Holocene East Asian Summer Monsoon Variation Recorded by Sensitive Grain Size Component from the Pearl River-Derived Mud in the Northern South China Sea
Holocene East Asian Summer Monsoon Variation Recorded by Sensitive Grain Size Component from the Pearl River-Derived Mud in the Northern South China Sea
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DOI：
10.2113/2022/6064591
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发表时间：
2022-08
期刊：
影响因子：
2.4
通讯作者：
Jin Xu;Chao Huang;Xin Huang
中科院分区：
文献类型：
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作者：
Jin Xu;Chao Huang;Xin Huang
为了更好地了解南海陆架沉积物粒度的环境意义，我们对来自南海北部泥沉积的YJ岩心沉积物进行了详细的粒度研究。基于粒径标准偏差法，确定了两个敏感粒径分量，分别为组分1 （8.2 ~ 9.3 μm）和组分2 （106.8 ~ 120.7 μm）。结果表明，敏感成分1可能来源于珠江的细粒物质。在东亚夏季风（EASM）的主导下，这些细颗粒物质可以在雨季被西南海岸流输送。因此，敏感分量1对气候变化较为敏感，具有很大的重建EASM变化细节的潜力。在7500 ~ 6800 cal yr BP期间，敏感分量1可能受海平面变化和EASM强度的双重控制。此外，YJ核敏感分量1曲线在6800 ~ 3500calyr BP区间表现为强的东亚季风，而在3500 ~ 2000calyr BP区间表现为弱的东亚季风，与华南地区其他古气候记录同步。在过去的2000年中，敏感分量1可能反映了人类活动的增加。在泥区开展更多、更高分辨率的研究，阐明整个全新世EASM强度的详细历史演变是必要的。
To better understand the environmental significance of sediment grain size in continental shelf of the South China Sea (SCS), we carried out a detailed grain size study of sediments from the YJ Core, derived from the mud deposits of the northern SCS. Based on the grain size-standard deviation method, two sensitive grain size components were identified, namely, component 1 (8.2 ~ 9.3 μm) and component 2 (106.8 ~ 120.7 μm), respectively. The results indicate that the sensitive component 1 is likely to derive from fine-grained materials of the Pearl River. These fine-grained materials could be transported by the southwestward coastal current during the wet season, with the domination of the East Asian summer monsoon (EASM). Accordingly, the sensitive component 1 could be sensitive to climate change and has a great potential to reconstruct details of EASM variations. During the period of 7500-6800 cal yr BP, the sensitive component 1 may be controlled by both sea level change and EASM intensity. Besides, the curve of the sensitive component 1 in the YJ Core presents a strong EASM during the interval 6800-3500 cal yr BP and a weak EASM during the period of 3500-2000 cal yr BP, which is synchronous with other paleoclimate records in southern China. In the past 2000 years, the sensitive component 1 may reflect the increasing of human activities. It is essential to carry out more studies with higher resolution in mud areas to clarify a detailed historical evolution of EASM intensity over the whole Holocene.