豆汝席^1,,
邹建军^1,2,
石学法^1,2,,,
朱爱美^1,2,
董智¹,
石丰登^1,2,
薛心如¹,
GorbarenkoSergey³
1. 自然资源部第一海洋研究所, 海洋地质与成矿作用重点实验室, 山东 青岛 266061
2. 青岛海洋科学与技术试点国家实验室, 海洋地质过程与环境功能实验室, 山东 青岛 266237
3. 俄罗斯科学院远东分院太平洋海洋研究所, 俄罗斯 符拉迪沃斯托克 690041

基金项目: 国家自然科学基金项目(批准号：41420104005)、自然资源部"全球变化与海气相互作用"专项项目(批准号：GASI-GEOGE-04)、中央级公益性科研院所基本科研业务费专项资金资助项目(批准号：2016Q09)、国家基金委-山东海洋科学研究中心项目(批准号：U1606401)和山东省"泰山****"建设工程专项经费项目(批准号：TSQN20182117)共同资助


详细信息

作者简介: 豆汝席, 男, 25岁, 硕士研究生, 海洋地质专业, E-mail:douruxi@163.com

通讯作者: 石学法, E-mail:xfshi@fio.org.cn

中图分类号: P722.3;P532

收稿日期:2020-01-07
修回日期:2020-02-28
刊出日期:2020-05-25

Reconstructed changes in sea ice in the western Sea of Japan over the last 30000 years

Dou Ruxi^1,,
Zou Jianjun^1,2,
Shi Xuefa^1,2,,,
Zhu Aimei^1,2,
Dong Zhi¹,
Shi Fengdeng^1,2,
Xue Xinru¹,
Gorbarenko Sergey³
1. Key Laboratory of Marine Geology and Metallogeny, First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, Shandong
2. Laboratory for Marine Geology, Pilot National Laboratory for Marine Science and Technology(Qingdao), Qingdao 266237, Shandong
3. V. I. Il'ichev Pacific Oceanological Institute, Vladivostok 690041, Russia


More Information

Corresponding author: Shi Xuefa,E-mail:xfshi@fio.org.cn

MSC: P722.3;P532

--> Received Date: 07 January 2020
Revised Date: 28 February 2020
Publish Date: 25 May 2020


摘要
摘要:海冰是现代气候系统的一个基本组成要素，对气候变化有着重要的调控作用。现今日本海西部仍发育有限的季节性海冰，也是深层水形成的关键区域。由于缺乏沉积岩芯，长期以来对日本海西部海冰范围变化的历史还缺乏深入的认识。本文对日本海西部LV53-18-2岩芯中长393 cm的沉积物进行了粒度分析，采用粒径端元分析方法，重建了过去30.0~5.0 ka海冰和底流活动历史。粒径端元(EM)分析显示，端元3(40~160 μm)是指示海冰活动的有效指标；EM1(2~20 μm)与可分选粉砂平均粒径呈现一致的变化趋势，是指示底流活动的有效指标，但在15.0~7.8 ka受到冰筏碎屑影响。日本海西部海冰活动由冬季海冰形成和春/夏季海冰融化条件的共同制约。末次冰期-冰盛期(30.0~18.0 ka)，在强盛东亚冬季风(EAWM)和低太阳辐射量控制下，日本海西部季节性海冰活动保持微弱；在末次冰消期晚期-中全新世早期(15.0~7.8 ka)，EAWM仍然强盛，同时北半球高纬日射量和海平面升高，导致海冰活动十分活跃；7.8~5.0 ka以来，随着EAWM减弱和对马暖流入侵，日本海西部季节性海冰活动显著减弱。在海因里希冰阶(HS)1时段(17.5~15.0 ka)，大西洋经向翻转流减弱诱发EAWM增强，同时北半球夏季太阳辐射量和海平面都相对较低，可能导致日本海西部海冰持续覆盖。在季节性海冰形成时期，盐析过程增强了水体垂向对流和底流活动，但是在HS1，深层水体形成源区被常年海冰覆盖，抑制了深层水形成，减弱了研究区底流活动。
关键词: 海冰/
底流活动/
粒径端元分析/
可分选粉砂/
末次冰期/
日本海

Abstract:Sea ice, as a fundamental component of climate change, plays an important role in regulating climate, ocean ecosystem, deep water formation and sediment deposition. The Sea of Japan(JS), one of the marginal seas in the western Pacific Ocean, communicates with adjacent seas through four shallow straits of less than 130 m and it has exhibited a high degree of sensitivity to climate and sea level changes. At present, both the East Asian Monsoon and the Tsushima Warm Current(TWC)exert great impacts on the ocean environment and climate of the JS. During the Quaternary glacial cycles, the role of eustatic sea level in controlling the environment of the JS has been taken seriously. The unique geographic features and climatic conditions make it an ideal location to archive past climate signals. There is still seasonal sea ice occurring in wintertime in the western JS due to frigid wind from Siberia. In the absence of study materials, it remains unclear for the variations in sea ice coverage in the western JS. In this study, a sediment core LV53-18-2 with a length of 393 cm is investigated, which was retrieved from the western JS(42°56'N, 134°44'E; 551 m depth)during the first China-Russia joint cruise in 2010. The core was sliced into centimeter-sized slices. The age model has been established on the basis of optical stimulated luminescence(OSL)dating and the basal age of core LV53-18-2 is 30.02 ka. The variations in grain-size data measured by Mastersizer2000 have been investigated carefully in order to reconstruct the history of sea ice and bottom current. With the end-member modeling algorithm, a meaningful decomposition of sediment grain-size record over the last 30.0 ka has been established. Among the three unmixing grain-size end members(EM)identified, EM3 (40~160 μm)and EM1 (2~20 μm)are thought to be reliable proxies for sea ice and deep circulation, respectively. In addition, the sortable silt mean grain size, one of proxies for bottom current speed, is also calculated. The variation in seasonal sea ice in the western JS is controlled by conditions in wintertime sea ice formation and melting in spring/summer seasons. Our data suggest variations in seasonal sea ice stayed weak, indicating by low content and mass accumulation rate(MAR)of Ice rafted debris(IRD), during the glacial lowstand of sea level(30.0 ka to 18.0 ka), which was related to intensified EAWM and low summer insolation at 45°N at that time. The drastic variations in seasonal sea ice had been corroborated by high contents and MARs of IRD during the last deglaciation and early middle Holocene(15.0~7.8 ka), which was due to a combination of strong EAWM, increased summer insolation and global sea level rise. After 7.8 ka, variations in seasonal sea ice weaken significantly in relation to dampened EAWM and incursion of TWC. Perennial sea ice may exist at the study site during the last early deglaciation(Heinrich Stadial 1), which was caused by intensified EAWM associated with a slowdown of Atlantic Meridional Overturning Circulation and a reduction in northward heat transport across the equator, low summer insolation at 45°N and low global sea level. In response to variations in sea ice, the states of convection and bottom current switched. During the formation of seasonal sea ice, the brine rejection enhanced the convection and bottom current vigor, whereas the formation of deep water decreased due to the perennial sea ice during HS1.
Key words:sea ice/
bottom current/
grain-size end-member analysis/
sortable silt/
the Last Glacial period/
the Sea of Japan



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