High-Resolution Records of Global Climatic and Oceanographic Responses from the Bering Sea and Northwestern Pacific during Late Pleistocene-Holocene

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基本資料

Project title

Code/計畫編號

MOST103-2923-M019-001-MY3

Translated Name/計畫中文名

白令海與西北太平洋自晚更新世–全新世的高解析度全球氣候與海洋反應紀錄

Project Coordinator/計畫主持人

Min-Te Chen

Funding Organization/主管機關

National Science and Technology Council

Department/Unit

Institute of Earth Sciences

Website

https://www.grb.gov.tw/search/planDetail?id=11264714

Year

2015

Start date/計畫起

01-01-2015

Expected Completion/計畫迄

01-12-2015

Bugetid/研究經費

600千元

ResearchField/研究領域

地球科學
環境科學

"白令海與西北太平洋為全球海洋與氣候變化的敏感區域。重建本區域百年至千年時間尺度的自然氣候變化動力與瞭解其推動機制，為鑑別人為活動是否對自然環境與氣候已造成衝擊，及適度的展望與預測未來氣候變遷的重要基礎。本研究為臺灣國科會與俄羅斯科學院遠東分院的國際合作計畫，將合作研究今年（2013）於白令海與西北太平洋大陸坡高沉積速率區探取的 3 支海洋沉積物岩心。本人的實驗室將負責使用岩心古菌類 TEX86、烯酮類不飽合度、有孔蟲殼體鎂鈣比等海水表面溫度代用指標的分析，重建自晚更新世至全新世本區域的表層海洋水文變化。俄羅斯 Sergey Gorbarenko 博士的研究團隊負責分析這 3 支岩心的定年與年代模式、生物生產力、生物源沉積物與微體古生物學如矽藻、放射蟲、有孔蟲、與殼體氧穩定同位素分析；將來雙方將共享分析數據，可完成白令海與西太平洋自晚更新世至全新世海洋與氣候變化重建，瞭解海冰分布與氣候變化的關係，並藉以比較大西洋垂直溫鹽環流（AMOC）對北太平洋氣候的影響、北大西洋與北太平洋氣候變化在千年至百年時間尺度的相位與時序關係、及與基於東亞石筍的碳酸鹽氧同位素亞洲季風變化的關係。本研究為人類活動是否影響區域海洋自然環境變遷的重要參考依據，並可提供政策制定者及關心環境議題之社會大眾參考。本研究所重建的白令海與西北太平氣候紀錄可用以研究控制自晚更新世至全新世北太平洋高緯氣候變化的動力與機制–及與亞洲季風的增強與減弱，或間熱帶輻合帶的遷移等的交互作用，也可用以評估人類活動，是否已對本區域的自然環境造成衝擊。本研究所分析的基於古菌類 TEX86 代用指標方法，將可進一步推展與應用在沉積物中碳酸鹽含量相對貧瘠的海域，如北極海、鄂霍次克海、與南冰洋等，並進行南北半球氣候變化之對比。" "Though changes in the surface hydrographic conditions which had been responsible for driving Atlantic Meridional Overturning Circulation (AMOC) is thought to be one of the major players in global climate and oceanographic variations since the last glacials to the Holocene, little evidence is available form the North Pacific and few knowledge is available for how the North Pacific had been involved in the global climate changes. One of the obstacles to obtain high quality and high resolution paleoceanographic records from the North Pacific is due to low carbonate preservation and detailed bathymetric survey for high sedimentation areas that allow us to retrieve high quality cores. This study aims to use high quality cores taken from the cruise of this summer (year 2013) for the Bering Sea and NW Pacific and based on which, attempts to understand how the Bering Sea had played a role in oceanic and climate change since the last glacial with focuses on millennial to centennial scale climate variations that have been driven by natural environmental changes. The proposed reconstructing natural climate change in the Bering Sea is essential to evaluating any possible anthropogenic interfering on our future climate. To address the important environmental prediction and mitigation issues, here we design a 3-year Taiwan-Russia cooperative program beginning with analyzing two cores with high sedimentation rates from the slope area in the Bering Sea, an ideal location for studying past sea surface temperature (SST), productivity, upwelling in the North Pacific. SSTs will be estimated by using multiple proxy methods (organic biomarker TEX86, alkenone, and trace metal content Mg/Ca from planktic foraminifer shells). The biogenic components (TOC, opal, and carbonate contents) of the cores will be measured for providing background information of the geology/sedimentology of the cores. The isotopic composition of oxygen measured from planktic fromainifer shells, combined with the multiple SST proxies will allow reconstructing Holocene-Quaternary hydrographic changes (i.e. salinity and productivity) over millennial to centennial scales. The combined isotope and SST proxy approaches in the proposed studies, if successfully established, could be further extended and applied to the other areas in the NW Pacific (Pacific margins of Kamchatka Peninsula, etc.). Our reconstruction of Holocene-Quaternary hydrographies will be further compared to more regional and global hydrographic records such as Chinese cave stalagmite monsoon records or marine records from the East and South China Seas. Further interhemispheric comparison based on the Bering Sea records will provide information on the linkages and different timing of climate variations expressed globally, and also provide important input information for modeling experiments. The new millennial to centennial scale hydrographic records will be used to any linkage with the AMOC from the North Pacific and any oceanic or atmospheric coupling between the North Pacific and North Atlantic. The new Bering Sea records will be further used to identify any ITCZ or monsoon amplification mechanism for explaining late Holocene cool/wet climatic trends in the western tropical Pacific, and further our understanding on what lessons are to be learned from the paleoceanographic records about climate and ocean dynamics for the early 21st century, with potential impacts on humanity. This work is designed under the framework of a joint program between Taiwan and Russia where the laboratory of Taiwanese PI will be responsible for measuring multiple SST proxies based on methods of organic biomarker TEX86, alkenone, and trace metal content Mg/Ca from planktic foraminifer shells. The laboratory of the Russian PI will take the responsibility of age model construction for these cores, measuring productivity proxy (chlorine, TOC, opal, carbonate), sea ice cover changes, micropaleontological results (diatom and benthic foraminifers and radiolarians), and δ18O and δ13C of benthic and planktic foraminifer. Both PI will participate in developing the new core data sets for paleoceanographic reconstruction and publish joint papers in international journals."

DSpace CRIS

High-Resolution Records of Global Climatic and Oceanographic Responses from the Bering Sea and Northwestern Pacific during Late Pleistocene-Holocene

基本資料

Description