The ‘Little Ice Age’ recorded by sediment chemistry in Lake Erhai, southwest China
The ‘Little Ice Age’ recorded by sediment chemistry in Lake Erhai, southwest China
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DOI：
10.1191/0959683605hl863rr
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发表时间：
2005-09
期刊：
影响因子：
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通讯作者：
Jing-an Chen;G. Wan;D. Zhang;Zhenlou Chen;Jingyi Xu;T. Xiao;Ronggui Huang
中科院分区：
文献类型：
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作者：
Jing-an Chen;G. Wan;D. Zhang;Zhenlou Chen;Jingyi Xu;T. Xiao;Ronggui Huang
根据洱海深水沉积物中21种主次元素的测定结果，主成分分析揭示了控制湖泊沉积物无机化学组成的三个主要因素。它们是流域的物理侵蚀(成分1)、湖水中的原生方解石沉淀(成分2)和沉积物中的早期成岩作用(成分3)。分量I和分量3因子得分的变化可能分别反映了湖区降水和温度的波动。在AD1340-1550和AD1890-1950之间，组分3的高因子得分与组分1的低因子得分相关，指示了两个暖干事件。成分3的低因子得分与成分1的高因子得分相关，表明欧洲处于冷湿气候，相当于小冰期。我们的研究为重建古气候提供了一种新的方法，并增加了越来越多的证据，证明小冰期期间存在广泛的降温。西南季风带和东南季风带气候类型为暖湿凉干气候，暖干和冷湿交替可能意味着西南季风区和东南季风区气候变化特征不同。
On the basis of concentrations of 21 major and minor elements in a well-dated sediment core from the deepwater part of Lake Erhai, principal component analysis (PCA) reveals three main factors controlling the inorganic chemical composition of lake sediments. These are physical erosion in the watershed (Component 1), autochthonous calcite precipitation in lake water (Component 2) and early diagenesis in sediments (Component 3). Variations of factor scores of Component I and Component 3 may reflect fluctuations in rainfall and temperature, respectively in the lake region. High factor scores of Component 3 correlate with low factor scores of Component 1 in sediments within the intervals AD 1340-1550 and AD 1890-1950, indicating two warm-dry episodes. Low factor scores of Component 3 correlate with high factor scores of Component 1 from AD 1550-1890, indicating a cold-wet climate corresponding to the ‘Little Ice Age’ in Europe. Our study provides a new approach to reconstructing palaeoclimate, and adds to a growing body of evidence for a widespread cooling during the ‘Little Ice Age’. The alternation between warm-dry and cool-humid conditions possibly implies different climate change characteristics between the southwest monsoon zone and the southeast monsoon zone where the climate pattern is warm-humid and cool-dry.