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Productivity in the Southern Ocean Antarctic Zone during the Northern Hemisphere Glaciation(NHG)and its link to atmospheric pCO_(2)

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Science China Earth Sciences 2024年第7期67卷 2242-2252页

作者： Yiming WU Jingteng GUO Xiangyu ZHAO Wenshen XIAO Heng liU Zhifang XIONG tiegang li Key Laboratory of Marine Geology and Metallogeny First Institute of OceanographyMinistry of Natural ResourcesQingdao 266061China Laboratory for Marine Geology Laoshan LaboratoryQingdao 266237China School of Oceanography Shanghai Jiao Tong UniversityShanghai 200030China Key Laboratoryof Polar Ecosystem and Climate Change Shanghai Jiao Tong UniversityMinistry of EducationShanghai 200030China State Key Laboratory of Marine Geology Tongji UniversityShanghai 200092China

A decrease in atmospheric CO_(2)partial pressure(pCO_(2))is considered an important prerequisite for the onset and intensification of Northern Hemisphere Glaciation(NHG).However,how the ocean sequestered missing CO_(2)during the NHG is still *** in surface productivity and deep ventilation in the Southern Ocean(SO)have been proposed to explain the variations in atmospheric pCO_(2)over the last eight glacial cycles,but it is unclear whether these mechanisms contributed to the decrease in atmospheric pCO_(2)during the *** titanium-normalized contents and mass accumulation rates of biogenic opal and total organic carbon from the International Ocean Discovery Program(IODP)Expedition 374 Site U1524A,we reconstruct the productivity in the Ross Sea,Antarctica,from 3.3 Ma to 2.4 *** productivity records exhibit a long-term decreasing trend and several distinct phased evolutionary ***,the local productivity fluctuated dramatically during 3.3-3.0 Ma,decreased gradually during 3.0-2.6 Ma,and remained relatively constant during 2.6-2.4 *** comparing productivity with its potential influences,we infer that the phased and long-term evolutions of productivity were mainly controlled by changes in deep ocean *** ice expansion might have decreased productivity during 3.3-3.0 Ma by light *** in eolian dust input have little effect on *** analysis revealed no coupling linkage between productivity and atmospheric pCO_(2),indicating that the productivity in the SO Antarctic Zone(AZ)was not the main factor controlling the atmospheric CO_(2)decrease during the *** improve our understanding of the role of SO processes in the NHG,further studies should focus on the potential influences of deep ocean ventilation on atmospheric pCO_(2)in the AZ,and similar studies should also be extended to the sea area in the Subantarctic Zone.

关键词： Ross Sea Biogenic opal Total organic carbon Deep ocean ventilation Sea ice Ocean carbon cycle

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Calcareous nannofossil bioevents and microtektite stratigraphy in the Western Philippine Sea during the Quaternary

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Chinese Science Bulletin 2011年第25期56卷 2732-2738页

作者： SUN HanJie li tiegang SUN RongTao YU XinKe CHANG FengMing TANG Zheng Key Laboratory of Marine Geology and Environment Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China Graduate University of the Chinese Academy of Sciences Beijing 100049 China School of Resource & Environment Engineering Shandong University of Technology Zibo 255049 China China Geological Survey Qingdao Institute of Marine Geology Qingdao 266007 China

Two sediment cores, MD06-3050 and MD06-3047, were analyzed to study the Quaternary calcareous nannofossil and microtektite records. We dated bioevents and the microtektite impact event by calibrating with oxygen isotope stratigraphy. Seven calcareous nannofossil bioevents were identified over the past 2.36 Ma including the last appearance of data for Discoaster brouweri, Calcidiscus macintyrei, large Gephyrocapsa and Pseudoemiliania lacunosa, the first appearance of data for large Gephyrocapsa and Emiliania huxleyi, and the abrupt increase in the abundance of Gephyrocapsa caribbeanica. In addition, we fortunately observed that Australasian microtektites were distributed in core MD06-3050 from 1340 to 1374 cm.

关键词：钙质超微化石同位素地层学第四纪菲律宾海西方沉积物岩心撞击事件

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Calcification of planktonic foraminifer Neogloboquadrina pachyderma(sinistral) controlled by seawater temperature rather than ocean acidification in the Antarctic Zone of modern Sothern Ocean

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Science China Earth Sciences 2022年第9期65卷 1824-1836页

作者： Qianwei SONG Bingbin QIN Zheng TANG Yanguang liU Zhihua CHEN Jingteng GUO Zhifang XIONG tiegang li Key Laboratory of Marine Geology and Metallogeny First Institute of OceanographyMinistry of Natural ResourcesQingdao 266061China Laboratory for Marine Geology Pilot National Laboratory for Marine Science and TechnologyQingdao 266237China

Neogloboquadrina pachyderma(sinistral), the dominant planktonic foraminiferal species in the mid-to-high latitude oceans, represents a major component of local calcium carbonate(CaCO) production. However, the predominant factors,governing the calcification of this species and its potential response to the future marine environmental changes, are poorly understood. The present study utilized an improved cleaning method for the size-normalized weight(SNW) measurement to estimate the SNW of N. pachyderma(sin.) in surface sediments from the Amundsen Sea, the Ross Sea, and the Prydz Bay in the Antarctic Zone of the Southern Ocean. It was found that SNW of N. pachyderma(sin.) is not controlled by deep-water carbonate dissolution post-mortem, and can be therefore, used to reflect the degree of calcification. The comparison between N. pachyderma(sin.) SNW and environmental parameters(temperature, salinity, nutrient concentration, and carbonate system) in the calcification depth revealed that N. pachyderma(sin.) SNWs in the size ranges of 200–250, 250–300, and 300–355 μm are significantly and positively correlated with seawater temperature. Moreover, SNW would increase by ~30% per degree increase in temperature, thereby suggesting that the calcification of N. pachyderma(sin.) in the modern Antarctic Zone of the Southern Ocean is mainly controlled by temperature, rather than by other environmental parameters such as ocean acidification. Importantly, a potential increase in calcification of N. pachyderma(sin.) in the Antarctic Zone to produce CaCOwill release COinto the atmosphere. In turn, the future ocean warming will weaken the ocean carbon sink, thereby generating positive feedback for global warming.

关键词： Planktonic foraminiferal SNW Sonication CaCO3 production Ocean carbon cycle Climate change

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Provenance of colorless and brown volcanic glass in late Pleistocene tephra layers in the Western Philippine Sea

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Journal of Oceanology and limnology 2024年第5期42卷 1438-1449页

作者： Fuqing JIANG Zhishun ZHANG Zhaohui ZHANG Guoliang ZHANG Peng HUANG Xiaojing ZHOU Zhifang XIONG Congying li tiegang li Key Laboratory of Ocean Observation and Forecasting and Key Laboratory of Marine Geology and Environment Institute of OceanologyChinese Academy of SciencesQingdao 266071China Laboratory for Marine Geology Qingdao Marine Science and Technology CenterQingdao 266237China University of Chinese Academy of Sciences Beijing 100049China Institute of Marine Chemistry and Environment Ocean CollegeZhejiang UniversityZhoushan 316021China College of Marine Technology and Environment Dalian Ocean UniversityDalian 116023China Key Laboratory of Marine Sedimentology and Environmental Geology First Institute of OceanographyMinistry of Natural ResourcesQingdao 266061China

Tephra layers in the western Philippine Sea,characterized by abundant volcanic glass shards,may provide crucial evidence on the eruption history of volcanoes and tectonic evolution of the western Pacific.A 220-ka sediment core from the Benham Rise in the western Philippine Sea offers new insights into the provenance of four intercalated tephra layers(T1–T4,in chronological order)containing either colorless or brown glass *** to primitive mantle,all glass shards are enriched in large-ion lithophile elements,such as Rb,Cs,and Pb,and depleted in high field-strength elements,such as Th,Nb,and Ta,indicating a subduction-related *** colorless glass shards are characterized by high SiO_(2)(>78%)and light rare earth element(LREE)contents as well as high La/Sm ratios(>9),low FeO and MgO contents(100),pointing to a rhyolitic composition and a medium-K calc-alkaline serial *** contrast,the brown glass shards are characterized by lower SiO_(2)(line andesite *** glass shards from layers T3(152 ka)and T4(172 ka)were correlated with volcanic deposits from the Taal and Laguna Caldera in the Maccolod Corridor,respectively,while the colorless glass shards from layers T1(36.5 ka)and T2(61.2 ka)were likely sourced from the Irosin Caldera in the Bicol *** the provenance of late Pleistocene tephra layers in the western Philippine Sea is helpful to complement a Philippine volcanic history and establish a regional tephrochronostratigraphy.

关键词： volcanic glass provenance chemical composition Philippine Sea late Pleistocene

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Geochemistry of rare earth elements in the mid-late Quaternary sediments of the western Philippine Sea and their paleoenvironmental significance

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Science China Earth Sciences 2014年第4期57卷 802-812页

作者： XU ZhaoKai li tiegang WAN ShiMing YIN XueBo JIANG FuQing SUN HanJie JinYong CHOI DhongIl liM Key Laboratory of Marine Geology and Environment Institute of OceanologyChinese Academy of Sciences Department of Oceanography Kunsan National University South Sea Institute Korea Institute of Ocean Science and Technology

Based on a δ180 chronology, rare earth elements （REE） and other typical elements in sediments from core MD06-3047 in the western Philippine Sea were analyzed to constrain the provenances of the sediments and investigate quantitative changes in the Asian eolian input to the study area over the last 700 ka. Among the competing processes that might affect REE compositions, sediment provenance is the most important one. Provenance analysis suggests that the study sediments have two provenance end-members; local volcanic sources are dominant, and eolian dust from the Asian continent has a smaller contribution. During glacial periods, eolian input to the western Philippine Sea was enhanced. In contrast, material supply from local volcanics in- creased during interglacial periods. Changes in eolian input to the study area were probably related to the strength of the East Asian winter monsoon （EAWM） as well as aridity in the Asian continent on an orbital time scale, and were partly influenced by local control factors on shorter time scales. Therefore, we propose that the present study expands the application of the REE-based method for quantitatively estimating the eolian component from the mid-latitude northern Pacific to the low-latitude western Pacific. Additionally, the study preliminarily confirms the influence of EAWM-transported eolian materi- al on sedimentation in the western Philippine Sea since 700 ka.

关键词： eolian dust sediment provenance rare earth elements East Asian winter monsoon glacial/interglacial cycle western Philippine Sea

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Paleoproductivity variations in the southern Okinawa Trough since the middle Holocene:Calcareous nannofossil records

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Chinese Science Bulletin 2012年第26期57卷 3917-3922页

作者： ZHAO JingTao li tiegang li Jun HU BangQi Key Laboratory of Marine Geology and Environment Institute of OceanologyChinese Academy of SciencesQingdao 266071China Key Laboratory of Marine Hydrocarbon Resource and Geology Ministry of Land and ResourcesQingdao Institute of Marine GeologyQingdao 266071China Key Laboratory of Marginal Sea Geology South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China

Based on 17 AMS 14 C age data,we reconstructed high-resolution records of sea surface primary productivity(PP) in the southern Okinawa Trough(MD05-2908) over the last 6.8 ka BP using the calcareous nannofossil carbon isotope and the relative percentage contents of Florisphaera profunda *** underlying mechanism controlling the sea surface PP was then *** sea surface PP,indicated by the coccolith δ 13 C and %Fp conversional equations,decreased with some fluctuations since 6.8 ka *** decrease may be connected to the decreased terrigenous input resulting from the reduced East Asian Summer Monsoon(EASM) *** the periods of 4-2 ka BP(PME) and 6.8-4.8 ka BP were characterized by relatively higher *** former was mainly controlled by the weakening of the Kuroshio Current,whereas the latter mainly resulted from the greater terrigenous input associated with the stronger EASM.

关键词：钙质超微化石冲绳海槽古生产力化石记录中全新世东亚夏季风高分辨率记录陆源物质

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Sediment transport in the Luanhe River delta:grain size trend analysis

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Journal of Oceanology and limnology 2019年第3期37卷 982-997页

作者： YU Xiaoxiao li tiegang GU Dongqi FENG Aiping liU Shihao li Ping XU Guoqiang YAN Wenwen ZHANG Zhiwei ZHU Zhengtao Key Laboratory of Marine Geology and Environment Institute of OceanologyChinese Academy of SciencesQingdao 266071China University of Chinese Academy of Sciences Beijing 100049China The First Institute of Oceanography Ministry of Natural Resources (MNR)Qingdao 266061China State Key Laboratory of Estuarine and Coastal Research East China Normal UniversityShanghai 200062China

Sediment grain size in the deltaic environment of the Luanhe River(LR),liaoning,China,contains sediment transport pathway information useful in elucidating the shoreline change and fluvialmarine *** this study,we utilized numerical partitioning of the sedimentary components and geostatistical grain size trend analysis(GSTA)to define the sediment transport pattern in the Luanhe River delta(LRD)and interpolated the sediment transport pattern using content changes of end numbers(EM).EM1(the mean grain size 7.12Ф,fine silt),EM2(2.37Ф,fine sand),and EM3(1.27Ф,medium sand)components were identified by the numerical partitioning by *** interpolation method was used to interpolate the parameters of the grain size for the regular grid,and the interpolation radius was 0.015 decimal *** chose 0.09 decimal degree as the characteristic distance for GSTA in the semivariogram model using the geostatistical *** FB(-)case(finer,better sorted and more negatively skewed)was adopted in GSTA for its satisfaction in the Global Moran’s I *** result of the GSTA shows that the sediments in the south barriers(SBs)were transported to the southwest of the study *** sediments in the north,in the SE direction of sediment transport trend from the river mouth,indicated that the sediments in the north of the study area were transported from the LR to the northern beaches,and to the south and east of the study *** sediment transport trend that simplified by GSTA as the FB(-)case was approved by the content changes of sedimentary components(***1,EM2,and EM3).In addition,the turbulent jet diffusion pattern indicated that the coarse sediments(EM3)were delivered by LR during the flood season,and the EM2 and EM1 were from wave and tide,respectively.

关键词： Luanhe River delta sediment transport grain-size partitioning geostatistical grain size trend analysis(GSTA)

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Relating the composition of continental margin surface sediments from the Ross Sea to the Amundsen Sea,West Antarctica,to modern environmental conditions

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Advances in Polar Science 2022年第1期33卷 55-70页

作者： WANG Jiakai li tiegang TANG Zheng XIONG Zhifang liU Yanguang CHEN Zhihua CHANG Fengming Key Laboratory of Marine Geology and Environment Institute of OceanologyChinese Academy of SciencesQingdao 266071China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Marine Geology and Metallogeny First Institute of OceanographyMinistry of Natural and ResourcesQingdao 266061China Laboratory for Marine Geology Qingdao National Laboratory for Marine Science and TechnologyQingdao 266237China

Investigating the multiple proxies involving productivity,organic geochemistry,and trace element(TE)enrichment in surface sediments could be used as paleoenvironment archives to gain insights into past and future environmental conditions *** present redox-sensitive TEs(Mn,Ni,Cu,U,P,Mo,Co,V,Zn,and Cd),productivity-related proxies(total organic carbon and opal),and total nitrogen and CaCO_(3) contents of bulk surface sediments of this *** productivity proxies from the shelf and coastal regions of the Ross and the Amundsen seas showed that higher productivity was affiliated with an area of nutrient-rich deep water *** upwelling of weakly corrosive deep water may be beneficial for preserving CaCO_(3),while highly corrosive dense water,if it forms on the shelf near the coastal region(coastal polynya),could limit the preservation of CaCO_(3) in modern *** were no oxic or anoxic conditions in the study area,as indicated by the enrichment factors of redox-sensitive TEs(Mn,Co,and U).The enrichment factor of Cd,which is redox-sensitive,indicated suboxic redox conditions in sediment environments because of high primary productivity and organic matter preservation/*** enrichment factors of other redox-sensitive TEs(P,Ni,Cu,V,and Zn)and the correlations between the element/Ti ratio with productivity and nutrient proxies indicated that the organic matter decomposed,and there was massive burial of phytoplankton *** was variation in the enrichment,such that sediments were enriched in P,Mo,and Zn,but depleted in Ni,Cu,and V.

关键词： redox nutrient productivity shelf and coastal region offshore of Ruppert and Hobbs coasts Ross Sea Amundsen Sea

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Response of the northwestern Pacific upper water δ^(13)C to the last deglacial ventilation of the deep Southern Ocean

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Chinese Science Bulletin 2011年第24期56卷 2628-2634页

作者： CHEN ShuangXi li tiegang TANG Zheng QIU XiaoHua XIONG ZhiFang NAN QingYun XU ZhaoKai CHANG FengMing Key Laboratory of Marine Geology and Environment Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China Key Laboratory of Marine Hydrocarbon Resources and Environmental Geology Qingdao Institute of Marine Geology Ministry of Land and Resources of China Qingdao 266071 China Graduate University of Chinese Academy of Sciences Beijing 100049 China

The deglacial δ~13C minimum events that originated from the ventilation of the deep Southern Ocean around Antarctica, have been recorded in a range of marine sediments from the southern to tropical oceans in late Pleistocene. However, the broad δ~13C minimum event was also reported as far as to the northern middle latitudes, in northwestern Pacific marginal sea areas, during the last deglaciation. In the northwestern Pacific, forcing from the northern high latitudes is strongly expressed, while the records of in- fluence from the southern high latitudes are few. The Kuroshio Source Region (KSR) forms a boundary between the northwestern Pacific and the southern, tropical Pacific. So, high-resolution planktonic foraminiferal records in core MD06-3054 from the KSR are well positioned to identify signals from the southern hemisphere in the northwestern Pacific. Planktonic foraminiferal tests from the upper 1030 cm of the core were subject to AMS14C, carbon and oxygen isotopic measurements. A negative excursion was found to occur from about 20.0-6.0 ka BP in δ~13C records of both surface (Globigerinoides ruber) and subsurface (Pulleni- atina obliquiloculata) dwellers, but the overall trends of the two curves have reversed since 26.5 ka BP. Moreover, the δ~13C rec- ord of G. ruber (the surface dweller) shows a robust link to the record of atmospheric CO2, and its changes precede the records of P. obliquiloculata (the subsurface dweller). According to the hydrologic conditions, the broad δ~13C minimum event recorded in the KSR is also a response to the increasing ventilation of the deep Southern Ocean around Antarctica during the last deglaciation. The inconsistency between the records of the surface and subsurface dwellers was possibly caused by the ways that the low δ~13C signal was transmitted. Subsurface water primarily received the low δ~13C signal from the Antarctic Intermediate Water (AAIW), whereas the surface water was probably mainly impacted by atmospheric CO2 i

关键词：西北太平洋边缘水文条件南大洋通风信号传输方式末次冰消期高纬度地区中纬度地区

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Epidemiological Survey and Analysis on an Outbreak of Gastroenteritis due to Water Contamination

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Biomedical and Environmental Sciences 2011年第3期24卷 275-283页

作者： YANG ZhlCong WU XinWei li tiegang li MeiXia ZHONG Yi liU YuFei DENG ZhiAi DI Biao HUANG Cong liANG HuiYing WANG Ming Guangzhou Center for Disease Control and Prevention Guangzhou 510080 Guangdong China

Objective To document the investigation and control of an outbreak of gastroenteritis in City G, South China, and provide a reference for preventing future outbreaks. Methods An ambispective cohort study was designed. Attack rate （AR） and relative risks （RR） were calculated to identify the causes of gastroenteritis. Investigations using questionnaires included personal interviews with patients and doctors, reviews of medical records, laboratory examinations of fecal specimens and continuous hygiene monitoring of water samples from the waterworks. Results Overall, 427/71534 （AR=5.97%o） cases were identified between October 31 and November 12 2010. Geographic distribution was highly localized, with 80% of cases occurring in the areas supplied by waterworks-A. Consumption of water provided solely by waterworks-A was found to be associated with illness （RR=8.20, 95 C1%：6.12-10.99） compared with that from waterworks-B. Microbiological analyses confirmed the presence of Norovirus in six of eight fecal samples from symptomatic patients, two water samples from waterworks-A and two sewage samples. After taking effective measures, the hygienic indices of waterworks-A met health criteria again on November 9 and no cases were reported 3 days *** The outbreak reported here was caused by drinking tap water contaminated with sewage at the source. Early identification of possible contamination sources and awareness of changes that might negatively impact water quality are important preventive measures to protect public health.

关键词： Water contamination Norovirus Outbreak Survey and analysis

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