冰芯δ^(18)O记录具有良好的一致性,支持北高纬驱动机制以及高低纬之间的气候联系.其中,在~11.71 ka B.P.氧、碳同位素明显正偏,δ^(18)O从-8.6‰快速正偏至-7.9‰,δ^(13)C从-7.4‰快速正偏至-6.0‰,指示YD内部存在百年尺度的弱季风事件,持续时间为~200 a.这些特征与南京葫芦洞石笋δ^(18)O记录H1事件的内部结构和转型特征十分相似,暗示两者很可能受到同一驱动机制的影响.通过高、低纬地质资料的对比研究和波谱分析,本文认为YD内部百年尺度季风突变事件可能与热带大洋水汽输送变化导致的亚洲季风区水文循环异常以及太阳活动密切相关.展开更多
Based on TIMS U-series dating results and annual band counting method, an annual-resolution time scale from 17450 to 14420 aBP has been established for a stalagmite from the Hulu Cave at Tangshan, Nanjing. A high-reso...Based on TIMS U-series dating results and annual band counting method, an annual-resolution time scale from 17450 to 14420 aBP has been established for a stalagmite from the Hulu Cave at Tangshan, Nanjing. A high-resolution oxygen isotopic record reveals decadral-centural oscillations in air temperature in the East Asian monsoon climate area during the last glacial maximum. The most conspicuous feature in the oxygen isotopic record in the period is the particular cold event synchronized with the last Heinrich event (H1) in the northern Atlantic deep-sea records. This particular cold event, beginning at 16140 ± 100 aBP, shows a rapid cooling down with a magnitude of 7–8°C in air temperature within 36 years. Furthermore, δ18O record demonstrates that the event lasted 790 years with gradually warming tendency (10 cycles of air temperature oscillations) after the remarkable cooling down. We believed that this unique pattern of event recorded in the stalagmite δ8O might be controlled by various factors including changes of insolation at mid-latitude Northern Hemisphere, the southern extend of the last ice-rafted event in the North Atlantic and changes of the Equatorial Pacific sea surface temperature.展开更多
文摘Heinrich 1事件(H1事件)是末次冰期一系列冰漂碎屑事件中最为突出的寒冷事件.本文基于闽西连城县仙云洞石笋(编号:XYⅣ-3)8个^(230)Th年龄和256个氧同位素结果,获得了16.8~15.2 ka BP期间平均分辨率达7 a的东亚夏季风演变序列.该石笋氧同位素记录最为显著的特征是在16.3~16.1 ka BP时段出现两个阶段的偏正过程,振幅达1.8‰,指示了一次显著的弱季风事件突变过程,对应于北大西洋显著的H1事件.与具有年层时标的南京葫芦洞和神农架青天洞石笋记录对比发现,尽管在定年误差范围内3个洞穴的石笋记录都捕捉到了H1事件的这次突变过程,但我国东南仙云洞记录的H1突变过程的时间(~260 a)明显比长江中下游的青天洞(18 a)和葫芦洞(19 a)长得多,表现出显著的差异响应.分析表明,在北半球突变事件诱发后,热带西太平洋的海气过程有可能是造成这种差异响应的原因.
文摘基于湖北省神农架龙腑宫洞一支石笋(LFG21)7个U/Th年龄和461组氧、碳同位素数据,建立了末次冰消期12.42~10.53 ka B.P.平均分辨率达3 a的亚洲夏季风强度演化序列.LFG21石笋δ^(18)O详细记录了新仙女木事件(YD)期间的季风突变细节,揭示了YD事件内部的不稳定性.在YD事件结构特征和转型模式上,石笋记录与格陵兰冰芯δ^(18)O记录具有良好的一致性,支持北高纬驱动机制以及高低纬之间的气候联系.其中,在~11.71 ka B.P.氧、碳同位素明显正偏,δ^(18)O从-8.6‰快速正偏至-7.9‰,δ^(13)C从-7.4‰快速正偏至-6.0‰,指示YD内部存在百年尺度的弱季风事件,持续时间为~200 a.这些特征与南京葫芦洞石笋δ^(18)O记录H1事件的内部结构和转型特征十分相似,暗示两者很可能受到同一驱动机制的影响.通过高、低纬地质资料的对比研究和波谱分析,本文认为YD内部百年尺度季风突变事件可能与热带大洋水汽输送变化导致的亚洲季风区水文循环异常以及太阳活动密切相关.
基金This study was supported by the National Natural Science Foundation of China (Grant No. 49972055).
文摘Based on TIMS U-series dating results and annual band counting method, an annual-resolution time scale from 17450 to 14420 aBP has been established for a stalagmite from the Hulu Cave at Tangshan, Nanjing. A high-resolution oxygen isotopic record reveals decadral-centural oscillations in air temperature in the East Asian monsoon climate area during the last glacial maximum. The most conspicuous feature in the oxygen isotopic record in the period is the particular cold event synchronized with the last Heinrich event (H1) in the northern Atlantic deep-sea records. This particular cold event, beginning at 16140 ± 100 aBP, shows a rapid cooling down with a magnitude of 7–8°C in air temperature within 36 years. Furthermore, δ18O record demonstrates that the event lasted 790 years with gradually warming tendency (10 cycles of air temperature oscillations) after the remarkable cooling down. We believed that this unique pattern of event recorded in the stalagmite δ8O might be controlled by various factors including changes of insolation at mid-latitude Northern Hemisphere, the southern extend of the last ice-rafted event in the North Atlantic and changes of the Equatorial Pacific sea surface temperature.
