刘焱光, 邹建军, 李朝新, 张伟滨, 石学法, Suk Bong-Chool. 日本海的末次盛冰期[J]. 海洋地质与第四纪地质, 2009, 29(4): 53-63. DOI: 10.3724/SP.J.1140.2009.04053
引用本文: 刘焱光, 邹建军, 李朝新, 张伟滨, 石学法, Suk Bong-Chool. 日本海的末次盛冰期[J]. 海洋地质与第四纪地质, 2009, 29(4): 53-63. DOI: 10.3724/SP.J.1140.2009.04053
LIU Yanguang, ZOU Jianjun, LI Chaoxin, ZHANG Weibin, SHI Xuefa, Suk Bong-Chool. THE LAST GLACIATION MAXIMUM IN THE SEA OF JAPAN/EAST SEA[J]. Marine Geology & Quaternary Geology, 2009, 29(4): 53-63. DOI: 10.3724/SP.J.1140.2009.04053
Citation: LIU Yanguang, ZOU Jianjun, LI Chaoxin, ZHANG Weibin, SHI Xuefa, Suk Bong-Chool. THE LAST GLACIATION MAXIMUM IN THE SEA OF JAPAN/EAST SEA[J]. Marine Geology & Quaternary Geology, 2009, 29(4): 53-63. DOI: 10.3724/SP.J.1140.2009.04053

日本海的末次盛冰期

THE LAST GLACIATION MAXIMUM IN THE SEA OF JAPAN/EAST SEA

  • 摘要: 日本海末次盛冰期的沉积层几乎都是以交替出现的深色纹层、浅色纹层状和均质沉积物为特征。根据日本海中部和南部两个岩心记录的末次盛冰期的沉积特征和表层海水温度变化,讨论了低海平面时期东亚季风对日本海沉积环境的控制作用。24.2~17.8 cal.kaBP,日本海南部纹层沉积的分布均对应了夏季风的相对增强,表明季风降水输入是引起该时期日本海底层水含氧量变化的主要原因。在夏季风的控制下,低盐富营养的东海沿岸水的强弱变化使冲绳海槽北部表层海水温度也在24.2~17.8 cal.kaBP期间出现低值并剧烈变化。30~24.2和17.8~15 cal.kaBP,受增强的冬季风(夏季风减弱)影响,日本海水体的流通性较强,底层水溶解氧含量相对较高。对23~17.5 cal.kaBP日本海的表层海水温度出现异常高值的原因存在很多争论,一般认为是由于季风降雨输入量大于蒸发量、表层水盐度普遍降低、水体出现密度分层、水层间的垂直交换受到限制所致。

     

    Abstract: Hemipelagic sediments in the Sea of Japan (East Sea) during the last glaciation maximum (LGM) were characterized by centimeter-to decimeter-scale alternations of organic-poor light-gray layers, organic-rich dark-gray layers and homogenous layers. In association with the sedimentary characteristics, the alkenone sea surface temperatures (Uk'37-SSTs) of the central and southern Japan Sea were estimated and the results enabled us to understand the paleoceanographic evolutions in the study area during the LGM and its linkage with the East Asian monsoon (EAM). During 24.2~17.8 cal kaBP,deposition of the laminated layers had good relationship with the strengthening summer EAM,indicating that the EAM precipitation was the main cause for the oxygen-level variation of bottom water in the Japan Sea. The low Uk'37-SSTs in the northern Okinawa Trough during 24.2~17.8 cal kaBP further implied that the strong influx of East China Sea Coastal Water (ECSCW), which was regarded as lower-salinity and nutrient-enriched watermass and derived from the precipitation of summer EAM, had influence on the northern part of the East China Sea. Under the influence of weakened summer EAM or intensified winter EAM, the ventilation of deep water was reinforced and the suboxic or oxic bottom water dominated in the basins of Japan Sea during 30~24.2 and 17.8~15cal kaBP.Why there was the anomaly of high Uk'37-SSTs in the Japan Sea during 23~17.5 cal kaBP was not fully understood so far. It was generally accepted that the ventilation of deep water was blocked during this period by the density stratification of the water column as a result of excessive EAM precipitation, the surface salinity was low and the bottom was filled with static, anoxic water.

     

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